WO2013099592A1 - Radiographic imaging apparatus, program, and radiographic imaging method - Google Patents

Radiographic imaging apparatus, program, and radiographic imaging method Download PDF

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Publication number
WO2013099592A1
WO2013099592A1 PCT/JP2012/082096 JP2012082096W WO2013099592A1 WO 2013099592 A1 WO2013099592 A1 WO 2013099592A1 JP 2012082096 W JP2012082096 W JP 2012082096W WO 2013099592 A1 WO2013099592 A1 WO 2013099592A1
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substrate
radiation
image
still image
moving image
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PCT/JP2012/082096
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French (fr)
Japanese (ja)
Inventor
大田　恭義
岩切　直人
北野　浩一
西納　直行
中津川　晴康
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富士フイルム株式会社
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B42/00—Obtaining records using waves other than optical waves; Visualisation of such records by using optical means
    • G03B42/02—Obtaining records using waves other than optical waves; Visualisation of such records by using optical means using X-rays
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/30—Transforming light or analogous information into electric information
    • H04N5/32—Transforming X-rays

Definitions

  • the present invention relates to a radiographic image capturing apparatus, a program, and a radiographic image capturing method, and more particularly to a radiographic image capturing apparatus, a program, and a radiographic image capturing method for capturing a radiographic image indicated by radiation transmitted through a subject.
  • radiation detectors such as FPD (Flat Panel Detector) that can directly convert radiation such as X-rays into digital data by arranging radiation sensitive layers on TFT (Thin Film Transistor) active matrix substrates have been put into practical use.
  • a radiation image capturing apparatus that captures a radiation image represented by irradiated radiation using this radiation detector has been put into practical use.
  • the radiation detector used in this radiographic imaging apparatus has an indirect conversion system in which radiation is converted into light by a scintillator and then converted into electric charge in a semiconductor layer such as a photodiode, or the like.
  • There is a direct conversion method in which a semiconductor layer such as amorphous selenium converts into electric charge, and there are various materials that can be used for the semiconductor layer in each method.
  • the afterimage as an artifact with respect to the radiographic image acquired by the radiographic imaging device is the radiation at the radiation detector depending on the temperature, the driving time, the magnitude of the bias, the magnitude of the tube voltage of the radiation source emitting the radiation, and the like. This occurs due to a change in response characteristics related to detection.
  • the indirect conversion type radiation detector in the photoelectric conversion element that converts light into electric charge, a part of the electric charge is once captured by the impurity level (defect) of the semiconductor constituting the photoelectric conversion element, and the next imaging is performed. In some cases, the captured partial charge is output together with the charge corresponding to the original image information, so that the afterimage is displayed on the display image together with the image information. Furthermore, the charge resulting from the dark current also causes afterimages.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2009-5374
  • Patent Document 2 Japanese Patent Application Laid-Open No. 2010-246835
  • Patent Document 3 In each document of Japanese Unexamined Patent Publication No. 2011-66514 (Patent Document 3), in a radiographic imaging apparatus having a radiation detector capable of converting radiation into a radiation image, reset processing is performed on the radiation detector.
  • a technique for suppressing the occurrence of the afterimage is disclosed.
  • some recent radiographic image capturing apparatuses can capture moving images in addition to still image capturing.
  • this type of radiographic imaging device while taking a moving image (perspective image), observing a moving image obtained by the moving image shooting in real time, taking a still image as needed, and taking the still image It is possible to restart the video recording at an arbitrary timing after the end of, which is excellent in convenience.
  • the present invention has been made to solve the above-described problems, and provides a radiographic image capturing apparatus, a program, and a radiographic image capturing method capable of capturing a high-quality radiographic image at an accurate timing. Objective.
  • a radiographic imaging apparatus is laminated on a first substrate for still image imaging that converts incident radiation into a radiographic image, and the first substrate.
  • a radiation detector having a second substrate for moving image capturing for converting incident radiation into a radiation image, and when taking a still image using the first substrate, and obtained by the still image capturing Control means for executing and controlling a reset process on the second substrate in at least one of the cases where a still image is displayed.
  • the first substrate for still image capturing that converts the incident radiation into a radiation image, and the incident radiation laminated on the first substrate are A still image shooting is performed using the first substrate, and a moving image shooting is performed using the second substrate by a radiation detector having a second substrate for moving image shooting to be converted into a radiation image.
  • the present invention when still image shooting is performed using the first substrate, which is a period in which no trouble occurs even if reset processing is performed on the second substrate, and obtained by the still image shooting.
  • the reset process is performed on the second substrate.
  • the radiographic image capturing apparatus when still image capturing is performed using the first substrate for still image capturing that converts incident radiation into a radiographic image. , And at least one of the cases where the still image obtained by the still image shooting is being displayed, the second for movie shooting that is stacked on the first substrate and converts the incident radiation into a radiation image. Since execution control of the reset process is performed on the substrate, radiographic images with high image quality can be taken at appropriate timing.
  • the invention according to the first aspect of the present invention further comprises a receiving means for receiving a still image shooting execution instruction, wherein the control means performs moving image shooting using the second substrate. And when the execution instruction is received by the receiving means, still image shooting is performed using the first substrate, and a still image obtained by the still image shooting is obtained by the moving image shooting.
  • the moving image may be applied as an image corresponding to the shooting timing of the still image, and the reset process may be executed and controlled on the second substrate at the timing when the still image shooting is performed. As a result, it is possible to prevent missing of an image during shooting of a moving image.
  • control means may continuously control moving image shooting using the second substrate regardless of whether the reset process is executed. As a result, it is possible to more reliably prevent moving images from being lost.
  • Radiation irradiation may be controlled to stop. Thereby, the irradiation amount of the radiation with respect to the to-be-photographed body can be suppressed.
  • the radiographic image capturing device is laminated on a first substrate for still image capturing that converts incident radiation into a radiographic image, and the first substrate,
  • a radiation detector having a second substrate for moving image capturing that converts incident radiation into a radiographic image, and when moving image capturing is performed using the second substrate, and a moving image obtained by the moving image capturing Control means for controlling execution of reset processing on the first substrate in at least one of the cases where the display is performed.
  • the first substrate for still image imaging that converts the incident radiation into a radiographic image, and the incident radiation that is laminated on the first substrate and converted into the radiographic image.
  • a radiation detector having a second substrate for moving image shooting to be converted performs still image shooting using the first substrate, while moving image shooting is performed using the second substrate.
  • the control means when the moving image is shot by the control means using the second substrate, and at least one of the cases where the moving image obtained by the moving image shooting is displayed.
  • the reset process is controlled for the first substrate.
  • the present invention when moving image shooting is performed using the second substrate, which is a period in which no trouble occurs even if reset processing is performed on the first substrate, and a moving image obtained by the moving image shooting.
  • a reset process is performed on the first substrate.
  • a high-quality radiographic image in which the influence of afterimages and the like is suppressed is suppressed. Shooting can be performed at the correct timing.
  • the radiographic image capturing device when moving image capturing is performed using the second substrate for moving image capturing that converts incident radiation into a radiation image, and the moving image capturing is performed.
  • the reset is performed on the first substrate for still image shooting which is stacked on the second substrate and converts the incident radiation into a radiation image. Since the process is controlled to be executed, it is possible to capture a high-quality radiographic image at an appropriate timing.
  • the substrate for which the reset process is performed is an indirect conversion type.
  • it may be at least one of the third reset processing by discharging the charge accumulated in each pixel of the substrate to be reset processing.
  • a photodiode made of amorphous silicon (a-Si) is a photodetecting element
  • a part of charges (electrons) converted from light (visible light) once enters an a-Si impurity level (defect).
  • an unnecessary current such as a dark current is generated, and a radiographic image (moving image May cause noise (afterimage).
  • the first reset process irradiates the photodiode with light (reset light) to preliminarily charge the impurity level, and then the charge converted from visible light upon irradiation of the radiation is the impurity. By preventing them from being captured by the level, the occurrence of afterimages can be effectively suppressed.
  • the photodetecting element is a MIS (Metal (Insulator Semiconductor) photodiode
  • the polarity of the bias supplied to the photodiode is reversed by the second reset process, or the photodiode is connected to the photodiode. It is preferable to execute reset processing for the photodiode by stopping supply of the bias.
  • a direct conversion type radiation detector absorbs a low energy component of radiation and converts it into an electric charge
  • an indirect conversion type radiation detector absorbs a high energy component of radiation and absorbs the absorbed energy component into light.
  • the light is converted into a charge once.
  • the low energy component of the radiation is the energy component of the radiation corresponding to the low voltage when the tube voltage of the radiation source emitting the radiation is relatively low, and the mammo and the soft part of the object to be imaged. It is easily absorbed by tissues and tumors.
  • the high energy component of radiation is an energy component of radiation corresponding to the high voltage when the tube voltage of the radiation source is relatively high, and is easily absorbed by the bone portion or the like of the subject.
  • the first substrate directly converts the incident radiation directly into charges.
  • the second substrate may be an indirect conversion method in which the second substrate converts incident light into light and then converts the light into electric charge. Thereby, a radiographic image can be obtained more effectively.
  • the second substrate is laminated on a surface opposite to the surface on which the radiation of the first substrate is incident. Also good. Thereby, a radiographic image can be obtained more effectively.
  • a program includes a computer, a first substrate for still image shooting that converts incident radiation into a radiation image, and a stack on the first substrate, A first state in which still image shooting is performed using the first substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and obtained by the still image shooting A determination unit that determines whether or not a still image is being displayed is at least one of the second states, and the determination unit is at least one of the first state and the second state.
  • the control unit is configured to function as a control unit that executes and controls a reset process on the second substrate.
  • the computer can be operated in the same manner as the radiographic image capturing apparatus according to the first aspect. Shooting can be performed at a precise timing.
  • a program includes a computer, a first substrate for still image shooting that converts incident radiation into a radiation image, and the first substrate.
  • a first state in which moving image shooting is performed using the second substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and a moving image obtained by the moving image shooting Determining means for determining whether or not the display is in at least one of the second states, and the determination means determines that the state is at least one of the first state and the second state.
  • the control unit is configured to function as a control unit that executes and controls a reset process on the first substrate.
  • the computer can be operated in the same manner as the radiographic image capturing apparatus according to the fifth aspect, the high-quality radiographic image can be obtained as in the radiographic image capturing apparatus. Shooting can be performed at a precise timing.
  • a radiographic image capturing method is laminated on a first substrate for still image capturing that converts incident radiation into a radiographic image, and the first substrate, A first state in which still image shooting is performed using the first substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and obtained by the still image shooting A determination step of determining whether or not a still image is being displayed is at least one of the second states, and at least one of the first state and the second state by the determination step; And a control step of controlling execution of reset processing for the second substrate when determined.
  • the eleventh aspect of the invention operates in the same manner as the radiographic image capturing apparatus according to the first aspect. Therefore, as with the radiographic image capturing apparatus, high-quality radiographic image capturing is precisely timed. Can be done.
  • the radiographic image capturing method is laminated on a first substrate for still image capturing that converts incident radiation into a radiographic image, and the first substrate,
  • a first state in which moving image shooting is performed using the second substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and a moving image obtained by the moving image shooting
  • the twelfth aspect of the invention operates in the same manner as the radiographic image capturing apparatus according to the fifth aspect. Therefore, as with the radiographic image capturing apparatus, it is possible to accurately capture a high-quality radiographic image. Can be done.
  • radiographic image capturing apparatus According to the radiographic image capturing apparatus, the program, and the radiographic image capturing method of the present invention, it is possible to produce an effect that radiographic images with high image quality can be captured at appropriate timing.
  • FIG. 1 is a schematic cross-sectional view schematically showing the configuration of three pixel portions of a radiation detector 20 according to an embodiment of the present invention.
  • the radiation detector 20 includes a TFT substrate 30A configured by sequentially forming a signal output unit 14, a sensor unit 13, and a transparent insulating film 7 on an insulating substrate 1,
  • the scintillator 8, the adhesive layer 22, and the TFT substrate 30B having the same configuration as the TFT substrate 30A are laminated in this order, and the pixel output by the signal output unit 14 and the sensor unit 13 of the TFT substrate 30A and the TFT substrate 30B.
  • the part is composed.
  • a plurality of pixel units are arranged on the substrate 1, and the signal output unit 14 and the sensor unit 13 in each pixel unit are configured to overlap each other.
  • the scintillator 8 is formed of a columnar crystal on the sensor unit 13 via the transparent insulating film 7, and forms a phosphor that emits light by converting radiation incident from above (TFT substrate 30 B side) into light. It is a thing. Providing such a scintillator 8 absorbs the radiation transmitted through the subject and the TFT substrate 30B and emits light.
  • the wavelength range of light emitted by the scintillator 8 is preferably the visible light range (wavelength 360 nm to 830 nm), and in order to enable monochrome imaging by the radiation detector 20, the wavelength range of green is included. Is more preferable.
  • the phosphor used in the scintillator 8 preferably contains cesium iodide (CsI) when imaging using X-rays as radiation, and the emission spectrum upon X-ray irradiation is, for example, 420 nm to It is particularly preferred to use CsI: Tl at 700 nm. Note that the emission peak wavelength in the visible light region of CsI: Tl is 565 nm.
  • CsI cesium iodide
  • the scintillator 8 is formed with a columnar portion made of a columnar crystal 71A on the radiation incident side (TFT substrate 30B side).
  • a non-columnar portion made of a non-columnar crystal 71B is formed on the opposite side.
  • a material containing CsI is used as the scintillator 8, and the material is directly deposited on the TFT substrate 30A, so that the columnar portion and the non-columnar portion are formed.
  • the formed scintillator 8 is obtained.
  • the average diameter of the columnar crystals 71A is approximately uniform along the longitudinal direction of the columnar crystals 71A.
  • the light generated by the scintillator 8 travels in the columnar crystal 71A and is emitted to the TFT substrate 30A via the non-columnar crystal 71B.
  • the light that has traveled toward the tip of the columnar crystal 71A of the scintillator 8 is emitted to the TFT substrate 30B, and contributes to an increase in the amount of light received by the TFT substrate 30B.
  • the non-columnar portion has a porosity close to 0 (zero), whereby reflection of light by the non-columnar portion can be suppressed. Further, it is preferable to make the non-columnar portion as thin as possible (about 10 ⁇ m).
  • the TFT substrate 30B is disposed on the radiation irradiation surface side of the scintillator 8, but the method of disposing the scintillator 8 and the TFT substrate 30B in such a positional relationship is “surface reading method (ISS). : Irradiation Side Sampling) ”.
  • the surface reading method (ISS) in which the TFT substrate is disposed on the radiation incident side of the scintillator is the “back surface reading method (in which the TFT substrate is disposed on the opposite side of the scintillator from the radiation incident side” Since the TFT substrate and the light emission position of the scintillator are closer to each other than PSS (Penetration Side Sampling), the resolution of the radiographic image obtained by imaging is high, and the amount of light received by the TFT substrate is increased, resulting in radiation. Image sensitivity is improved.
  • the sensor unit 13 includes an upper electrode 6, a lower electrode 2, and a photoelectric conversion film 4 disposed between the upper and lower electrodes.
  • the photoelectric conversion film 4 absorbs light emitted from the scintillator 8 and charges are generated. It is comprised with the organic photoelectric conversion material to generate
  • the upper electrode 6 is preferably made of a conductive material transparent to at least the emission wavelength of the scintillator because it is necessary to make the light generated by the scintillator enter the photoelectric conversion film 4. It is preferable to use a transparent conductive oxide (TCO) having a high transmittance with respect to the surface and a low resistance value. Although a metal thin film such as Au can be used as the upper electrode 6, TCO is preferable because it tends to increase the resistance value when it is desired to obtain a transmittance of 90% or more.
  • TCO transparent conductive oxide
  • the upper electrode 6 may have a single configuration common to all the pixel portions, or may be divided for each pixel portion.
  • the photoelectric conversion film 4 includes an organic photoelectric conversion material, absorbs light emitted from the scintillator 8, and generates electric charges according to the absorbed light.
  • the photoelectric conversion film 4 containing an organic photoelectric conversion material has a sharp absorption spectrum in the visible range, and electromagnetic waves other than light emitted by the scintillator 8 are hardly absorbed by the photoelectric conversion film 4.
  • the noise generated by the radiation such as being absorbed by the photoelectric conversion film 4 can be effectively suppressed.
  • the organic photoelectric conversion material constituting the photoelectric conversion film 4 is preferably such that its absorption peak wavelength is closer to the emission peak wavelength of the scintillator in order to absorb light emitted by the scintillator 8 most efficiently.
  • the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator, but if the difference between the two is small, the light emitted from the scintillator can be sufficiently absorbed.
  • the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength with respect to the radiation of the scintillator is preferably within 10 nm, and more preferably within 5 nm.
  • Examples of the organic photoelectric conversion material that can satisfy such conditions include quinacridone organic compounds and phthalocyanine organic compounds.
  • quinacridone organic compounds since the absorption peak wavelength in the visible region of quinacridone is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI: Tl is used as the material of the scintillator 8, the difference in peak wavelength can be made within 10 nm. The amount of charge generated in the photoelectric conversion film 4 can be substantially maximized.
  • the electromagnetic wave absorption / photoelectric conversion site in the radiation detector 20 is constituted by an organic layer including a pair of electrodes 2 and 6 and an organic photoelectric conversion film 4 sandwiched between the electrodes 2 and 6. be able to. More specifically, this organic layer is a part that absorbs electromagnetic waves, a photoelectric conversion part, an electron transport part, a hole transport part, an electron blocking part, a hole blocking part, a crystallization preventing part, an electrode, and an interlayer contact improvement. It can be formed by stacking or mixing parts.
  • the organic layer preferably contains an organic p-type compound or an organic n-type compound.
  • An organic p-type semiconductor is a donor organic semiconductor (compound) typified by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound.
  • An organic n-type semiconductor is an acceptor organic semiconductor (compound) typified by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound.
  • the thickness of the photoelectric conversion film 4 is preferably as large as possible in terms of absorbing light from the scintillator 8. However, when the thickness is more than a certain level, the photoelectric conversion film 4 is generated in the photoelectric conversion film 4 by a bias voltage applied from both ends of the photoelectric conversion film 4. Since electric field strength is reduced and charges cannot be collected, the thickness is preferably 30 nm to 300 nm, more preferably 50 nm to 250 nm, and particularly preferably 80 nm to 200 nm.
  • the photoelectric conversion film 4 has a single-sheet configuration common to all the pixel portions, but may be divided for each pixel portion.
  • the lower electrode 2 is a thin film divided for each pixel portion.
  • the lower electrode 2 can be made of a transparent or opaque conductive material, and aluminum, silver, or the like can be suitably used.
  • the thickness of the lower electrode 2 can be, for example, 30 nm or more and 300 nm or less.
  • the sensor unit 13 by applying a predetermined bias voltage between the upper electrode 6 and the lower electrode 2, one of electric charges (holes, electrons) generated in the photoelectric conversion film 4 is moved to the upper electrode 6.
  • the other can be moved to the lower electrode 2.
  • a wiring is connected to the upper electrode 6, and a bias voltage is applied to the upper electrode 6 through this wiring.
  • the polarity of the bias voltage is determined so that electrons generated in the photoelectric conversion film 4 move to the upper electrode 6 and holes move to the lower electrode 2, but this polarity is reversed. May be.
  • the sensor unit 13 constituting each pixel unit only needs to include at least the lower electrode 2, the photoelectric conversion film 4, and the upper electrode 6. In order to suppress an increase in dark current, the electron blocking film 3 and hole blocking are performed. It is preferable to provide at least one of the films 5, and it is more preferable to provide both.
  • the electron blocking film 3 can be provided between the lower electrode 2 and the photoelectric conversion film 4.
  • a bias voltage is applied between the lower electrode 2 and the upper electrode 6, electrons are transferred from the lower electrode 2 to the photoelectric conversion film 4. It is possible to suppress the dark current from increasing due to the injection of.
  • An electron donating organic material can be used for the electron blocking film 3.
  • the material actually used for the electron blocking film 3 may be selected according to the material of the adjacent electrode, the material of the adjacent photoelectric conversion film 4 and the like, and 1.3 eV or more from the work function (Wf) of the material of the adjacent electrode. Those having a large electron affinity (Ea) and an Ip equivalent to or smaller than the ionization potential (Ip) of the material of the adjacent photoelectric conversion film 4 are preferable. Since the material applicable as the electron donating organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.
  • the photoelectric conversion film 4 may be formed by further containing fullerenes or carbon nanotubes.
  • the thickness of the electron blocking film 3 is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 13. It is 50 nm or more and 100 nm or less.
  • the hole blocking film 5 can be provided between the photoelectric conversion film 4 and the upper electrode 6.
  • a bias voltage is applied between the lower electrode 2 and the upper electrode 6, the hole blocking film 5 is transferred from the upper electrode 6 to the photoelectric conversion film 4. It is possible to suppress the increase in dark current due to the injection of holes.
  • An electron-accepting organic material can be used for the hole blocking film 5.
  • the thickness of the hole blocking film 5 is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 13. Is from 50 nm to 100 nm.
  • the material actually used for the hole blocking film 5 may be selected according to the material of the adjacent electrode, the material of the adjacent photoelectric conversion film 4 and the like, and 1.3 eV from the work function (Wf) of the material of the adjacent electrode. As described above, it is preferable that the ionization potential (Ip) is large and that the Ea is equal to or larger than the electron affinity (Ea) of the material of the adjacent photoelectric conversion film 4. Since the material applicable as the electron-accepting organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.
  • the electron blocking film 3 and the hole blocking are set.
  • the position of the film 5 may be reversed.
  • a signal output unit 14 is formed on the surface of the substrate 1 below the lower electrode 2 of each pixel unit.
  • FIG. 3 schematically shows the configuration of the signal output unit 14.
  • a capacitor 9 that accumulates the charges transferred to the lower electrode 2 and a field effect thin film transistor (Thin Transistor, hereinafter simply referred to as an electric signal converted from the electric charge accumulated in the capacitor 9) "Thin film transistor") 10 is formed.
  • the region in which the capacitor 9 and the thin film transistor 10 are formed has a portion that overlaps the lower electrode 2 in a plan view. With such a configuration, the signal output unit 14 and the sensor unit 13 in each pixel unit are connected to each other. There will be overlap in the thickness direction. In order to minimize the plane area of the radiation detector 20 (pixel portion), it is desirable that the region where the capacitor 9 and the thin film transistor 10 are formed is completely covered by the lower electrode 2.
  • the capacitor 9 is electrically connected to the corresponding lower electrode 2 via a wiring made of a conductive material penetrating an insulating film 11 provided between the substrate 1 and the lower electrode 2. Thereby, the electric charge collected by the lower electrode 2 can be moved to the capacitor 9.
  • a gate electrode 15, a gate insulating film 16, and an active layer (channel layer) 17 are stacked, and a source electrode 18 and a drain electrode 19 are formed on the active layer 17 at a predetermined interval.
  • the active layer 17 can be formed of, for example, amorphous silicon, amorphous oxide, organic semiconductor material, carbon nanotube, or the like.
  • the material which comprises the active layer 17 is not limited to these.
  • the amorphous oxide that can form the active layer 17 is preferably an oxide containing at least one of In, Ga, and Zn (for example, In—O-based), and at least 2 of In, Ga, and Zn.
  • In—Zn—O, In—Ga—O, and Ga—Zn—O are more preferable, and oxides including In, Ga, and Zn are particularly preferable.
  • In—Ga—Zn—O-based amorphous oxide an amorphous oxide whose composition in a crystalline state is represented by InGaO 3 (ZnO) m (m is a natural number of less than 6) is preferable, and InGaZnO is particularly preferable. 4 is more preferable.
  • the amorphous oxide which can comprise the active layer 17 is not limited to these.
  • Examples of the organic semiconductor material that can form the active layer 17 include, but are not limited to, phthalocyanine compounds, pentacene, vanadyl phthalocyanine, and the like. Note that the configuration of the phthalocyanine compound is described in detail in JP-A-2009-212389, and thus the description thereof is omitted.
  • the active layer 17 of the thin film transistor 10 is formed of an amorphous oxide, an organic semiconductor material, or a carbon nanotube, it will not absorb radiation such as X-rays, or even if it absorbs it, it will remain in a very small amount. Generation of noise in the portion 14 can be effectively suppressed.
  • the switching speed of the thin film transistor 10 can be increased, and the thin film transistor 10 having a low degree of light absorption in the visible light region can be formed.
  • the performance of the thin film transistor 10 is remarkably deteriorated only by mixing a very small amount of metallic impurities into the active layer 17. It is necessary to form by separating and extracting.
  • the substrate 1 is not limited to a substrate having high heat resistance such as a semiconductor substrate, a quartz substrate, and a glass substrate, and a flexible substrate such as plastic, aramid, or bio-nanofiber can also be used.
  • flexible materials such as polyesters such as polyethylene terephthalate, polybutylene phthalate, and polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, and poly (chlorotrifluoroethylene).
  • a conductive substrate can be used. If such a plastic flexible substrate is used, it is possible to reduce the weight, which is advantageous for carrying around, for example.
  • the substrate 1 is provided with an insulating layer for ensuring insulation, a gas barrier layer for preventing permeation of moisture and oxygen, an undercoat layer for improving flatness or adhesion to electrodes, and the like. May be.
  • the transparent electrode material can be cured at a high temperature to lower its resistance, and can also be used for automatic mounting of a driver IC including a solder reflow process.
  • Aramid has a thermal expansion coefficient close to that of ITO (Indium Tin Oxide) or glass substrate, so there is little warping after manufacturing and it is difficult to crack.
  • aramid can form a substrate thinner than a glass substrate or the like.
  • the substrate 1 may be formed by laminating an ultrathin glass substrate and aramid.
  • Bionanofiber is a composite of cellulose microfibril bundle (bacterial cellulose) produced by bacteria (acetic acid bacteria, Acetobacter® Xylinum) and transparent resin.
  • the cellulose microfibril bundle has a width of 50 nm and a size of 1/10 of the visible light wavelength, and has high strength, high elasticity, and low thermal expansion.
  • a transparent resin such as acrylic resin or epoxy resin into bacterial cellulose
  • a bio-nanofiber having a light transmittance of about 90% at a wavelength of 500 nm can be obtained while containing 60-70% of the fiber.
  • Bionanofiber has a low coefficient of thermal expansion (3-7ppm) comparable to silicon crystals, and is as strong as steel (460MPa), highly elastic (30GPa), and flexible. Compared to glass substrates, etc.
  • the substrate 1 can be formed thinly.
  • the TFT substrate 30B according to the present embodiment is configured in the same manner as the TFT substrate 30A, illustration and description of the configuration are omitted, but the surface opposite to the substrate 1 (photoelectric conversion film 4). Side surface) is laminated on the surface of the scintillator 8 opposite to the TFT substrate 30A.
  • the scintillator 8 is formed directly on the TFT substrate 30A by vapor deposition, while the side of the scintillator 8 opposite to the surface on which the TFT substrate 30A is provided.
  • the TFT substrate 30B is bonded to the surface of the TFT substrate 30 via the adhesive layer 22.
  • the present invention is not limited to this.
  • the scintillator 8 is formed directly on the TFT substrate 30B by vapor deposition.
  • the TFT substrate 30A may be formed by other methods such as a method of bonding the TFT substrate 30A to the surface opposite to the surface on which the substrate 30B is provided via the adhesive layer 22.
  • the tip of each columnar part of the scintillator 8 it is preferable to control the tip of each columnar part of the scintillator 8 to be as flat as possible. Specifically, it can be realized by controlling the temperature of the evaporation target substrate at the end of evaporation. For example, if the temperature of the substrate to be deposited at the end of vapor deposition is 110 ° C., the tip angle is about 170 degrees, and if the temperature of the substrate to be deposited at the end of vapor deposition is 140 degrees Celsius, the tip angle is about 60 degrees.
  • the tip angle is approximately 70 degrees, and if the temperature of the vapor deposition substrate at the end of vapor deposition is 260 ° C., the tip angle is approximately 120 degrees. Since this control is described in detail in Japanese Patent Application Laid-Open No. 2010-25620, further description is omitted.
  • pixels 32 including the above-described sensor unit 13, capacitor 9, and thin film transistor 10 are arranged in a certain direction (scanning line direction in FIG. 4) and A plurality of two-dimensional shapes are provided in the intersecting direction (signal wiring direction in FIG. 4) with respect to the certain direction.
  • the radiation detector 20 extends in the predetermined direction (scanning line direction), and extends in the intersecting direction (signal wiring direction) with a plurality of gate wirings 34 for turning on and off each thin film transistor 10.
  • a plurality of data wirings 36 for reading out charges through the thin film transistor 10 in the on state are provided in two sets corresponding to the TFT substrate 30A and the TFT substrate 30B, respectively.
  • the radiation detector 20 is flat and has a quadrilateral shape with four sides at the outer edge in plan view. Specifically, it is formed in a rectangular shape.
  • FIG. 5 is a perspective view showing the configuration of the electronic cassette 40 according to the present exemplary embodiment.
  • the electronic cassette 40 includes a flat housing 41 made of a material that transmits radiation, and has a waterproof and airtight structure. Inside the housing 41 are a radiation detector 20 that detects the radiation X that has passed through the subject from the irradiation surface side of the housing 41 that is irradiated with the radiation X, and a lead plate 43 that absorbs backscattered rays of the radiation X. Are arranged in order.
  • the case 41 has a quadrilateral imaging region 41A capable of detecting radiation in a region corresponding to the arrangement position of the radiation detector 20 on one flat surface. As shown in FIG. 6, the radiation detector 20 is disposed such that the TFT substrate 30B is on the imaging region 41A side, and is attached to the inside of the casing 41 that constitutes the imaging region 41A.
  • a case 42 that houses a cassette control unit 58, a power supply unit 70, and the like, which will be described later, is disposed at one end inside the housing 41 at a position that does not overlap the radiation detector 20 (outside the range of the imaging region 41A). ing.
  • FIG. 7 is a block diagram showing the main configuration of the electrical system of the electronic cassette 40 according to the present embodiment.
  • a gate line driver 52 is disposed on one side of two adjacent sides, and a signal processing unit 54 is disposed on the other side.
  • the gate line driver 52 and the signal processing unit 54 provided corresponding to the two TFT substrates 30A and 30B are distinguished from each other, the gate line driver 52 and the signal processing unit 54 corresponding to the TFT substrate 30A are denoted by A.
  • the gate line driver 52 and the signal processing unit 54 corresponding to the TFT substrate 30B will be described with reference character B.
  • Each gate wiring 34 of the TFT substrate 30A is connected to the gate line driver 52A, each data wiring 36 of the TFT substrate 30A is connected to the signal processing unit 54A, and each gate wiring 34 of the TFT substrate 30B is a gate line. Connected to the driver 52B, each data wiring 36 of the TFT substrate 30B is connected to the signal processing unit 54B.
  • the housing 41 includes an image memory 56, a cassette control unit 58, a wireless communication unit 60, and a bias power source 72.
  • the thin film transistors 10 on the TFT substrates 30A and 30B are sequentially turned on in units of scanning lines by signals supplied from the gate line drivers 52A and 52B via the gate wiring 34, and the electric charges read by the thin film transistors 10 turned on. Is transmitted through the data wiring 36 as an electrical signal and input to the signal processing units 54A and 54B. As a result, the charges are sequentially read in units of scanning lines, and a two-dimensional radiation image can be acquired.
  • the bias power source 72 applies a bias voltage (DC voltage) necessary for converting the light generated by the scintillator 8 into electric charges in the TFT substrate 30A and the TFT substrate 30B.
  • a bias voltage is applied to the photoelectric conversion film 4 of the TFT substrate 30B, while when moving image shooting is performed, a bias voltage is applied to the photoelectric conversion film 4 of the TFT substrate 30A.
  • FIG. 8 is a circuit diagram showing a configuration of the signal processing unit 54A according to the present embodiment.
  • the signal processing unit 54A includes a variable gain preamplifier (charge amplifier) 82 and a sample hold circuit 86 corresponding to each of the data wirings 36 of the TFT substrate 30A. Is provided.
  • the variable gain preamplifier 82 includes an operational amplifier 82A whose positive input side is grounded, a capacitor 82B connected in parallel between the negative input side and the output side of the operational amplifier 82A, and a reset switch 82C.
  • the reset switch 82C is switched by the cassette control unit 58.
  • the signal processing unit 54A includes a multiplexer 88 and an A / D (analog / digital) converter 89. Note that the sample control of the sample hold circuit 86 and the selection output by the switch 88A provided in the multiplexer 88 are also switched by the cassette control unit 58.
  • the cassette control unit 58 When detecting the radiation image, the cassette control unit 58 first discharges the charge accumulated in the capacitor 82B by turning on the reset switch 82C of the variable gain preamplifier 82 for a predetermined period.
  • the electric charge accumulated in each capacitor 9 of each pixel 32 of the TFT substrate 30A by being irradiated with the radiation X is connected as an electric signal when the connected thin film transistor 10 is turned on.
  • the electric signal transmitted through the data line 36 and transmitted through the data line 36 is amplified by the corresponding variable gain preamplifier 82 at a predetermined amplification factor.
  • the cassette control unit 58 causes the sample hold circuit 86 to hold the signal level of the electric signal amplified by the variable gain preamplifier 82 by driving the sample hold circuit 86 for a predetermined period after performing the above-described discharge.
  • the signal levels held in each sample and hold circuit 86 are sequentially selected by the multiplexer 88 in accordance with control by the cassette control unit 58 and are A / D converted by the A / D converter 89 and photographed. Image data indicating a radiation image is generated.
  • an image memory 56 is connected to the signal processing unit 54A, and the image data output from the A / D converter 89 of the signal processing unit 54A is stored in the image memory 56 in order.
  • the image memory 56 has a storage capacity capable of storing a predetermined number of image data, and image data obtained by imaging is sequentially stored in the image memory 56 each time a radiographic image is captured.
  • FIG. 9 shows a circuit diagram showing a configuration of the signal processing unit 54B according to the present embodiment.
  • the signal processing unit 54B similarly to the signal processing unit 54A, corresponds to each of the data wirings 36 of the TFT substrate 30B and a variable gain preamplifier (charge amplifier) 92. , A sample hold circuit 96 is provided.
  • the variable gain preamplifier 92 includes an operational amplifier 92A whose positive input side is grounded, a capacitor 92B connected in parallel between the negative input side and the output side of the operational amplifier 92A, and a reset switch 92C.
  • the reset switch 92C is switched by the cassette control unit 58.
  • the signal processing unit 54B is also provided with a multiplexer 98 and an A / D (analog / digital) converter 99, similarly to the signal processing unit 54A. Note that the sample control of the sample hold circuit 96 and the selection output by the switch 98A provided in the multiplexer 98 are also switched by the cassette control unit 58.
  • the cassette control unit 58 When detecting the radiation image, the cassette control unit 58 first discharges the charge accumulated in the capacitor 92B by turning on the reset switch 92C of the variable gain preamplifier 92 for a predetermined period.
  • the electric charge accumulated in each capacitor 9 of each pixel 32 of the TFT substrate 30B by being irradiated with the radiation X is connected as an electric signal when the connected thin film transistor 10 is turned on.
  • the electrical signal transmitted through the data line 36 and transmitted through the data line 36 is amplified by a corresponding variable gain preamplifier 92 at a predetermined amplification factor.
  • the cassette control unit 58 causes the sample and hold circuit 96 to hold the signal level of the electric signal amplified by the variable gain preamplifier 92 by driving the sample and hold circuit 96 for a predetermined period after performing the above-described discharge.
  • the signal levels held in the sample and hold circuits 96 are sequentially selected by the multiplexer 98 in accordance with the control by the cassette control unit 58 and are A / D converted by the A / D converter 99 to be photographed. Image data indicating a radiation image is generated.
  • the image memory 56 is also connected to the signal processing unit 54B, and the image data output from the A / D converter 99 of the signal processing unit 54B is also stored in the image memory 56 in order.
  • reset processing is performed on the TFT substrate 30A and the TFT substrate 30B by discharging the charges accumulated in the respective pixels 32 of the TFT substrate 30A and the TFT substrate 30B. It has an electrical reset function.
  • the cassette control unit 58 controls the gate line driver 52A to turn on the thin film transistors 10 of all the pixels 32 provided on the TFT substrate 30A for a predetermined period.
  • the reset switches 82C of all the variable gain preamplifiers 82 in the signal processing unit 54A for a predetermined period the charges accumulated in the capacitors 82B of the variable gain preamplifiers 82 are transferred by the capacitors 82B and the reset switches 82C.
  • the charge accumulated in the capacitor 9 of each pixel 32 is discharged to the ground through the thin film transistor 10, the reset switch 82C, and the operational amplifier 82A.
  • the cassette control unit 58 controls the gate line driver 52B to control the thin film transistors 10 of all the pixels 32 provided on the TFT substrate 30B.
  • the reset switches 92C of all the variable gain preamplifiers 92 in the signal processing unit 54B for a predetermined period while being turned on for a predetermined period the charges accumulated in the capacitors 92B of the variable gain preamplifiers 92 are In addition to discharging by the closed circuit constituted by 92B and the reset switch 92C, the charge accumulated in the capacitor 9 of each pixel 32 is discharged to the ground via the thin film transistor 10, the reset switch 92C, and the operational amplifier 92A.
  • the image memory 56 is connected to a cassette control unit 58.
  • the cassette control unit 58 is constituted by a microcomputer, and includes a CPU (Central Processing Unit) 58A, a memory 58B including a ROM (Read Only Memory) and a RAM (Random Access Memory), a non-volatile storage unit 58C including a flash memory and the like. The operation of the entire electronic cassette 40 is controlled.
  • a wireless communication unit 60 is connected to the cassette control unit 58.
  • the wireless communication unit 60 corresponds to a wireless LAN (Local Area Network) standard represented by IEEE (Institute of Electrical and Electronics Electronics) (802.11a / b / g / n), etc., and communicates with an external device by wireless communication. Control the transmission of various information between them.
  • the cassette control unit 58 can wirelessly communicate with an external device such as a console for controlling the entire radiation imaging via the wireless communication unit 60, and can transmit and receive various types of information to and from the console. .
  • the electronic cassette 40 is provided with a power supply unit 70, and the various circuits and elements described above (gate line drivers 52A and 52B, signal processing units 54A and 54B, image memory 56, wireless communication unit 60, and cassette control).
  • the microcomputer functioning as the unit 58 is operated by the electric power supplied from the power supply unit 70.
  • the power supply unit 70 incorporates a battery (a rechargeable secondary battery) so as not to impair the portability of the electronic cassette 40, and supplies power from the charged battery to various circuits and elements.
  • the power supply unit 70, various circuits, and wirings for connecting each element are omitted. Further, in FIG. 7, wirings that connect the bias power source 72 and the respective pixels 32 of the TFT substrate 30A and the TFT substrate 30B are also omitted.
  • the electronic cassette 40 according to the present embodiment is configured to be able to perform both still image shooting and moving image shooting.
  • the TFT substrate 30A is used as a moving image shooting substrate
  • the TFT substrate 30B is used as a still image shooting substrate.
  • the electronic cassette 40 When radiographic images are captured, the electronic cassette 40 according to the present embodiment is arranged with the imaging region 41A facing upward and spaced apart from the radiation generator 80 that generates radiation, as shown in FIG.
  • the imaging target region B of the patient is arranged on the imaging area.
  • the radiation generator 80 emits radiation X having a radiation dose according to imaging conditions given in advance.
  • the radiation X when capturing a moving image, the radiation X is intermittently irradiated (so-called pulse irradiation) at a relatively low dose and in a predetermined cycle to capture a still image.
  • the radiation X is irradiated at a relatively high dose (in this embodiment, about 100 times that during moving image shooting) and in a single shot.
  • the radiation X emitted from the radiation generator 80 reaches the electronic cassette 40 after passing through the imaging target region B.
  • charges corresponding to the dose of the irradiated radiation X are generated in each sensor unit 13 of the radiation detector 20 incorporated in the electronic cassette 40, and the charges generated by the sensor unit 13 are accumulated in the capacitor 9.
  • the cassette control unit 58 controls the gate line driver 52B when shooting a still image, and sequentially outputs an ON signal line by line from the gate line driver 52B to each gate wiring 34 of the TFT substrate 30B.
  • Read image information Accordingly, the image information read from the TFT substrate 30B of the radiation detector 20 is stored in the image memory 56 as image data (hereinafter referred to as “still image data”) after passing through the signal processing unit 54B.
  • the cassette control unit 58 reads the still image data from the image memory 56 and transmits it to the console via the wireless communication unit 60.
  • the console stores the received still image data in a predetermined storage device, and causes the display device to display a still image indicated by the image data.
  • the cassette control unit 58 controls the gate line driver 52A when shooting a moving image, and sequentially outputs an ON signal line by line from the gate line driver 52A to each gate wiring 34 of the TFT substrate 30A.
  • the image information is read out in accordance with a frame rate (30 in the present embodiment) determined in advance according to the period of irradiation of radiation X that is intermittently emitted from the radiation generation apparatus 80 during moving image shooting. It is repeatedly executed at a speed corresponding to (frame / second).
  • the image information read from the TFT substrate 30A of the radiation detector 20 is sequentially stored in the image memory 56 as image data (hereinafter referred to as “moving image data”) after passing through the signal processing unit 54A.
  • the cassette control unit 58 continuously reads out the moving image data from the image memory 56 and transmits the moving image data to the console via the wireless communication unit 60 in real time.
  • the console displays a moving image (perspective image) by displaying the moving image indicated by the moving image data received from the electronic cassette 40 in real time on the display device.
  • the moving image data read from the TFT substrate 30A and the still image data read from the TFT substrate 30B are stored in different storage areas of the image memory 56, respectively. It is supposed to be.
  • FIG. 10 shows the flow of processing of a photographing processing program executed by the CPU 58A in the cassette control unit 58 of the electronic cassette 40 when instruction information for instructing the start of photographing of a moving image (perspective image) is received from the console.
  • This program is stored in advance in the ROM of the memory 58B.
  • description of control related to irradiation of the radiation X from the radiation generation apparatus 80 is omitted.
  • step 100 in the figure the cassette control unit 58 starts the operation at the time of moving image shooting described above.
  • transmission of moving image data to the console at a speed corresponding to the frame rate is started, and display of a moving image (perspective image) is started on the console display device.
  • various conventionally known methods can be applied.
  • the dose of the radiation X being irradiated is derived based on the pixel data obtained by the predetermined pixel 32 of the TFT substrate 30A or the TFT substrate 30B, and the derived dose is determined in advance.
  • a method of synchronizing is applied by assuming that a time point when a predetermined threshold is reached is a time point when pulse irradiation is started.
  • the present invention is not limited to this, and as another embodiment, a method of using a dedicated radiation sensor in place of the predetermined pixel 32, the timing of irradiation of the radiation X by the radiation generator 80 by the console, and the electronic cassette 40 A method for performing synchronization control with the timing of photographing can be exemplified.
  • the cassette controller 58 executes an electrical reset process by using the electrical reset function described above for the TFT substrate 30B.
  • the charge accumulated in the capacitor 92B of each variable gain preamplifier 92 of the signal processing unit 54B and the charge accumulated in the capacitor 9 in each pixel 32 of the TFT substrate 30B are discharged.
  • the photographer refers to a fluoroscopic image displayed on the display device of the console, and performs a pressing operation when instructing the photographing of the still image when the electronic cassette 40 performs the photographing of the still image. Press the shooting button (not shown).
  • the photographing button is connected to the console, and when the pressing operation is performed, the console transmits instruction information for instructing photographing of a still image to the electronic cassette 40.
  • the cassette control unit 58 waits until receiving the instruction information for instructing the photographing of the still image, and in the next step 106, the operation at the time of still image photographing is executed.
  • the cassette control unit 58 performs the electric reset process by using the electric reset function described above for the TFT substrate 30A, and then in the next step 110, the above-mentioned image is captured. Wait for the operation to finish.
  • the electric reset process in step 108 the charge accumulated in the capacitor 82B of each variable gain preamplifier 82 of the signal processing unit 54A and the charge accumulated in the capacitor 9 in each pixel 32 of the TFT substrate 30A are discharged.
  • the cassette control unit 58 reads the still image data stored in the image memory 56, and in the next step 114, transmits the read still image data to the console.
  • the console displays the still image indicated by the received still image data on the display device instead of the moving image displayed so far.
  • the cassette control unit 58 determines whether or not the timing for ending the present photographing processing program has arrived. If a negative determination is made, the process returns to the above step 102, while a positive determination is made. Then, the process proceeds to the next step 118, the operation at the time of moving image shooting started by the processing of step 100 is stopped, and then the shooting processing program is ended.
  • the cassette control unit 58 receives, from the console, instruction information for instructing the end of shooting, as to whether or not it is time to end the shooting processing program executed in the processing of step 116. This is done by determining whether or not it has been done, but is not limited to this.
  • the electronic cassette 40 it is possible to capture a high-quality radiographic image in which the influence of afterimages and the like is suppressed in both the still image and the moving image.
  • the non-columnar portion is provided in the scintillator 8 since the adhesion with the TFT substrate 30A can be increased.
  • the non-columnar part is not essential, and the non-columnar part may not be provided.
  • the photoelectric conversion film 4 is made of an organic photoelectric conversion material, and radiation is hardly absorbed by the photoelectric conversion film 4. For this reason, in the radiation detector 20 according to the present embodiment, the radiation X passes through the TFT substrate 30B due to the ISS configuration, but the radiation X absorbed by the photoelectric conversion film 4 of the TFT substrate 30B is small. It is possible to suppress a decrease in sensitivity to In the ISS, the radiation X passes through the TFT substrate 30B and reaches the scintillator 8. In this way, when the photoelectric conversion film 4 of the TFT substrate 30B is made of an organic photoelectric conversion material, the radiation X in the photoelectric conversion film 4 is obtained. Therefore, it is suitable for ISS.
  • both the amorphous oxide constituting the active layer 17 of the thin film transistor 10 and the organic photoelectric conversion material constituting the photoelectric conversion film 4 can be formed at a low temperature.
  • substrate 1 can be formed with a plastic resin, aramid, and bio-nanofiber with little radiation absorption. Since the substrate 1 formed in this way has a small amount of radiation absorption, a decrease in sensitivity to the radiation X can be suppressed even when the radiation X passes through the TFT substrate 30B by ISS.
  • the radiation detector 20 is attached to the imaging region 41A portion in the housing 41 so that the TFT substrate 30B is on the imaging region 41A side.
  • the substrate 1 is formed of a highly rigid plastic resin, aramid, or bionanofiber
  • the radiation detector 20 itself has a high rigidity, so that the imaging region 41A portion of the housing 41 can be formed thin.
  • the radiation detector 20 itself has flexibility, so that even when an impact is applied to the imaging region 41A, the radiation detector 20 is damaged. It ’s hard.
  • still image shooting is performed using the first substrate for still image shooting (in this embodiment, the TFT substrate 30B) that converts incident radiation into a radiation image.
  • reset control is executed on the second substrate (TFT substrate 30A in the present embodiment) that is laminated on the first substrate and converts the incident radiation into a radiation image. Therefore, radiographic images (moving images) with high image quality can be taken at appropriate timing.
  • still image shooting is performed using the first substrate
  • still image shooting is performed using the first substrate
  • the still image obtained by the still image shooting is applied as an image corresponding to the shooting timing of the still image of the moving image obtained by the moving image shooting, and at the timing when the still image shooting is performed. Since execution control of the reset process is performed on the substrate, it is possible to prevent image loss during moving image shooting.
  • the moving image shooting is continuously controlled using the second substrate regardless of the execution of the reset process, so that the loss of moving images can be prevented more reliably.
  • the first substrate is controlled to perform a reset process, so that a high-quality radiation image ( (Still image) can be taken at an appropriate timing.
  • a high-quality radiation image (Still image)
  • a reset process is performed by releasing the charge accumulated in each pixel of the substrate that is the target of the reset process. Can be suppressed.
  • the second substrate is laminated on the surface of the first substrate opposite to the surface on which the radiation is incident, a radiation image can be obtained more effectively.
  • the electronic cassette 40 according to the second embodiment is equipped with a bias reset function for performing a bias reset process by controlling the supply state of the bias voltage to each pixel of the TFT substrate 30A and the TFT substrate 30B.
  • the bias power source 72 can be controlled to perform a bias reset process on the photodiode.
  • the charge accumulated in the photoelectric conversion film 4 is reversed by inverting the polarity of the bias voltage supplied from the bias power source 72 to the photoelectric conversion film 4 or stopping the supply of the bias voltage to the photoelectric conversion film 4. Extinguish or release.
  • the polarity of the bias voltage supplied from the bias power source 72 to the photoelectric conversion film 4 is restored or the supply of the bias voltage is performed in order to acquire a moving image of the next frame. Therefore, it takes some time for the photoelectric conversion film 4 to return to a stable operating state, but it is possible to effectively suppress the occurrence of afterimages.
  • the bias reset process a process of executing a process of returning the polarity of the bias voltage after inverting the polarity of the bias voltage supplied from the bias power supply 72 to the photoelectric conversion film 4 is performed. Applicable.
  • the configuration of the electronic cassette 40 according to the second embodiment is substantially the same as that of the electronic cassette 40 according to the first embodiment, and a description thereof is omitted here.
  • FIG. 12 shows the flow of processing of the imaging processing program executed by the CPU 58A in the cassette control unit 58 of the electronic cassette 40 when instruction information for instructing the start of imaging of a moving image (perspective image) is received from the console.
  • This program is stored in advance in the ROM of the memory 58B. Also, steps in FIG. 10 for executing the same processing as in FIG. 10 are assigned the same step numbers as in FIG.
  • step 102 'in FIG. 5 the cassette control unit 58 executes a bias reset process by using the bias reset function for the TFT substrate 30B. Thereby, the electric charge accumulated in the photoelectric conversion film 4 of the TFT substrate 30B is extinguished.
  • step 108 ′ the cassette controller 58 executes a bias reset process by using the bias reset function for the TFT substrate 30 ⁇ / b> A. Thereby, the electric charge accumulated in the photoelectric conversion film 4 of the TFT substrate 30A is extinguished.
  • an electrical reset process is applied as a reset process for the TFT substrate 30A and the TFT substrate 30B.
  • a bias reset process is performed as a reset process for the TFT substrate 30A and the TFT substrate 30B.
  • reset process in addition to the bias reset process, reset is performed by irradiating each pixel of the TFT substrate 30A with light. An example of a case where processing (hereinafter referred to as “optical reset processing”) is applied will be described.
  • FIG. 13 shows the configuration of the radiation detector 20 'in the electronic cassette 40 according to the third embodiment.
  • symbol as the said radiation detector 20 is attached
  • a radiation conversion layer 8 ′ made of amorphous selenium (a-Se) is laminated between the scintillator 8 and the TFT substrate 30B.
  • a-Se amorphous selenium
  • the TFT substrate 30A side employs an indirect conversion method in which radiation is converted into light by the scintillator 8, and then the light is converted into electric charge by the photoelectric conversion film 4.
  • a direct conversion method is adopted in which radiation is directly converted into charges by the radiation conversion layer 8 ′ made of amorphous selenium and the charges are read out by the TFT substrate 30B.
  • the electronic cassette 40 is equipped with an optical reset function for executing an optical reset process on the TFT substrate 30A by irradiating each pixel of the TFT substrate 30A with light.
  • the reset light source 50 is provided for this optical reset function, and the reset light source 50 according to the present embodiment is an edge light type backlight light source, and a light guide plate 50B is provided on the bottom surface of the TFT substrate 30A.
  • the cold cathode fluorescent lamp 50A is arranged on the side of the light guide plate 50B, which is a non-irradiated region of the radiation X.
  • a diffusion sheet 50C is interposed between the light guide plate 50B and the TFT substrate 30A.
  • a reflection sheet 50D is also disposed so as to surround the light guide plate 50B and the cold cathode tube 50A.
  • the cold cathode tube 50A is driven by the control of the cassette control unit 58 and light enters the light guide plate 50B from the cold cathode tube 50A, the light incident on the light guide plate 50B diffuses inside the light guide plate 50B. After surface reflection is repeated between the sheet 50C and the reflection sheet 50D, the light is emitted as reset light 50E from the diffusion sheet 50C to the TFT substrate 30A.
  • the backlight type reset light source 50 functions as a surface emitting light source, and uniformly irradiates the reset light 50E to the TFT substrate 30A.
  • the reset process for suppressing generation
  • the photoelectric conversion film 4 made of a-Si or the like a part of charges (electrons) converted from light (visible light) is once trapped in the impurity level (defect) of a-Si. After that, when charge is re-released due to a temperature rise of the photoelectric conversion film 4 due to long-time shooting such as moving image shooting, an unnecessary current such as dark current is generated, and a radiographic image (moving image) ) May cause noise (afterimage).
  • the reset light source 50 including an edge light type backlight light source is illustrated, but the present invention is not limited to this, and the photoelectric conversion film 4 of the pixels 32 arranged in a matrix is illustrated. Any light reset process can be performed as long as the reset light 50E can be reliably irradiated. Therefore, the reset light source 50 may be configured by arranging an array of light emitting elements or an electroluminescence light source on the bottom surface of the TFT substrate 30A.
  • FIG. 14 shows the flow of processing of the photographing processing program executed by the CPU 58A in the cassette control unit 58 of the electronic cassette 40 when instruction information for instructing the start of moving image (perspective image) photographing is received from the console.
  • This program is stored in advance in the ROM of the memory 58B.
  • description of control related to irradiation of the radiation X from the radiation generation apparatus 80 is omitted as much as possible.
  • step 200 of the figure the cassette control unit 58 starts an operation at the time of moving image shooting, similarly to the processing of step 100 of the shooting processing program according to the first embodiment.
  • transmission of moving image data to the console at a speed corresponding to the frame rate is started, and display of a moving image (perspective image) is started on the console display device.
  • the cassette control unit 58 executes a bias reset process by applying a bias reset function similar to that of the second embodiment to the TFT substrate 30B. Thereby, the electric charge accumulated in the photoelectric conversion film 4 of the TFT substrate 30B is extinguished.
  • the photographer refers to a fluoroscopic image displayed on the display device of the console, and performs a pressing operation when instructing the photographing of the still image when the electronic cassette 40 performs the photographing of the still image. Press the shooting button (not shown).
  • the photographing button is connected to the console, and when the pressing operation is performed, the console transmits instruction information for instructing photographing of a still image to the electronic cassette 40.
  • the cassette control unit 58 waits until receiving the instruction information for instructing the photographing of the still image, and in the next step 206, the photographing processing program according to the first embodiment. Similar to the processing in step 106, the operation at the time of still image shooting is executed.
  • the cassette control unit 58 executes the light reset process by using the above-described light reset function for the TFT substrate 30A, and then in the next step 210, the above-described still image shooting time. Wait for the operation to finish.
  • a light reset process for suppressing the occurrence of an afterimage or the like is performed on the photoelectric conversion film 4 of each pixel 32 included in the TFT substrate 30A.
  • the cassette control unit 58 transmits instruction information for instructing to stop irradiation of the radiation X from the radiation generator 80 to the console.
  • the console receives the instruction information, the console instructs the radiation generator 80 to stop the radiation X irradiation. In response to this, the radiation generator 80 stops the irradiation of the radiation X.
  • the cassette control unit 58 reads the still image data stored in the image memory 56, and in the next step 216, transmits the read still image data to the console via the wireless communication unit 60.
  • the console displays the still image indicated by the received still image data on the display device instead of the moving image displayed so far.
  • step 218 the cassette control unit 58 determines whether or not the timing for ending the present photographing processing program has come. If the determination is negative, the process proceeds to step 220. In the present embodiment as well, it is determined whether or not the timing for ending the shooting processing program executed in the processing of step 218 has been reached, and whether or not instruction information for instructing the end of shooting has been received from the console. Needless to say, this is not limited to this.
  • the photographer when the photographer resumes the display of the moving image while referring to the still image displayed on the display device of the console, the photographer inputs instruction information instructing the resume to the console.
  • the console transmits to the electronic cassette 40 instruction information for instructing resumption of moving image shooting.
  • step 220 the cassette control unit 58 waits until receiving the instruction information, and in the next step 222, an instruction for instructing to resume the pulse irradiation of the radiation X stopped by the processing in step 212.
  • the process returns to step 202.
  • the console receives the instruction information, the console transmits to the radiation generation apparatus 80 instruction information that instructs the radiation generation apparatus 80 to resume pulse irradiation.
  • the radiation generator 80 resumes the radiation X pulse irradiation.
  • step 218 determines whether the cassette control unit 58 is affirmative. If the determination in step 218 is affirmative, the cassette control unit 58 proceeds to step 224, stops the operation at the time of moving image shooting started by the processing of step 200, and then executes the main shooting processing program. finish.
  • still image photographing is performed using the TFT substrate 30B in which no trouble occurs even if reset processing is performed on the TFT substrate 30A.
  • a reset process is executed on the TFT substrate 30A.
  • the reset process is performed on the TFT substrate 30B when the moving image shooting is performed using the TFT substrate 30A in which no trouble occurs even if the reset process is performed on the TFT substrate 30B. is doing.
  • the radiation dose to the subject (patient) can be suppressed.
  • each of the above embodiments does not limit the invention according to the claims (claims), and all combinations of features described in each embodiment are indispensable for solving means of the invention. Not always.
  • Each embodiment described above includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.
  • the present invention is applied to the electronic cassette 40 which is a portable radiographic image capturing apparatus.
  • the present invention is not limited to this, and a stationary radiographic image is provided. You may apply to an imaging device.
  • the TFT substrate 30A, the scintillator 8, and the TFT substrate 30B are laminated in this order, and as shown in FIG.
  • the present invention is not limited to this.
  • FIG. It is good also as a form which applies the thing of the structure shown as a radiation detector.
  • the radiation detector shown in FIG. 15 (A) is an example in which a radiation conversion layer 8 ′ made of amorphous selenium is applied instead of the scintillator 8 in the radiation detector 20 according to the first embodiment. It is shown. 15 (B) to 15 (D) show examples in which two scintillators 8A and 8B are provided as radiation sensitive layers. 15 (E) to 15 (G) show an example in the case where the radiation conversion layer 8A ′ and the radiation conversion layer 8B ′ made of two amorphous selenium are provided as the radiation sensitive layer. Has been. Further, FIGS.
  • 15 (H) to 15 (J) show an example in which a radiation converting layer 8A ′ composed of one scintillator 8B and one amorphous selenium is provided as a radiation sensitive layer. ing.
  • Si silicon
  • CdTe cadmium telluride
  • the reset processing of the TFT substrate for moving image shooting is performed when still image shooting is performed, and the reset processing of the TFT substrate for still image shooting is performed when moving image shooting is performed.
  • the present invention has been described, the present invention is not limited to this, and a moving image shooting TFT when a still image obtained by still image shooting is displayed on a display device such as a console display device.
  • an electrical reset process or a bias reset process is performed on both the TFT substrate 30A and the TFT substrate 30B.
  • the TFT substrate 30B is applied to the TFT substrate 30B.
  • the optical reset process is performed on the TFT substrate 30A while the bias reset process is performed on the TFT substrate 30A has been described, the present invention is not limited to this, and the optical reset process is not limited to the indirect conversion type TFT. Any substrate can be applied, and the electrical reset process and the bias reset process can be applied to either an indirect conversion type TFT substrate or a direct conversion type TFT substrate.
  • the cassette control unit 58, the power supply unit 70, and the like are arranged inside the housing 41 of the electronic cassette 40 so as not to overlap the radiation detector.
  • the present invention is not limited to this. It is not something. For example, you may arrange
  • At least one of the TFT substrate 30A and the TFT substrate 30B is a flexible substrate.
  • a flexible substrate to be applied it is preferable to use a substrate using ultra-thin glass by a recently developed float method as a base material in order to improve the radiation transmittance.
  • ultra-thin glass for example, “Asahi Glass Co., Ltd.,“ Successfully developed the world's thinnest 0.1 mm thick ultra-thin glass by the float method ”, [online], [2011 Aug. 20 search], Internet ⁇ URL: http://www.agc.com/news/2011/0516.pdf> ”.
  • the organic CMOS sensor which comprised the photoelectric converting film 4 with the material containing an organic photoelectric conversion material as the sensor part 13 of the radiation detector 20, and it is a thin-film transistor as TFT board
  • An organic TFT array sheet in which organic transistors including the organic material 10 are arranged in an array on a flexible sheet may be used.
  • the above organic CMOS sensor is disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-212377.
  • CMOS sensor When a CMOS sensor is used as the sensor unit 13 of each radiation detector, the advantage that photoelectric conversion can be performed at a high speed and the result that the substrate can be thinned can suppress radiation absorption when the ISS method is adopted. There is an advantage that it can be suitably applied to mammography photography.
  • a technique using a SiC (silicon carbide) substrate as a semiconductor substrate having high resistance to radiation can be applied.
  • Advantages that can be used as an ISS method by using a SiC substrate and because SiC has a lower internal resistance and a smaller amount of heat generation than Si, it suppresses the amount of heat generation when shooting movies, and raises the temperature of CsI There is an advantage that it is possible to suppress a decrease in sensitivity due to.
  • a substrate having high resistance to radiation such as a SiC substrate is generally a wide cap (about 3 eV), and as an example, as shown in FIG. 16, the absorption edge is about 440 nm corresponding to the blue region. Therefore, in this case, a scintillator such as CsI: Tl or GOS that emits light in the green region cannot be used.
  • FIG. 16 shows spectra of various materials when quinacridone is used as the organic photoelectric conversion material.
  • the scintillator that emits light in these green regions has been actively researched due to the sensitivity characteristics of amorphous silicon, and therefore there is a high demand for using the scintillator.
  • region can be used by comprising the photoelectric converting film 4 with the material containing the organic photoelectric conversion material which absorbs light emission in a green area
  • the photoelectric conversion film 4 When the photoelectric conversion film 4 is formed of a material containing an organic photoelectric conversion material and the thin film transistor 10 is formed using a SiC substrate, the photoelectric conversion film 4 and the thin film transistor 10 have different sensitivity wavelength regions, and thus the light emitted by the scintillator is emitted. There is no noise of the thin film transistor 10.
  • the photoelectric conversion film 4 in addition to receiving light emission mainly in the blue region, such as CsI: Na, light emission in the green region is also received. As a result, the sensitivity can be improved. In addition, since the organic photoelectric conversion material hardly absorbs radiation, it can be suitably used for the ISS system.
  • SiC is highly resistant to radiation because it is difficult for nuclear nuclei to be blown away even when exposed to radiation.
  • Develop semiconductor devices that can be used for a long time [online], [Search May 8, 2011], Internet ⁇ URL: http://www.jaea.go.jp/jari/jpn/publish/01/ff/ ff36 / sic.html> ”.
  • C diamond
  • BN diamond
  • GaN gallium-nitride
  • AlN gallium-nitride
  • ZnO zinc-nitride
  • These light element semiconductor materials have high radiation resistance because they are mainly wide-gap semiconductors, so they require high energy for ionization (electron-hole pair formation), small reaction cross-sections, This is due to the fact that bonding is strong and atomic displacement is less likely to occur.
  • GaN has good thermal conductivity as a use other than blue LEDs and has high insulation resistance
  • ICs are being studied in the field of power systems.
  • ZnO an LED that emits light mainly in the blue to ultraviolet region has been studied.
  • the band gap Eg is changed from about 1.1 eV to about 2.8 eV of Si, so that the light absorption wavelength ⁇ shifts to the short wavelength side.
  • the wavelength ⁇ 1.24 / Eg ⁇ 1000
  • the sensitivity changes to wavelengths up to about 440 nm. Therefore, when using SiC, as shown in FIG. 17 as an example, the scintillator emits light in the blue region more than CsI: Tl (peak wavelength: about 565 nm) that emits light in the green region, and the peak wavelength: about 420 nm. This is more suitable as the emission wavelength.
  • CsI Na (peak wavelength: about 420 nm)
  • BaFX Eu (X is a halogen such as Br and I, peak wavelength: about 380 nm)
  • CaWO 4 peak wavelength: about 425 nm
  • ZnS Ag (peak wavelength: about 450 nm)
  • LaOBr Tb, Y 2 O 2 S: Tb, and the like
  • BaFX Eu used in CsI: Na and CR cassettes
  • CaWO 4 used in screens and films are preferably used.
  • a CMOS sensor having high resistance to radiation may be configured by using a configuration of Si substrate / thick film SiO 2 / organic photoelectric conversion material by SOI (Silicon On Insulator).
  • SOI Silicon On Insulator
  • examples of the high radiation durability element include a complete separation type thick film SOI and a partial separation type thick film SOI.
  • SOIs for example, “Patent Office,“ Patent Application Technology Trend Survey Report on SOI (Silicon On Insulator) Technology ”, [online], [Search May 8, 2011], Internet ⁇ URL: http://www.jpo.go.jp/shiryou/pdf/gidou-houkoku/soi.pdf> ”.
  • the thin film transistor 10 or the like of the radiation detector 20 does not have light transmission (for example, a structure in which the active layer 17 is formed of a material having no light transmission such as amorphous silicon), the thin film transistor 10 or the like.
  • a light-transmitting substrate 1 for example, a flexible substrate made of synthetic resin
  • a portion of the substrate 1 where the thin film transistor 10 or the like is not formed is configured to transmit light. It is possible to obtain a radiation detector 20 having optical transparency.
  • Arranging the thin film transistor 10 or the like having a non-light-transmitting structure on the light-transmitting substrate 1 is performed by separating the micro device block manufactured on the first substrate from the first substrate.
  • FSA Fluid Self-Assembly
  • the above FSA is, for example, “Toyama University,“ Study on Self-Aligned Placement Technology of Small Semiconductor Blocks ”, [online], [Search May 8, 2011], Internet ⁇ URL: http: //www3.u- toyama.ac.jp/maezawa/Research/FSA.html> ”.

Abstract

Provided are a radiographic imaging apparatus, a program, and a radiographic imaging method, wherein capturing of a high-quality radiographic image can be executed at an appropriate timing. When a cassette control unit is executing still-image capturing using a still-image capturing TFT substrate that converts incident radiation into a radiographic image, the cassette control unit performs and controls reset processing on a video capturing TFT substrate that is layered on the still-image capturing TFT substrate and that converts incident radiation into a radiographic image.

Description

放射線画像撮影装置、プログラムおよび放射線画像撮影方法Radiographic imaging apparatus, program, and radiographic imaging method
　本発明は、放射線画像撮影装置、プログラムおよび放射線画像撮影方法に関し、特に、被写体を透過した放射線により示される放射線画像を撮影する放射線画像撮影装置、プログラムおよび放射線画像撮影方法に関する。 The present invention relates to a radiographic image capturing apparatus, a program, and a radiographic image capturing method, and more particularly to a radiographic image capturing apparatus, a program, and a radiographic image capturing method for capturing a radiographic image indicated by radiation transmitted through a subject.
　近年、ＴＦＴ（Thin Film Transistor）アクティブマトリクス基板上に放射線感応層を配置し、Ｘ線等の放射線を直接デジタルデータに変換できるＦＰＤ（Flat Panel Detector）等の放射線検出器が実用化されており、この放射線検出器を用いて、照射された放射線により表わされる放射線画像を撮影する放射線画像撮影装置が実用化されている。なお、この放射線画像撮影装置に用いられる放射線検出器には、放射線を変換する方式として、放射線をシンチレータで光に変換した後にフォトダイオード等の半導体層で電荷に変換する間接変換方式や、放射線をアモルファスセレン等の半導体層で電荷に変換する直接変換方式等があり、各方式でも半導体層に使用可能な材料が種々存在する。 In recent years, radiation detectors such as FPD (Flat Panel Detector) that can directly convert radiation such as X-rays into digital data by arranging radiation sensitive layers on TFT (Thin Film Transistor) active matrix substrates have been put into practical use. A radiation image capturing apparatus that captures a radiation image represented by irradiated radiation using this radiation detector has been put into practical use. The radiation detector used in this radiographic imaging apparatus has an indirect conversion system in which radiation is converted into light by a scintillator and then converted into electric charge in a semiconductor layer such as a photodiode, or the like. There is a direct conversion method in which a semiconductor layer such as amorphous selenium converts into electric charge, and there are various materials that can be used for the semiconductor layer in each method.
　ところで、放射線画像撮影装置によって取得される放射線画像に対するアーチファクトとしての残像は、温度、駆動時間、バイアスの大きさ、放射線を射出する放射線源の管電圧の大きさ等によって、放射線検出器での放射線検出に関する応答特性が変化することに起因して発生する。また、間接変換方式の放射線検出器では、光を電荷に変換する光電変換素子において、当該光電変換素子を構成する半導体の不純物準位（欠陥）に一部の電荷が一旦捕捉され、次回の撮影で、捕捉された一部の電荷が、本来の画像情報に応じた電荷と共に出力されることにより、残像が前記画像情報とともに表示画像に表示されてしまう場合もある。さらに、暗電流に起因した電荷も残像の発生原因となる。 By the way, the afterimage as an artifact with respect to the radiographic image acquired by the radiographic imaging device is the radiation at the radiation detector depending on the temperature, the driving time, the magnitude of the bias, the magnitude of the tube voltage of the radiation source emitting the radiation, and the like. This occurs due to a change in response characteristics related to detection. In addition, in the indirect conversion type radiation detector, in the photoelectric conversion element that converts light into electric charge, a part of the electric charge is once captured by the impurity level (defect) of the semiconductor constituting the photoelectric conversion element, and the next imaging is performed. In some cases, the captured partial charge is output together with the charge corresponding to the original image information, so that the afterimage is displayed on the display image together with the image information. Furthermore, the charge resulting from the dark current also causes afterimages.
　従来、以上のような残像の発生を抑制するために適用することのできる技術として、特開２００９－５３７４号公報（特許文献１）、特開２０１０－２４６８３５号公報（特許文献２）、および特開２０１１－６６５１４号公報（特許文献３）の各文献には、放射線を放射線画像に変換可能な放射線検出器を有する放射線画像撮影装置において、当該放射線検出器に対してリセット処理を実行することにより、上記残像の発生を抑制する技術が開示されている。 Conventionally, as a technique that can be applied to suppress the occurrence of the afterimage as described above, Japanese Patent Application Laid-Open No. 2009-5374 (Patent Document 1), Japanese Patent Application Laid-Open No. 2010-246835 (Patent Document 2), and In each document of Japanese Unexamined Patent Publication No. 2011-66514 (Patent Document 3), in a radiographic imaging apparatus having a radiation detector capable of converting radiation into a radiation image, reset processing is performed on the radiation detector. A technique for suppressing the occurrence of the afterimage is disclosed.
　ところで、近年の放射線画像撮影装置には、静止画像の撮影に加えて動画像の撮影を行うことができるものがある。この種の放射線画像撮影装置では、動画撮影（透視画撮影）を行いつつ、当該動画撮影によって得られた動画像をリアルタイムで観察しながら、必要に応じて静止画撮影を行い、当該静止画撮影が終了した後の任意のタイミングで動画撮影を再開するといったことができ、利便性に優れている。 Incidentally, some recent radiographic image capturing apparatuses can capture moving images in addition to still image capturing. With this type of radiographic imaging device, while taking a moving image (perspective image), observing a moving image obtained by the moving image shooting in real time, taking a still image as needed, and taking the still image It is possible to restart the video recording at an arbitrary timing after the end of, which is excellent in convenience.
　しかしながら、このような動画撮影と静止画撮影の双方が可能とされた放射線画像撮影装置では、任意のタイミングで動画撮影や静止画撮影が開始される場合が多いため、撮影開始が指示された後にリセット処理を実行したのでは、実際に撮影が開始されるまでに時間差が生じ、的確なタイミングで撮影を行うことができない場合がある、という問題点があった。なお、上記特許文献１～特許文献３に開示されている技術においても、動画撮影と静止画撮影の双方が可能とされた放射線画像撮影装置において、任意のタイミングで撮影が開始される点については考慮されていないため、この問題点については無力である。 However, in such a radiographic image capturing apparatus capable of both moving image shooting and still image shooting, moving image shooting and still image shooting are often started at an arbitrary timing. When the reset process is executed, there is a problem in that there is a time difference until the actual shooting is started, and there is a case where the shooting cannot be performed at an accurate timing. Note that in the techniques disclosed in Patent Documents 1 to 3, the radiographic image capturing apparatus capable of both moving image capturing and still image capturing can start capturing at an arbitrary timing. This issue is powerless because it has not been considered.
　本発明は、上記問題点を解決するためになされたものであり、高画質な放射線画像の撮影を的確なタイミングで行うことができる放射線画像撮影装置、プログラムおよび放射線画像撮影方法を提供することを目的とする。 The present invention has been made to solve the above-described problems, and provides a radiographic image capturing apparatus, a program, and a radiographic image capturing method capable of capturing a high-quality radiographic image at an accurate timing. Objective.
　上記目的を達成するために、本発明の第１の態様に係る放射線画像撮影装置は、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器と、前記第１基板を用いて静止画撮影を行っている場合、および当該静止画撮影によって得られた静止画像の表示が行われている場合の少なくとも一方の場合に、前記第２基板に対してリセット処理を実行制御する制御手段と、を備えている。 In order to achieve the above object, a radiographic imaging apparatus according to a first aspect of the present invention is laminated on a first substrate for still image imaging that converts incident radiation into a radiographic image, and the first substrate. A radiation detector having a second substrate for moving image capturing for converting incident radiation into a radiation image, and when taking a still image using the first substrate, and obtained by the still image capturing Control means for executing and controlling a reset process on the second substrate in at least one of the cases where a still image is displayed.
　本発明の第１の態様に係る放射線画像撮影装置によれば、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器により、前記第１基板を用いて静止画撮影が行われる一方、前記第２基板を用いて動画撮影が行われる。 According to the radiographic image capturing device of the first aspect of the present invention, the first substrate for still image capturing that converts the incident radiation into a radiation image, and the incident radiation laminated on the first substrate are A still image shooting is performed using the first substrate, and a moving image shooting is performed using the second substrate by a radiation detector having a second substrate for moving image shooting to be converted into a radiation image.
　ここで、本発明では、制御手段により、前記第１基板を用いて静止画撮影を行っている場合、および当該静止画撮影によって得られた静止画像の表示が行われている場合の少なくとも一方の場合に、前記第２基板に対してリセット処理を実行制御される。 Here, in the present invention, at least one of the case where the control unit performs still image shooting using the first substrate and the case where the still image obtained by the still image shooting is displayed. In this case, execution control of reset processing is performed on the second substrate.
　すなわち、本発明では、第２基板に対してリセット処理を実行しても支障が生じない期間である、第１基板を用いて静止画撮影を行っている場合、および当該静止画撮影によって得られた静止画像の表示が行われている場合の少なくとも一方の場合に、第２基板に対してリセット処理を実行するようにしており、この結果として、残像の影響等が抑制された高画質な放射線画像の撮影を的確なタイミングで行うことができるようにしている。 That is, according to the present invention, when still image shooting is performed using the first substrate, which is a period in which no trouble occurs even if reset processing is performed on the second substrate, and obtained by the still image shooting. In at least one of the cases where a still image is being displayed, the reset process is performed on the second substrate. As a result, high-quality radiation in which the influence of afterimages is suppressed Images can be taken at appropriate timing.
　このように、本発明の第１の態様に係る放射線画像撮影装置によれば、入射された放射線を放射線画像に変換する静止画撮影用の第１基板を用いて静止画撮影を行っている場合、および当該静止画撮影によって得られた静止画像の表示が行われている場合の少なくとも一方の場合に、第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板に対してリセット処理を実行制御しているので、高画質な放射線画像の撮影を的確なタイミングで行うことができる。 As described above, according to the radiographic image capturing apparatus according to the first aspect of the present invention, when still image capturing is performed using the first substrate for still image capturing that converts incident radiation into a radiographic image. , And at least one of the cases where the still image obtained by the still image shooting is being displayed, the second for movie shooting that is stacked on the first substrate and converts the incident radiation into a radiation image. Since execution control of the reset process is performed on the substrate, radiographic images with high image quality can be taken at appropriate timing.
　なお、本発明の第１の態様に係る発明は、第２の態様として、静止画撮影の実行指示を受け付ける受付手段をさらに備え、前記制御手段が、前記第２基板を用いて動画撮影を行っている場合で、かつ前記受付手段によって前記実行指示が受け付けられた場合、前記第１基板を用いて静止画撮影を行い、かつ当該静止画撮影によって得られた静止画像を前記動画撮影によって得られた動画像の当該静止画像の撮影タイミングに対応する画像として適用すると共に、前記静止画撮影を行っているタイミングで前記第２基板に対してリセット処理を実行制御してもよい。これにより、動画像の撮影中における画像の抜けを防止することができる。 The invention according to the first aspect of the present invention, as the second aspect, further comprises a receiving means for receiving a still image shooting execution instruction, wherein the control means performs moving image shooting using the second substrate. And when the execution instruction is received by the receiving means, still image shooting is performed using the first substrate, and a still image obtained by the still image shooting is obtained by the moving image shooting. The moving image may be applied as an image corresponding to the shooting timing of the still image, and the reset process may be executed and controlled on the second substrate at the timing when the still image shooting is performed. As a result, it is possible to prevent missing of an image during shooting of a moving image.
　特に、第２の態様に係る発明は、第３の態様として、前記制御手段が、前記リセット処理の実行の如何にかかわらず、前記第２基板を用いて動画撮影を継続制御してもよい。これにより、動画像の抜けを、より確実に防止することができる。 Particularly, in the invention according to the second aspect, as a third aspect, the control means may continuously control moving image shooting using the second substrate regardless of whether the reset process is executed. As a result, it is possible to more reliably prevent moving images from being lost.
　また、第１の態様から第３の態様の何れか１項に記載の発明は、第４の態様に係る発明のように、前記制御手段が、前記静止画像の表示が行われている場合に放射線の照射を停止制御してもよい。これにより、被撮影体に対する放射線の照射量を抑制することができる。 Further, in the invention according to any one of the first to third aspects, when the control unit is displaying the still image as in the invention according to the fourth aspect, Radiation irradiation may be controlled to stop. Thereby, the irradiation amount of the radiation with respect to the to-be-photographed body can be suppressed.
　一方、上記目的を達成するために、第５の態様に係る放射線画像撮影装置は、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器と、前記第２基板を用いて動画撮影を行っている場合、および当該動画撮影によって得られた動画像の表示が行われている場合の少なくとも一方の場合に、前記第１基板に対してリセット処理を実行制御する制御手段と、を備えている。 On the other hand, in order to achieve the above object, the radiographic image capturing device according to the fifth aspect is laminated on a first substrate for still image capturing that converts incident radiation into a radiographic image, and the first substrate, A radiation detector having a second substrate for moving image capturing that converts incident radiation into a radiographic image, and when moving image capturing is performed using the second substrate, and a moving image obtained by the moving image capturing Control means for controlling execution of reset processing on the first substrate in at least one of the cases where the display is performed.
　第５の態様に係る放射線画像撮影装置によれば、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器により、前記第１基板を用いて静止画撮影が行われる一方、前記第２基板を用いて動画撮影が行われる。 According to the radiographic imaging device according to the fifth aspect, the first substrate for still image imaging that converts the incident radiation into a radiographic image, and the incident radiation that is laminated on the first substrate and converted into the radiographic image. A radiation detector having a second substrate for moving image shooting to be converted performs still image shooting using the first substrate, while moving image shooting is performed using the second substrate.
　ここで、本発明では、制御手段により、前記第２基板を用いて動画撮影を行っている場合、および当該動画撮影によって得られた動画像の表示が行われている場合の少なくとも一方の場合に、前記第１基板に対してリセット処理を実行制御される。 Here, in the present invention, when the moving image is shot by the control means using the second substrate, and at least one of the cases where the moving image obtained by the moving image shooting is displayed. The reset process is controlled for the first substrate.
　すなわち、本発明では、第１基板に対してリセット処理を実行しても支障が生じない期間である、第２基板を用いて動画撮影を行っている場合、および当該動画撮影によって得られた動画像の表示が行われている場合の少なくとも一方の場合に、第１基板に対してリセット処理を実行するようにしており、この結果として、残像の影響等が抑制された高画質な放射線画像の撮影を的確なタイミングで行うことができるようにしている。 That is, in the present invention, when moving image shooting is performed using the second substrate, which is a period in which no trouble occurs even if reset processing is performed on the first substrate, and a moving image obtained by the moving image shooting. In at least one of the cases where an image is displayed, a reset process is performed on the first substrate. As a result, a high-quality radiographic image in which the influence of afterimages and the like is suppressed is suppressed. Shooting can be performed at the correct timing.
　このように、第５の態様に係る放射線画像撮影装置によれば、入射された放射線を放射線画像に変換する動画撮影用の第２基板を用いて動画撮影を行っている場合、および当該動画撮影によって得られた動画像の表示が行われている場合の少なくとも一方の場合に、第２基板に積層され、入射された放射線を放射線画像に変換する静止画撮影用の第１基板に対してリセット処理を実行するように制御しているので、高画質な放射線画像の撮影を的確なタイミングで行うことができる。 Thus, according to the radiographic image capturing device according to the fifth aspect, when moving image capturing is performed using the second substrate for moving image capturing that converts incident radiation into a radiation image, and the moving image capturing is performed. In at least one of the cases where the moving image obtained by the above is displayed, the reset is performed on the first substrate for still image shooting which is stacked on the second substrate and converts the incident radiation into a radiation image. Since the process is controlled to be executed, it is possible to capture a high-quality radiographic image at an appropriate timing.
　なお、第１の態様から第５の態様の何れか１項に記載の発明は、第６の態様に係る発明のように、前記リセット処理を、リセット処理の対象とする基板が間接変換方式のものである場合における当該基板の各画素に対して光を照射することによる第１リセット処理、リセット処理の対象とする基板の各画素に対するバイアス電圧の供給状態を制御することによる第２リセット処理、およびリセット処理の対象とする基板の各画素に蓄積された電荷を放出させることによる第３リセット処理の少なくとも１つとしてもよい。これにより、適用したリセット処理によって効果的に残像等の影響を抑制することができる。 In the invention according to any one of the first to fifth aspects, as in the invention according to the sixth aspect, the substrate for which the reset process is performed is an indirect conversion type. A first reset process by irradiating light on each pixel of the substrate in the case of a second, a second reset process by controlling a supply state of a bias voltage to each pixel of the substrate to be reset; In addition, it may be at least one of the third reset processing by discharging the charge accumulated in each pixel of the substrate to be reset processing. Thereby, the influence of afterimage etc. can be effectively suppressed by the applied reset process.
　例えば、アモルファスシリコン（ａ－Ｓｉ）からなるフォトダイオードが光検出素子である場合、光（可視光）から変換された電荷（電子）の一部がａ－Ｓｉの不純物準位（欠陥）に一旦捕捉され、その後、動画撮影のような長時間の撮影による前記フォトダイオードの温度上昇等に起因して前記電荷が再放出されると、暗電流等の不要な電流が発生し、放射線画像（動画像）に対するノイズ（残像）の原因となる場合がある。 For example, when a photodiode made of amorphous silicon (a-Si) is a photodetecting element, a part of charges (electrons) converted from light (visible light) once enters an a-Si impurity level (defect). When the electric charge is re-emitted due to a temperature rise of the photodiode due to a long time shooting such as moving image shooting, an unnecessary current such as a dark current is generated, and a radiographic image (moving image May cause noise (afterimage).
　そこで、前記第１リセット処理により前記フォトダイオードに光（リセット光）を照射して、前記不純物準位に電荷を予め埋めておき、その後、放射線の照射時に可視光から変換された電荷が前記不純物準位に捕捉されないようにすることで、残像の発生等を効果的に抑制することができる。 Therefore, the first reset process irradiates the photodiode with light (reset light) to preliminarily charge the impurity level, and then the charge converted from visible light upon irradiation of the radiation is the impurity. By preventing them from being captured by the level, the occurrence of afterimages can be effectively suppressed.
　また、上記光検出素子がＭＩＳ（Metal Insulator Semiconductor）構造のフォトダイオードである場合には、前記第２リセット処理により、前記フォトダイオードに供給するバイアスの極性を反転するか、または前記フォトダイオードへのバイアスの供給を停止することにより、当該フォトダイオードに対するリセット処理を実行することが好ましい。 When the photodetecting element is a MIS (Metal （Insulator Semiconductor) photodiode, the polarity of the bias supplied to the photodiode is reversed by the second reset process, or the photodiode is connected to the photodiode. It is preferable to execute reset processing for the photodiode by stopping supply of the bias.
　この場合には、第２リセット処理の終了後、次のフレームの動画像を取得するために、前記バイアスの極性を元に戻すか、または前記バイアスの供給を再開する処理が必要となるため、前記フォトダイオードが安定した動作状態に復帰するまで多少の時間はかかるが、残像の発生等を効果的に抑制することができる。 In this case, after completion of the second reset process, in order to acquire a moving image of the next frame, it is necessary to restore the bias polarity or restart the supply of the bias. Although it takes some time until the photodiode returns to a stable operating state, it is possible to effectively suppress the occurrence of afterimages.
　さらに、上記リセット処理として第３リセット処理を適用する場合にも、各画素における残像の発生等を効果的に抑制することができる。 Furthermore, even when the third reset process is applied as the reset process, it is possible to effectively suppress the occurrence of afterimages in each pixel.
　ところで、一般に、直接変換方式の放射線検出器は放射線の低エネルギー成分を吸収して電荷に変換する一方、間接変換方式の放射線検出器は放射線の高エネルギー成分を吸収し、吸収したエネルギー成分を光に一旦変換して、当該光を電荷に変換している。ここで、放射線の低エネルギー成分とは、放射線を射出する放射線源の管電圧が比較的低電圧である場合での当該低電圧に応じた放射線のエネルギー成分であり、被撮影体のマンモ、軟部組織、腫瘍等に吸収されやすい。また、放射線の高エネルギー成分とは、放射線源の管電圧が比較的高電圧である場合での当該高電圧に応じた放射線のエネルギー成分であり、被撮影体の骨部等に吸収されやすい。 By the way, in general, a direct conversion type radiation detector absorbs a low energy component of radiation and converts it into an electric charge, whereas an indirect conversion type radiation detector absorbs a high energy component of radiation and absorbs the absorbed energy component into light. The light is converted into a charge once. Here, the low energy component of the radiation is the energy component of the radiation corresponding to the low voltage when the tube voltage of the radiation source emitting the radiation is relatively low, and the mammo and the soft part of the object to be imaged. It is easily absorbed by tissues and tumors. Further, the high energy component of radiation is an energy component of radiation corresponding to the high voltage when the tube voltage of the radiation source is relatively high, and is easily absorbed by the bone portion or the like of the subject.
　そこで、第１の態様から第６の態様の何れか１項に記載の発明は、第６の態様に係る発明のように、前記第１基板が、入射された放射線を電荷に直接変換する直接変換方式のものであり、前記第２基板が、入射された放射線を光に変換した後、当該光を電荷に変換する間接変換方式のものとしてもよい。これにより、より効果的に放射線画像を得ることができる。 Therefore, in the invention according to any one of the first to sixth aspects, as in the invention according to the sixth aspect, the first substrate directly converts the incident radiation directly into charges. The second substrate may be an indirect conversion method in which the second substrate converts incident light into light and then converts the light into electric charge. Thereby, a radiographic image can be obtained more effectively.
　特に、第７の態様に係る発明は、第８の態様に係る発明のように、前記第２基板が、前記第１基板の放射線が入射される面とは反対側の面に積層されていてもよい。これにより、より効果的に放射線画像を得ることができる。 Particularly, in the invention according to the seventh aspect, as in the invention according to the eighth aspect, the second substrate is laminated on a surface opposite to the surface on which the radiation of the first substrate is incident. Also good. Thereby, a radiographic image can be obtained more effectively.
　一方、上記目的を達成するために、第９の態様に係るプログラムは、コンピュータを、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第１基板を用いて静止画撮影を行っている第１状態、および当該静止画撮影によって得られた静止画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定手段と、前記判定手段によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第２基板に対してリセット処理を実行制御する制御手段と、として機能させるためのものである。 On the other hand, in order to achieve the above object, a program according to a ninth aspect includes a computer, a first substrate for still image shooting that converts incident radiation into a radiation image, and a stack on the first substrate, A first state in which still image shooting is performed using the first substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and obtained by the still image shooting A determination unit that determines whether or not a still image is being displayed is at least one of the second states, and the determination unit is at least one of the first state and the second state. When the determination is made, the control unit is configured to function as a control unit that executes and controls a reset process on the second substrate.
　従って、第９の態様に係る発明によれば、コンピュータを第１の態様に係る放射線画像撮影装置と同様に作用させることができるので、当該放射線画像撮影装置と同様に、高画質な放射線画像の撮影を的確なタイミングで行うことができる。 Therefore, according to the ninth aspect of the invention, the computer can be operated in the same manner as the radiographic image capturing apparatus according to the first aspect. Shooting can be performed at a precise timing.
　また、上記目的を達成するために、第１０の態様に係るプログラムは、コンピュータを、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第２基板を用いて動画撮影を行っている第１状態、および当該動画撮影によって得られた動画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定手段と、前記判定手段によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第１基板に対してリセット処理を実行制御する制御手段と、として機能させるためのものである。 In order to achieve the above object, a program according to a tenth aspect includes a computer, a first substrate for still image shooting that converts incident radiation into a radiation image, and the first substrate. A first state in which moving image shooting is performed using the second substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and a moving image obtained by the moving image shooting Determining means for determining whether or not the display is in at least one of the second states, and the determination means determines that the state is at least one of the first state and the second state. In this case, the control unit is configured to function as a control unit that executes and controls a reset process on the first substrate.
　従って、第１０の態様に係る発明によれば、コンピュータを請求項５に記載の放射線画像撮影装置と同様に作用させることができるので、当該放射線画像撮影装置と同様に、高画質な放射線画像の撮影を的確なタイミングで行うことができる。 Therefore, according to the tenth aspect of the invention, since the computer can be operated in the same manner as the radiographic image capturing apparatus according to the fifth aspect, the high-quality radiographic image can be obtained as in the radiographic image capturing apparatus. Shooting can be performed at a precise timing.
　一方、上記目的を達成するために、第１１の態様に係る放射線画像撮影方法は、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第１基板を用いて静止画撮影を行っている第１状態、および当該静止画撮影によって得られた静止画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定工程と、前記判定工程によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第２基板に対してリセット処理を実行制御する制御工程と、を有している。 On the other hand, in order to achieve the above object, a radiographic image capturing method according to an eleventh aspect is laminated on a first substrate for still image capturing that converts incident radiation into a radiographic image, and the first substrate, A first state in which still image shooting is performed using the first substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and obtained by the still image shooting A determination step of determining whether or not a still image is being displayed is at least one of the second states, and at least one of the first state and the second state by the determination step; And a control step of controlling execution of reset processing for the second substrate when determined.
　従って、第１１の態様に係る発明によれば、第１の態様に係る放射線画像撮影装置と同様に作用するので、当該放射線画像撮影装置と同様に、高画質な放射線画像の撮影を的確なタイミングで行うことができる。 Therefore, according to the eleventh aspect of the invention, it operates in the same manner as the radiographic image capturing apparatus according to the first aspect. Therefore, as with the radiographic image capturing apparatus, high-quality radiographic image capturing is precisely timed. Can be done.
　さらに、上記目的を達成するために、第１２の態様に係る放射線画像撮影方法は、入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第２基板を用いて動画撮影を行っている第１状態、および当該動画撮影によって得られた動画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定工程と、前記判定工程によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第１基板に対してリセット処理を実行制御する制御工程と、を有している。 Furthermore, in order to achieve the above object, the radiographic image capturing method according to the twelfth aspect is laminated on a first substrate for still image capturing that converts incident radiation into a radiographic image, and the first substrate, A first state in which moving image shooting is performed using the second substrate in a radiation detector having a second substrate for moving image shooting for converting incident radiation into a radiation image, and a moving image obtained by the moving image shooting A determination step of determining whether or not the display is in at least one of the second states, and the determination step determines that the state is at least one of the first state and the second state. A control step of controlling execution of reset processing on the first substrate.
　従って、第１２の態様に係る発明によれば、第５の態様に係る放射線画像撮影装置と同様に作用するので、当該放射線画像撮影装置と同様に、高画質な放射線画像の撮影を的確なタイミングで行うことができる。 Therefore, according to the twelfth aspect of the invention, it operates in the same manner as the radiographic image capturing apparatus according to the fifth aspect. Therefore, as with the radiographic image capturing apparatus, it is possible to accurately capture a high-quality radiographic image. Can be done.
　本発明に係る放射線画像撮影装置、プログラムおよび放射線画像撮影方法によれば、高画質な放射線画像の撮影を的確なタイミングで行うことができる、という効果を奏することができる。 According to the radiographic image capturing apparatus, the program, and the radiographic image capturing method of the present invention, it is possible to produce an effect that radiographic images with high image quality can be captured at appropriate timing.
実施の形態に係る放射線検出器の３画素部分の概略構成を示す断面模式図である。It is a cross-sectional schematic diagram which shows schematic structure of the 3 pixel part of the radiation detector which concerns on embodiment. 実施の形態に係るシンチレータの結晶構成の一例を模式的に示す概略図である。It is the schematic which shows typically an example of the crystal structure of the scintillator which concerns on embodiment. 実施の形態に係る放射線検出器の１画素部分の信号出力部の構成を概略的に示した断面図である。It is sectional drawing which showed roughly the structure of the signal output part of 1 pixel part of the radiation detector which concerns on embodiment. 実施の形態に係るＴＦＴ基板の構成を示す平面図である。It is a top view which shows the structure of the TFT substrate which concerns on embodiment. 実施の形態に係る電子カセッテの構成を示す斜視図である。It is a perspective view which shows the structure of the electronic cassette concerning embodiment. 実施の形態に係る電子カセッテの構成を示す断面図である。It is sectional drawing which shows the structure of the electronic cassette concerning embodiment. 実施の形態に係る電子カセッテの電気系の要部構成を示すブロック図である。It is a block diagram which shows the principal part structure of the electric system of the electronic cassette concerning embodiment. 実施の形態に係る信号処理部５４Ａの構成を示す回路図である。It is a circuit diagram which shows the structure of signal processing part 54A which concerns on embodiment. 実施の形態に係る信号処理部５４Ｂの構成を示す回路図である。It is a circuit diagram which shows the structure of the signal processing part 54B which concerns on embodiment. 第１の実施の形態に係る撮影処理プログラムの処理の流れを示すフローチャートである。It is a flowchart which shows the flow of a process of the imaging | photography processing program which concerns on 1st Embodiment. 実施の形態に係る撮影処理プログラムによる処理の説明に供するタイムチャートである。It is a time chart with which it uses for description of the process by the imaging | photography process program which concerns on embodiment. 第２の実施の形態に係る撮影処理プログラムの処理の流れを示すフローチャートである。It is a flowchart which shows the flow of a process of the imaging | photography processing program which concerns on 2nd Embodiment. 第３の実施の形態に係る放射線検出器の構成を示す側面図である。It is a side view which shows the structure of the radiation detector which concerns on 3rd Embodiment. 第３の実施の形態に係る撮影処理プログラムの処理の流れを示すフローチャートである。14 is a flowchart illustrating a flow of processing of a photographing processing program according to a third embodiment. 他の実施の形態に係る放射線検出器の構成を示す概略側面図である。It is a schematic side view which shows the structure of the radiation detector which concerns on other embodiment. 各種材料の感度特性の一例を示すグラフである。It is a graph which shows an example of the sensitivity characteristic of various materials. 各種材料の感度特性の一例を示すグラフである。It is a graph which shows an example of the sensitivity characteristic of various materials.
　以下、図面を参照して、本発明を実施するための形態について詳細に説明する。 Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
　［第１の実施の形態］
　まず、本実施の形態に係る放射線検出器２０の構成について説明する。図１は、本発明の一実施の形態である放射線検出器２０の３つの画素部分の構成を概略的に示す断面模式図である。 [First Embodiment]
First, the configuration of the radiation detector 20 according to the present embodiment will be described. FIG. 1 is a schematic cross-sectional view schematically showing the configuration of three pixel portions of a radiation detector 20 according to an embodiment of the present invention.
　同図に示すように、この放射線検出器２０は、絶縁性の基板１上に、信号出力部１４、センサ部１３、および透明絶縁膜７を順に形成することにより構成されたＴＦＴ基板３０Ａと、シンチレータ８と、接着層２２と、ＴＦＴ基板３０Ａと同様の構成とされたＴＦＴ基板３０Ｂとが、この順に積層しており、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの信号出力部１４、センサ部１３により画素部が構成されている。画素部は、基板１上に複数配列されており、各画素部における信号出力部１４とセンサ部１３とが重なりを有するように構成されている。 As shown in the figure, the radiation detector 20 includes a TFT substrate 30A configured by sequentially forming a signal output unit 14, a sensor unit 13, and a transparent insulating film 7 on an insulating substrate 1, The scintillator 8, the adhesive layer 22, and the TFT substrate 30B having the same configuration as the TFT substrate 30A are laminated in this order, and the pixel output by the signal output unit 14 and the sensor unit 13 of the TFT substrate 30A and the TFT substrate 30B. The part is composed. A plurality of pixel units are arranged on the substrate 1, and the signal output unit 14 and the sensor unit 13 in each pixel unit are configured to overlap each other.
　シンチレータ８は、センサ部１３上に透明絶縁膜７を介して柱状結晶により形成されており、上方（ＴＦＴ基板３０Ｂ側）から入射してくる放射線を光に変換して発光する蛍光体を成膜したものである。このようなシンチレータ８を設けることで、被写体およびＴＦＴ基板３０Ｂを透過した放射線を吸収して発光することになる。 The scintillator 8 is formed of a columnar crystal on the sensor unit 13 via the transparent insulating film 7, and forms a phosphor that emits light by converting radiation incident from above (TFT substrate 30 B side) into light. It is a thing. Providing such a scintillator 8 absorbs the radiation transmitted through the subject and the TFT substrate 30B and emits light.
　シンチレータ８が発する光の波長域は、可視光域（波長３６０ｎｍ～８３０ｎｍ）であることが好ましく、この放射線検出器２０によってモノクロ撮像を可能とするためには、緑色の波長域を含んでいることがより好ましい。 The wavelength range of light emitted by the scintillator 8 is preferably the visible light range (wavelength 360 nm to 830 nm), and in order to enable monochrome imaging by the radiation detector 20, the wavelength range of green is included. Is more preferable.
　シンチレータ８に用いる蛍光体としては、具体的には、放射線としてＸ線を用いて撮像する場合、ヨウ化セシウム（ＣｓＩ）を含むものが好ましく、Ｘ線照射時の発光スペクトルが、例えば、４２０ｎｍ～７００ｎｍにあるＣｓＩ：Ｔｌを用いることが特に好ましい。なお、ＣｓＩ：Ｔｌの可視光域における発光ピーク波長は５６５ｎｍである。 Specifically, the phosphor used in the scintillator 8 preferably contains cesium iodide (CsI) when imaging using X-rays as radiation, and the emission spectrum upon X-ray irradiation is, for example, 420 nm to It is particularly preferred to use CsI: Tl at 700 nm. Note that the emission peak wavelength in the visible light region of CsI: Tl is 565 nm.
　また、本実施の形態では、一例として図２に示すように、シンチレータ８を、放射線入射側（ＴＦＴ基板３０Ｂ側）に柱状結晶７１Ａからなる柱状部が形成され、シンチレータ８の放射線入射側とは反対側に非柱状結晶７１Ｂからなる非柱状部が形成された構成としており、シンチレータ８としてＣｓＩを含む材料を用い、当該材料をＴＦＴ基板３０Ａに直接蒸着させることで、柱状部および非柱状部が形成されたシンチレータ８を得ている。なお、本実施の形態に係るシンチレータ８は、柱状結晶７１Ａの平均径が柱状結晶７１Ａの長手方向に沿っておよそ均一とされている。 In the present embodiment, as shown in FIG. 2 as an example, the scintillator 8 is formed with a columnar portion made of a columnar crystal 71A on the radiation incident side (TFT substrate 30B side). A non-columnar portion made of a non-columnar crystal 71B is formed on the opposite side. A material containing CsI is used as the scintillator 8, and the material is directly deposited on the TFT substrate 30A, so that the columnar portion and the non-columnar portion are formed. The formed scintillator 8 is obtained. In the scintillator 8 according to the present embodiment, the average diameter of the columnar crystals 71A is approximately uniform along the longitudinal direction of the columnar crystals 71A.
　上記のように、シンチレータ８を柱状部が形成された構成にすることで、シンチレータ８で発生された光は柱状結晶７１Ａ内を進行し、非柱状結晶７１Ｂを介してＴＦＴ基板３０Ａへ射出され、ＴＦＴ基板３０Ａ側へ射出される光の拡散が抑制されることで、結果的に得られる放射線画像の鮮鋭度の低下が抑制される。また、シンチレータ８の柱状結晶７１Ａの先端部側に進行した光はＴＦＴ基板３０Ｂに射出され、ＴＦＴ基板３０Ｂによる受光量の増加に寄与する。 As described above, by forming the scintillator 8 with the columnar portion, the light generated by the scintillator 8 travels in the columnar crystal 71A and is emitted to the TFT substrate 30A via the non-columnar crystal 71B. By suppressing the diffusion of the light emitted to the TFT substrate 30A side, a reduction in the sharpness of the resultant radiographic image is suppressed. Further, the light that has traveled toward the tip of the columnar crystal 71A of the scintillator 8 is emitted to the TFT substrate 30B, and contributes to an increase in the amount of light received by the TFT substrate 30B.
　なお、非柱状部の空隙率を０（零）に近づけることにより、当該非柱状部による光の反射を抑制することができ、好ましい。また、非柱状部はできるだけ薄く（１０μｍ程度）することが好ましい。 Note that it is preferable that the non-columnar portion has a porosity close to 0 (zero), whereby reflection of light by the non-columnar portion can be suppressed. Further, it is preferable to make the non-columnar portion as thin as possible (about 10 μm).
　なお、本実施の形態では、シンチレータ８の放射線照射面側にＴＦＴ基板３０Ｂが配置されているが、シンチレータ８とＴＦＴ基板３０Ｂとをこのような位置関係で配置する方式は「表面読取方式（ＩＳＳ：Irradiation Side Sampling）」と称する。シンチレータは放射線入射側がより強く発光するので、シンチレータの放射線入射側にＴＦＴ基板を配置する表面読取方式（ＩＳＳ）は、シンチレータの放射線入射側とは反対側にＴＦＴ基板を配置する「裏面読取方式（ＰＳＳ：Penetration Side Sampling）」よりもＴＦＴ基板とシンチレータの発光位置とが接近することから、撮影によって得られる放射線画像の分解能が高く、また、ＴＦＴ基板の受光量が増大することで、結果として放射線画像の感度が向上する。 In the present embodiment, the TFT substrate 30B is disposed on the radiation irradiation surface side of the scintillator 8, but the method of disposing the scintillator 8 and the TFT substrate 30B in such a positional relationship is “surface reading method (ISS). : Irradiation Side Sampling) ”. Since the scintillator emits light more strongly on the radiation incident side, the surface reading method (ISS) in which the TFT substrate is disposed on the radiation incident side of the scintillator is the “back surface reading method (in which the TFT substrate is disposed on the opposite side of the scintillator from the radiation incident side” Since the TFT substrate and the light emission position of the scintillator are closer to each other than PSS (Penetration Side Sampling), the resolution of the radiographic image obtained by imaging is high, and the amount of light received by the TFT substrate is increased, resulting in radiation. Image sensitivity is improved.
　一方、センサ部１３は、上部電極６、下部電極２、および該上下の電極間に配置された光電変換膜４を有し、光電変換膜４は、シンチレータ８が発する光を吸収して電荷が発生する有機光電変換材料により構成されている。 On the other hand, the sensor unit 13 includes an upper electrode 6, a lower electrode 2, and a photoelectric conversion film 4 disposed between the upper and lower electrodes. The photoelectric conversion film 4 absorbs light emitted from the scintillator 8 and charges are generated. It is comprised with the organic photoelectric conversion material to generate | occur | produce.
　上部電極６は、シンチレータにより生じた光を光電変換膜４に入射させる必要があるため、少なくともシンチレータの発光波長に対して透明な導電性材料で構成することが好ましく、具体的には、可視光に対する透過率が高く、抵抗値が小さい透明導電性酸化物（TCO;Transparent Conducting Oxide）を用いることが好ましい。なお、上部電極６としてＡｕなどの金属薄膜を用いることもできるが、透過率を９０％以上得ようとすると抵抗値が増大し易いため、ＴＣＯの方が好ましい。例えば、ＩＴＯ、ＩＺＯ、ＡＺＯ、ＦＴＯ、ＳｎＯ２、ＴｉＯ２、ＺｎＯ２等を好ましく用いることができ、プロセス簡易性、低抵抗性、透明性の観点からはＩＴＯが最も好ましい。なお、上部電極６は、全画素部で共通の一枚構成としてもよく、画素部毎に分割してもよい。 The upper electrode 6 is preferably made of a conductive material transparent to at least the emission wavelength of the scintillator because it is necessary to make the light generated by the scintillator enter the photoelectric conversion film 4. It is preferable to use a transparent conductive oxide (TCO) having a high transmittance with respect to the surface and a low resistance value. Although a metal thin film such as Au can be used as the upper electrode 6, TCO is preferable because it tends to increase the resistance value when it is desired to obtain a transmittance of 90% or more. For example, ITO, IZO, AZO, FTO, SnO 2 , TiO 2 , ZnO 2 and the like can be preferably used, and ITO is most preferable from the viewpoint of process simplicity, low resistance, and transparency. Note that the upper electrode 6 may have a single configuration common to all the pixel portions, or may be divided for each pixel portion.
　光電変換膜４は、有機光電変換材料を含み、シンチレータ８から発せられた光を吸収し、吸収した光に応じた電荷を発生する。このように有機光電変換材料を含む光電変換膜４であれば、可視域にシャープな吸収スペクトルを持ち、シンチレータ８による発光以外の電磁波が光電変換膜４に吸収されることがほとんどなく、Ｘ線等の放射線が光電変換膜４で吸収されることによって発生するノイズを効果的に抑制することができる。 The photoelectric conversion film 4 includes an organic photoelectric conversion material, absorbs light emitted from the scintillator 8, and generates electric charges according to the absorbed light. In this way, the photoelectric conversion film 4 containing an organic photoelectric conversion material has a sharp absorption spectrum in the visible range, and electromagnetic waves other than light emitted by the scintillator 8 are hardly absorbed by the photoelectric conversion film 4. The noise generated by the radiation such as being absorbed by the photoelectric conversion film 4 can be effectively suppressed.
　光電変換膜４を構成する有機光電変換材料は、シンチレータ８で発光した光を最も効率よく吸収するために、その吸収ピーク波長が、シンチレータの発光ピーク波長と近いほど好ましい。有機光電変換材料の吸収ピーク波長とシンチレータの発光ピーク波長とが一致することが理想的であるが、双方の差が小さければシンチレータから発された光を十分に吸収することが可能である。具体的には、有機光電変換材料の吸収ピーク波長と、シンチレータの放射線に対する発光ピーク波長との差が、１０ｎｍ以内であることが好ましく、５ｎｍ以内であることがより好ましい。 The organic photoelectric conversion material constituting the photoelectric conversion film 4 is preferably such that its absorption peak wavelength is closer to the emission peak wavelength of the scintillator in order to absorb light emitted by the scintillator 8 most efficiently. Ideally, the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator, but if the difference between the two is small, the light emitted from the scintillator can be sufficiently absorbed. Specifically, the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength with respect to the radiation of the scintillator is preferably within 10 nm, and more preferably within 5 nm.
　このような条件を満たすことが可能な有機光電変換材料としては、例えばキナクリドン系有機化合物およびフタロシアニン系有機化合物が挙げられる。例えばキナクリドンの可視域における吸収ピーク波長は５６０ｎｍであるため、有機光電変換材料としてキナクリドンを用い、シンチレータ８の材料としてＣｓＩ：Ｔｌを用いれば、上記ピーク波長の差を１０ｎｍ以内にすることが可能となり、光電変換膜４で発生する電荷量をほぼ最大にすることができる。 Examples of the organic photoelectric conversion material that can satisfy such conditions include quinacridone organic compounds and phthalocyanine organic compounds. For example, since the absorption peak wavelength in the visible region of quinacridone is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI: Tl is used as the material of the scintillator 8, the difference in peak wavelength can be made within 10 nm. The amount of charge generated in the photoelectric conversion film 4 can be substantially maximized.
　次に、本実施の形態に係る放射線検出器２０に適用可能な光電変換膜４について具体的に説明する。 Next, the photoelectric conversion film 4 applicable to the radiation detector 20 according to the present embodiment will be specifically described.
　本実施の形態に係る放射線検出器２０における電磁波吸収／光電変換部位は、１対の電極２，６と、該電極２，６間に挟まれた有機光電変換膜４を含む有機層により構成することができる。この有機層は、より具体的には、電磁波を吸収する部位、光電変換部位、電子輸送部位、正孔輸送部位、電子ブロッキング部位、正孔ブロッキング部位、結晶化防止部位、電極、および層間接触改良部位等の積み重ねもしくは混合により形成することができる。 The electromagnetic wave absorption / photoelectric conversion site in the radiation detector 20 according to the present embodiment is constituted by an organic layer including a pair of electrodes 2 and 6 and an organic photoelectric conversion film 4 sandwiched between the electrodes 2 and 6. be able to. More specifically, this organic layer is a part that absorbs electromagnetic waves, a photoelectric conversion part, an electron transport part, a hole transport part, an electron blocking part, a hole blocking part, a crystallization preventing part, an electrode, and an interlayer contact improvement. It can be formed by stacking or mixing parts.
　上記有機層は、有機ｐ型化合物または有機ｎ型化合物を含有することが好ましい。 The organic layer preferably contains an organic p-type compound or an organic n-type compound.
　有機ｐ型半導体（化合物）は、主に正孔輸送性有機化合物に代表されるドナー性有機半導体（化合物）であり、電子を供与しやすい性質がある有機化合物をいう。さらに詳しくは２つの有機材料を接触させて用いたときにイオン化ポテンシャルの小さい方の有機化合物をいう。したがって、ドナー性有機化合物としては、電子供与性のある有機化合物であればいずれの有機化合物も使用可能である。 An organic p-type semiconductor (compound) is a donor organic semiconductor (compound) typified by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound.
　有機ｎ型半導体（化合物）は、主に電子輸送性有機化合物に代表されるアクセプター性有機半導体（化合物）であり、電子を受容しやすい性質がある有機化合物をいう。さらに詳しくは２つの有機化合物を接触させて用いたときに電子親和力の大きい方の有機化合物をいう。したがって、アクセプター性有機化合物は、電子受容性のある有機化合物であればいずれの有機化合物も使用可能である。 An organic n-type semiconductor (compound) is an acceptor organic semiconductor (compound) typified by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound.
　この有機ｐ型半導体および有機ｎ型半導体として適用可能な材料、および光電変換膜４の構成については、特開２００９－３２８５４号公報において詳細に説明されているため説明を省略する。 The materials applicable as the organic p-type semiconductor and the organic n-type semiconductor, and the configuration of the photoelectric conversion film 4 are described in detail in Japanese Patent Application Laid-Open No. 2009-32854, and thus the description thereof is omitted.
　光電変換膜４の厚みは、シンチレータ８からの光を吸収する点では膜厚は大きいほど好ましいが、ある程度以上厚くなると光電変換膜４の両端から印加されるバイアス電圧により光電変換膜４に発生する電界の強度が低下して電荷が収集できなくなるため、３０ｎｍ以上３００ｎｍ以下が好ましく、より好ましくは、５０ｎｍ以上２５０ｎｍ以下、特に好ましくは８０ｎｍ以上２００ｎｍ以下である。 The thickness of the photoelectric conversion film 4 is preferably as large as possible in terms of absorbing light from the scintillator 8. However, when the thickness is more than a certain level, the photoelectric conversion film 4 is generated in the photoelectric conversion film 4 by a bias voltage applied from both ends of the photoelectric conversion film 4. Since electric field strength is reduced and charges cannot be collected, the thickness is preferably 30 nm to 300 nm, more preferably 50 nm to 250 nm, and particularly preferably 80 nm to 200 nm.
　なお、図１に示す放射線検出器２０では、光電変換膜４は、全画素部で共通の一枚構成であるが、画素部毎に分割してもよい。 In the radiation detector 20 shown in FIG. 1, the photoelectric conversion film 4 has a single-sheet configuration common to all the pixel portions, but may be divided for each pixel portion.
　下部電極２は、画素部毎に分割された薄膜とする。下部電極２は、透明又は不透明の導電性材料で構成することができ、アルミニウム、銀等を好適に用いることができる。 The lower electrode 2 is a thin film divided for each pixel portion. The lower electrode 2 can be made of a transparent or opaque conductive material, and aluminum, silver, or the like can be suitably used.
　下部電極２の厚みは、例えば、３０ｎｍ以上３００ｎｍ以下とすることができる。 The thickness of the lower electrode 2 can be, for example, 30 nm or more and 300 nm or less.
　センサ部１３では、上部電極６と下部電極２の間に所定のバイアス電圧を印加することで、光電変換膜４で発生した電荷（正孔、電子）のうちの一方を上部電極６に移動させ、他方を下部電極２に移動させることができる。本実施の形態の放射線検出器２０では、上部電極６に配線が接続され、この配線を介してバイアス電圧が上部電極６に印加されるものとする。また、バイアス電圧は、光電変換膜４で発生した電子が上部電極６に移動し、正孔が下部電極２に移動するように極性が決められているものとするが、この極性は逆であってもよい。 In the sensor unit 13, by applying a predetermined bias voltage between the upper electrode 6 and the lower electrode 2, one of electric charges (holes, electrons) generated in the photoelectric conversion film 4 is moved to the upper electrode 6. The other can be moved to the lower electrode 2. In the radiation detector 20 of the present embodiment, a wiring is connected to the upper electrode 6, and a bias voltage is applied to the upper electrode 6 through this wiring. In addition, the polarity of the bias voltage is determined so that electrons generated in the photoelectric conversion film 4 move to the upper electrode 6 and holes move to the lower electrode 2, but this polarity is reversed. May be.
　各画素部を構成するセンサ部１３は、少なくとも下部電極２、光電変換膜４、および上部電極６を含んでいればよいが、暗電流の増加を抑制するため、電子ブロッキング膜３および正孔ブロッキング膜５の少なくともいずれかを設けることが好ましく、両方を設けることがより好ましい。 The sensor unit 13 constituting each pixel unit only needs to include at least the lower electrode 2, the photoelectric conversion film 4, and the upper electrode 6. In order to suppress an increase in dark current, the electron blocking film 3 and hole blocking are performed. It is preferable to provide at least one of the films 5, and it is more preferable to provide both.
　電子ブロッキング膜３は、下部電極２と光電変換膜４との間に設けることができ、下部電極２と上部電極６間にバイアス電圧を印加したときに、下部電極２から光電変換膜４に電子が注入されて暗電流が増加してしまうのを抑制することができる。 The electron blocking film 3 can be provided between the lower electrode 2 and the photoelectric conversion film 4. When a bias voltage is applied between the lower electrode 2 and the upper electrode 6, electrons are transferred from the lower electrode 2 to the photoelectric conversion film 4. It is possible to suppress the dark current from increasing due to the injection of.
　電子ブロッキング膜３には、電子供与性有機材料を用いることができる。 An electron donating organic material can be used for the electron blocking film 3.
　実際に電子ブロッキング膜３に用いる材料は、隣接する電極の材料および隣接する光電変換膜４の材料等に応じて選択すればよく、隣接する電極の材料の仕事関数（Ｗｆ）より１．３ｅＶ以上電子親和力（Ｅａ）が大きく、かつ、隣接する光電変換膜４の材料のイオン化ポテンシャル（Ｉｐ）と同等のＩｐもしくはそれより小さいＩｐを持つものが好ましい。この電子供与性有機材料として適用可能な材料については、特開２００９－３２８５４号公報において詳細に説明されているため説明を省略する。なお、光電変換膜４は、さらにフラーレン若しくはカーボンナノチューブを含有させて形成してもよい。 The material actually used for the electron blocking film 3 may be selected according to the material of the adjacent electrode, the material of the adjacent photoelectric conversion film 4 and the like, and 1.3 eV or more from the work function (Wf) of the material of the adjacent electrode. Those having a large electron affinity (Ea) and an Ip equivalent to or smaller than the ionization potential (Ip) of the material of the adjacent photoelectric conversion film 4 are preferable. Since the material applicable as the electron donating organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted. The photoelectric conversion film 4 may be formed by further containing fullerenes or carbon nanotubes.
　電子ブロッキング膜３の厚みは、暗電流抑制効果を確実に発揮させるとともに、センサ部１３の光電変換効率の低下を防ぐため、１０ｎｍ以上２００ｎｍ以下が好ましく、さらに好ましくは３０ｎｍ以上１５０ｎｍ以下、特に好ましくは５０ｎｍ以上１００ｎｍ以下である。 The thickness of the electron blocking film 3 is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 13. It is 50 nm or more and 100 nm or less.
　正孔ブロッキング膜５は、光電変換膜４と上部電極６との間に設けることができ、下部電極２と上部電極６間にバイアス電圧を印加したときに、上部電極６から光電変換膜４に正孔が注入されて暗電流が増加してしまうのを抑制することができる。 The hole blocking film 5 can be provided between the photoelectric conversion film 4 and the upper electrode 6. When a bias voltage is applied between the lower electrode 2 and the upper electrode 6, the hole blocking film 5 is transferred from the upper electrode 6 to the photoelectric conversion film 4. It is possible to suppress the increase in dark current due to the injection of holes.
　正孔ブロッキング膜５には、電子受容性有機材料を用いることができる。 An electron-accepting organic material can be used for the hole blocking film 5.
　正孔ブロッキング膜５の厚みは、暗電流抑制効果を確実に発揮させるとともに、センサ部１３の光電変換効率の低下を防ぐため、１０ｎｍ以上２００ｎｍ以下が好ましく、さらに好ましくは３０ｎｍ以上１５０ｎｍ以下、特に好ましくは５０ｎｍ以上１００ｎｍ以下である。 The thickness of the hole blocking film 5 is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 13. Is from 50 nm to 100 nm.
　実際に正孔ブロッキング膜５に用いる材料は、隣接する電極の材料および隣接する光電変換膜４の材料等に応じて選択すればよく、隣接する電極の材料の仕事関数（Ｗｆ）より１．３ｅＶ以上イオン化ポテンシャル（Ｉｐ）が大きく、かつ、隣接する光電変換膜４の材料の電子親和力（Ｅａ）と同等のＥａもしくはそれより大きいＥａを持つものが好ましい。この電子受容性有機材料として適用可能な材料については、特開２００９－３２８５４号公報において詳細に説明されているため説明を省略する。 The material actually used for the hole blocking film 5 may be selected according to the material of the adjacent electrode, the material of the adjacent photoelectric conversion film 4 and the like, and 1.3 eV from the work function (Wf) of the material of the adjacent electrode. As described above, it is preferable that the ionization potential (Ip) is large and that the Ea is equal to or larger than the electron affinity (Ea) of the material of the adjacent photoelectric conversion film 4. Since the material applicable as the electron-accepting organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.
　なお、光電変換膜４で発生した電荷のうち、正孔が上部電極６に移動し、電子が下部電極２に移動するようにバイアス電圧を設定する場合には、電子ブロッキング膜３と正孔ブロッキング膜５の位置を逆にすればよい。また、電子ブロッキング膜３と正孔ブロッキング膜５は両方設けなくてもよく、いずれかを設けておけば、ある程度の暗電流抑制効果を得ることができる。 In addition, when a bias voltage is set so that holes move to the upper electrode 6 and electrons move to the lower electrode 2 among the charges generated in the photoelectric conversion film 4, the electron blocking film 3 and the hole blocking are set. The position of the film 5 may be reversed. Moreover, it is not necessary to provide both the electron blocking film 3 and the hole blocking film 5. If either one is provided, a certain degree of dark current suppressing effect can be obtained.
　各画素部の下部電極２下方の基板１の表面には信号出力部１４が形成されている。 A signal output unit 14 is formed on the surface of the substrate 1 below the lower electrode 2 of each pixel unit.
　図３には、信号出力部１４の構成が概略的に示されている。 FIG. 3 schematically shows the configuration of the signal output unit 14.
　下部電極２に対応して、下部電極２に移動した電荷を蓄積するコンデンサ９と、コンデンサ９に蓄積された電荷を電気信号に変換して出力する電界効果型薄膜トランジスタ（Thin Film Transistor、以下、単に「薄膜トランジスタ」という。）１０が形成されている。コンデンサ９および薄膜トランジスタ１０の形成された領域は、平面視において下部電極２と重なる部分を有しており、このような構成とすることで、各画素部における信号出力部１４とセンサ部１３とが厚さ方向で重なりを有することとなる。なお、放射線検出器２０（画素部）の平面積を最小にするために、コンデンサ９および薄膜トランジスタ１０の形成された領域が下部電極２によって完全に覆われていることが望ましい。 Corresponding to the lower electrode 2, a capacitor 9 that accumulates the charges transferred to the lower electrode 2, and a field effect thin film transistor (Thin Transistor, hereinafter simply referred to as an electric signal converted from the electric charge accumulated in the capacitor 9) "Thin film transistor") 10 is formed. The region in which the capacitor 9 and the thin film transistor 10 are formed has a portion that overlaps the lower electrode 2 in a plan view. With such a configuration, the signal output unit 14 and the sensor unit 13 in each pixel unit are connected to each other. There will be overlap in the thickness direction. In order to minimize the plane area of the radiation detector 20 (pixel portion), it is desirable that the region where the capacitor 9 and the thin film transistor 10 are formed is completely covered by the lower electrode 2.
　コンデンサ９は、基板１と下部電極２との間に設けられた絶縁膜１１を貫通して形成された導電性材料の配線を介して対応する下部電極２と電気的に接続されている。これにより、下部電極２で捕集された電荷をコンデンサ９に移動させることができる。 The capacitor 9 is electrically connected to the corresponding lower electrode 2 via a wiring made of a conductive material penetrating an insulating film 11 provided between the substrate 1 and the lower electrode 2. Thereby, the electric charge collected by the lower electrode 2 can be moved to the capacitor 9.
　薄膜トランジスタ１０は、ゲート電極１５、ゲート絶縁膜１６、および活性層（チャネル層）１７が積層され、さらに、活性層１７上にソース電極１８とドレイン電極１９が所定の間隔を開けて形成されている。 In the thin film transistor 10, a gate electrode 15, a gate insulating film 16, and an active layer (channel layer) 17 are stacked, and a source electrode 18 and a drain electrode 19 are formed on the active layer 17 at a predetermined interval. .
　活性層１７は、例えば、アモルファスシリコンや非晶質酸化物、有機半導体材料、カーボンナノチューブなどにより形成することができる。なお、活性層１７を構成する材料は、これらに限定されるものではない。 The active layer 17 can be formed of, for example, amorphous silicon, amorphous oxide, organic semiconductor material, carbon nanotube, or the like. In addition, the material which comprises the active layer 17 is not limited to these.
　活性層１７を構成可能な非晶質酸化物としては、Ｉｎ、ＧａおよびＺｎのうちの少なくとも１つを含む酸化物（例えばＩｎ－Ｏ系）が好ましく、Ｉｎ、ＧａおよびＺｎのうちの少なくとも２つを含む酸化物（例えばＩｎ－Ｚｎ－Ｏ系、Ｉｎ－Ｇａ－Ｏ系、Ｇａ－Ｚｎ－Ｏ系）がより好ましく、Ｉｎ、ＧａおよびＺｎを含む酸化物が特に好ましい。Ｉｎ－Ｇａ－Ｚｎ－Ｏ系非晶質酸化物としては、結晶状態における組成がＩｎＧａＯ３（ＺｎＯ）ｍ（ｍは６未満の自然数）で表される非晶質酸化物が好ましく、特に、ＩｎＧａＺｎＯ４がより好ましい。なお、活性層１７を構成可能な非晶質酸化物は、これらに限定されるものではない。 The amorphous oxide that can form the active layer 17 is preferably an oxide containing at least one of In, Ga, and Zn (for example, In—O-based), and at least 2 of In, Ga, and Zn. (Eg, In—Zn—O, In—Ga—O, and Ga—Zn—O) are more preferable, and oxides including In, Ga, and Zn are particularly preferable. As the In—Ga—Zn—O-based amorphous oxide, an amorphous oxide whose composition in a crystalline state is represented by InGaO 3 (ZnO) m (m is a natural number of less than 6) is preferable, and InGaZnO is particularly preferable. 4 is more preferable. In addition, the amorphous oxide which can comprise the active layer 17 is not limited to these.
　活性層１７を構成可能な有機半導体材料としては、フタロシアニン化合物や、ペンタセン、バナジルフタロシアニン等を挙げることができるが、これらに限定されるものではない。なお、フタロシアニン化合物の構成については、特開２００９－２１２３８９号公報において詳細に説明されているため説明を省略する。 Examples of the organic semiconductor material that can form the active layer 17 include, but are not limited to, phthalocyanine compounds, pentacene, vanadyl phthalocyanine, and the like. Note that the configuration of the phthalocyanine compound is described in detail in JP-A-2009-212389, and thus the description thereof is omitted.
　薄膜トランジスタ１０の活性層１７を非晶質酸化物や有機半導体材料、カーボンナノチューブで形成したものとすれば、Ｘ線等の放射線を吸収せず、あるいは吸収したとしても極めて微量に留まるため、信号出力部１４におけるノイズの発生を効果的に抑制することができる。 If the active layer 17 of the thin film transistor 10 is formed of an amorphous oxide, an organic semiconductor material, or a carbon nanotube, it will not absorb radiation such as X-rays, or even if it absorbs it, it will remain in a very small amount. Generation of noise in the portion 14 can be effectively suppressed.
　また、活性層１７をカーボンナノチューブで形成した場合、薄膜トランジスタ１０のスイッチング速度を高速化することができ、また、可視光域での光の吸収度合の低い薄膜トランジスタ１０を形成できる。なお、カーボンナノチューブで活性層１７を形成する場合、活性層１７に極微量の金属性不純物が混入するだけで、薄膜トランジスタ１０の性能は著しく低下するため、遠心分離などにより極めて高純度のカーボンナノチューブを分離・抽出して形成する必要がある。 Further, when the active layer 17 is formed of carbon nanotubes, the switching speed of the thin film transistor 10 can be increased, and the thin film transistor 10 having a low degree of light absorption in the visible light region can be formed. Note that when the active layer 17 is formed of carbon nanotubes, the performance of the thin film transistor 10 is remarkably deteriorated only by mixing a very small amount of metallic impurities into the active layer 17. It is necessary to form by separating and extracting.
　ここで、上述した非晶質酸化物、有機半導体材料、カーボンナノチューブや、有機光電変換材料は、いずれも低温での成膜が可能である。従って、基板１としては、半導体基板、石英基板、およびガラス基板等の耐熱性の高い基板に限定されず、プラスチック等の可撓性基板、アラミド、バイオナノファイバを用いることもできる。具体的には、ポリエチレンテレフタレート、ポリブチレンフタレート、ポリエチレンナフタレート等のポリエステル、ポリスチレン、ポリカーボネート、ポリエーテルスルホン、ポリアリレート、ポリイミド、ポリシクロオレフィン、ノルボルネン樹脂、ポリ（クロロトリフルオロエチレン）等の可撓性基板を用いることができる。このようなプラスチック製の可撓性基板を用いれば、軽量化を図ることもでき、例えば持ち運び等に有利となる。 Here, any of the above-described amorphous oxide, organic semiconductor material, carbon nanotube, and organic photoelectric conversion material can be formed at a low temperature. Therefore, the substrate 1 is not limited to a substrate having high heat resistance such as a semiconductor substrate, a quartz substrate, and a glass substrate, and a flexible substrate such as plastic, aramid, or bio-nanofiber can also be used. Specifically, flexible materials such as polyesters such as polyethylene terephthalate, polybutylene phthalate, and polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, and poly (chlorotrifluoroethylene). A conductive substrate can be used. If such a plastic flexible substrate is used, it is possible to reduce the weight, which is advantageous for carrying around, for example.
　また、基板１には、絶縁性を確保するための絶縁層、水分や酸素の透過を防止するためのガスバリア層、平坦性あるいは電極等との密着性を向上するためのアンダーコート層等を設けてもよい。 In addition, the substrate 1 is provided with an insulating layer for ensuring insulation, a gas barrier layer for preventing permeation of moisture and oxygen, an undercoat layer for improving flatness or adhesion to electrodes, and the like. May be.
　アラミドは、２００度以上の高温プロセスを適用できるために、透明電極材料を高温硬化させて低抵抗化でき、また、ハンダのリフロー工程を含むドライバＩＣの自動実装にも対応できる。また、アラミドは、ＩＴＯ（Indium Tin Oxide）やガラス基板と熱膨張係数が近いため、製造後の反りが少なく、割れにくい。また、アラミドは、ガラス基板等と比べて薄く基板を形成できる。なお、超薄型ガラス基板とアラミドを積層して基板１を形成してもよい。 Since aramid can be applied to a high-temperature process of 200 ° C. or higher, the transparent electrode material can be cured at a high temperature to lower its resistance, and can also be used for automatic mounting of a driver IC including a solder reflow process. Aramid has a thermal expansion coefficient close to that of ITO (Indium Tin Oxide) or glass substrate, so there is little warping after manufacturing and it is difficult to crack. In addition, aramid can form a substrate thinner than a glass substrate or the like. The substrate 1 may be formed by laminating an ultrathin glass substrate and aramid.
　バイオナノファイバは、バクテリア（酢酸菌、Acetobacter Xylinum）が産出するセルロースミクロフィブリル束（バクテリアセルロース）と透明樹脂との複合したものである。セルロースミクロフィブリル束は、幅５０ｎｍと可視光波長に対して１／１０のサイズで、かつ、高強度、高弾性、低熱膨である。バクテリアセルロースにアクリル樹脂、エポキシ樹脂等の透明樹脂を含浸・硬化させることで、繊維を６０－７０％も含有しながら、波長５００nmで約９０％の光透過率を示すバイオナノファイバが得られる。バイオナノファイバは、シリコン結晶に匹敵する低い熱膨張係数（３－７ｐｐｍ）を有し、鋼鉄並の強度(４６０ＭＰa)、高弾性(３０ＧＰａ)で、かつフレキシブルであることから、ガラス基板等と比べて薄く基板１を形成できる。 Bionanofiber is a composite of cellulose microfibril bundle (bacterial cellulose) produced by bacteria (acetic acid bacteria, Acetobacter® Xylinum) and transparent resin. The cellulose microfibril bundle has a width of 50 nm and a size of 1/10 of the visible light wavelength, and has high strength, high elasticity, and low thermal expansion. By impregnating and curing a transparent resin such as acrylic resin or epoxy resin into bacterial cellulose, a bio-nanofiber having a light transmittance of about 90% at a wavelength of 500 nm can be obtained while containing 60-70% of the fiber. Bionanofiber has a low coefficient of thermal expansion (3-7ppm) comparable to silicon crystals, and is as strong as steel (460MPa), highly elastic (30GPa), and flexible. Compared to glass substrates, etc. The substrate 1 can be formed thinly.
　一方、本実施の形態に係るＴＦＴ基板３０Ｂは、ＴＦＴ基板３０Ａと同様に構成されているため、当該構成についての図示および説明は省略するが、基板１とは反対側の面（光電変換膜４側の面）がシンチレータ８のＴＦＴ基板３０Ａとは反対側の面に積層されている。 On the other hand, since the TFT substrate 30B according to the present embodiment is configured in the same manner as the TFT substrate 30A, illustration and description of the configuration are omitted, but the surface opposite to the substrate 1 (photoelectric conversion film 4). Side surface) is laminated on the surface of the scintillator 8 opposite to the TFT substrate 30A.
　なお、前述したように、本実施の形態に係る放射線検出器２０では、シンチレータ８をＴＦＴ基板３０Ａ上に直接蒸着により形成する一方、シンチレータ８のＴＦＴ基板３０Ａが設けられている面とは反対側の面にＴＦＴ基板３０Ｂを、接着層２２を介して接着することにより構成しているが、これに限らず、例えば、シンチレータ８をＴＦＴ基板３０Ｂ上に直接蒸着により形成する一方、シンチレータ８のＴＦＴ基板３０Ｂが設けられている面とは反対側の面にＴＦＴ基板３０Ａを、接着層２２を介して接着することにより構成する方法等、他の方法により構成してもよいことは言うまでもない。 As described above, in the radiation detector 20 according to the present embodiment, the scintillator 8 is formed directly on the TFT substrate 30A by vapor deposition, while the side of the scintillator 8 opposite to the surface on which the TFT substrate 30A is provided. The TFT substrate 30B is bonded to the surface of the TFT substrate 30 via the adhesive layer 22. However, the present invention is not limited to this. For example, the scintillator 8 is formed directly on the TFT substrate 30B by vapor deposition. It goes without saying that the TFT substrate 30A may be formed by other methods such as a method of bonding the TFT substrate 30A to the surface opposite to the surface on which the substrate 30B is provided via the adhesive layer 22.
　また、本実施の形態に係る放射線検出器２０では、シンチレータ８の各柱状部の先端部は、できるだけ平坦になるように制御することが好ましい。具体的には、蒸着終了時の被蒸着基板の温度を制御することで実現できる。例えば、蒸着終了時の被蒸着基板の温度を１１０℃とすれば先端角度がおよそ１７０度となり、蒸着終了時の被蒸着基板の温度を１４０℃とすれば先端角度がおよそ６０度となり、蒸着終了時の被蒸着基板の温度を２００℃とすれば先端角度がおよそ７０度となり、蒸着終了時の被蒸着基板の温度を２６０℃とすれば先端角度がおよそ１２０度となる。なお、この制御については、特開２０１０－２５６２０号公報において詳細に説明されているため、これ以上の説明を省略する。 Also, in the radiation detector 20 according to the present embodiment, it is preferable to control the tip of each columnar part of the scintillator 8 to be as flat as possible. Specifically, it can be realized by controlling the temperature of the evaporation target substrate at the end of evaporation. For example, if the temperature of the substrate to be deposited at the end of vapor deposition is 110 ° C., the tip angle is about 170 degrees, and if the temperature of the substrate to be deposited at the end of vapor deposition is 140 degrees Celsius, the tip angle is about 60 degrees. If the temperature of the vapor deposition substrate at that time is 200 ° C., the tip angle is approximately 70 degrees, and if the temperature of the vapor deposition substrate at the end of vapor deposition is 260 ° C., the tip angle is approximately 120 degrees. Since this control is described in detail in Japanese Patent Application Laid-Open No. 2010-25620, further description is omitted.
　一方、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂには、図４に示すように、上述のセンサ部１３、コンデンサ９、薄膜トランジスタ１０を含んで構成される画素３２が一定方向（図４の走査線方向）および当該一定方向に対する交差方向（図４の信号配線方向）に２次元状に複数設けられている。 On the other hand, on the TFT substrate 30A and the TFT substrate 30B, as shown in FIG. 4, pixels 32 including the above-described sensor unit 13, capacitor 9, and thin film transistor 10 are arranged in a certain direction (scanning line direction in FIG. 4) and A plurality of two-dimensional shapes are provided in the intersecting direction (signal wiring direction in FIG. 4) with respect to the certain direction.
　また、放射線検出器２０には、上記一定方向（走査線方向）に延設され、各薄膜トランジスタ１０をオン・オフさせるための複数本のゲート配線３４と、上記交差方向（信号配線方向）に延設され、オン状態の薄膜トランジスタ１０を介して電荷を読み出すための複数本のデータ配線３６と、が各々ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂに対応して２組分設けられている。 In addition, the radiation detector 20 extends in the predetermined direction (scanning line direction), and extends in the intersecting direction (signal wiring direction) with a plurality of gate wirings 34 for turning on and off each thin film transistor 10. A plurality of data wirings 36 for reading out charges through the thin film transistor 10 in the on state are provided in two sets corresponding to the TFT substrate 30A and the TFT substrate 30B, respectively.
　放射線検出器２０は、平板状で平面視において外縁に４辺を有する四辺形状をしている。具体的には矩形状に形成されている。 The radiation detector 20 is flat and has a quadrilateral shape with four sides at the outer edge in plan view. Specifically, it is formed in a rectangular shape.
　次に、この放射線検出器２０を内蔵し、放射線画像を撮影する可搬型の放射線画像撮影装置（以下、「電子カセッテ」という。）４０の構成について説明する。図５には、本実施の形態に係る電子カセッテ４０の構成を示す斜視図が示されている。 Next, the configuration of a portable radiation image capturing apparatus (hereinafter referred to as “electronic cassette”) 40 that incorporates the radiation detector 20 and captures a radiation image will be described. FIG. 5 is a perspective view showing the configuration of the electronic cassette 40 according to the present exemplary embodiment.
　同図に示すように、この電子カセッテ４０は、放射線を透過させる材料からなる平板状の筐体４１を備えており、防水性、密閉性を有する構造とされている。筐体４１の内部には、放射線Ｘが照射される筐体４１の照射面側から、被写体を透過した放射線Ｘを検出する放射線検出器２０、および放射線Ｘのバック散乱線を吸収する鉛板４３が順に配設される。筐体４１は、平板状の一方の面の放射線検出器２０の配設位置に対応する領域が放射線を検出可能な四辺形状の撮影領域４１Ａとされている。放射線検出器２０は、図６に示すように、ＴＦＴ基板３０Ｂが撮影領域４１Ａ側となるように配置されており、撮影領域４１Ａを構成する筐体４１内側に貼り付けられている。 As shown in the figure, the electronic cassette 40 includes a flat housing 41 made of a material that transmits radiation, and has a waterproof and airtight structure. Inside the housing 41 are a radiation detector 20 that detects the radiation X that has passed through the subject from the irradiation surface side of the housing 41 that is irradiated with the radiation X, and a lead plate 43 that absorbs backscattered rays of the radiation X. Are arranged in order. The case 41 has a quadrilateral imaging region 41A capable of detecting radiation in a region corresponding to the arrangement position of the radiation detector 20 on one flat surface. As shown in FIG. 6, the radiation detector 20 is disposed such that the TFT substrate 30B is on the imaging region 41A side, and is attached to the inside of the casing 41 that constitutes the imaging region 41A.
　また、筐体４１の内部の一端側には、放射線検出器２０と重ならない位置（撮影領域４１Ａの範囲外）に、後述するカセッテ制御部５８や電源部７０等を収容するケース４２が配置されている。 In addition, a case 42 that houses a cassette control unit 58, a power supply unit 70, and the like, which will be described later, is disposed at one end inside the housing 41 at a position that does not overlap the radiation detector 20 (outside the range of the imaging region 41A). ing.
　図７には、本実施の形態に係る電子カセッテ４０の電気系の要部構成を示すブロック図が示されている。 FIG. 7 is a block diagram showing the main configuration of the electrical system of the electronic cassette 40 according to the present embodiment.
　同図に示すように、ＴＦＴ基板３０Ａ、３０Ｂは、それぞれ隣り合う２辺の一辺側にゲート線ドライバ５２が配置され、他辺側に信号処理部５４が配置されている。以下、２つのＴＦＴ基板３０Ａ、３０Ｂに対応して設けられたゲート線ドライバ５２および信号処理部５４を区別する場合、ＴＦＴ基板３０Ａに対応するゲート線ドライバ５２および信号処理部５４に符号Ａを付し、ＴＦＴ基板３０Ｂに対応するゲート線ドライバ５２および信号処理部５４に符号Ｂを付して説明する。 As shown in the figure, in the TFT substrates 30A and 30B, a gate line driver 52 is disposed on one side of two adjacent sides, and a signal processing unit 54 is disposed on the other side. Hereinafter, when the gate line driver 52 and the signal processing unit 54 provided corresponding to the two TFT substrates 30A and 30B are distinguished from each other, the gate line driver 52 and the signal processing unit 54 corresponding to the TFT substrate 30A are denoted by A. The gate line driver 52 and the signal processing unit 54 corresponding to the TFT substrate 30B will be described with reference character B.
　ＴＦＴ基板３０Ａの個々のゲート配線３４はゲート線ドライバ５２Ａに接続され、ＴＦＴ基板３０Ａの個々のデータ配線３６は信号処理部５４Ａに接続されており、ＴＦＴ基板３０Ｂの個々のゲート配線３４はゲート線ドライバ５２Ｂに接続されており、ＴＦＴ基板３０Ｂの個々のデータ配線３６は信号処理部５４Ｂに接続されている。 Each gate wiring 34 of the TFT substrate 30A is connected to the gate line driver 52A, each data wiring 36 of the TFT substrate 30A is connected to the signal processing unit 54A, and each gate wiring 34 of the TFT substrate 30B is a gate line. Connected to the driver 52B, each data wiring 36 of the TFT substrate 30B is connected to the signal processing unit 54B.
　また、筐体４１の内部には、画像メモリ５６と、カセッテ制御部５８と、無線通信部６０と、バイアス電源７２と、を備えている。 Also, the housing 41 includes an image memory 56, a cassette control unit 58, a wireless communication unit 60, and a bias power source 72.
　ＴＦＴ基板３０Ａ、３０Ｂの各薄膜トランジスタ１０は、ゲート線ドライバ５２Ａ、５２Ｂからゲート配線３４を介して供給される信号により走査線単位で順にオンされ、オン状態とされた薄膜トランジスタ１０によって読み出された電荷は、電気信号としてデータ配線３６を伝送されて信号処理部５４Ａ、５４Ｂに入力される。これにより、電荷は走査線単位で順に読み出され、二次元状の放射線画像が取得可能となる。 The thin film transistors 10 on the TFT substrates 30A and 30B are sequentially turned on in units of scanning lines by signals supplied from the gate line drivers 52A and 52B via the gate wiring 34, and the electric charges read by the thin film transistors 10 turned on. Is transmitted through the data wiring 36 as an electrical signal and input to the signal processing units 54A and 54B. As a result, the charges are sequentially read in units of scanning lines, and a two-dimensional radiation image can be acquired.
　なお、バイアス電源７２は、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂにおいて、シンチレータ８により生じた光を電荷に変換するために必要なバイアス電圧（直流電圧）を光電変換膜４に印加するものであり、電子カセッテ４０において静止画撮影を行う際にはＴＦＴ基板３０Ｂの光電変換膜４にバイアス電圧を印加する一方、動画撮影を行う際にはＴＦＴ基板３０Ａの光電変換膜４にバイアス電圧を印加する。 The bias power source 72 applies a bias voltage (DC voltage) necessary for converting the light generated by the scintillator 8 into electric charges in the TFT substrate 30A and the TFT substrate 30B. When the cassette 40 performs still image shooting, a bias voltage is applied to the photoelectric conversion film 4 of the TFT substrate 30B, while when moving image shooting is performed, a bias voltage is applied to the photoelectric conversion film 4 of the TFT substrate 30A.
　ここで、本実施の形態に係る信号処理部５４Ａおよび信号処理部５４Ｂの構成について説明する。図８には、本実施の形態に係る信号処理部５４Ａの構成を示す回路図が示されている。 Here, the configuration of the signal processing unit 54A and the signal processing unit 54B according to the present embodiment will be described. FIG. 8 is a circuit diagram showing a configuration of the signal processing unit 54A according to the present embodiment.
　同図に示すように、本実施の形態に係る信号処理部５４Ａは、ＴＦＴ基板３０Ａのデータ配線３６の各々に対応して、可変ゲインプリアンプ（チャージアンプ）８２と、サンプルホールド回路８６と、が備えられている。 As shown in the figure, the signal processing unit 54A according to the present embodiment includes a variable gain preamplifier (charge amplifier) 82 and a sample hold circuit 86 corresponding to each of the data wirings 36 of the TFT substrate 30A. Is provided.
　可変ゲインプリアンプ８２は、正入力側が接地されたオペアンプ８２Ａと、オペアンプ８２Ａの負入力側と出力側との間に、それぞれ並列に接続されるコンデンサ８２Ｂと、リセットスイッチ８２Ｃとを含んで構成されており、リセットスイッチ８２Ｃは、カセッテ制御部５８により切り換えられる。 The variable gain preamplifier 82 includes an operational amplifier 82A whose positive input side is grounded, a capacitor 82B connected in parallel between the negative input side and the output side of the operational amplifier 82A, and a reset switch 82C. The reset switch 82C is switched by the cassette control unit 58.
　また、本実施の形態に係る信号処理部５４Ａは、マルチプレクサ８８およびＡ／Ｄ（アナログ／デジタル）変換器８９が備えられている。なお、サンプルホールド回路８６のサンプルタイミング、およびマルチプレクサ８８に設けられたスイッチ８８Ａによる選択出力も、カセッテ制御部５８により切り換えられる。 The signal processing unit 54A according to the present embodiment includes a multiplexer 88 and an A / D (analog / digital) converter 89. Note that the sample control of the sample hold circuit 86 and the selection output by the switch 88A provided in the multiplexer 88 are also switched by the cassette control unit 58.
　放射線画像を検出する際に、カセッテ制御部５８は、まず、可変ゲインプリアンプ８２のリセットスイッチ８２Ｃを所定期間オン状態とすることにより、コンデンサ８２Ｂに蓄積されていた電荷を放電する。 When detecting the radiation image, the cassette control unit 58 first discharges the charge accumulated in the capacitor 82B by turning on the reset switch 82C of the variable gain preamplifier 82 for a predetermined period.
　一方、放射線Ｘが照射されることによってＴＦＴ基板３０Ａの各画素３２の各々のコンデンサ９に蓄積された電荷は、接続されている薄膜トランジスタ１０がオン状態とされることにより電気信号として接続されているデータ配線３６を伝送され、データ配線３６を伝送された電気信号は、対応する可変ゲインプリアンプ８２により、予め定められた増幅率で増幅される。 On the other hand, the electric charge accumulated in each capacitor 9 of each pixel 32 of the TFT substrate 30A by being irradiated with the radiation X is connected as an electric signal when the connected thin film transistor 10 is turned on. The electric signal transmitted through the data line 36 and transmitted through the data line 36 is amplified by the corresponding variable gain preamplifier 82 at a predetermined amplification factor.
　一方、カセッテ制御部５８は、上述した放電を行った後、サンプルホールド回路８６を所定期間駆動させることより、可変ゲインプリアンプ８２によって増幅された電気信号の信号レベルをサンプルホールド回路８６に保持させる。 On the other hand, the cassette control unit 58 causes the sample hold circuit 86 to hold the signal level of the electric signal amplified by the variable gain preamplifier 82 by driving the sample hold circuit 86 for a predetermined period after performing the above-described discharge.
　そして、各サンプルホールド回路８６に保持された信号レベルは、カセッテ制御部５８による制御に応じてマルチプレクサ８８により順次選択され、Ａ／Ｄ変換器８９によってＡ／Ｄ変換されることにより、撮影された放射線画像を示す画像データが生成される。 The signal levels held in each sample and hold circuit 86 are sequentially selected by the multiplexer 88 in accordance with control by the cassette control unit 58 and are A / D converted by the A / D converter 89 and photographed. Image data indicating a radiation image is generated.
　一方、信号処理部５４Ａには画像メモリ５６が接続されており、信号処理部５４ＡのＡ／Ｄ変換器８９から出力された画像データは画像メモリ５６に順に記憶される。画像メモリ５６は所定枚分の画像データを記憶可能な記憶容量を有しており、放射線画像の撮影が行われる毎に、撮影によって得られた画像データが画像メモリ５６に順次記憶される。 On the other hand, an image memory 56 is connected to the signal processing unit 54A, and the image data output from the A / D converter 89 of the signal processing unit 54A is stored in the image memory 56 in order. The image memory 56 has a storage capacity capable of storing a predetermined number of image data, and image data obtained by imaging is sequentially stored in the image memory 56 each time a radiographic image is captured.
　一方、図９には、本実施の形態に係る信号処理部５４Ｂの構成を示す回路図が示されている。 On the other hand, FIG. 9 shows a circuit diagram showing a configuration of the signal processing unit 54B according to the present embodiment.
　同図に示すように、本実施の形態に係る信号処理部５４Ｂは、信号処理部５４Ａと同様に、ＴＦＴ基板３０Ｂのデータ配線３６の各々に対応して、可変ゲインプリアンプ（チャージアンプ）９２と、サンプルホールド回路９６と、が備えられている。 As shown in the figure, the signal processing unit 54B according to the present exemplary embodiment, similarly to the signal processing unit 54A, corresponds to each of the data wirings 36 of the TFT substrate 30B and a variable gain preamplifier (charge amplifier) 92. , A sample hold circuit 96 is provided.
　可変ゲインプリアンプ９２は、正入力側が接地されたオペアンプ９２Ａと、オペアンプ９２Ａの負入力側と出力側との間に、それぞれ並列に接続されるコンデンサ９２Ｂと、リセットスイッチ９２Ｃとを含んで構成されており、リセットスイッチ９２Ｃは、カセッテ制御部５８により切り換えられる。 The variable gain preamplifier 92 includes an operational amplifier 92A whose positive input side is grounded, a capacitor 92B connected in parallel between the negative input side and the output side of the operational amplifier 92A, and a reset switch 92C. The reset switch 92C is switched by the cassette control unit 58.
　また、本実施の形態に係る信号処理部５４Ｂもまた、信号処理部５４Ａと同様に、マルチプレクサ９８およびＡ／Ｄ（アナログ／デジタル）変換器９９が備えられている。なお、サンプルホールド回路９６のサンプルタイミング、およびマルチプレクサ９８に設けられたスイッチ９８Ａによる選択出力も、カセッテ制御部５８により切り換えられる。 Also, the signal processing unit 54B according to the present embodiment is also provided with a multiplexer 98 and an A / D (analog / digital) converter 99, similarly to the signal processing unit 54A. Note that the sample control of the sample hold circuit 96 and the selection output by the switch 98A provided in the multiplexer 98 are also switched by the cassette control unit 58.
　放射線画像を検出する際に、カセッテ制御部５８は、まず、可変ゲインプリアンプ９２のリセットスイッチ９２Ｃを所定期間オン状態とすることにより、コンデンサ９２Ｂに蓄積されていた電荷を放電する。 When detecting the radiation image, the cassette control unit 58 first discharges the charge accumulated in the capacitor 92B by turning on the reset switch 92C of the variable gain preamplifier 92 for a predetermined period.
　一方、放射線Ｘが照射されることによってＴＦＴ基板３０Ｂの各画素３２の各々のコンデンサ９に蓄積された電荷は、接続されている薄膜トランジスタ１０がオン状態とされることにより電気信号として接続されているデータ配線３６を伝送され、データ配線３６を伝送された電気信号は、対応する可変ゲインプリアンプ９２により、予め定められた増幅率で増幅される。 On the other hand, the electric charge accumulated in each capacitor 9 of each pixel 32 of the TFT substrate 30B by being irradiated with the radiation X is connected as an electric signal when the connected thin film transistor 10 is turned on. The electrical signal transmitted through the data line 36 and transmitted through the data line 36 is amplified by a corresponding variable gain preamplifier 92 at a predetermined amplification factor.
　一方、カセッテ制御部５８は、上述した放電を行った後、サンプルホールド回路９６を所定期間駆動させることより、可変ゲインプリアンプ９２によって増幅された電気信号の信号レベルをサンプルホールド回路９６に保持させる。 On the other hand, the cassette control unit 58 causes the sample and hold circuit 96 to hold the signal level of the electric signal amplified by the variable gain preamplifier 92 by driving the sample and hold circuit 96 for a predetermined period after performing the above-described discharge.
　そして、各サンプルホールド回路９６に保持された信号レベルは、カセッテ制御部５８による制御に応じてマルチプレクサ９８により順次選択され、Ａ／Ｄ変換器９９によってＡ／Ｄ変換されることにより、撮影された放射線画像を示す画像データが生成される。 The signal levels held in the sample and hold circuits 96 are sequentially selected by the multiplexer 98 in accordance with the control by the cassette control unit 58 and are A / D converted by the A / D converter 99 to be photographed. Image data indicating a radiation image is generated.
　一方、信号処理部５４Ｂにも画像メモリ５６が接続されており、信号処理部５４ＢのＡ／Ｄ変換器９９から出力された画像データもまた画像メモリ５６に順に記憶される。 On the other hand, the image memory 56 is also connected to the signal processing unit 54B, and the image data output from the A / D converter 99 of the signal processing unit 54B is also stored in the image memory 56 in order.
　ところで、本実施の形態に係る電子カセッテ４０には、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの各画素３２に蓄積された電荷を放出することにより、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂに対してリセット処理を実行する電気リセット機能が搭載されている。 By the way, in the electronic cassette 40 according to the present embodiment, reset processing is performed on the TFT substrate 30A and the TFT substrate 30B by discharging the charges accumulated in the respective pixels 32 of the TFT substrate 30A and the TFT substrate 30B. It has an electrical reset function.
　ＴＦＴ基板３０Ａに対して電気リセット機能を働かせる際に、カセッテ制御部５８は、ゲート線ドライバ５２Ａを制御してＴＦＴ基板３０Ａに設けられている全ての画素３２の薄膜トランジスタ１０を所定期間オン状態にすると共に、信号処理部５４Ａの全ての可変ゲインプリアンプ８２のリセットスイッチ８２Ｃを所定期間オン状態とすることにより、各可変ゲインプリアンプ８２のコンデンサ８２Ｂに蓄積されていた電荷を、コンデンサ８２Ｂおよびリセットスイッチ８２Ｃで構成される閉回路により放電すると共に、各画素３２のコンデンサ９に蓄積されていた電荷を、薄膜トランジスタ１０、リセットスイッチ８２Ｃ、およびオペアンプ８２Ａを介してグランドに放電する。 When the electric reset function is applied to the TFT substrate 30A, the cassette control unit 58 controls the gate line driver 52A to turn on the thin film transistors 10 of all the pixels 32 provided on the TFT substrate 30A for a predetermined period. At the same time, by turning on the reset switches 82C of all the variable gain preamplifiers 82 in the signal processing unit 54A for a predetermined period, the charges accumulated in the capacitors 82B of the variable gain preamplifiers 82 are transferred by the capacitors 82B and the reset switches 82C. In addition to discharging by the configured closed circuit, the charge accumulated in the capacitor 9 of each pixel 32 is discharged to the ground through the thin film transistor 10, the reset switch 82C, and the operational amplifier 82A.
　また、ＴＦＴ基板３０Ｂに対して電気リセット機能を働かせる際にも、同様に、カセッテ制御部５８は、ゲート線ドライバ５２Ｂを制御してＴＦＴ基板３０Ｂに設けられている全ての画素３２の薄膜トランジスタ１０を所定期間オン状態にすると共に、信号処理部５４Ｂの全ての可変ゲインプリアンプ９２のリセットスイッチ９２Ｃを所定期間オン状態とすることにより、各可変ゲインプリアンプ９２のコンデンサ９２Ｂに蓄積されていた電荷を、コンデンサ９２Ｂおよびリセットスイッチ９２Ｃで構成される閉回路により放電すると共に、各画素３２のコンデンサ９に蓄積されていた電荷を、薄膜トランジスタ１０、リセットスイッチ９２Ｃ、およびオペアンプ９２Ａを介してグランドに放電する。 Similarly, when the electric reset function is applied to the TFT substrate 30B, the cassette control unit 58 controls the gate line driver 52B to control the thin film transistors 10 of all the pixels 32 provided on the TFT substrate 30B. By turning on the reset switches 92C of all the variable gain preamplifiers 92 in the signal processing unit 54B for a predetermined period while being turned on for a predetermined period, the charges accumulated in the capacitors 92B of the variable gain preamplifiers 92 are In addition to discharging by the closed circuit constituted by 92B and the reset switch 92C, the charge accumulated in the capacitor 9 of each pixel 32 is discharged to the ground via the thin film transistor 10, the reset switch 92C, and the operational amplifier 92A.
　一方、図７に示すように、画像メモリ５６はカセッテ制御部５８と接続されている。カセッテ制御部５８はマイクロコンピュータによって構成され、ＣＰＵ（中央処理装置）５８Ａ、ＲＯＭ（Read Only Memory）およびＲＡＭ（Random Access Memory）を含むメモリ５８Ｂ、フラッシュメモリ等からなる不揮発性の記憶部５８Ｃを備えており、電子カセッテ４０全体の動作を制御する。 On the other hand, as shown in FIG. 7, the image memory 56 is connected to a cassette control unit 58. The cassette control unit 58 is constituted by a microcomputer, and includes a CPU (Central Processing Unit) 58A, a memory 58B including a ROM (Read Only Memory) and a RAM (Random Access Memory), a non-volatile storage unit 58C including a flash memory and the like. The operation of the entire electronic cassette 40 is controlled.
　また、カセッテ制御部５８には無線通信部６０が接続されている。無線通信部６０は、ＩＥＥＥ（Institute of Electrical and Electronics Engineers）８０２．１１ａ／ｂ／ｇ／ｎ等に代表される無線ＬＡＮ（Local Area Network）規格に対応しており、無線通信による外部機器との間での各種情報の伝送を制御する。カセッテ制御部５８は、無線通信部６０を介して、放射線撮影全体を制御するコンソールなどの外部装置と無線通信が可能とされており、コンソールとの間で各種情報の送受信が可能とされている。 Also, a wireless communication unit 60 is connected to the cassette control unit 58. The wireless communication unit 60 corresponds to a wireless LAN (Local Area Network) standard represented by IEEE (Institute of Electrical and Electronics Electronics) (802.11a / b / g / n), etc., and communicates with an external device by wireless communication. Control the transmission of various information between them. The cassette control unit 58 can wirelessly communicate with an external device such as a console for controlling the entire radiation imaging via the wireless communication unit 60, and can transmit and receive various types of information to and from the console. .
　また、電子カセッテ４０には、電源部７０が設けられており、上述した各種回路や各素子（ゲート線ドライバ５２Ａ、５２Ｂ、信号処理部５４Ａ、５４Ｂ、画像メモリ５６、無線通信部６０やカセッテ制御部５８として機能するマイクロコンピュータ等）は、電源部７０から供給された電力によって作動する。電源部７０は、電子カセッテ４０の可搬性を損なわないように、バッテリ（充電可能な二次電池）を内蔵しており、充電されたバッテリから各種回路・素子へ電力を供給する。なお、図７では、電源部７０と各種回路や各素子を接続する配線を省略している。また、図７では、バイアス電源７２とＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの各画素３２とを接続する配線も省略している。 In addition, the electronic cassette 40 is provided with a power supply unit 70, and the various circuits and elements described above ( gate line drivers 52A and 52B, signal processing units 54A and 54B, image memory 56, wireless communication unit 60, and cassette control). The microcomputer functioning as the unit 58 is operated by the electric power supplied from the power supply unit 70. The power supply unit 70 incorporates a battery (a rechargeable secondary battery) so as not to impair the portability of the electronic cassette 40, and supplies power from the charged battery to various circuits and elements. In FIG. 7, the power supply unit 70, various circuits, and wirings for connecting each element are omitted. Further, in FIG. 7, wirings that connect the bias power source 72 and the respective pixels 32 of the TFT substrate 30A and the TFT substrate 30B are also omitted.
　ところで、本実施の形態に係る電子カセッテ４０は、静止画像の撮影と動画像の撮影の双方を行うことができるものとして構成されている。ここで、本実施の形態に係る電子カセッテ４０では、ＴＦＴ基板３０Ａが動画像の撮影用の基板として用いられ、ＴＦＴ基板３０Ｂが静止画像の撮影用の基板として用いられる。 By the way, the electronic cassette 40 according to the present embodiment is configured to be able to perform both still image shooting and moving image shooting. Here, in the electronic cassette 40 according to the present exemplary embodiment, the TFT substrate 30A is used as a moving image shooting substrate, and the TFT substrate 30B is used as a still image shooting substrate.
　そして、本実施の形態に係る電子カセッテ４０は、放射線画像の撮影を行う場合、撮影領域４１Ａを上とし、図６に示すように、放射線を発生する放射線発生装置８０と間隔を空けて配置され、撮影領域上に患者の撮影対象部位Ｂが配置される。放射線発生装置８０は予め与えられた撮影条件等に応じた放射線量の放射線Ｘを射出する。なお、本実施の形態では、動画像の撮影を行う場合は、比較的低線量で、かつ予め定められた周期で間欠的に放射線Ｘを照射（所謂パルス照射）し、静止画像の撮影を行う場合には、比較的高線量（本実施の形態では、動画撮影時の１００倍程度）で、かつ単発的に放射線Ｘを照射する。 When radiographic images are captured, the electronic cassette 40 according to the present embodiment is arranged with the imaging region 41A facing upward and spaced apart from the radiation generator 80 that generates radiation, as shown in FIG. The imaging target region B of the patient is arranged on the imaging area. The radiation generator 80 emits radiation X having a radiation dose according to imaging conditions given in advance. In this embodiment, when capturing a moving image, the radiation X is intermittently irradiated (so-called pulse irradiation) at a relatively low dose and in a predetermined cycle to capture a still image. In this case, the radiation X is irradiated at a relatively high dose (in this embodiment, about 100 times that during moving image shooting) and in a single shot.
　放射線発生装置８０から照射された放射線Ｘは、撮影対象部位Ｂを透過した後に電子カセッテ４０に到達する。これにより、電子カセッテ４０に内蔵された放射線検出器２０の各センサ部１３には照射された放射線Ｘの線量に応じた電荷が発生し、コンデンサ９にはセンサ部１３で発生した電荷が蓄積される。 The radiation X emitted from the radiation generator 80 reaches the electronic cassette 40 after passing through the imaging target region B. As a result, charges corresponding to the dose of the irradiated radiation X are generated in each sensor unit 13 of the radiation detector 20 incorporated in the electronic cassette 40, and the charges generated by the sensor unit 13 are accumulated in the capacitor 9. The
　一方、カセッテ制御部５８は、静止画像の撮影を行う場合には、ゲート線ドライバ５２Ｂを制御し、ゲート線ドライバ５２ＢからＴＦＴ基板３０Ｂの各ゲート配線３４に１ラインずつ順にオン信号を出力させて画像情報の読み出しを行う。これにより、放射線検出器２０のＴＦＴ基板３０Ｂから読み出された画像情報は、信号処理部５４Ｂを経た後に画像データ（以下、「静止画像データ」という。）として画像メモリ５６に記憶されるので、カセッテ制御部５８は、当該静止画像データを画像メモリ５６から読み出し、無線通信部６０を介してコンソールに送信する。コンソールは、受信した静止画像データを予め定められた記憶装置に記憶すると共に、当該画像データにより示される静止画像をディスプレイ装置により表示させる。 On the other hand, the cassette control unit 58 controls the gate line driver 52B when shooting a still image, and sequentially outputs an ON signal line by line from the gate line driver 52B to each gate wiring 34 of the TFT substrate 30B. Read image information. Accordingly, the image information read from the TFT substrate 30B of the radiation detector 20 is stored in the image memory 56 as image data (hereinafter referred to as “still image data”) after passing through the signal processing unit 54B. The cassette control unit 58 reads the still image data from the image memory 56 and transmits it to the console via the wireless communication unit 60. The console stores the received still image data in a predetermined storage device, and causes the display device to display a still image indicated by the image data.
　これに対し、カセッテ制御部５８は、動画像の撮影を行う場合には、ゲート線ドライバ５２Ａを制御し、ゲート線ドライバ５２ＡからＴＦＴ基板３０Ａの各ゲート配線３４に１ラインずつ順にオン信号を出力させて画像情報の読み出しを行うことを、動画撮影の際に放射線発生装置８０から間欠的に照射される放射線Ｘの照射の周期に応じて予め定められたフレームレート（本実施の形態では、３０フレーム／秒）に応じた速度で繰り返し実行する。これにより、放射線検出器２０のＴＦＴ基板３０Ａから読み出された画像情報は、信号処理部５４Ａを経た後に画像データ（以下、「動画像データ」という。）として画像メモリ５６に順次記憶されるので、カセッテ制御部５８は、当該動画像データを画像メモリ５６から連続的に読み出し、無線通信部６０を介してコンソールにリアルタイムで送信する。コンソールは、電子カセッテ４０から受信した動画像データにより示される動画像をディスプレイ装置によってリアルタイムで表示することにより、動画像（透視画像）の表示を行う。 On the other hand, the cassette control unit 58 controls the gate line driver 52A when shooting a moving image, and sequentially outputs an ON signal line by line from the gate line driver 52A to each gate wiring 34 of the TFT substrate 30A. In this embodiment, the image information is read out in accordance with a frame rate (30 in the present embodiment) determined in advance according to the period of irradiation of radiation X that is intermittently emitted from the radiation generation apparatus 80 during moving image shooting. It is repeatedly executed at a speed corresponding to (frame / second). Thus, the image information read from the TFT substrate 30A of the radiation detector 20 is sequentially stored in the image memory 56 as image data (hereinafter referred to as “moving image data”) after passing through the signal processing unit 54A. The cassette control unit 58 continuously reads out the moving image data from the image memory 56 and transmits the moving image data to the console via the wireless communication unit 60 in real time. The console displays a moving image (perspective image) by displaying the moving image indicated by the moving image data received from the electronic cassette 40 in real time on the display device.
　なお、本実施の形態に係る電子カセッテ４０では、ＴＦＴ基板３０Ａから読み出された動画像データとＴＦＴ基板３０Ｂから読み出された静止画像データとを、各々画像メモリ５６の異なる記憶領域に記憶するものとされている。 In the electronic cassette 40 according to the present embodiment, the moving image data read from the TFT substrate 30A and the still image data read from the TFT substrate 30B are stored in different storage areas of the image memory 56, respectively. It is supposed to be.
　次に、図１０を参照して、本実施の形態に係る電子カセッテ４０の作用について詳細に説明する。なお、図１０は、動画像（透視画像）の撮影開始を指示する指示情報がコンソールから受信された際に電子カセッテ４０のカセッテ制御部５８におけるＣＰＵ５８Ａにより実行される撮影処理プログラムの処理の流れを示すフローチャートであり、当該プログラムはメモリ５８ＢのＲＯＭに予め記憶されている。また、ここでは、錯綜を回避するために、放射線発生装置８０からの放射線Ｘの照射に関する制御の説明は省略する。 Next, the action of the electronic cassette 40 according to the present exemplary embodiment will be described in detail with reference to FIG. Note that FIG. 10 shows the flow of processing of a photographing processing program executed by the CPU 58A in the cassette control unit 58 of the electronic cassette 40 when instruction information for instructing the start of photographing of a moving image (perspective image) is received from the console. This program is stored in advance in the ROM of the memory 58B. In addition, here, in order to avoid complications, description of control related to irradiation of the radiation X from the radiation generation apparatus 80 is omitted.
　同図のステップ１００では、カセッテ制御部５８は、前述した動画撮影時の動作を開始させる。これにより、上記フレームレートに応じた速度での動画像データのコンソールへの送信が開始され、コンソールのディスプレイ装置には動画像（透視画像）の表示が開始される。なお、この際、放射線発生装置８０からの放射線Ｘの間欠的な照射と動画像の撮影との同期をとる必要があるが、この手法としては、従来既知の種々の手法を適用することができる。本実施の形態では、この手法として、ＴＦＴ基板３０ＡまたはＴＦＴ基板３０Ｂの予め定められた画素３２によって得られた画素データに基づき、照射されている放射線Ｘの線量を導出し、導出した線量が予め定められた閾値に達した時点をパルス照射が開始された時点であるとして同期をとる方法を適用している。しかし、これに限らず、他の形態例として、上記予め定められた画素３２に代えて専用の放射線センサを用いる方法、コンソールによって放射線発生装置８０による放射線Ｘの照射のタイミングと、電子カセッテ４０による撮影のタイミングとの同期制御を行う方法等を例示することができる。 In step 100 in the figure, the cassette control unit 58 starts the operation at the time of moving image shooting described above. As a result, transmission of moving image data to the console at a speed corresponding to the frame rate is started, and display of a moving image (perspective image) is started on the console display device. At this time, it is necessary to synchronize the intermittent irradiation of the radiation X from the radiation generator 80 and the capturing of the moving image. As this method, various conventionally known methods can be applied. . In the present embodiment, as this method, the dose of the radiation X being irradiated is derived based on the pixel data obtained by the predetermined pixel 32 of the TFT substrate 30A or the TFT substrate 30B, and the derived dose is determined in advance. A method of synchronizing is applied by assuming that a time point when a predetermined threshold is reached is a time point when pulse irradiation is started. However, the present invention is not limited to this, and as another embodiment, a method of using a dedicated radiation sensor in place of the predetermined pixel 32, the timing of irradiation of the radiation X by the radiation generator 80 by the console, and the electronic cassette 40 A method for performing synchronization control with the timing of photographing can be exemplified.
　次のステップ１０２では、カセッテ制御部５８は、ＴＦＴ基板３０Ｂに対して前述した電気リセット機能を働かせることによって電気リセット処理を実行する。これにより、信号処理部５４Ｂの各可変ゲインプリアンプ９２のコンデンサ９２Ｂに蓄積された電荷、およびＴＦＴ基板３０Ｂの各画素３２におけるコンデンサ９に蓄積された電荷が放電される。 In the next step 102, the cassette controller 58 executes an electrical reset process by using the electrical reset function described above for the TFT substrate 30B. As a result, the charge accumulated in the capacitor 92B of each variable gain preamplifier 92 of the signal processing unit 54B and the charge accumulated in the capacitor 9 in each pixel 32 of the TFT substrate 30B are discharged.
　一方、撮影者は、コンソールのディスプレイ装置に表示されている透視画像を参照し、電子カセッテ４０によって静止画像の撮影を実行する際には、当該静止画像の撮影を指示する際に押圧操作される撮影ボタン（図示省略。）を押圧操作する。この撮影ボタンはコンソールに接続されており、当該押圧操作が行われると、コンソールは、静止画像の撮影を指示する指示情報を電子カセッテ４０に送信する。 On the other hand, the photographer refers to a fluoroscopic image displayed on the display device of the console, and performs a pressing operation when instructing the photographing of the still image when the electronic cassette 40 performs the photographing of the still image. Press the shooting button (not shown). The photographing button is connected to the console, and when the pressing operation is performed, the console transmits instruction information for instructing photographing of a still image to the electronic cassette 40.
　そこで、次のステップ１０４では、カセッテ制御部５８は、上記静止画像の撮影を指示する指示情報を受信するまで待機し、次のステップ１０６にて、前述した静止画撮影時の動作を実行させる。そして、次のステップ１０８では、カセッテ制御部５８は、ＴＦＴ基板３０Ａに対して前述した電気リセット機能を働かせることによって電気リセット処理を実行した後、次のステップ１１０にて、上記静止画撮影時の動作が終了するまで待機する。上記ステップ１０８の電気リセット処理により、信号処理部５４Ａの各可変ゲインプリアンプ８２のコンデンサ８２Ｂに蓄積された電荷、およびＴＦＴ基板３０Ａの各画素３２におけるコンデンサ９に蓄積された電荷が放電される。 Therefore, in the next step 104, the cassette control unit 58 waits until receiving the instruction information for instructing the photographing of the still image, and in the next step 106, the operation at the time of still image photographing is executed. In the next step 108, the cassette control unit 58 performs the electric reset process by using the electric reset function described above for the TFT substrate 30A, and then in the next step 110, the above-mentioned image is captured. Wait for the operation to finish. By the electric reset process in step 108, the charge accumulated in the capacitor 82B of each variable gain preamplifier 82 of the signal processing unit 54A and the charge accumulated in the capacitor 9 in each pixel 32 of the TFT substrate 30A are discharged.
　なお、この静止画撮影の際にも、放射線発生装置８０からの放射線Ｘの照射と同期をとる必要があるが、この手法としても、前述したような従来既知の種々の手法を適用することができる。ただし、前述したように、静止画撮影時には、動画撮影時の１００倍程度の線量の放射線Ｘが放射線発生装置８０から照射されるため、上記手法として、照射されている放射線Ｘの線量が予め定められた閾値に達したか否かによって静止画撮影用の放射線Ｘの照射が開始されたか否かを判定する手法を適用する場合には、当該閾値として動画撮影時よりも大きな値を適用する必要がある。 In this still image shooting, it is necessary to synchronize with the irradiation of the radiation X from the radiation generation apparatus 80. As this method, various conventionally known methods as described above can be applied. it can. However, as described above, at the time of still image shooting, the dose of radiation X about 100 times that at the time of moving image shooting is emitted from the radiation generation apparatus 80. Therefore, as the above method, the dose of the irradiated radiation X is determined in advance. In the case of applying a method for determining whether or not the irradiation of the radiation X for still image shooting is started based on whether or not the threshold value reached is reached, it is necessary to apply a larger value as the threshold value than during moving image shooting. There is.
　次のステップ１１２では、カセッテ制御部５８は、画像メモリ５６に記憶された静止画像データを読み出し、次のステップ１１４にて、読み出した静止画像データをコンソールに送信する。静止画像データを受信すると、コンソールでは、受信した静止画像データにより示される静止画像を、それまでに表示していた動画像に代えてディスプレイ装置に表示する。 In the next step 112, the cassette control unit 58 reads the still image data stored in the image memory 56, and in the next step 114, transmits the read still image data to the console. When the still image data is received, the console displays the still image indicated by the received still image data on the display device instead of the moving image displayed so far.
　次のステップ１１６では、カセッテ制御部５８は、本撮影処理プログラムを終了するタイミングが到来したか否かを判定し、否定判定となった場合は上記ステップ１０２に戻る一方、肯定判定となった時点で次のステップ１１８に移行し、上記ステップ１００の処理によって開始された動画撮影時の動作を停止させた後、本撮影処理プログラムを終了する。なお、本実施の形態では、カセッテ制御部５８は、上記ステップ１１６の処理において実行する撮影処理プログラムを終了するタイミングが到来したか否かの判定を、撮影終了を指示する指示情報がコンソールから受信されたか否かを判定することにより行っているが、これに限るものでない。 In the next step 116, the cassette control unit 58 determines whether or not the timing for ending the present photographing processing program has arrived. If a negative determination is made, the process returns to the above step 102, while a positive determination is made. Then, the process proceeds to the next step 118, the operation at the time of moving image shooting started by the processing of step 100 is stopped, and then the shooting processing program is ended. In the present embodiment, the cassette control unit 58 receives, from the console, instruction information for instructing the end of shooting, as to whether or not it is time to end the shooting processing program executed in the processing of step 116. This is done by determining whether or not it has been done, but is not limited to this.
　以上の撮影処理プログラムにより、一例として図１１に示すように、ＴＦＴ基板３０Ａに対してリセット処理を実行しても支障が生じない期間であるＴＦＴ基板３０Ｂを用いて静止画撮影を行っている際に、ＴＦＴ基板３０Ａに対してリセット処理を実行している。また、同様に、ＴＦＴ基板３０Ｂに対してリセット処理を実行しても支障が生じない期間であるＴＦＴ基板３０Ａを用いて動画撮影を行っている際に、ＴＦＴ基板３０Ｂに対してリセット処理を実行している。 As shown in FIG. 11 as an example by the above shooting processing program, when still image shooting is performed using the TFT substrate 30B in which no trouble occurs even if reset processing is performed on the TFT substrate 30A. In addition, a reset process is performed on the TFT substrate 30A. Similarly, the reset process is performed on the TFT substrate 30B when the moving image shooting is performed using the TFT substrate 30A in which no trouble occurs even if the reset process is performed on the TFT substrate 30B. is doing.
　このため、本実施の形態に係る電子カセッテ４０では、静止画像および動画像の双方の撮影とも、残像の影響等が抑制された高画質な放射線画像の撮影を的確なタイミングで行うことができる。 For this reason, in the electronic cassette 40 according to the present embodiment, it is possible to capture a high-quality radiographic image in which the influence of afterimages and the like is suppressed in both the still image and the moving image.
　ところで、本実施の形態に係る放射線検出器２０では、シンチレータ８に非柱状部を設けているため、ＴＦＴ基板３０Ａとの密着性を高くすることができる。但し、非柱状部は必須ではなく、非柱状部を設けない形態としてもよい。 Incidentally, in the radiation detector 20 according to the present embodiment, since the non-columnar portion is provided in the scintillator 8, the adhesion with the TFT substrate 30A can be increased. However, the non-columnar part is not essential, and the non-columnar part may not be provided.
　また、本実施の形態に係る放射線検出器２０は、光電変換膜４を有機光電変換材料により構成しており、光電変換膜４で放射線がほとんど吸収されない。このため、本実施の形態に係る放射線検出器２０は、ＩＳＳの構成により放射線ＸがＴＦＴ基板３０Ｂを透過するが、当該ＴＦＴ基板３０Ｂの光電変換膜４による放射線の吸収量が少ないため、放射線Ｘに対する感度の低下を抑えることができる。ＩＳＳでは、放射線ＸがＴＦＴ基板３０Ｂを透過してシンチレータ８に到達するが、このように、ＴＦＴ基板３０Ｂの光電変換膜４を有機光電変換材料により構成した場合、光電変換膜４での放射線Ｘの吸収が殆どなく放射線Ｘの減衰を少なく抑えることができるため、ＩＳＳに適している。 Further, in the radiation detector 20 according to the present embodiment, the photoelectric conversion film 4 is made of an organic photoelectric conversion material, and radiation is hardly absorbed by the photoelectric conversion film 4. For this reason, in the radiation detector 20 according to the present embodiment, the radiation X passes through the TFT substrate 30B due to the ISS configuration, but the radiation X absorbed by the photoelectric conversion film 4 of the TFT substrate 30B is small. It is possible to suppress a decrease in sensitivity to In the ISS, the radiation X passes through the TFT substrate 30B and reaches the scintillator 8. In this way, when the photoelectric conversion film 4 of the TFT substrate 30B is made of an organic photoelectric conversion material, the radiation X in the photoelectric conversion film 4 is obtained. Therefore, it is suitable for ISS.
　また、薄膜トランジスタ１０の活性層１７を構成する非晶質酸化物や光電変換膜４を構成する有機光電変換材料は、いずれも低温での成膜が可能である。このため、基板１を放射線の吸収が少ないプラスチック樹脂、アラミド、バイオナノファイバで形成することができる。このように形成された基板１は放射線の吸収量が少ないため、ＩＳＳにより放射線ＸがＴＦＴ基板３０Ｂを透過する場合でも、放射線Ｘに対する感度の低下を抑えることができる。 Further, both the amorphous oxide constituting the active layer 17 of the thin film transistor 10 and the organic photoelectric conversion material constituting the photoelectric conversion film 4 can be formed at a low temperature. For this reason, the board | substrate 1 can be formed with a plastic resin, aramid, and bio-nanofiber with little radiation absorption. Since the substrate 1 formed in this way has a small amount of radiation absorption, a decrease in sensitivity to the radiation X can be suppressed even when the radiation X passes through the TFT substrate 30B by ISS.
　また、本実施の形態によれば、図６に示すように、放射線検出器２０をＴＦＴ基板３０Ｂが撮影領域４１Ａ側となるように筐体４１内の撮影領域４１Ａ部分に貼り付けているが、基板１を剛性の高いプラスチック樹脂やアラミド、バイオナノファイバで形成した場合、放射線検出器２０自体の剛性が高いため、筐体４１の撮影領域４１Ａ部分を薄く形成することができる。また、基板１を剛性の高いプラスチック樹脂やアラミド、バイオナノファイバで形成した場合、放射線検出器２０自体が可撓性を有するため、撮影領域４１Ａに衝撃が加わった場合でも放射線検出器２０が破損しづらい。 Further, according to the present embodiment, as shown in FIG. 6, the radiation detector 20 is attached to the imaging region 41A portion in the housing 41 so that the TFT substrate 30B is on the imaging region 41A side. When the substrate 1 is formed of a highly rigid plastic resin, aramid, or bionanofiber, the radiation detector 20 itself has a high rigidity, so that the imaging region 41A portion of the housing 41 can be formed thin. In addition, when the substrate 1 is formed of a highly rigid plastic resin, aramid, or bionanofiber, the radiation detector 20 itself has flexibility, so that even when an impact is applied to the imaging region 41A, the radiation detector 20 is damaged. It ’s hard.
　以上詳細に説明したように、本実施の形態では、入射された放射線を放射線画像に変換する静止画撮影用の第１基板（本実施の形態では、ＴＦＴ基板３０Ｂ）を用いて静止画撮影を行っている場合に、第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板（本実施の形態では、ＴＦＴ基板３０Ａ）に対してリセット処理を実行制御しているので、高画質な放射線画像（動画像）の撮影を的確なタイミングで行うことができる。 As described above in detail, in this embodiment, still image shooting is performed using the first substrate for still image shooting (in this embodiment, the TFT substrate 30B) that converts incident radiation into a radiation image. When performing, reset control is executed on the second substrate (TFT substrate 30A in the present embodiment) that is laminated on the first substrate and converts the incident radiation into a radiation image. Therefore, radiographic images (moving images) with high image quality can be taken at appropriate timing.
　また、本実施の形態では、前記第２基板を用いて動画撮影を行っている場合で、かつ静止画撮影の実行指示が受け付けられた場合、前記第１基板を用いて静止画撮影を行い、かつ当該静止画撮影によって得られた静止画像を前記動画撮影によって得られた動画像の当該静止画像の撮影タイミングに対応する画像として適用すると共に、前記静止画撮影を行っているタイミングで前記第２基板に対してリセット処理を実行制御しているので、動画像の撮影中における画像の抜けを防止することができる。 Further, in the present embodiment, when moving image shooting is performed using the second substrate and an execution instruction for still image shooting is received, still image shooting is performed using the first substrate, In addition, the still image obtained by the still image shooting is applied as an image corresponding to the shooting timing of the still image of the moving image obtained by the moving image shooting, and at the timing when the still image shooting is performed. Since execution control of the reset process is performed on the substrate, it is possible to prevent image loss during moving image shooting.
　特に、本実施の形態では、前記リセット処理の実行の如何にかかわらず、前記第２基板を用いて動画撮影を継続制御しているので、動画像の抜けを、より確実に防止することができる。 In particular, in the present embodiment, the moving image shooting is continuously controlled using the second substrate regardless of the execution of the reset process, so that the loss of moving images can be prevented more reliably. .
　また、本実施の形態では、前記第２基板を用いて動画撮影を行っている場合に、前記第１基板に対してリセット処理を実行するように制御しているので、高画質な放射線画像（静止画像）の撮影を的確なタイミングで行うことができる。 Further, in the present embodiment, when moving image shooting is performed using the second substrate, the first substrate is controlled to perform a reset process, so that a high-quality radiation image ( (Still image) can be taken at an appropriate timing.
　また、本実施の形態では、前記リセット処理として、リセット処理の対象とする基板の各画素に蓄積された電荷を放出させることによるリセット処理を適用しているので、効果的に残像等の影響を抑制することができる。 In the present embodiment, as the reset process, a reset process is performed by releasing the charge accumulated in each pixel of the substrate that is the target of the reset process. Can be suppressed.
　さらに、本実施の形態では、前記第２基板が、前記第１基板の放射線が入射される面とは反対側の面に積層されているので、より効果的に放射線画像を得ることができる。 Furthermore, in the present embodiment, since the second substrate is laminated on the surface of the first substrate opposite to the surface on which the radiation is incident, a radiation image can be obtained more effectively.
　［第２の実施の形態］
　上記第１の実施の形態では、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂに対するリセット処理として電気リセット処理を適用した場合の形態例について説明したが、本第２の実施の形態では、上記リセット処理として、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの各画素に対するバイアス電圧の供給状態を制御することによるリセット処理（以下、「バイアスリセット処理」という。）を適用した場合の形態例について説明する。 [Second Embodiment]
In the first embodiment, an example in which an electrical reset process is applied as a reset process for the TFT substrate 30A and the TFT substrate 30B has been described. However, in the second embodiment, a TFT is used as the reset process. An example in which a reset process (hereinafter referred to as “bias reset process”) by controlling a supply state of a bias voltage to each pixel of the substrate 30A and the TFT substrate 30B is applied will be described.
　本第２の実施の形態に係る電子カセッテ４０では、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの各画素に対するバイアス電圧の供給状態を制御することによりバイアスリセット処理を実行するバイアスリセット機能が搭載されている。 The electronic cassette 40 according to the second embodiment is equipped with a bias reset function for performing a bias reset process by controlling the supply state of the bias voltage to each pixel of the TFT substrate 30A and the TFT substrate 30B.
　すなわち、光電変換膜４がＭＩＳ構造のフォトダイオードである場合、バイアス電源７２を制御して当該フォトダイオードに対するバイアスリセット処理を実行させることができる。この場合、バイアス電源７２から光電変換膜４に供給されるバイアス電圧の極性を反転するか、または光電変換膜４へのバイアス電圧の供給を停止することにより、光電変換膜４に蓄積された電荷を消滅させるか、または放出させる。 That is, when the photoelectric conversion film 4 is a photodiode having a MIS structure, the bias power source 72 can be controlled to perform a bias reset process on the photodiode. In this case, the charge accumulated in the photoelectric conversion film 4 is reversed by inverting the polarity of the bias voltage supplied from the bias power source 72 to the photoelectric conversion film 4 or stopping the supply of the bias voltage to the photoelectric conversion film 4. Extinguish or release.
　従って、このバイアスリセット処理の終了後、次のフレームの動画像を取得するために、バイアス電源７２から光電変換膜４に供給されるバイアス電圧の極性を元に戻すか、または当該バイアス電圧の供給を再開する処理が必要となるため、光電変換膜４が安定した動作状態に復帰するまで多少の時間はかかるが、残像の発生等を効果的に抑制することができる。 Accordingly, after the bias reset process is completed, the polarity of the bias voltage supplied from the bias power source 72 to the photoelectric conversion film 4 is restored or the supply of the bias voltage is performed in order to acquire a moving image of the next frame. Therefore, it takes some time for the photoelectric conversion film 4 to return to a stable operating state, but it is possible to effectively suppress the occurrence of afterimages.
　本第２の実施の形態では、バイアスリセット処理として、バイアス電源７２から光電変換膜４に供給されるバイアス電圧の極性を反転した後に、当該バイアス電圧の極性を元に戻す処理を実行する処理を適用している。なお、本第２の実施の形態に係る電子カセッテ４０の構成は、上記第１の実施の形態に係る電子カセッテ４０と略同一であるため、ここでの説明は省略する。 In the second embodiment, as the bias reset process, a process of executing a process of returning the polarity of the bias voltage after inverting the polarity of the bias voltage supplied from the bias power supply 72 to the photoelectric conversion film 4 is performed. Applicable. The configuration of the electronic cassette 40 according to the second embodiment is substantially the same as that of the electronic cassette 40 according to the first embodiment, and a description thereof is omitted here.
　次に、図１２を参照して、本第２の実施の形態に係る電子カセッテ４０の作用について詳細に説明する。なお、図１２は、動画像（透視画像）の撮影開始を指示する指示情報がコンソールから受信された際に電子カセッテ４０のカセッテ制御部５８におけるＣＰＵ５８Ａにより実行される撮影処理プログラムの処理の流れを示すフローチャートであり、当該プログラムはメモリ５８ＢのＲＯＭに予め記憶されている。また、同図における図１０と同一の処理を実行するステップについては図１０と同一のステップ番号を付して、その説明を省略する。 Next, the operation of the electronic cassette 40 according to the second exemplary embodiment will be described in detail with reference to FIG. Note that FIG. 12 shows the flow of processing of the imaging processing program executed by the CPU 58A in the cassette control unit 58 of the electronic cassette 40 when instruction information for instructing the start of imaging of a moving image (perspective image) is received from the console. This program is stored in advance in the ROM of the memory 58B. Also, steps in FIG. 10 for executing the same processing as in FIG. 10 are assigned the same step numbers as in FIG.
　同図のステップ１０２’では、カセッテ制御部５８は、ＴＦＴ基板３０Ｂに対して上記バイアスリセット機能を働かせることによってバイアスリセット処理を実行する。これにより、ＴＦＴ基板３０Ｂの光電変換膜４に蓄積された電荷が消滅される。 In step 102 'in FIG. 5, the cassette control unit 58 executes a bias reset process by using the bias reset function for the TFT substrate 30B. Thereby, the electric charge accumulated in the photoelectric conversion film 4 of the TFT substrate 30B is extinguished.
　その後、ステップ１０８’では、カセッテ制御部５８は、ＴＦＴ基板３０Ａに対して上記バイアスリセット機能を働かせることによってバイアスリセット処理を実行する。これにより、ＴＦＴ基板３０Ａの光電変換膜４に蓄積された電荷が消滅される。 Thereafter, in step 108 ′, the cassette controller 58 executes a bias reset process by using the bias reset function for the TFT substrate 30 </ b> A. Thereby, the electric charge accumulated in the photoelectric conversion film 4 of the TFT substrate 30A is extinguished.
　本第２の実施の形態においても、上記第１の実施の形態と同様の効果を奏することができる。 Also in the second embodiment, the same effects as those of the first embodiment can be obtained.
　［第３の実施の形態］
　上記第１の実施の形態では、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂに対するリセット処理として電気リセット処理を適用し、上記第２の実施の形態では、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂに対するリセット処理としてバイアスリセット処理を適用した場合の形態例について説明したが、本第３の実施の形態では、上記リセット処理として、上記バイアスリセット処理に加えて、ＴＦＴ基板３０Ａの各画素に対して光を照射することによるリセット処理（以下、「光リセット処理」という。）を適用した場合の形態例について説明する。 [Third Embodiment]
In the first embodiment, an electrical reset process is applied as a reset process for the TFT substrate 30A and the TFT substrate 30B. In the second embodiment, a bias reset process is performed as a reset process for the TFT substrate 30A and the TFT substrate 30B. In the third embodiment, as the reset process, in addition to the bias reset process, reset is performed by irradiating each pixel of the TFT substrate 30A with light. An example of a case where processing (hereinafter referred to as “optical reset processing”) is applied will be described.
　図１３には、本第３の実施の形態に係る電子カセッテ４０における放射線検出器２０’の構成が示されている。なお、同図における、上記第１の実施の形態に係る放射線検出器２０と同様の構成部位には当該放射線検出器２０と同一の符号を付して、その説明を極力省略する。 FIG. 13 shows the configuration of the radiation detector 20 'in the electronic cassette 40 according to the third embodiment. In addition, the same code | symbol as the said radiation detector 20 is attached | subjected to the component similar to the radiation detector 20 which concerns on the said 1st Embodiment in the same figure, and the description is abbreviate | omitted as much as possible.
　同図に示すように、本実施の形態に係る放射線検出器２０’は、シンチレータ８とＴＦＴ基板３０Ｂとの間にアモルファスセレン（ａ－Ｓｅ）からなる放射線変換層８’が積層されると共に、ＴＦＴ基板３０Ａのシンチレータ８が設けられている面とは反対側の面にリセット光源５０が設けられている点が、上記第１の実施の形態に係る放射線検出器２０と異なっている。 As shown in the figure, in the radiation detector 20 ′ according to the present embodiment, a radiation conversion layer 8 ′ made of amorphous selenium (a-Se) is laminated between the scintillator 8 and the TFT substrate 30B. The point which the reset light source 50 is provided in the surface on the opposite side to the surface in which the scintillator 8 of TFT substrate 30A is provided differs from the radiation detector 20 which concerns on the said 1st Embodiment.
　本実施の形態に係る放射線検出器２０’では、ＴＦＴ基板３０Ａ側については放射線をシンチレータ８によって光に変換した後に、光電変換膜４によって当該光を電荷に変換する間接変換方式を採用する一方、ＴＦＴ基板３０Ｂ側については、アモルファスセレンからなる放射線変換層８’により放射線を電荷に直接変換して当該電荷をＴＦＴ基板３０Ｂにより読み出す直接変換方式を採用している。 In the radiation detector 20 ′ according to the present embodiment, the TFT substrate 30A side employs an indirect conversion method in which radiation is converted into light by the scintillator 8, and then the light is converted into electric charge by the photoelectric conversion film 4. On the TFT substrate 30B side, a direct conversion method is adopted in which radiation is directly converted into charges by the radiation conversion layer 8 ′ made of amorphous selenium and the charges are read out by the TFT substrate 30B.
　ところで、本実施の形態に係る電子カセッテ４０では、ＴＦＴ基板３０Ａの各画素に対して光を照射することによりＴＦＴ基板３０Ａに対して光リセット処理を実行する光リセット機能が搭載されている。 By the way, the electronic cassette 40 according to the present embodiment is equipped with an optical reset function for executing an optical reset process on the TFT substrate 30A by irradiating each pixel of the TFT substrate 30A with light.
　リセット光源５０は、この光リセット機能のために設けられたものであり、本実施の形態に係るリセット光源５０は、エッジライト方式のバックライト光源であり、ＴＦＴ基板３０Ａの底面に導光板５０Ｂを配置し、放射線Ｘの非照射領域である導光板５０Ｂの側部に冷陰極管５０Ａを配置している。導光板５０ＢとＴＦＴ基板３０Ａとの間には拡散シート５０Ｃが介挿されている。リセット光源５０における拡散シート５０Ｃの箇所以外の外表面には、導光板５０Ｂおよび冷陰極管５０Ａを取り囲むように反射シート５０Ｄも配置されている。 The reset light source 50 is provided for this optical reset function, and the reset light source 50 according to the present embodiment is an edge light type backlight light source, and a light guide plate 50B is provided on the bottom surface of the TFT substrate 30A. The cold cathode fluorescent lamp 50A is arranged on the side of the light guide plate 50B, which is a non-irradiated region of the radiation X. A diffusion sheet 50C is interposed between the light guide plate 50B and the TFT substrate 30A. On the outer surface of the reset light source 50 other than the location of the diffusion sheet 50C, a reflection sheet 50D is also disposed so as to surround the light guide plate 50B and the cold cathode tube 50A.
　ここで、カセッテ制御部５８の制御により冷陰極管５０Ａが駆動して、当該冷陰極管５０Ａから導光板５０Ｂに光が入射すると、導光板５０Ｂに入射した光は、当該導光板５０Ｂ内部で拡散シート５０Ｃおよび反射シート５０Ｄとの間で表面反射を繰り返した後、拡散シート５０ＣからＴＦＴ基板３０Ａにリセット光５０Ｅとして出射される。 Here, when the cold cathode tube 50A is driven by the control of the cassette control unit 58 and light enters the light guide plate 50B from the cold cathode tube 50A, the light incident on the light guide plate 50B diffuses inside the light guide plate 50B. After surface reflection is repeated between the sheet 50C and the reflection sheet 50D, the light is emitted as reset light 50E from the diffusion sheet 50C to the TFT substrate 30A.
　図１３では、１本のリセット光５０Ｅのみ図示されているが、実際に冷陰極管５０Ａから導光板５０Ｂに入射した光は、表面反射を繰り返して導光板５０Ｂ全体に広がり、拡散シート５０Ｃから面発光のリセット光５０Ｅとして出射される。従って、バックライト方式のリセット光源５０は、面発光光源として機能し、ＴＦＴ基板３０Ａに対して均一にリセット光５０Ｅを照射することになる。これにより、ＴＦＴ基板３０Ａに含まれる各画素３２の光電変換膜４に対して、残像の発生等を抑制するためのリセット処理（光リセット処理）を行うことができる。 In FIG. 13, only one reset light 50E is shown, but the light that actually enters the light guide plate 50B from the cold cathode fluorescent lamp 50A repeats the surface reflection and spreads over the entire light guide plate 50B, and the surface from the diffusion sheet 50C. The emitted light is emitted as reset light 50E. Therefore, the backlight type reset light source 50 functions as a surface emitting light source, and uniformly irradiates the reset light 50E to the TFT substrate 30A. Thereby, the reset process (light reset process) for suppressing generation | occurrence | production of an afterimage etc. can be performed with respect to the photoelectric conversion film 4 of each pixel 32 included in the TFT substrate 30A.
　前述したように、例えば、ａ－Ｓｉ等からなる光電変換膜４の場合、光（可視光）から変換された電荷（電子）の一部がａ－Ｓｉの不純物準位（欠陥）に一旦捕捉され、その後、動画撮影のような長時間の撮影による光電変換膜４の温度上昇等に起因して電荷が再放出されると、暗電流等の不要な電流が発生し、放射線画像（動画像）に対するノイズ（残像）の原因となる場合がある。 As described above, for example, in the case of the photoelectric conversion film 4 made of a-Si or the like, a part of charges (electrons) converted from light (visible light) is once trapped in the impurity level (defect) of a-Si. After that, when charge is re-released due to a temperature rise of the photoelectric conversion film 4 due to long-time shooting such as moving image shooting, an unnecessary current such as dark current is generated, and a radiographic image (moving image) ) May cause noise (afterimage).
　そこで、光リセット処理を行って、光電変換膜４にリセット光５０Ｅを照射することにより、不純物準位に電荷を予め埋めておいて、その後、放射線Ｘの照射時に可視光から変換された電荷が不純物準位に捕捉されないようにすれば、残像の発生等を効果的に抑制することができる。 Therefore, by performing a light reset process and irradiating the photoelectric conversion film 4 with the reset light 50E, charges are pre-filled in the impurity level, and then the charges converted from the visible light upon irradiation with the radiation X are changed. If it is prevented from being trapped by the impurity level, the occurrence of afterimages can be effectively suppressed.
　なお、図１３では、一例として、エッジライト方式のバックライト光源で構成されるリセット光源５０を図示したが、これに限るものではなく、行列状に配置された画素３２の光電変換膜４に対して、確実にリセット光５０Ｅを照射して、光リセット処理を実行できるものであればよい。従って、ＴＦＴ基板３０Ａの底面に、発光素子のアレイ、またはエレクトロ・ルミネッセンス光源を配置することで、リセット光源５０を構成してもよい。 In FIG. 13, as an example, the reset light source 50 including an edge light type backlight light source is illustrated, but the present invention is not limited to this, and the photoelectric conversion film 4 of the pixels 32 arranged in a matrix is illustrated. Any light reset process can be performed as long as the reset light 50E can be reliably irradiated. Therefore, the reset light source 50 may be configured by arranging an array of light emitting elements or an electroluminescence light source on the bottom surface of the TFT substrate 30A.
　次に、図１４を参照して、本実施の形態に係る電子カセッテ４０の作用について詳細に説明する。なお、図１４は、動画像（透視画像）の撮影開始を指示する指示情報がコンソールから受信された際に電子カセッテ４０のカセッテ制御部５８におけるＣＰＵ５８Ａにより実行される撮影処理プログラムの処理の流れを示すフローチャートであり、当該プログラムはメモリ５８ＢのＲＯＭに予め記憶されている。また、ここでは、錯綜を回避するために、放射線発生装置８０からの放射線Ｘの照射に関する制御の説明は極力省略する。 Next, the operation of the electronic cassette 40 according to the present exemplary embodiment will be described in detail with reference to FIG. FIG. 14 shows the flow of processing of the photographing processing program executed by the CPU 58A in the cassette control unit 58 of the electronic cassette 40 when instruction information for instructing the start of moving image (perspective image) photographing is received from the console. This program is stored in advance in the ROM of the memory 58B. In addition, here, in order to avoid complications, description of control related to irradiation of the radiation X from the radiation generation apparatus 80 is omitted as much as possible.
　同図のステップ２００では、カセッテ制御部５８は、上記第１の実施の形態に係る撮影処理プログラムのステップ１００の処理と同様に、動画撮影時の動作を開始させる。これにより、上記フレームレートに応じた速度での動画像データのコンソールへの送信が開始され、コンソールのディスプレイ装置には動画像（透視画像）の表示が開始される。 In step 200 of the figure, the cassette control unit 58 starts an operation at the time of moving image shooting, similarly to the processing of step 100 of the shooting processing program according to the first embodiment. As a result, transmission of moving image data to the console at a speed corresponding to the frame rate is started, and display of a moving image (perspective image) is started on the console display device.
　次のステップ２０２では、カセッテ制御部５８は、ＴＦＴ基板３０Ｂに対して、上記第２の実施の形態と同様のバイアスリセット機能を働かせることによってバイアスリセット処理を実行する。これにより、ＴＦＴ基板３０Ｂの光電変換膜４に蓄積された電荷が消滅される。 In the next step 202, the cassette control unit 58 executes a bias reset process by applying a bias reset function similar to that of the second embodiment to the TFT substrate 30B. Thereby, the electric charge accumulated in the photoelectric conversion film 4 of the TFT substrate 30B is extinguished.
　一方、撮影者は、コンソールのディスプレイ装置に表示されている透視画像を参照し、電子カセッテ４０によって静止画像の撮影を実行する際には、当該静止画像の撮影を指示する際に押圧操作される撮影ボタン（図示省略。）を押圧操作する。この撮影ボタンはコンソールに接続されており、当該押圧操作が行われると、コンソールは、静止画像の撮影を指示する指示情報を電子カセッテ４０に送信する。 On the other hand, the photographer refers to a fluoroscopic image displayed on the display device of the console, and performs a pressing operation when instructing the photographing of the still image when the electronic cassette 40 performs the photographing of the still image. Press the shooting button (not shown). The photographing button is connected to the console, and when the pressing operation is performed, the console transmits instruction information for instructing photographing of a still image to the electronic cassette 40.
　そこで、次のステップ２０４では、カセッテ制御部５８は、上記静止画像の撮影を指示する指示情報を受信するまで待機し、次のステップ２０６にて、上記第１の実施の形態に係る撮影処理プログラムのステップ１０６の処理と同様に、静止画撮影時の動作を実行させる。そして、次のステップ２０８では、カセッテ制御部５８は、ＴＦＴ基板３０Ａに対して前述した光リセット機能を働かせることによって光リセット処理を実行した後、次のステップ２１０にて、上記静止画撮影時の動作が終了するまで待機する。上記ステップ２０８の光リセット処理により、ＴＦＴ基板３０Ａに含まれる各画素３２の光電変換膜４に対して、残像の発生等を抑制するための光リセット処理が実行される。 Therefore, in the next step 204, the cassette control unit 58 waits until receiving the instruction information for instructing the photographing of the still image, and in the next step 206, the photographing processing program according to the first embodiment. Similar to the processing in step 106, the operation at the time of still image shooting is executed. In the next step 208, the cassette control unit 58 executes the light reset process by using the above-described light reset function for the TFT substrate 30A, and then in the next step 210, the above-described still image shooting time. Wait for the operation to finish. By the light reset process in step 208 described above, a light reset process for suppressing the occurrence of an afterimage or the like is performed on the photoelectric conversion film 4 of each pixel 32 included in the TFT substrate 30A.
　次のステップ２１２では、カセッテ制御部５８は、放射線発生装置８０からの放射線Ｘの照射の停止を指示する指示情報をコンソールに対して送信する。コンソールは、当該指示情報を受信すると、放射線発生装置８０に対して、放射線Ｘの照射の停止を指示する。これに応じて、放射線発生装置８０は、放射線Ｘの照射を停止する。 In the next step 212, the cassette control unit 58 transmits instruction information for instructing to stop irradiation of the radiation X from the radiation generator 80 to the console. When the console receives the instruction information, the console instructs the radiation generator 80 to stop the radiation X irradiation. In response to this, the radiation generator 80 stops the irradiation of the radiation X.
　次のステップ２１４では、カセッテ制御部５８は、画像メモリ５６に記憶された静止画像データを読み出し、次のステップ２１６にて、読み出した静止画像データをコンソールに無線通信部６０を介して送信する。静止画像データを受信すると、コンソールでは、受信した静止画像データにより示される静止画像を、それまでに表示していた動画像に代えてディスプレイ装置に表示する。 In the next step 214, the cassette control unit 58 reads the still image data stored in the image memory 56, and in the next step 216, transmits the read still image data to the console via the wireless communication unit 60. When the still image data is received, the console displays the still image indicated by the received still image data on the display device instead of the moving image displayed so far.
　次のステップ２１８では、カセッテ制御部５８は、本撮影処理プログラムを終了するタイミングが到来したか否かを判定し、否定判定となった場合はステップ２２０に移行する。なお、本実施の形態でも、上記ステップ２１８の処理において実行する撮影処理プログラムを終了するタイミングが到来したか否かの判定を、撮影終了を指示する指示情報がコンソールから受信されたか否かを判定することにより行っているが、これに限るものでないことは言うまでもない。 In the next step 218, the cassette control unit 58 determines whether or not the timing for ending the present photographing processing program has come. If the determination is negative, the process proceeds to step 220. In the present embodiment as well, it is determined whether or not the timing for ending the shooting processing program executed in the processing of step 218 has been reached, and whether or not instruction information for instructing the end of shooting has been received from the console. Needless to say, this is not limited to this.
　ここで、撮影者は、コンソールのディスプレイ装置に表示されている静止画像を参照しつつ、動画像の表示を再開させる際に、当該再開を指示する指示情報をコンソールに入力する。これに応じて、コンソールは、電子カセッテ４０に対して、動画像の撮影の再開を指示する指示情報を送信する。 Here, when the photographer resumes the display of the moving image while referring to the still image displayed on the display device of the console, the photographer inputs instruction information instructing the resume to the console. In response to this, the console transmits to the electronic cassette 40 instruction information for instructing resumption of moving image shooting.
　そこで、ステップ２２０では、カセッテ制御部５８は、当該指示情報を受信するまで待機し、次のステップ２２２にて、上記ステップ２１２の処理によって停止した放射線Ｘのパルス照射を再開することを指示する指示情報をコンソールに送信した後、上記ステップ２０２に戻る。コンソールは、当該指示情報を受信すると、放射線発生装置８０に対して、パルス照射の再開を指示する指示情報を放射線発生装置８０に送信する。これによって、放射線発生装置８０では、放射線Ｘのパルス照射を再開する。 Therefore, in step 220, the cassette control unit 58 waits until receiving the instruction information, and in the next step 222, an instruction for instructing to resume the pulse irradiation of the radiation X stopped by the processing in step 212. After the information is transmitted to the console, the process returns to step 202. When the console receives the instruction information, the console transmits to the radiation generation apparatus 80 instruction information that instructs the radiation generation apparatus 80 to resume pulse irradiation. As a result, the radiation generator 80 resumes the radiation X pulse irradiation.
　一方、カセッテ制御部５８は、上記ステップ２１８において肯定判定となった場合はステップ２２４に移行し、上記ステップ２００の処理によって開始された動画撮影時の動作を停止させた後、本撮影処理プログラムを終了する。 On the other hand, if the determination in step 218 is affirmative, the cassette control unit 58 proceeds to step 224, stops the operation at the time of moving image shooting started by the processing of step 200, and then executes the main shooting processing program. finish.
　以上の撮影処理プログラムによっても、一例として図１１に示すように、ＴＦＴ基板３０Ａに対してリセット処理を実行しても支障が生じない期間であるＴＦＴ基板３０Ｂを用いて静止画撮影を行っている際に、ＴＦＴ基板３０Ａに対してリセット処理を実行している。また、同様に、ＴＦＴ基板３０Ｂに対してリセット処理を実行しても支障が生じない期間であるＴＦＴ基板３０Ａを用いて動画撮影を行っている際に、ＴＦＴ基板３０Ｂに対してリセット処理を実行している。 Also by the above photographing processing program, as shown in FIG. 11 as an example, still image photographing is performed using the TFT substrate 30B in which no trouble occurs even if reset processing is performed on the TFT substrate 30A. At this time, a reset process is executed on the TFT substrate 30A. Similarly, the reset process is performed on the TFT substrate 30B when the moving image shooting is performed using the TFT substrate 30A in which no trouble occurs even if the reset process is performed on the TFT substrate 30B. is doing.
　このため、本実施の形態に係る電子カセッテ４０でも、静止画像および動画像の双方の撮影とも、残像の影響等が抑制された高画質な放射線画像の撮影を的確なタイミングで行うことができる。 For this reason, even with the electronic cassette 40 according to the present embodiment, it is possible to capture a high-quality radiographic image in which the influence of afterimages is suppressed in both the still image and the moving image.
　また、本実施の形態では、静止画像の表示が行われている場合に放射線の照射を停止するように制御しているので、被撮影体（患者）に対する放射線の照射量を抑制することができる。 Further, in the present embodiment, since the irradiation is controlled to be stopped when the still image is displayed, the radiation dose to the subject (patient) can be suppressed. .
　以上、本発明を各実施の形態を用いて説明したが、本発明の技術的範囲は上記各実施の形態に記載の範囲には限定されない。発明の要旨を逸脱しない範囲で上記実施の形態に多様な変更または改良を加えることができ、当該変更または改良を加えた形態も本発明の技術的範囲に含まれる。 As mentioned above, although this invention was demonstrated using each embodiment, the technical scope of this invention is not limited to the range as described in each said embodiment. Various modifications or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which such modifications or improvements are added are also included in the technical scope of the present invention.
　また、上記の各実施の形態は、クレーム（請求項）にかかる発明を限定するものではなく、また各実施の形態の中で説明されている特徴の組み合わせの全てが発明の解決手段に必須であるとは限らない。前述した各実施の形態には種々の段階の発明が含まれており、開示される複数の構成要件における適宜の組み合わせにより種々の発明を抽出できる。実施の形態に示される全構成要件から幾つかの構成要件が削除されても、効果が得られる限りにおいて、この幾つかの構成要件が削除された構成が発明として抽出され得る。 In addition, each of the above embodiments does not limit the invention according to the claims (claims), and all combinations of features described in each embodiment are indispensable for solving means of the invention. Not always. Each embodiment described above includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.
　たとえば、上記各実施の形態では、本発明を可搬型の放射線画像撮影装置である電子カセッテ４０に適用した場合について説明したが、本発明はこれに限定されるものではなく、据置型の放射線画像撮影装置に適用してもよい。 For example, in each of the above embodiments, the case where the present invention is applied to the electronic cassette 40 which is a portable radiographic image capturing apparatus has been described. However, the present invention is not limited to this, and a stationary radiographic image is provided. You may apply to an imaging device.
　また、上記各実施の形態では、放射線検出器として、図１に示したように、ＴＦＴ基板３０Ａ、シンチレータ８、ＴＦＴ基板３０Ｂを、この順で積層したもの、および図１３に示したように、ＴＦＴ基板３０Ａ、シンチレータ８、放射線変換層８’、ＴＦＴ基板３０Ｂを、この順で積層したものを適用した場合について説明したが、本発明はこれに限定されるものではなく、例えば、図１５に示した構成のものを放射線検出器として適用する形態としてもよい。 In each of the above embodiments, as a radiation detector, as shown in FIG. 1, the TFT substrate 30A, the scintillator 8, and the TFT substrate 30B are laminated in this order, and as shown in FIG. Although the case where the TFT substrate 30A, the scintillator 8, the radiation conversion layer 8 ′, and the TFT substrate 30B are stacked in this order has been described, the present invention is not limited to this. For example, FIG. It is good also as a form which applies the thing of the structure shown as a radiation detector.
　図１５（Ａ）に示す放射線検出器は、上記第１の実施の形態に係る放射線検出器２０におけるシンチレータ８に代えてアモルファスセレンにより構成された放射線変換層８’を適用した場合の形態例が示されている。また、図１５（Ｂ）～図１５（Ｄ）には、放射線感応層として２つのシンチレータ８Ａおよびシンチレータ８Ｂが備えられている場合の形態例が示されている。また、図１５（Ｅ）～図１５（Ｇ）には、放射線感応層として２つのアモルファスセレンにより構成された放射線変換層８Ａ’および放射線変換層８Ｂ’が備えられている場合の形態例が示されている。さらに、図１５（Ｈ）～図１５（Ｊ）には、放射線感応層として１つのシンチレータ８Ｂと１つのアモルファスセレンにより構成された放射線変換層８Ａ’が備えられている場合の形態例が示されている。なお、直接変換型の放射線感応層の他の例として、アモルファスセレンに代えて、Si(シリコン)、CdTe(テルル化カドミュウム)等により構成してもよい。 The radiation detector shown in FIG. 15 (A) is an example in which a radiation conversion layer 8 ′ made of amorphous selenium is applied instead of the scintillator 8 in the radiation detector 20 according to the first embodiment. It is shown. 15 (B) to 15 (D) show examples in which two scintillators 8A and 8B are provided as radiation sensitive layers. 15 (E) to 15 (G) show an example in the case where the radiation conversion layer 8A ′ and the radiation conversion layer 8B ′ made of two amorphous selenium are provided as the radiation sensitive layer. Has been. Further, FIGS. 15 (H) to 15 (J) show an example in which a radiation converting layer 8A ′ composed of one scintillator 8B and one amorphous selenium is provided as a radiation sensitive layer. ing. As another example of the direct conversion type radiation sensitive layer, Si (silicon), CdTe (cadmium telluride), or the like may be used instead of amorphous selenium.
　これらの形態においても、上記各実施の形態と同様の効果を奏することができる。 In these embodiments, the same effects as those in the above embodiments can be obtained.
　また、上記各実施の形態では、静止画撮影を行っている場合に動画撮影用のＴＦＴ基板のリセット処理を実行し、動画撮影を行っている場合に静止画撮影用のＴＦＴ基板のリセット処理を実行する場合について説明したが、本発明はこれに限定されるものではなく、静止画撮影によって得られた静止画像がコンソールのディスプレイ装置等の表示装置によって表示している場合に動画撮影用のＴＦＴ基板のリセット処理を実行する形態としてもよく、動画撮影によって得られた動画像がコンソールのディスプレイ装置等の表示装置によって表示している場合に静止画撮影用のＴＦＴ基板のリセット処理を実行する形態としてもよい。これらの場合も、上記各実施の形態と同様の効果を奏することができる。 In each of the above embodiments, the reset processing of the TFT substrate for moving image shooting is performed when still image shooting is performed, and the reset processing of the TFT substrate for still image shooting is performed when moving image shooting is performed. Although the present invention has been described, the present invention is not limited to this, and a moving image shooting TFT when a still image obtained by still image shooting is displayed on a display device such as a console display device. A form in which the reset process of the substrate may be executed, and a form in which the reset process of the TFT substrate for still image shooting is executed when a moving image obtained by moving image shooting is displayed on a display device such as a console display device. It is good. In these cases, the same effects as those of the above embodiments can be obtained.
　また、上記各実施の形態では、電気リセット処理、光リセット処理、およびバイアスリセット処理を各々単独で実行する場合について説明したが、本発明はこれに限定されるものではなく、これらのリセット処理の２つ以上の組み合わせを実行する形態としてもよい。 Further, in each of the above-described embodiments, the case where the electric reset process, the optical reset process, and the bias reset process are executed individually has been described, but the present invention is not limited to this, and the reset process is not limited thereto. Two or more combinations may be executed.
　また、上記第１、第２の実施の形態では、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの双方に対して電気リセット処理またはバイアスリセット処理を実行し、上記第３の実施の形態では、ＴＦＴ基板３０Ｂに対してバイアスリセット処理を実行する一方、ＴＦＴ基板３０Ａに対して光リセット処理を実行する場合について説明したが、本発明はこれに限定されるものではなく、光リセット処理については間接変換型のＴＦＴ基板であれば適用することができ、電気リセット処理およびバイアスリセット処理については、間接変換型のＴＦＴ基板でも直接変換型のＴＦＴ基板でも適用することができる。 In the first and second embodiments, an electrical reset process or a bias reset process is performed on both the TFT substrate 30A and the TFT substrate 30B. In the third embodiment, the TFT substrate 30B is applied to the TFT substrate 30B. Although the case where the optical reset process is performed on the TFT substrate 30A while the bias reset process is performed on the TFT substrate 30A has been described, the present invention is not limited to this, and the optical reset process is not limited to the indirect conversion type TFT. Any substrate can be applied, and the electrical reset process and the bias reset process can be applied to either an indirect conversion type TFT substrate or a direct conversion type TFT substrate.
　また、上記第３の実施の形態では、直接変換方式の放射線感応層としてＣｓＩを含んで構成されたものを適用した場合について説明したが、本発明はこれに限定されるものではなく、ＣｓＢｒ等の他の柱状結晶を含むものを適用する形態としてもよい。 In the third embodiment, the case where a direct conversion radiation sensitive layer including CsI is applied has been described. However, the present invention is not limited to this, and CsBr or the like is not limited thereto. It is good also as a form which applies what contains other columnar crystals.
　また、上記各実施の形態では、電子カセッテ４０の筐体４１の内部にカセッテ制御部５８や電源部７０等を放射線検出器とは重ならないように配置した場合について説明したが、これに限定されるものではない。例えば、放射線検出器とカセッテ制御部５８や電源部７０を重なるように配置してもよい。 In each of the above embodiments, the case has been described in which the cassette control unit 58, the power supply unit 70, and the like are arranged inside the housing 41 of the electronic cassette 40 so as not to overlap the radiation detector. However, the present invention is not limited to this. It is not something. For example, you may arrange | position so that a radiation detector and the cassette control part 58 and the power supply part 70 may overlap.
　また、上記各実施の形態では特に言及しなかったが、ＴＦＴ基板３０ＡおよびＴＦＴ基板３０Ｂの少なくとも一方がフレキシブル基板であることが好ましい。これにより、シンチレータ８の柱状結晶の先端部の位置が揃っていない場合でも、シンチレータ８と、当該シンチレータ８に積層されるＴＦＴ基板との密着性を向上させることができる。なお、この場合、適用するフレキシブル基板として、近年開発されたフロート法による超薄板ガラスを基材として用いたものを適用することが、放射線の透過率を向上させるうえで好ましい。なお、この際に適用できる超薄板ガラスについては、例えば、「旭硝子株式会社、“フロート法による世界最薄０．１ミリ厚の超薄板ガラスの開発に成功”、[online]、[平成２３年８月２０日検索]、インターネット＜ＵＲＬ：http://www.agc.com/news/2011/0516.pdf＞」に開示されている。 Although not particularly mentioned in the above embodiments, it is preferable that at least one of the TFT substrate 30A and the TFT substrate 30B is a flexible substrate. Thereby, even when the positions of the end portions of the columnar crystals of the scintillator 8 are not aligned, the adhesion between the scintillator 8 and the TFT substrate stacked on the scintillator 8 can be improved. In this case, as a flexible substrate to be applied, it is preferable to use a substrate using ultra-thin glass by a recently developed float method as a base material in order to improve the radiation transmittance. As for the ultra-thin glass that can be applied at this time, for example, “Asahi Glass Co., Ltd.,“ Successfully developed the world's thinnest 0.1 mm thick ultra-thin glass by the float method ”, [online], [2011 Aug. 20 search], Internet <URL: http://www.agc.com/news/2011/0516.pdf> ”.
　また、放射線検出器２０のセンサ部１３として、光電変換膜４を、有機光電変換材料を含む材料で構成した有機ＣＭＯＳセンサを用いてもよく、放射線検出器２０のＴＦＴ基板３０Ａ、３０Ｂとして、薄膜トランジスタ１０としての有機材料を含む有機トランジスタを、可撓性を有するシート上にアレイ状に配列した有機ＴＦＴアレイ・シートを用いてもよい。上記の有機ＣＭＯＳセンサは、例えば、特開２００９－２１２３７７号公報に開示されている。また、上記の有機ＴＦＴアレイ・シートは、例えば「日本経済新聞、“東京大学、「ウルトラフレキシブル」な有機トランジスタを開発”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://www.nikkei.com/tech/trend/article/g=96958A9C93819499E2EAE2E0E48DE2EAE3E3E0E2E3E2E2E2E2E2E2E2;p=9694E0E7E2E6E0E2E3E2E2E0E2E0＞」に開示されている。 Moreover, you may use the organic CMOS sensor which comprised the photoelectric converting film 4 with the material containing an organic photoelectric conversion material as the sensor part 13 of the radiation detector 20, and it is a thin-film transistor as TFT board | substrate 30A, 30B of the radiation detector 20. An organic TFT array sheet in which organic transistors including the organic material 10 are arranged in an array on a flexible sheet may be used. The above organic CMOS sensor is disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-212377. In addition, the organic TFT array sheet described above is, for example, “Nihon Keizai Shimbun,“ The University of Tokyo, “Developing“ Ultra Flexible ”Organic Transistor” ”, [online], [Search May 8, 2011], Internet <URL : Http://www.nikkei.com/tech/trend/article/g=96958A9C93819499E2EAE2E0E48DE2EAE3E3E0E2E3E2E2E2E2E2E2E2; p = 9694E0E7E2E6E0E2E3E2E2E0E2E0> ”
　各放射線検出器のセンサ部１３としてＣＭＯＳセンサを用いる場合、高速に光電変換を行うことができる利点や、基板を薄くすることができる結果、ＩＳＳ方式を採用した場合に放射線の吸収を抑制することができると共に、マンモグラフィによる撮影にも好適に適用することができる利点がある。 When a CMOS sensor is used as the sensor unit 13 of each radiation detector, the advantage that photoelectric conversion can be performed at a high speed and the result that the substrate can be thinned can suppress radiation absorption when the ISS method is adopted. There is an advantage that it can be suitably applied to mammography photography.
　これに対し、各放射線検出器のセンサ部１３としてＣＭＯＳセンサを用いる場合の欠点として、結晶シリコン基板を用いた場合において放射線に対する耐性が低いことが挙げられる。このため、従来は、センサ部とＴＦＴ基板との間にＦＯＰ（ファイバ光学プレート）を設ける等といった対策を行う技術もあった。 On the other hand, as a defect when a CMOS sensor is used as the sensor unit 13 of each radiation detector, the resistance to radiation is low when a crystalline silicon substrate is used. For this reason, conventionally, there has been a technique for taking measures such as providing an FOP (fiber optical plate) between the sensor unit and the TFT substrate.
　この欠点を踏まえて、放射線に対する耐性の高い半導体基板として、ＳｉＣ（炭化ケイ素）基板を用いる技術が適用できる。ＳｉＣ基板を用いることにより、ＩＳＳ方式として用いることができる利点や、ＳｉＣはＳｉと比較して内部抵抗が小さく、発熱量が少ないため、動画撮影を行う際の発熱量の抑制、ＣｓＩの温度上昇に伴う感度低下を抑制することができる利点がある。 Based on this drawback, a technique using a SiC (silicon carbide) substrate as a semiconductor substrate having high resistance to radiation can be applied. Advantages that can be used as an ISS method by using a SiC substrate, and because SiC has a lower internal resistance and a smaller amount of heat generation than Si, it suppresses the amount of heat generation when shooting movies, and raises the temperature of CsI There is an advantage that it is possible to suppress a decrease in sensitivity due to.
　このように、ＳｉＣ基板等の放射線に対する耐性が高い基板は一般にワイドキャップ（～３ｅＶ程度）なので、一例として図１６に示すように、吸収端が青領域に対応する４４０ｎｍ程度である。よって、この場合は、緑領域で発光するＣｓＩ：Ｔｌや、ＧＯＳ等のシンチレータを用いることができない。なお、図１６は、有機光電変換材料としてキナクリドンを用いた場合の各種材料のスペクトルである。 As described above, a substrate having high resistance to radiation such as a SiC substrate is generally a wide cap (about 3 eV), and as an example, as shown in FIG. 16, the absorption edge is about 440 nm corresponding to the blue region. Therefore, in this case, a scintillator such as CsI: Tl or GOS that emits light in the green region cannot be used. FIG. 16 shows spectra of various materials when quinacridone is used as the organic photoelectric conversion material.
　これに対し、アモルファスシリコンの感度特性から、これらの緑領域で発光するシンチレータの研究が盛んに行われてきたため、当該シンチレータを用いることの要望が高い。このため、光電変換膜４を緑領域での発光を吸収する有機光電変換材料を含む材料で構成することにより、緑領域で発光するシンチレータを用いることができる。 In contrast, the scintillator that emits light in these green regions has been actively researched due to the sensitivity characteristics of amorphous silicon, and therefore there is a high demand for using the scintillator. For this reason, the scintillator which light-emits in a green area | region can be used by comprising the photoelectric converting film 4 with the material containing the organic photoelectric conversion material which absorbs light emission in a green area | region.
　光電変換膜４を、有機光電変換材料を含む材料により構成し、薄膜トランジスタ１０を、ＳｉＣ基板を用いて構成した場合、光電変換膜４と薄膜トランジスタ１０との感度波長領域が異なるので、シンチレータによる発光が薄膜トランジスタ１０のノイズとならない。 When the photoelectric conversion film 4 is formed of a material containing an organic photoelectric conversion material and the thin film transistor 10 is formed using a SiC substrate, the photoelectric conversion film 4 and the thin film transistor 10 have different sensitivity wavelength regions, and thus the light emitted by the scintillator is emitted. There is no noise of the thin film transistor 10.
　また、光電変換膜４として、ＳｉＣと有機光電変換材料を含む材料とを積層させれば、ＣｓＩ：Ｎａのような、主として青領域の発光を受光することに加えて、緑領域の発光も受光することができる結果、感度の向上に繋がる。また、有機光電変換材料は放射線の吸収が殆どないため、ＩＳＳ方式に好適に用いることができる。 Further, if SiC and a material containing an organic photoelectric conversion material are laminated as the photoelectric conversion film 4, in addition to receiving light emission mainly in the blue region, such as CsI: Na, light emission in the green region is also received. As a result, the sensitivity can be improved. In addition, since the organic photoelectric conversion material hardly absorbs radiation, it can be suitably used for the ISS system.
　なお、ＳｉＣが放射線に対する耐性が高いのは、放射線が当たっても原子核が弾き飛ばされにくいためであり、この点は、例えば、「日本原子力研究所、“宇宙や原子力分野などの高放射線環境下で長く使える半導体素子を開発”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://www.jaea.go.jp/jari/jpn/publish/01/ff/ff36/sic.html＞」に開示されている。 Note that SiC is highly resistant to radiation because it is difficult for nuclear nuclei to be blown away even when exposed to radiation. Develop semiconductor devices that can be used for a long time ", [online], [Search May 8, 2011], Internet <URL: http://www.jaea.go.jp/jari/jpn/publish/01/ff/ ff36 / sic.html> ”.
　また、ＳｉＣ以外の放射線に対する耐性が高い半導体材料として、Ｃ（ダイヤモンド）、ＢＮ、ＧａＮ、ＡｌＮ、ＺｎＯ等が挙げられる。これらの軽元素半導体材料が耐放射線性が高いのは、主としてワイドギャップ半導体であるがために電離（電子－正孔対形成）に要するエネルギーが高く、反応断面積が小さいことや、原子間のボンディングが強く、原子変位生成が起こりにくいことに起因する。なお、この点については、例えば、「電子技術総合研究所、“原子力エレクトロニクスの新展開”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://www.aist.go.jp/ETL/jp/results/bulletin/pdf/62-10to11/kobayashi150.pdf＞」や、「“酸化亜鉛系電子デバイスの耐放射線特性に関する研究”、平成２１年度（財）若狭湾エネルギー研究センター　公募型共同研究　報告書，平成２２年３月」等に開示されている。また、ＧａＮの耐放射線性については、例えば、「東北大学、“窒化ガリウム素子の放射線耐性評価”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://cycgw1.cyric.tohoku.ac.jp/~sakemi/ws2007/ws/pdf/narita.pdf＞」に開示されている。 Moreover, C (diamond), BN, GaN, AlN, ZnO etc. are mentioned as a semiconductor material with high tolerance with respect to radiations other than SiC. These light element semiconductor materials have high radiation resistance because they are mainly wide-gap semiconductors, so they require high energy for ionization (electron-hole pair formation), small reaction cross-sections, This is due to the fact that bonding is strong and atomic displacement is less likely to occur. Regarding this point, for example, “Electronics Research Institute,“ New Development of Nuclear Electronics ”, [online], [Search May 8, 2011], Internet <URL: http: //www.aist .go.jp / ETL / jp / results / bulletin / pdf / 62-10to11 / kobayashi150.pdf> and “Research on Radiation Resistance of Zinc Oxide Electronic Devices”, 2009 Wakasa Bay Energy It is disclosed in “Research Center Public Research Report, March 2010”. Regarding the radiation resistance of GaN, for example, “Tohoku University,“ Evaluation of radiation resistance of gallium nitride device ”, [online], [Search May 8, 2011], Internet <URL: http: // cycgw1 .cyric.tohoku.ac.jp / ~ sakemi / ws2007 / ws / pdf / narita.pdf> ”.
　なお、ＧａＮは青色ＬＥＤ以外の用途として熱伝導性がよいことと、絶縁耐性が高いことから、パワー系の分野でＩＣ化が研究されている。また、ＺｎＯは、主に青～紫外線領域で発光するＬＥＤが研究されている。 In addition, since GaN has good thermal conductivity as a use other than blue LEDs and has high insulation resistance, ICs are being studied in the field of power systems. As for ZnO, an LED that emits light mainly in the blue to ultraviolet region has been studied.
　ところで、ＳｉＣを用いる場合、バンドギャップＥｇがＳｉの約１．１ｅＶから約２．８ｅＶとなるため、光の吸収波長λが短波長側にシフトする。具体的には、波長λ＝１．２４／Ｅｇ×１０００であるので、４４０ｎｍ程度までの波長に感度が変化する。よって、ＳｉＣを用いる場合、一例として図１７に示すように、シンチレータも緑領域で発光するＣｓＩ：Ｔｌ（ピーク波長：約５６５ｎｍ）よりも青領域で発光するＣｓＩ：Ｎａ（ピーク波長：約４２０ｎｍ）の方が発光波長として適していることになる。蛍光体としては青発光がよいので、ＣｓＩ：Ｎａ（ピーク波長：約４２０ｎｍ）、ＢａＦＸ：Ｅｕ（ＸはＢｒ，Ｉ等のハロゲン、ピーク波長：約３８０ｎｍ）、ＣａＷＯ４（ピーク波長：約４２５ｎｍ）、ＺｎＳ：Ａｇ（ピーク波長：約４５０ｎｍ）、ＬａＯＢｒ：Ｔｂ、Ｙ２Ｏ２Ｓ：Ｔｂ等が適している。特に、ＣｓＩ：ＮａとＣＲカセッテ等で用いられているＢａＦＸ：Ｅｕ、スクリーンやフイルム等で用いられているＣａＷＯ４が好適に用いられる。 By the way, when SiC is used, the band gap Eg is changed from about 1.1 eV to about 2.8 eV of Si, so that the light absorption wavelength λ shifts to the short wavelength side. Specifically, since the wavelength λ = 1.24 / Eg × 1000, the sensitivity changes to wavelengths up to about 440 nm. Therefore, when using SiC, as shown in FIG. 17 as an example, the scintillator emits light in the blue region more than CsI: Tl (peak wavelength: about 565 nm) that emits light in the green region, and the peak wavelength: about 420 nm. This is more suitable as the emission wavelength. Since the phosphor emits blue light well, CsI: Na (peak wavelength: about 420 nm), BaFX: Eu (X is a halogen such as Br and I, peak wavelength: about 380 nm), CaWO 4 (peak wavelength: about 425 nm) ZnS: Ag (peak wavelength: about 450 nm), LaOBr: Tb, Y 2 O 2 S: Tb, and the like are suitable. In particular, BaFX: Eu used in CsI: Na and CR cassettes, and CaWO 4 used in screens and films are preferably used.
　一方、放射線に対する耐性が高いＣＭＯＳセンサとして、ＳＯＩ（Silicon On Insulator）によりＳｉ基板／厚膜ＳｉＯ２／有機光電変換材料の構成を用いてＣＭＯＳセンサを構成してもよい。 On the other hand, as a CMOS sensor having high resistance to radiation, a CMOS sensor may be configured by using a configuration of Si substrate / thick film SiO 2 / organic photoelectric conversion material by SOI (Silicon On Insulator).
　なお、この構成に適用可能な技術としては、例えば、「宇宙航空研究開発機構（ＪＡＸＡ）宇宙科学研究所、“民生用最先端ＳＯＩ技術と宇宙用耐放射線技術の融合により耐放射線性を持つ高機能論理集積回路の開発基盤を世界で初めて構築”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://www.jaxa.jp/press/2010/11/20101122_soi_j.html＞」が挙げられる。 Technologies that can be applied to this configuration include, for example, “Japan Aerospace Exploration Agency (JAXA) Institute for Space Science,“ High radiation resistance by combining the most advanced consumer SOI technology and radiation resistance technology for space. “Development of functional logic integrated circuit development platform for the first time in the world”, [online], [Search May 8, 2011], Internet <URL: http://www.jaxa.jp/press/2010/11/20101122_soi_j .html> ".
　なお、ＳＯＩにおいては膜厚ＳＯＩの放射線耐性が高いため、高放射線耐久性素子としては、完全分離型厚膜ＳＯＩ、部分分離型厚膜ＳＯＩ等が例示される。なお、これらのＳＯＩについては、例えば、「特許庁、“ＳＯＩ（Silicon On Insulator）技術に関する特許出願技術動向調査報告”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://www.jpo.go.jp/shiryou/pdf/gidou-houkoku/soi.pdf＞」に開示されている。 In addition, since the radiation resistance of the film thickness SOI is high in the SOI, examples of the high radiation durability element include a complete separation type thick film SOI and a partial separation type thick film SOI. As for these SOIs, for example, “Patent Office,“ Patent Application Technology Trend Survey Report on SOI (Silicon On Insulator) Technology ”, [online], [Search May 8, 2011], Internet <URL: http://www.jpo.go.jp/shiryou/pdf/gidou-houkoku/soi.pdf> ”.
　また、放射線検出器２０の薄膜トランジスタ１０等が光透過性を有しない構成（例えば、アモルファスシリコン等の光透過性を有しない材料で活性層１７を形成した構成）であっても、この薄膜トランジスタ１０等を、光透過性を有する基板１（例えば合成樹脂製の可撓性基板）上に配置し、基板１のうち薄膜トランジスタ１０等が形成されていない部分は光が透過するように構成することで、光透過性を有する放射線検出器２０を得ることは可能である。光透過性を有しない構成の薄膜トランジスタ１０等を、光透過性を有する基板１上に配置することは、第１の基板上に作製した微小デバイスブロックを第１の基板から切り離して第２の基板上に配置する技術、具体的には、例えばＦＳＡ（Fluidic Self-Assembly）を適用することで実現できる。上記のＦＳＡは、例えば「富山大学、“微少半導体ブロックの自己整合配置技術の研究”、[online]、[平成２３年５月８日検索]、インターネット＜ＵＲＬ：http://www3.u-toyama.ac.jp/maezawa/Research/FSA.html＞」に開示されている。 Even if the thin film transistor 10 or the like of the radiation detector 20 does not have light transmission (for example, a structure in which the active layer 17 is formed of a material having no light transmission such as amorphous silicon), the thin film transistor 10 or the like. Is disposed on a light-transmitting substrate 1 (for example, a flexible substrate made of synthetic resin), and a portion of the substrate 1 where the thin film transistor 10 or the like is not formed is configured to transmit light. It is possible to obtain a radiation detector 20 having optical transparency. Arranging the thin film transistor 10 or the like having a non-light-transmitting structure on the light-transmitting substrate 1 is performed by separating the micro device block manufactured on the first substrate from the first substrate. This can be realized by applying the technology disposed above, specifically, for example, FSA (Fluidic Self-Assembly). The above FSA is, for example, “Toyama University,“ Study on Self-Aligned Placement Technology of Small Semiconductor Blocks ”, [online], [Search May 8, 2011], Internet <URL: http: //www3.u- toyama.ac.jp/maezawa/Research/FSA.html> ”.
　日本出願特願２０１１－２８６８６３の開示はその全体が参照により本明細書に取り込まれる。 The entire disclosure of Japanese Patent Application No. 2011-286863 is incorporated herein by reference.
　本明細書に記載された全ての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.
８、８Ａ、８Ｂ　シンチレータ
８’、８Ａ’、８Ｂ’　放射線変換層
１０　薄膜トランジスタ
１３　センサ部
１４　信号出力部
２０、２０’　放射線検出器
２２　ベース
３０Ａ　ＴＦＴ基板（第２基板）
３０Ｂ　ＴＦＴ基板（第１基板）
４０　電子カセッテ
５４Ａ　信号処理部
５４Ｂ　信号処理部
５８Ａ　ＣＰＵ（制御手段、受付手段）
７１Ａ　柱状結晶
７１Ｂ　非柱状結晶 8, 8A, 8B Scintillator 8 ', 8A', 8B 'Radiation conversion layer 10 Thin film transistor 13 Sensor unit 14 Signal output unit 20, 20' Radiation detector 22 Base 30A TFT substrate (second substrate)
30B TFT substrate (first substrate)
40 Electronic cassette 54A Signal processor 54B Signal processor 58A CPU (control means, acceptance means)
71A Columnar crystal 71B Non-columnar crystal

Claims (12)

  1. 　入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器と、
    　前記第１基板を用いて静止画撮影を行っている場合、および当該静止画撮影によって得られた静止画像の表示が行われている場合の少なくとも一方の場合に、前記第２基板に対してリセット処理を実行制御する制御手段と、
    　を備えた放射線画像撮影装置。     A radiation detector having a first substrate for still image photographing that converts incident radiation into a radiation image, and a second substrate for moving image photographing that is laminated on the first substrate and converts incident radiation into a radiation image. When,
    Reset to the second substrate when taking a still image using the first substrate and / or displaying a still image obtained by taking the still image Control means for controlling execution of processing;
    A radiographic imaging apparatus comprising:
  2. 　静止画撮影の実行指示を受け付ける受付手段をさらに備え、
    　前記制御手段は、前記第２基板を用いて動画撮影を行っている場合で、かつ前記受付手段によって前記実行指示が受け付けられた場合、前記第１基板を用いて静止画撮影を行い、かつ当該静止画撮影によって得られた静止画像を前記動画撮影によって得られた動画像の当該静止画像の撮影タイミングに対応する画像として適用すると共に、前記静止画撮影を行っているタイミングで前記第２基板に対してリセット処理を実行制御する
    　請求項１記載の放射線画像撮影装置。     A receiving means for receiving an instruction to execute still image shooting;
    The control unit performs still image shooting using the first substrate when the moving image is shot using the second substrate and the execution instruction is received by the receiving unit, and The still image obtained by still image shooting is applied as an image corresponding to the still image shooting timing of the moving image obtained by moving image shooting, and is applied to the second substrate at the timing when the still image shooting is performed. The radiation image capturing apparatus according to claim 1, wherein execution control of reset processing is performed on the radiographic image capturing apparatus.
  3. 　前記制御手段は、前記リセット処理の実行の如何にかかわらず、前記第２基板を用いて動画撮影を継続制御する
    　請求項２記載の放射線画像撮影装置。     The radiographic image capturing apparatus according to claim 2, wherein the control unit continuously controls moving image capturing using the second substrate regardless of execution of the reset process.
  4. 　前記制御手段は、前記静止画像の表示が行われている場合に放射線の照射を停止制御する
    　請求項１から請求項３の何れか１項記載の放射線画像撮影装置。     The radiographic imaging apparatus according to any one of claims 1 to 3, wherein the control unit performs stop control of radiation irradiation when the still image is being displayed.
  5. 　入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器と、
    　前記第２基板を用いて動画撮影を行っている場合、および当該動画撮影によって得られた動画像の表示が行われている場合の少なくとも一方の場合に、前記第１基板に対してリセット処理を実行制御する制御手段と、
    　を備えた放射線画像撮影装置。     A radiation detector having a first substrate for still image photographing that converts incident radiation into a radiation image, and a second substrate for moving image photographing that is laminated on the first substrate and converts incident radiation into a radiation image. When,
    In at least one of the case where moving image shooting is performed using the second substrate and the display of moving images obtained by moving image shooting is performed, the reset processing is performed on the first substrate. Control means for controlling execution;
    A radiographic imaging apparatus comprising:
  6. 　前記リセット処理は、リセット処理の対象とする基板が間接変換方式のものである場合における当該基板の各画素に対して光を照射することによる第１リセット処理、リセット処理の対象とする基板の各画素に対するバイアス電圧の供給状態を制御することによる第２リセット処理、およびリセット処理の対象とする基板の各画素に蓄積された電荷を放出させることによる第３リセット処理の少なくとも１つである
    　請求項１から請求項５の何れか１項記載の放射線画像撮影装置。     The reset process includes a first reset process by irradiating each pixel of the substrate with light when the substrate to be reset is of the indirect conversion type, and each substrate to be reset. The second reset process by controlling the supply state of the bias voltage to the pixel, and the third reset process by releasing the charge accumulated in each pixel of the substrate to be reset. The radiographic imaging apparatus of any one of Claims 1-5.
  7. 　前記第１基板は、入射された放射線を電荷に直接変換する直接変換方式のものであり、
    　前記第２基板は、入射された放射線を光に変換した後、当該光を電荷に変換する間接変換方式のものである
    　請求項１から請求項６の何れか１項記載の放射線画像撮影装置。     The first substrate is of a direct conversion system that directly converts incident radiation into electric charge,
    The radiographic imaging apparatus according to any one of claims 1 to 6, wherein the second substrate is of an indirect conversion system that converts incident radiation into light and then converts the light into electric charge.
  8. 　前記第２基板は、前記第１基板の放射線が入射される面とは反対側の面に積層されている
    　請求項７記載の放射線画像撮影装置。     The radiographic imaging apparatus according to claim 7, wherein the second substrate is laminated on a surface opposite to a surface on which radiation of the first substrate is incident.
  9. 　コンピュータを、
    　入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第１基板を用いて静止画撮影を行っている第１状態、および当該静止画撮影によって得られた静止画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定手段と、
    　前記判定手段によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第２基板に対してリセット処理を実行制御する制御手段と、
    　として機能させるためのプログラム。     Computer
    A radiation detector having a first substrate for still image photographing that converts incident radiation into a radiation image, and a second substrate for moving image photographing that is laminated on the first substrate and converts incident radiation into a radiation image. Whether or not the first state in which still image shooting is performed using the first substrate and the second state in which still images obtained by the still image shooting are displayed Determining means for determining
    Control means for executing and controlling reset processing on the second substrate when the determination means determines that the state is at least one of the first state and the second state;
    Program to function as.
  10. 　コンピュータを、
    　入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第２基板を用いて動画撮影を行っている第１状態、および当該動画撮影によって得られた動画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定手段と、
    　前記判定手段によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第１基板に対してリセット処理を実行制御する制御手段と、
    　として機能させるためのプログラム。     Computer
    A radiation detector having a first substrate for still image photographing that converts incident radiation into a radiation image, and a second substrate for moving image photographing that is laminated on the first substrate and converts incident radiation into a radiation image. It is determined whether or not it is at least one of a first state in which moving image shooting is performed using the second substrate and a second state in which a moving image obtained by moving image shooting is displayed Determination means to perform,
    Control means for executing and controlling reset processing on the first substrate when the determination means determines that the state is at least one of the first state and the second state;
    Program to function as.
  11. 　入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第１基板を用いて静止画撮影を行っている第１状態、および当該静止画撮影によって得られた静止画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定工程と、
    　前記判定工程によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第２基板に対してリセット処理を実行制御する制御工程と、
    　を有する放射線画像撮影方法。     A radiation detector having a first substrate for still image photographing that converts incident radiation into a radiation image, and a second substrate for moving image photographing that is laminated on the first substrate and converts incident radiation into a radiation image. Whether or not the first state in which still image shooting is performed using the first substrate and the second state in which still images obtained by the still image shooting are displayed A determination step of determining
    A control step of controlling execution of reset processing on the second substrate when it is determined by the determination step that the state is at least one of the first state and the second state;
    A radiographic imaging method comprising:
  12. 　入射された放射線を放射線画像に変換する静止画撮影用の第１基板、および当該第１基板に積層され、入射された放射線を放射線画像に変換する動画撮影用の第２基板を有する放射線検出器における前記第２基板を用いて動画撮影を行っている第１状態、および当該動画撮影によって得られた動画像の表示が行われている第２状態の少なくとも一方の状態であるか否かを判定する判定工程と、
    　前記判定工程によって前記第１状態および前記第２状態の少なくとも一方の状態であると判定された場合に、前記第１基板に対してリセット処理を実行制御する制御工程と、
    　を有する放射線画像撮影方法。     A radiation detector having a first substrate for still image photographing that converts incident radiation into a radiation image, and a second substrate for moving image photographing that is laminated on the first substrate and converts incident radiation into a radiation image. It is determined whether or not it is at least one of a first state in which moving image shooting is performed using the second substrate and a second state in which a moving image obtained by moving image shooting is displayed A determination step to
    A control step of controlling execution of reset processing on the first substrate when it is determined by the determination step that the state is at least one of the first state and the second state;
    A radiographic imaging method comprising:
PCT/JP2012/082096 2011-12-27 2012-12-11 Radiographic imaging apparatus, program, and radiographic imaging method WO2013099592A1 (en)

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JP2011286863 2011-12-27

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0772257A (en) * 1993-09-01 1995-03-17 Fuji Photo Film Co Ltd Radiation detector
JPH09294738A (en) * 1996-03-08 1997-11-18 Hitachi Medical Corp X-ray radiographic system
JPH10258046A (en) * 1997-03-18 1998-09-29 Toshiba Iyou Syst Eng Kk X-ray diagnostic device
JP2002102213A (en) * 2000-10-03 2002-04-09 Hitachi Medical Corp X-ray photographing apparatus
JP2011000235A (en) * 2009-06-17 2011-01-06 Fujifilm Corp Radiation detecting device and radiation image detection system
JP2011252730A (en) * 2010-05-31 2011-12-15 Fujifilm Corp Radiographic device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0772257A (en) * 1993-09-01 1995-03-17 Fuji Photo Film Co Ltd Radiation detector
JPH09294738A (en) * 1996-03-08 1997-11-18 Hitachi Medical Corp X-ray radiographic system
JPH10258046A (en) * 1997-03-18 1998-09-29 Toshiba Iyou Syst Eng Kk X-ray diagnostic device
JP2002102213A (en) * 2000-10-03 2002-04-09 Hitachi Medical Corp X-ray photographing apparatus
JP2011000235A (en) * 2009-06-17 2011-01-06 Fujifilm Corp Radiation detecting device and radiation image detection system
JP2011252730A (en) * 2010-05-31 2011-12-15 Fujifilm Corp Radiographic device

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