WO2019167424A1 - Radiation imaging panel, radiation imaging device, and radiation imaging system - Google Patents

Radiation imaging panel, radiation imaging device, and radiation imaging system Download PDF

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Publication number
WO2019167424A1
WO2019167424A1 PCT/JP2018/048506 JP2018048506W WO2019167424A1 WO 2019167424 A1 WO2019167424 A1 WO 2019167424A1 JP 2018048506 W JP2018048506 W JP 2018048506W WO 2019167424 A1 WO2019167424 A1 WO 2019167424A1
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Prior art keywords
radiation imaging
substrate
scintillator
pixels
radiation
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PCT/JP2018/048506
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French (fr)
Japanese (ja)
Inventor
尚志郎 猿田
竹中 克郎
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キヤノン株式会社
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Publication of WO2019167424A1 publication Critical patent/WO2019167424A1/en

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01TMEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16Measuring radiation intensity
    • G01T1/20Measuring radiation intensity with scintillation detectors

Definitions

  • the present invention relates to a radiation imaging panel, a radiation imaging apparatus, and a radiation imaging system.
  • Patent Document 1 discloses a radiation detection apparatus in which a scintillator is disposed on both surfaces of a substrate on which pixels are disposed, thereby increasing the amount of light converted from radiation and improving sensitivity.
  • the optical path length is compared with the light that is converted by the other scintillator and reaches the pixel without passing through the substrate. Becomes longer. As the optical path length becomes longer, the spatial resolution may be reduced due to the influence of scattering and the like.
  • An object of the present invention is to provide a technique advantageous in improving the spatial resolution of a radiation imaging panel.
  • a radiation imaging panel is disposed on a first surface so as to cover a substrate, a plurality of pixels disposed on the first surface of the substrate, and the plurality of pixels.
  • a radiation imaging panel including a first scintillator and a second scintillator disposed so as to cover a second surface opposite to the first surface of the substrate.
  • the substrate includes a central region including a pixel region where a plurality of pixels are arranged, and a peripheral region between the outer edge of the central region and the outer edge of the substrate, and the central region is thicker than the peripheral region.
  • the second surface is provided with a recess so that the thickness of the second scintillator is reduced, and the second scintillator is disposed in the recess.
  • the above means provide a technique advantageous for improving the spatial resolution of the radiation imaging panel.
  • Sectional drawing which shows the structural example of the radiation imaging panel which concerns on embodiment of this invention.
  • the top view which shows the structural example of the radiation imaging panel which concerns on embodiment of this invention.
  • Sectional drawing which shows arrangement
  • FIG. 1A and 1B Sectional drawing which shows arrangement
  • the radiation in the present invention includes ⁇ -rays, ⁇ -rays, ⁇ -rays, etc., which are beams produced by particles (including photons) emitted by radiation decay, as well as beams having the same or higher energy, such as X-rays, It can also include particle beams, cosmic rays, and the like.
  • FIG. 1A is a cross-sectional view illustrating a configuration example of the radiation imaging panel 100 according to the first embodiment of the present invention
  • FIG. 1B is a plan view illustrating a configuration example of the radiation imaging panel 100.
  • the radiation imaging panel 100 includes a substrate 101 and a pixel region 102 including a plurality of pixels arranged on a first surface of the substrate 101 (hereinafter sometimes referred to as a surface 109).
  • the radiation imaging panel 100 includes a wavelength conversion unit 113 (first wavelength conversion unit) including a scintillator 104 (first scintillator) disposed so as to cover the surface 109 of the substrate 101, and a surface 109 of the substrate 101.
  • a wavelength conversion unit 114 second wavelength conversion unit
  • a scintillator 106 second scintillator
  • a plurality of pixels each including a photoelectric conversion element that generates a signal corresponding to light converted from radiation by the scintillators 104 and 106 are arranged in a two-dimensional array.
  • 3300 ⁇ 2800 pixels are arranged on a substrate 101 of 550 mm ⁇ 445 mm.
  • 10 pixels arranged on the outer periphery of 3300 ⁇ 2800 pixels are dummy pixels, and the pixel region 102 is configured by 3280 ⁇ 2780 pixels arranged on the inner side.
  • the number of pixels arranged on the substrate 101 and the number of pixels arranged on the pixel region 102 may be set as appropriate according to the size of the substrate, the imaging target, and the like.
  • the pixel region 102 is further provided with column signal lines for extracting signals generated in the respective pixels, row signal lines for driving the respective elements including the pixels disposed in the pixel region 102, and the like. .
  • the column signal line and the row signal line can be electrically connected to each other via a readout circuit board, a drive circuit board, a flexible wiring board, and the like.
  • the connection terminal portion 103 is provided on the substrate 101. A signal generated in each pixel of the pixel region 102 is output from the radiation imaging panel 100 via the connection terminal portion 103.
  • the reading circuit and the driving circuit are arranged outside the radiation imaging panel 100
  • the reading circuit and the driving circuit may be arranged in the radiation imaging panel 100.
  • the connection terminal portion 103 is arranged on the substrate 101, and signals generated by the respective pixels in the pixel region 102 can be output from the radiation imaging panel 100 via the connection terminal portion 103.
  • the wavelength converters 113 and 114 include scintillators 104 and 106 that convert radiation into light that can be converted into electric signals by pixels, and reflective layers 105 and 107.
  • the reflective layers 105 and 107 are arranged so as to reflect light traveling in a direction different from the direction toward the pixel region 102 among the light generated in the scintillators 104 and 106. As a result, the light generated by the scintillators 104 and 106 can be used efficiently, and the sensitivity of the radiation imaging panel 100 is improved.
  • the substrate 101 is made of a material that is transparent to the light generated by the scintillator 106 so that the light generated by the scintillator 106 is transmitted to the pixel region 102.
  • the substrate 101 can be a transparent substrate such as glass or plastic.
  • the substrate 101 in orthogonal projection with respect to the surface 109 of the substrate 101, the substrate 101 includes a central region 108 including a pixel region 102 in which a plurality of pixels are arranged, an outer edge of the central region 108, and an outer edge of the substrate 101. And the peripheral region 112 between the two. In the configuration shown in FIG.
  • the outer edge of the pixel region 102 is arranged inside the outer edge of the central region 108 in the orthogonal projection with respect to the surface 109 of the substrate 101.
  • the back surface 110 includes a recess 115 so that the central region 108 is thinner than the peripheral region 112.
  • a region of the back surface 110 where the recess 115 is disposed can be referred to as a central region 108.
  • the central region 108 of the substrate 101 can have a uniform thickness.
  • the wavelength converter 114 is disposed in the recess 115.
  • the surface 109 of the substrate 101 is not provided with a recess, and the surface 109 may not have a step between the central region 108 and the peripheral region 112.
  • the surface 109 of the substrate 101 may be flat.
  • the thickness of the central region 108 of the substrate 101 is the thickness t1
  • the thickness of the peripheral region 112 is the thickness t2.
  • the thickness of the substrate 101 may mean the size of the substrate in a direction orthogonal to the front surface 109 and the back surface 110 of the substrate 101.
  • the scintillator 106 that covers the back surface 110 side of the substrate 101 has a longer distance to the pixel region 102 disposed on the surface 109 side of the substrate 101.
  • the central region 108 of the substrate 101 is thinned by providing the recess 115 in the central region 108 of the substrate 101 where the pixel region 102 of the back surface 110 is disposed. Thereby, a decrease in spatial resolution can be suppressed.
  • the peripheral region 112 of the substrate 101 is thicker than the central region 108.
  • the peripheral region 112 of the substrate 101 has an appropriate thickness, a kind of beam structure can be realized, and warping of the substrate 101 during and after the production of the radiation imaging panel 100 can be suppressed.
  • FIGS. 2A to 2C regarding a method for manufacturing the radiation imaging panel 100 including the recess 115 on the back surface 110 of the substrate 101.
  • an alkali-free glass having a thickness of 550 mm ⁇ 445 mm and a thickness of 500 ⁇ m was prepared as the substrate 101.
  • the pixel region 102 was formed on the surface 109 of the prepared substrate 101 using a known manufacturing process such as a film formation process, a photolithography process, and an etching process.
  • the connection terminal part 103 was formed using the known manufacturing process.
  • a sensor protective layer (not shown) was formed so as to cover the entire pixel region 102.
  • this sensor protective layer for example, various materials such as an inorganic amorphous film and a resin film film can be used.
  • the material for the sensor protective layer needs to be a material having heat resistance that can withstand the temperature of the process of forming the scintillators 104 and 106 later.
  • the sensor protective layer was formed by applying polyimide resin by a slit coat method and drying it. After the formation of the sensor protective film, the array inspection was performed again, and it was confirmed that there were no missing pixels in the process of forming the sensor protective layer.
  • a slightly adhesive resin film 201 was transferred to the surface 109 of the substrate 101 where the recess 115 was not formed for the purpose of protection from etching with hydrofluoric acid for forming the recess 115.
  • a mask pattern for forming the recess 115 was formed on the back surface 110 of the substrate 101.
  • the substrate was set on a spin coater with the back surface 110 of the substrate 101 facing upward, and a photoresist was applied.
  • the photoresist is applied using a spin coater, but, for example, a dry film resist may be transferred.
  • the substrate 101 covered with the photoresist was placed on a UV exposure table and exposed using a predetermined photomask.
  • the photomask an area wider than the pixel area 102 of the substrate 101 is opened in the orthogonal projection with respect to the surface 109 of the substrate 101. This makes it possible for the scintillator 106 formed in the recess 115 described later to reliably cover the pixel region 102 in the orthogonal projection with respect to the surface 109 of the substrate 101.
  • the photoresist 101 was developed by immersing the substrate 101 in an aqueous sodium carbonate solution, followed by washing with pure water rinse and drying. Through the above steps, the mask pattern 202 shown in FIG. 2A was formed.
  • the mask pattern 202 is formed using a photolithography process, but the formation of the mask pattern 202 is not limited to this.
  • the pattern for forming the recess 115 has a simple shape that covers the portion of the back surface 110 of the substrate 101 that becomes the peripheral region 112 in FIG. 1B. For this reason, for example, it can be formed by transferring a film and peeling only a desired portion. In this case, a lithography process for applying, exposing, and developing a photoresist becomes unnecessary.
  • the substrate 101 was immersed in a hydrofluoric acid solution.
  • the immersion time is calculated based on the etching rate of the substrate 101 calculated in advance, and the portion of the back surface 110 of the substrate 101 that is not covered with the mask pattern 202 is etched to a desired thickness.
  • the substrate 101 was rinsed with pure water, and then the substrate 101 was immersed in a resist stripping solution to strip the mask pattern 202.
  • rinsing was performed using pure water, and moisture was removed with an air knife. Further, the resin film 201 attached to the surface 109 of the substrate 101 was peeled off.
  • a recess 115 having a wider area range than the pixel region 102 was formed on the back surface 110 of the substrate 101.
  • the thickness t1 of the central region of the substrate 101 is 200 ⁇ m.
  • the thickness t2 of the peripheral region 112 in the substrate 101 was set to 500 ⁇ m, which is the thickness of the prepared substrate 101.
  • the width of the peripheral region 112, that is, the distance between the recess 115 and the end of the substrate 101 was 46.5 mm on the short side of the substrate 101 and 61.0 mm on the long side.
  • the distance between the recess 115 and the end of the substrate 101 when forming the radiation imaging panel 100 may be in the range of, for example, 40 mm or more and 100 mm or less.
  • the recess 115 is formed by wet etching.
  • the method for forming the recess 115 is not limited to this.
  • the recess 115 may be formed by polishing.
  • the wavelength converter 114 was formed. First, after setting a vapor deposition mask that covers a peripheral portion excluding a region where the scintillator 106 is formed so that the scintillator 106 is formed in the concave portion 115 of the substrate 101, the substrate 101 is vapor deposited so that the concave portion 115 becomes a vapor deposition surface. Placed on the device. Next, thallium-added cesium iodide (CsI: Tl) was deposited to form a scintillator 106 with a thickness of 250 ⁇ m as shown in FIG. 2C. In the orthogonal projection with respect to the surface 109 of the substrate 101, the outer edge of the scintillator 106 can be arranged outside the outer edge of the pixel region 102.
  • CsI cesium iodide
  • the substrate 101 is taken out from the vapor deposition apparatus.
  • a vapor deposition mask that covers the peripheral portion excluding the region where the scintillator 104 is formed is set so that the scintillator 104 is formed in a range where the pixel region 102 of the surface 109 of the substrate 101 taken out is covered.
  • the substrate 101 was placed again on the vapor deposition apparatus so that the surface 109 on which the vapor deposition mask was set became the vapor deposition surface.
  • CsI: Tl was vapor-deposited to form a scintillator 104 having a thickness of 350 ⁇ m as shown in FIG. 2C.
  • the outer edge of the scintillator 104 can be arranged outside the outer edge of the pixel region 102.
  • the substrate 101 was taken out from the vapor deposition apparatus, and immediately set on the transfer apparatus so that the back surface 110 of the substrate 101 faced upward.
  • the reflective layer 107 was formed by thermally transferring a 20 ⁇ m-thick aluminum thin film coated with a 30 ⁇ m-thick hot melt resin onto the scintillator 106.
  • the thickness t3 is 300 ⁇ m.
  • the wavelength conversion unit 114 protrudes and the peripheral region 112 of the substrate 101 floats.
  • a process of connecting a wiring to the connection terminal portion 103 to be described later is performed in a state where the peripheral region 112 is floating, there is a problem that the substrate 101 becomes unstable and the yield decreases during the process of connecting the wiring. May occur.
  • a jig or the like is required, which may increase the manufacturing cost.
  • the reflective layer 105 was formed by setting the transfer device so that the surface 109 of the substrate 101 faced upward and thermally transferring the same material as the reflective layer 107.
  • These reflective layers 105 and 107 not only have the effect of effectively directing the light generated by the scintillators 104 and 106 toward the pixel region 102, but can also have a function as a moisture-proof layer of CsI: Tl used as the scintillators 104 and 106. .
  • CsI: Tl is used for the scintillators 104 and 106, but the present invention is not limited to this.
  • the scintillator 106 may be formed by transferring a thick film sheet of a particulate scintillator such as terbium-added gadolinium oxysulfide (GOS: Tb).
  • GOS gadolinium oxysulfide
  • the distance between the recess 115 and the end of the substrate 101 after removing unnecessary regions of the substrate 101 and chamfering by the scribing device was set to 6.2 mm.
  • the distance between the recess 115 and the end of the substrate 101 needs to be at least 5.0 mm in order to maintain sufficient strength to withstand the mounting process.
  • the distance between the recess 115 and the end of the substrate 101 may be 50 mm or less.
  • the distance between the concave portion 115 of the substrate of the radiation imaging panel 100 mounted on the radiation imaging apparatus and the end portion of the substrate 101 may be in a range of 5.0 mm or more and 50 mm or less.
  • connection terminal portion 103 was able to secure sufficient strength, and troubles such as breakage of the substrate 101 did not occur.
  • the same trial manufacture was performed using the same non-alkali glass having a thickness of 260 ⁇ m as a substrate without providing a recess on the back surface of the substrate.
  • damage such as cracking of the substrate occurred during the formation of the reflective layer 107 and the OLB process.
  • the entire substrate was as thin as 260 ⁇ m, the substrate was warped and bent by a normal gripping method, and destruction of elements such as some pixels was confirmed by array inspection.
  • the peripheral region 112 of the substrate 101 of this example is thick, the warpage of the substrate 101 is suppressed, and element destruction due to deformation of the substrate 101 was not confirmed.
  • the radiation imaging panel 100 shown in FIG. 1A was obtained by the above-described steps.
  • the radiation imaging panel 100 of this example was obtained by connecting the radiation imaging panel 100 to a circuit board via a flexible wiring board and arranging the radiation imaging panel 100 in a housing.
  • the circuit board includes a control unit for controlling the radiation imaging panel 100 and a signal processing unit for processing a signal output from the radiation imaging panel 100.
  • the obtained radiation imaging apparatus was driven under the quality condition of RQA5, and the detection quantum efficiency (DQE: Detect Quantum Efficiency) and the optical transfer coefficient (MTF: Modulation Transfer Function) were measured.
  • DQE Detect Quantum Efficiency
  • MTF Modulation Transfer Function
  • the same measurement was performed on a radiation imaging apparatus including a radiation imaging panel including the wavelength conversion unit 113 and not including the wavelength conversion unit 114.
  • the DQE of the comparative radiation imaging apparatus was 0.610, and the MTF was 0.40.
  • the radiation imaging panel 100 is high by making light converted from radiation by the scintillators 104 and 106 arranged on both the front surface 109 and the back surface 110 of the substrate 101 enter the pixel region 102. It was confirmed that DQE was shown. Further, light from the scintillator 106 disposed on the back surface 110 side of the substrate 101 enters the pixel region 102 through the substrate 101, but a recess 115 is formed in the back surface 110 of the substrate 101, and the scintillator 106 is formed in the recess 115. By suppressing the increase in the optical path length, it was suppressed. As a result, the degradation of the MTF was suppressed, and in the radiation imaging apparatus including the radiation imaging panel 100 of the present example, an MTF equivalent to the radiation imaging apparatus including the radiation imaging panel of the comparative example could be realized.
  • Second Embodiment A configuration of a radiation imaging panel 100 according to an embodiment of the present invention will be described with reference to FIGS. 3A to 5B.
  • an energy subtraction image is acquired using the radiation imaging panel 100 described above.
  • Energy subtraction is the acquisition of radiation images (sometimes called high energy images and low energy images) using radiation with different energies between high energy and low energy. It is a method of separating and displaying different substances. For example, it is possible to separate bones from tissues other than bones, and improvement of diagnostic ability is expected. A high energy image and a low energy image can be easily acquired by two irradiations of radiation.
  • the radiation imaging panel 100 of this embodiment can acquire an energy subtraction image by one-time radiation irradiation as will be described later. That is, the radiation imaging panel 100 capable of suppressing the exposure dose can be realized.
  • 3A to 3C are a plan view and a cross-sectional view showing the arrangement of two types of pixels 300 and 301 in the pixel region 102 of the radiation imaging panel 100 according to the second embodiment of the present invention.
  • the pixel 300 similarly to the first embodiment described above, light generated by the scintillator 104 disposed on the front surface 109 side of the substrate 101 and light generated by the scintillator 106 disposed on the back surface 110 side of the substrate 101 are generated. Both light and incident light are incident.
  • the pixel 301 includes a light shielding layer that prevents light converted from radiation by the scintillator 104 from entering the photoelectric conversion element of the pixel 301 between the scintillator 104 and the pixel 301.
  • 302 is provided. That is, although the light generated by the scintillator 106 is incident on the pixel 301, the light generated by the scintillator 104 is blocked by the light blocking layer 302, and thus a part of the light generated by the scintillator 104 is incident. All of the light generated by the scintillator 104 may be blocked by the light blocking layer 302, and only the light generated by the scintillator 106 may enter the pixel 301.
  • the pixel 301 can also be referred to as a light-shielded pixel.
  • the light shielding layer 302 is provided between the scintillator 104 and the pixel 301 so as to suppress the light converted from the radiation by the scintillator 104 from entering the pixel 301, but is not limited thereto. There is no.
  • the light shielding layer 302 may be provided between the scintillator 106 and the pixel 301 so as to prevent light converted from radiation by the scintillator 106 from entering the pixel 301.
  • the radiation imaging panel 100 of this embodiment is different from the first embodiment described above in that the light shielding layer 302 is provided in some pixels. Other configurations of the radiation imaging panel 100 may be the same as those in the first embodiment.
  • the scintillator 104 converts low energy radiation into light
  • the scintillator 106 converts high energy radiation into light.
  • Pixel 300 can acquire light converted from radiation at scintillator 104 and scintillator 106, that is, signals resulting from both high energy and low energy radiation.
  • the pixel 301 can acquire light converted from radiation by the scintillator 106, that is, a signal resulting from high-energy radiation.
  • the radiation imaging panel 100 of this embodiment can acquire the radiation image of energy in two types, high energy and low energy, and can acquire the energy subtraction image by one shot.
  • the case where radiation enters from the front surface 109 side of the substrate 101 of the radiation imaging panel 100 will be described, but the radiation may be incident from the back surface 110 side of the substrate 101.
  • the arrangement pattern of the pixels 301 that are light-shielding pixels is not limited to that shown in FIG.
  • the ratio of the pixels 301 is increased, the pixel pitch of the pixels 300 is increased, and there is a possibility that the quality of the obtained radiation image is deteriorated.
  • the pixel 301 can be compensated by image compensation technology, as is the case with a defective pixel that outputs a signal that is significantly different from the surrounding pixels.
  • the arrangement of the pixels 300 and the pixels 301 may be adjusted so that the number of the plurality of pixels 301 is equal to or less than 1 ⁇ 2 of the total of the plurality of pixels (the sum of the pixels 300 and 301). .
  • the number of pixels 301 may be, for example, 1/3 or less of the entire pixels, 1/4 or less, or 1/5 or less. .
  • the light shielding layer 302 is disposed in some of the pixels 301 among the pixels disposed in the pixel region 102, but is not limited thereto.
  • a plurality of pixels arranged in the pixel region 102 may include two types of light-shielding pixels, a pixel 310 and a pixel 311.
  • a light shielding layer 302 a that suppresses the light converted from the radiation by the scintillator 106 from entering the pixel 310 is disposed.
  • a light shielding layer 302 b that suppresses the light converted from the radiation by the scintillator 104 from entering the pixel 311 is disposed between the scintillator 104 and the pixel 311.
  • the pixel region 102 and the connection terminal portion 103 were formed on the substrate 101.
  • a light shielding layer 302 was formed on the substrate 101.
  • a mask pattern having an opening is formed on the pixel 301 by applying a photoresist in advance and patterning.
  • a light-reflective layer 302 was formed so as to cover the pixels 301 by applying and developing a low-reflectance chromium dispersion by spin coating.
  • the thickness of the light shielding layer 302 was about 1.2 ⁇ m, and the visible light transmittance was about 1.0%.
  • the radiation imaging panel 100 was manufactured by performing the respective steps shown in FIGS. 2A to 2C.
  • the radiation imaging panel 100 of this example was obtained by connecting the radiation imaging panel 100 to a circuit board via a flexible wiring board and arranging the radiation imaging panel 100 in a housing.
  • the thickness t1 of the central region 108 of the substrate 101 is 250 ⁇ m
  • the thickness t2 of the peripheral region 112 is 500 ⁇ m
  • the thickness of the scintillator 104 is 400 ⁇ m
  • the thickness of the scintillator 106 is 200 ⁇ m
  • the reflective layer 105 The thickness of 107 was 50 ⁇ m.
  • the thickness t3 of the wavelength conversion unit 114 is 250 ⁇ m, which satisfies the above-described expression (1). Also in this example, similarly to the example of the first embodiment described above, problems such as breakage, bending, and warping of the glass serving as the substrate 101 did not occur. Moreover, as a comparative example, a radiation imaging panel similar to that of this example except that the substrate thickness is 500 ⁇ m and the recess 115 is not provided, and a radiation imaging apparatus of a comparative example equipped with this radiation imaging panel is prepared. Obtained.
  • E is the energy of radiation
  • ⁇ i is the linear attenuation constant of component i
  • t i is the thickness of component i
  • N (E) is the energy distribution of the irradiated radiation.
  • the signal values of high energy and low energy were determined as follows.
  • High energy signal value signal value observed at pixel 301
  • Low energy signal value (median average of signal values of eight neighboring pixels 300 surrounding pixel 301)
  • signal value observed at pixel 301)
  • FIG. 4 shows an MTF under the condition that the thickness t1 of the substrate 101 in the central region 108 and the spatial frequency of light emission of the scintillator 106 are 2 lp / mm when the thickness of the scintillator 104 is 400 ⁇ m and the thickness of the scintillator 106 is 200 ⁇ m. Shows the relationship. As shown in FIG. 1A, radiation 111 enters from the wavelength conversion unit 113 side, is converted into light by the scintillator 106 of the wavelength conversion unit 114, and the light passes through the substrate 101 and reaches the pixel region 102. The MTF.
  • the MTF for light emission of the scintillator 104 (the MTF until the radiation 111 enters from the wavelength conversion unit 113 side, is converted into light by the scintillator 104 of the wavelength conversion unit 113, and this light reaches the pixel region 102. ) Is the same value as when the thickness t1 of the substrate 101 is 0 ⁇ m, that is, 0.35.
  • the MTF difference is 0.2 or less.
  • the MTF difference is about 0.35 in the radiation imaging apparatus having a substrate thickness of 500 ⁇ m and no recesses in the comparative example.
  • FIG. 5A shows a bone separation of a radiation imaging apparatus including the radiation imaging panel 100 of the present embodiment, which is obtained by using the transmission image of a hand phantom photographed with a tube voltage of 80 kV of the radiation source and using the above-described equation (2). An image is shown.
  • FIG. 5B is a bone separation image acquired using a radiation imaging apparatus including the radiation imaging panel of the comparative example under the same conditions. From FIG. 5A, a sufficiently high-quality bone separation image is obtained in the radiation imaging apparatus of the present embodiment in which the difference between the MTF for the light emission of the scintillator 104 and the MTF for the light emission of the scintillator 106 is 0.2 or less. I understand that. On the other hand, in the radiation imaging apparatus of the comparative example in which the difference in MTF is 0.35, it can be seen that the bone is an isolated bone image with a strong edge and a strong sense of discomfort.
  • the thickness t1 of the central region 108 of the substrate 101 is 300 ⁇ m or less.
  • the thickness of the central region 108 of the substrate 101 may be 250 ⁇ m or less as in the present embodiment. Further, for example, the thickness of the central region 108 of the substrate 101 may be 200 ⁇ m or less. However, if the thickness t1 of the central region 108 of the substrate 101 becomes too thin, the strength of the substrate 101 may not be maintained. Therefore, for example, the thickness of the central region 108 of the substrate 101 may be 50 ⁇ m or more.
  • FIG. 6 illustrates a radiation imaging system 600 using the radiation imaging apparatus in which the radiation imaging panel 100 is incorporated. It explains using.
  • the radiation imaging system 600 is configured to electrically capture an optical image formed by radiation and obtain an electrical radiation image (ie, radiation image data).
  • the radiation imaging system 600 includes, for example, a radiation imaging apparatus 601, an exposure control unit 602, a radiation source 603, and a computer 604.
  • the radiation source 603 for irradiating the radiation imaging apparatus 601 starts irradiation according to the exposure command from the exposure control unit 602.
  • the radiation emitted from the radiation source 603 is irradiated to the radiation imaging apparatus 601 through an unillustrated object.
  • the radiation source 603 stops radiation emission in accordance with a stop command from the exposure control unit 602.
  • the radiation imaging apparatus 601 includes the radiation imaging panel 100 described above, a control unit 605 for controlling the radiation imaging panel 100, and a signal processing unit 606 for processing a signal output from the radiation imaging panel 100.
  • the signal processing unit 606 may perform A / D conversion of a signal output from the radiation imaging panel 100 and output the signal to the computer 604 as radiation image data.
  • the signal processing unit 606 may generate a stop signal for stopping irradiation of radiation from the radiation source 603 based on a signal output from the radiation imaging panel 100, for example.
  • the stop signal is supplied to the exposure control unit 602 via the computer 604, and the exposure control unit 602 sends a stop command to the radiation source 603 in response to the stop signal.
  • the control unit 605 includes, for example, PLD (abbreviation of Programmable Logic Device) such as FPGA (abbreviation of Field Programmable Gate Array), or ASIC (Application Specific Integrated, an abbreviation of General Integrated Circuit). It can be constituted by a computer, or a combination of all or part thereof.
  • PLD abbreviation of Programmable Logic Device
  • FPGA abbreviation of Field Programmable Gate Array
  • ASIC Application Specific Integrated, an abbreviation of General Integrated Circuit
  • the signal processing unit 606 is shown as being disposed in the control unit 605 or a part of the function of the control unit 605, but is not limited thereto.
  • the control unit 605 and the signal processing unit 606 may have different configurations.
  • the computer 604 can perform processing for controlling the radiation imaging apparatus 601 and the exposure control unit 602 and receiving radiation image data from the radiation imaging apparatus 601 and displaying it as a radiation image.
  • the computer 604 can function as an input unit for the user to input conditions for capturing a radiographic image.
  • the exposure control unit 602 includes an exposure switch.
  • the exposure control unit 602 sends an exposure command to the radiation source 603 and sends a start notification indicating the start of radiation emission to the computer.
  • the computer 604 receives the start notification, notifies the start of radiation irradiation to the control unit 605 of the radiation imaging apparatus 601 in response to the start notification.
  • the control unit 605 causes the radiation imaging panel 100 to generate a signal corresponding to the incident radiation.

Abstract

The present invention comprises: a substrate, a plurality of pixels disposed on a first surface of the substrate, a first scintillator disposed on the first surface so as to cover the plurality of pixels, and a second scintillator disposed so as to cover a second surface of the substrate on the reverse side from the first surface. In an orthographic projection of the first surface, the substrate includes a central area including a pixel area where the plurality of pixels are disposed and a peripheral area between the outer edge of the central area and the outer edge of the substrate, the second surface has a recessed part such that the thickness of the substrate at the central area is thinner than that at the peripheral area, and the second scintillator is disposed in the recessed part.

Description

放射線撮像パネル、放射線撮像装置および放射線撮像システムRadiation imaging panel, radiation imaging apparatus and radiation imaging system
 本発明は、放射線撮像パネル、放射線撮像装置および放射線撮像システムに関するものである。 The present invention relates to a radiation imaging panel, a radiation imaging apparatus, and a radiation imaging system.
 医療画像診断や非破壊検査において、放射線撮像パネル(フラットパネルディテクタ:FPD)を用いた放射線撮像装置が広く使用されている。特許文献1には、画素が配された基板の両面にシンチレータを配することによって、放射線から変換される光量を増加させ、感度を向上させた放射線検出装置が示されている。 Radiation imaging devices using radiation imaging panels (flat panel detectors: FPDs) are widely used in medical imaging diagnosis and nondestructive inspection. Patent Document 1 discloses a radiation detection apparatus in which a scintillator is disposed on both surfaces of a substrate on which pixels are disposed, thereby increasing the amount of light converted from radiation and improving sensitivity.
特開2009-133837号公報JP 2009-133837 A
 特許文献1の放射線検出装置において、一方のシンチレータで変換された光は基板を介して画素に到達するため、他方のシンチレータで変換され基板を介さずに画素に到達する光と比較して光路長が長くなる。光路長が長くなると、散乱などの影響によって空間分解能が低下しうる。 In the radiation detection apparatus of Patent Document 1, since the light converted by one scintillator reaches the pixel through the substrate, the optical path length is compared with the light that is converted by the other scintillator and reaches the pixel without passing through the substrate. Becomes longer. As the optical path length becomes longer, the spatial resolution may be reduced due to the influence of scattering and the like.
 本発明は、放射線撮像パネルの空間分解能の向上に有利な技術を提供することを目的とする。 An object of the present invention is to provide a technique advantageous in improving the spatial resolution of a radiation imaging panel.
 上記課題に鑑みて、本発明の実施形態に係る放射線撮像パネルは、基板と、基板の第1の面に配された複数の画素と、複数の画素を覆うように第1の面に配された第1のシンチレータと、基板の第1の面とは反対側の第2の面を覆うように配された第2のシンチレータと、を含む放射線撮像パネルであって、第1の面に対する正射影において、基板は、複数の画素が配された画素領域を含む中央領域と、中央領域の外縁と基板の外縁との間の周辺領域とを含み、中央領域が周辺領域よりも基板の厚さが薄くなるように、第2の面は凹部を備え、第2のシンチレータが、凹部に配されることを特徴とする。 In view of the above problems, a radiation imaging panel according to an embodiment of the present invention is disposed on a first surface so as to cover a substrate, a plurality of pixels disposed on the first surface of the substrate, and the plurality of pixels. A radiation imaging panel including a first scintillator and a second scintillator disposed so as to cover a second surface opposite to the first surface of the substrate. In the projection, the substrate includes a central region including a pixel region where a plurality of pixels are arranged, and a peripheral region between the outer edge of the central region and the outer edge of the substrate, and the central region is thicker than the peripheral region. The second surface is provided with a recess so that the thickness of the second scintillator is reduced, and the second scintillator is disposed in the recess.
 上記手段によって、放射線撮像パネルの空間分解能の向上に有利な技術を提供する。 The above means provide a technique advantageous for improving the spatial resolution of the radiation imaging panel.
 本発明のその他の特徴及び利点は、添付図面を参照とした以下の説明により明らかになるであろう。なお、添付図面においては、同じ若しくは同様の構成には、同じ参照番号を付す。 Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are denoted by the same reference numerals.
 添付図面は明細書に含まれ、その一部を構成し、本発明の実施の形態を示し、その記述と共に本発明の原理を説明するために用いられる。
本発明の実施形態に係る放射線撮像パネルの構成例を示す断面図。 本発明の実施形態に係る放射線撮像パネルの構成例を示す平面図。 図1A、1Bの放射線撮像パネルの製造方法を示す図。 図1A、1Bの放射線撮像パネルの製造方法を示す図。 図1A、1Bの放射線撮像パネルの製造方法を示す図。 図1A、1Bの放射線撮像パネルの画素の配置を示す平面図。 図1A、1Bの放射線撮像パネルの画素の配置を示す断面図。 図1A、1Bの放射線撮像パネルの画素の配置を示す断面図。 図1A、1Bの放射線撮像パネルの基板の厚さとMTFとの関係を示す図。 図1A、1Bの放射線撮像パネルによって得られた放射線画像を示す図。 比較例の放射線撮像パネルによって得られた放射線画像を示す図。 図1A、1Bの放射線撮像パネルを用いた放射線撮像装置および放射線撮像システムの構成例を示す図。
The accompanying drawings are included in the specification, constitute a part thereof, show an embodiment of the present invention, and are used to explain the principle of the present invention together with the description.
Sectional drawing which shows the structural example of the radiation imaging panel which concerns on embodiment of this invention. The top view which shows the structural example of the radiation imaging panel which concerns on embodiment of this invention. The figure which shows the manufacturing method of the radiation imaging panel of FIG. 1A and 1B. The figure which shows the manufacturing method of the radiation imaging panel of FIG. 1A and 1B. The figure which shows the manufacturing method of the radiation imaging panel of FIG. 1A and 1B. The top view which shows arrangement | positioning of the pixel of the radiation imaging panel of FIG. 1A and 1B. Sectional drawing which shows arrangement | positioning of the pixel of the radiation imaging panel of FIG. 1A and 1B. Sectional drawing which shows arrangement | positioning of the pixel of the radiation imaging panel of FIG. 1A and 1B. The figure which shows the relationship between the thickness of the board | substrate of the radiation imaging panel of FIG. 1A and 1B, and MTF. The figure which shows the radiographic image obtained by the radiation imaging panel of FIG. 1A and 1B. The figure which shows the radiographic image obtained by the radiation imaging panel of a comparative example. The figure which shows the structural example of the radiation imaging device and radiation imaging system which used the radiation imaging panel of FIG. 1A and 1B.
 以下、本発明に係る放射線撮像パネルの具体的な実施形態を、添付図面を参照して説明する。本発明における放射線には、放射線崩壊によって放出される粒子(光子を含む)の作るビームであるα線、β線、γ線などの他に、同程度以上のエネルギを有するビーム、例えばX線や粒子線、宇宙線なども含みうる。 Hereinafter, specific embodiments of the radiation imaging panel according to the present invention will be described with reference to the accompanying drawings. The radiation in the present invention includes α-rays, β-rays, γ-rays, etc., which are beams produced by particles (including photons) emitted by radiation decay, as well as beams having the same or higher energy, such as X-rays, It can also include particle beams, cosmic rays, and the like.
 第1の実施形態
 図1A~2Cを参照して、本発明の実施形態による放射線撮像パネル100の構成について説明する。図1Aは、本発明の第1の実施形態における放射線撮像パネル100の構成例を示す断面図、図1Bは、放射線撮像パネル100の構成例を示す平面図である。
First Embodiment A configuration of a radiation imaging panel 100 according to an embodiment of the present invention will be described with reference to FIGS. 1A to 2C. FIG. 1A is a cross-sectional view illustrating a configuration example of the radiation imaging panel 100 according to the first embodiment of the present invention, and FIG. 1B is a plan view illustrating a configuration example of the radiation imaging panel 100.
 放射線撮像パネル100は、基板101と、基板101の第1の面(以下、表面109と呼ぶ場合がある。)に配された複数の画素を含む画素領域102と、を含む。また、放射線撮像パネル100は、基板101の表面109を覆うように配されたシンチレータ104(第1のシンチレータ)を含む波長変換部113(第1の波長変換部)と、基板101の表面109とは反対側の第2の面(以下、裏面110と呼ぶ場合がある。)を覆うように配されたシンチレータ106(第2のシンチレータ)を含む波長変換部114(第2の波長変換部)と、を含む。 The radiation imaging panel 100 includes a substrate 101 and a pixel region 102 including a plurality of pixels arranged on a first surface of the substrate 101 (hereinafter sometimes referred to as a surface 109). The radiation imaging panel 100 includes a wavelength conversion unit 113 (first wavelength conversion unit) including a scintillator 104 (first scintillator) disposed so as to cover the surface 109 of the substrate 101, and a surface 109 of the substrate 101. Includes a wavelength conversion unit 114 (second wavelength conversion unit) including a scintillator 106 (second scintillator) arranged so as to cover a second surface on the opposite side (hereinafter also referred to as a back surface 110). ,including.
 画素領域102には、シンチレータ104、106で放射線から変換された光に応じた信号を生成する光電変換素子をそれぞれ含む複数の画素が、2次元アレイ状に配される。例えば、550mm×445mmの基板101に対して、3300×2800の画素が配される。本実施形態において、3300×2800画素のうち外周に配された10画素はダミー画素とし、内側に配される3280×2780画素によって画素領域102が構成される。基板101に配される画素の数や、画素領域102に配される画素の数は、基板の大きさや撮像対象などに応じて、適宜設定すればよい。 In the pixel region 102, a plurality of pixels each including a photoelectric conversion element that generates a signal corresponding to light converted from radiation by the scintillators 104 and 106 are arranged in a two-dimensional array. For example, 3300 × 2800 pixels are arranged on a substrate 101 of 550 mm × 445 mm. In the present embodiment, 10 pixels arranged on the outer periphery of 3300 × 2800 pixels are dummy pixels, and the pixel region 102 is configured by 3280 × 2780 pixels arranged on the inner side. The number of pixels arranged on the substrate 101 and the number of pixels arranged on the pixel region 102 may be set as appropriate according to the size of the substrate, the imaging target, and the like.
 画素領域102には、さらにそれぞれの画素で生成される信号を取り出すための列信号線や、画素領域102に配される画素を含むそれぞれの素子を駆動するための行信号線などが配される。列信号線や行信号線は、それぞれ読出回路基板や駆動回路基板とフレキシブル配線基板などを介して電気的に接続されうる。列信号線および行信号線と、読出回路基板および駆動回路基板と、の接続を行うために、基板101には、接続端子部103が設けられる。接続端子部103を介して、画素領域102のそれぞれの画素で生成された信号が、放射線撮像パネル100から出力される。ここでは、読出回路および駆動回路が、放射線撮像パネル100の外部に配される例を示すが、読出回路および駆動回路が放射線撮像パネル100に配されていてもよい。この場合であっても、基板101には接続端子部103が配され、画素領域102のそれぞれの画素で生成された信号は、接続端子部103を介して放射線撮像パネル100から出力されうる。 The pixel region 102 is further provided with column signal lines for extracting signals generated in the respective pixels, row signal lines for driving the respective elements including the pixels disposed in the pixel region 102, and the like. . The column signal line and the row signal line can be electrically connected to each other via a readout circuit board, a drive circuit board, a flexible wiring board, and the like. In order to connect the column signal line and the row signal line to the reading circuit board and the driving circuit board, the connection terminal portion 103 is provided on the substrate 101. A signal generated in each pixel of the pixel region 102 is output from the radiation imaging panel 100 via the connection terminal portion 103. Here, an example in which the reading circuit and the driving circuit are arranged outside the radiation imaging panel 100 is shown, but the reading circuit and the driving circuit may be arranged in the radiation imaging panel 100. Even in this case, the connection terminal portion 103 is arranged on the substrate 101, and signals generated by the respective pixels in the pixel region 102 can be output from the radiation imaging panel 100 via the connection terminal portion 103.
 波長変換部113、114は、放射線を画素が電気信号に変換可能な光に変換するシンチレータ104、106と、反射層105、107を含む。反射層105、107は、シンチレータ104、106で生じた光のうち画素領域102に向かう方向とは異なる方向に進む光を反射するように配される。これによって、シンチレータ104、106で生じた光を効率的に利用することが可能となり、放射線撮像パネル100の感度が向上する。 The wavelength converters 113 and 114 include scintillators 104 and 106 that convert radiation into light that can be converted into electric signals by pixels, and reflective layers 105 and 107. The reflective layers 105 and 107 are arranged so as to reflect light traveling in a direction different from the direction toward the pixel region 102 among the light generated in the scintillators 104 and 106. As a result, the light generated by the scintillators 104 and 106 can be used efficiently, and the sensitivity of the radiation imaging panel 100 is improved.
 基板101には、シンチレータ106で生じた光が画素領域102まで透過するように、シンチレータ106で生じた光に対して透明な材料が用いられる。例えば、基板101には、ガラスやプラスティックなどの透明な基板が用いられうる。図1Bに示されるように、基板101の表面109に対する正射影において、基板101は、複数の画素が配された画素領域102を含む中央領域108と、中央領域108の外縁と基板101の外縁との間の周辺領域112とを含む。図1Bに示される構成では、基板101の表面109に対する正射影において、画素領域102の外縁が、中央領域108の外縁の内側に配される。また、図1Aに示されるように、中央領域108が周辺領域112よりも基板101の厚さが薄くなるように、裏面110は凹部115を備える。裏面110のうち凹部115が配される領域が、中央領域108と呼ばれうる。基板101の中央領域108は、一様の厚さを有しうる。波長変換部114は、この凹部115に配される。一方、基板101の表面109には凹部は設けられず、表面109が、中央領域108と周辺領域112との間で段差を有さなくてもよい。つまり、基板101の表面109は平坦であってもよい。ここで、基板101のうち中央領域108の厚さを厚さt1、周辺領域112の厚さを厚さt2とする。また、基板101の厚さとは、基板101の表面109および裏面110と直交する方向の基板の大きさを意味しうる。 The substrate 101 is made of a material that is transparent to the light generated by the scintillator 106 so that the light generated by the scintillator 106 is transmitted to the pixel region 102. For example, the substrate 101 can be a transparent substrate such as glass or plastic. As shown in FIG. 1B, in orthogonal projection with respect to the surface 109 of the substrate 101, the substrate 101 includes a central region 108 including a pixel region 102 in which a plurality of pixels are arranged, an outer edge of the central region 108, and an outer edge of the substrate 101. And the peripheral region 112 between the two. In the configuration shown in FIG. 1B, the outer edge of the pixel region 102 is arranged inside the outer edge of the central region 108 in the orthogonal projection with respect to the surface 109 of the substrate 101. In addition, as shown in FIG. 1A, the back surface 110 includes a recess 115 so that the central region 108 is thinner than the peripheral region 112. A region of the back surface 110 where the recess 115 is disposed can be referred to as a central region 108. The central region 108 of the substrate 101 can have a uniform thickness. The wavelength converter 114 is disposed in the recess 115. On the other hand, the surface 109 of the substrate 101 is not provided with a recess, and the surface 109 may not have a step between the central region 108 and the peripheral region 112. That is, the surface 109 of the substrate 101 may be flat. Here, it is assumed that the thickness of the central region 108 of the substrate 101 is the thickness t1, and the thickness of the peripheral region 112 is the thickness t2. Further, the thickness of the substrate 101 may mean the size of the substrate in a direction orthogonal to the front surface 109 and the back surface 110 of the substrate 101.
 基板101の表面109の側を覆うシンチレータ104と比較して基板101の裏面110の側を覆うシンチレータ106は、基板101の表面109の側に配された画素領域102までの距離が長い。シンチレータ106から画素領域102までの光路長が長くなると、シンチレータ106で生じた光は基板101中での散乱などの影響によって空間分解能が低下してしまう可能性がある。そこで、本実施形態において、基板101のうち裏面110の画素領域102が配された中央領域108に凹部115を設けることによって、基板101のうち中央領域108の厚さを薄くする。これによって、空間分解能の低下を抑制できる。一方、基板101の周辺領域112の厚さは、中央領域108よりも厚い。基板101の周辺領域112が適当な厚さを備えることによって一種の梁構造が実現でき、放射線撮像パネル100の製造中および完成後の基板101の反りを抑制することが可能となる。 Compared with the scintillator 104 that covers the surface 109 side of the substrate 101, the scintillator 106 that covers the back surface 110 side of the substrate 101 has a longer distance to the pixel region 102 disposed on the surface 109 side of the substrate 101. When the optical path length from the scintillator 106 to the pixel region 102 is increased, the spatial resolution of the light generated by the scintillator 106 may be reduced due to the influence of scattering in the substrate 101. Therefore, in this embodiment, the central region 108 of the substrate 101 is thinned by providing the recess 115 in the central region 108 of the substrate 101 where the pixel region 102 of the back surface 110 is disposed. Thereby, a decrease in spatial resolution can be suppressed. On the other hand, the peripheral region 112 of the substrate 101 is thicker than the central region 108. When the peripheral region 112 of the substrate 101 has an appropriate thickness, a kind of beam structure can be realized, and warping of the substrate 101 during and after the production of the radiation imaging panel 100 can be suppressed.
 次に、基板101の裏面110に凹部115を備える放射線撮像パネル100の製造方法について、図2A~2Cを用いて本実施形態の実施例を説明する。 Next, an example of the present embodiment will be described with reference to FIGS. 2A to 2C regarding a method for manufacturing the radiation imaging panel 100 including the recess 115 on the back surface 110 of the substrate 101.
 まず、550mm×445mm、厚み500μmの無アルカリガラスを基板101として準備した。次いで、準備した基板101の表面109に、成膜工程、フォトリソグラフィ工程、エッチング工程など既知の製造プロセスを用いて画素領域102を形成した。また、既知の製造プロセスを用いて接続端子部103を形成した。 First, an alkali-free glass having a thickness of 550 mm × 445 mm and a thickness of 500 μm was prepared as the substrate 101. Next, the pixel region 102 was formed on the surface 109 of the prepared substrate 101 using a known manufacturing process such as a film formation process, a photolithography process, and an etching process. Moreover, the connection terminal part 103 was formed using the known manufacturing process.
 画素領域102および接続端子部103を形成した後、画素領域102に形成された画素の動作をチェックするためのアレイ検査を実施した。アレイ検査で動作が良好であることを確認した後、画素領域102の全体を覆うようにセンサ保護層(不図示)を形成した。このセンサ保護層には、例えば、無機系のアモルファス膜や樹脂フィルム膜などの種々の材料を用いることができる。ただし、センサ保護層の材料は、後のシンチレータ104、106を形成する工程の温度に耐えうる耐熱特性を有する材料を用いる必要がある。本実施例では、ポリイミド樹脂をスリットコート法によって塗布し、乾燥させることによって、センサ保護層を形成した。センサ保護膜の形成後、再びアレイ検査を実施し、センサ保護層を形成する工程によって欠損した画素が無いことを確認した。 After forming the pixel region 102 and the connection terminal portion 103, an array inspection for checking the operation of the pixel formed in the pixel region 102 was performed. After confirming that the operation was good by the array inspection, a sensor protective layer (not shown) was formed so as to cover the entire pixel region 102. For this sensor protective layer, for example, various materials such as an inorganic amorphous film and a resin film film can be used. However, the material for the sensor protective layer needs to be a material having heat resistance that can withstand the temperature of the process of forming the scintillators 104 and 106 later. In this example, the sensor protective layer was formed by applying polyimide resin by a slit coat method and drying it. After the formation of the sensor protective film, the array inspection was performed again, and it was confirmed that there were no missing pixels in the process of forming the sensor protective layer.
 次に、基板101の裏面110に凹部115を形成する工程について説明する。まず凹部115を形成しない基板101の表面109に、凹部115を形成するためのフッ酸によるエッチングからの保護を目的として微粘着の樹脂フィルム201を転写した。次いで、基板101の裏面110に凹部115を形成するためのマスクパターンを形成した。具体的には、まず、基板101の裏面110を上側にして、スピンコータにセットし、フォトレジストを塗布した。本実施例では、スピンコータを用いてフォトレジストを塗布したが、例えば、ドライフィルムレジストを転写してもよい。フォトレジストを塗布した後、フォトレジストによって覆われた基板101をUV露光台に載置し、所定のフォトマスクを用いて露光した。フォトマスクは、基板101の表面109に対する正射影において、基板101の画素領域102よりも広い領域が開口している。これによって、基板101の表面109に対する正射影において、後述する凹部115に形成されるシンチレータ106が、確実に画素領域102を覆うことが可能となる。露光後、炭酸ナトリウム水溶液に基板101を浸漬することによってフォトレジストの現像を行い、純水リンス洗浄後乾燥を行った。以上の工程によって、図2Aに示されるマスクパターン202が形成された。 Next, a process of forming the recess 115 on the back surface 110 of the substrate 101 will be described. First, a slightly adhesive resin film 201 was transferred to the surface 109 of the substrate 101 where the recess 115 was not formed for the purpose of protection from etching with hydrofluoric acid for forming the recess 115. Next, a mask pattern for forming the recess 115 was formed on the back surface 110 of the substrate 101. Specifically, first, the substrate was set on a spin coater with the back surface 110 of the substrate 101 facing upward, and a photoresist was applied. In this embodiment, the photoresist is applied using a spin coater, but, for example, a dry film resist may be transferred. After applying the photoresist, the substrate 101 covered with the photoresist was placed on a UV exposure table and exposed using a predetermined photomask. In the photomask, an area wider than the pixel area 102 of the substrate 101 is opened in the orthogonal projection with respect to the surface 109 of the substrate 101. This makes it possible for the scintillator 106 formed in the recess 115 described later to reliably cover the pixel region 102 in the orthogonal projection with respect to the surface 109 of the substrate 101. After exposure, the photoresist 101 was developed by immersing the substrate 101 in an aqueous sodium carbonate solution, followed by washing with pure water rinse and drying. Through the above steps, the mask pattern 202 shown in FIG. 2A was formed.
 本実施例において、マスクパターン202は、フォトリソグラフィ工程を用いて形成したが、マスクパターン202の形成はこれに限られるものではない。凹部115を形成するためのパターンは、基板101の裏面110のうち図1Bの周辺領域112となる部分を覆う単純な形状である。このため、例えば、フィルムを転写し、所望の部分のみを剥離することでも形成可能であり、この場合、フォトレジストの塗布、露光、現像を行うリソグラフィ工程は不要となる。 In this embodiment, the mask pattern 202 is formed using a photolithography process, but the formation of the mask pattern 202 is not limited to this. The pattern for forming the recess 115 has a simple shape that covers the portion of the back surface 110 of the substrate 101 that becomes the peripheral region 112 in FIG. 1B. For this reason, for example, it can be formed by transferring a film and peeling only a desired portion. In this case, a lithography process for applying, exposing, and developing a photoresist becomes unnecessary.
 次いで、基板101をフッ酸溶液に浸漬した。予め算出した基板101のエッチングレートよって浸漬時間を計算し、基板101の裏面110のマスクパターン202に覆われていない部分を、所望の厚さまでエッチングする。エッチングを行った後、純水を用いて基板101をリンスした後、基板101をレジスト剥離液に浸漬させてマスクパターン202を剥離した。マスクパターン202の剥離を行った後、純水を用いてリンスを行い、エアーナイフにて水分を除去した。さらに基板101の表面109に貼り付けられた樹脂フィルム201を剥離した。 Next, the substrate 101 was immersed in a hydrofluoric acid solution. The immersion time is calculated based on the etching rate of the substrate 101 calculated in advance, and the portion of the back surface 110 of the substrate 101 that is not covered with the mask pattern 202 is etched to a desired thickness. After etching, the substrate 101 was rinsed with pure water, and then the substrate 101 was immersed in a resist stripping solution to strip the mask pattern 202. After peeling off the mask pattern 202, rinsing was performed using pure water, and moisture was removed with an air knife. Further, the resin film 201 attached to the surface 109 of the substrate 101 was peeled off.
 上述の方法によって、図2Bに示されるように、基板101の裏面110に、画素領域102よりも広い面積の範囲を備える凹部115が形成された。本実施例において、基板101のうち中央領域の厚さt1は200μmとした。また、基板101のうち周辺領域112の厚さt2は、準備した基板101の厚さである500μmとした。また、周辺領域112の幅、つまり凹部115と基板101の端部との距離は、基板101の短辺側で46.5mm、長辺側で61.0mmとした。周辺領域112の幅が狭い場合、上述の梁構造を実現できず、基板101が撓んでしまう可能性がある。一方、周辺領域112の幅が広い場合、複数の画素が配される画素領域102が狭くなってしまう。したがって、放射線撮像パネル100を形成する際の凹部115と基板101の端部との距離は、例えば40mm以上かつ100mm以下の範囲としてもよい。また、本実施例においてウエットエッチングによって凹部115を形成したが、凹部115の形成方法は、これに限られることはなく、例えば研磨などを用いて凹部115を形成してもよい。 By the above-described method, as shown in FIG. 2B, a recess 115 having a wider area range than the pixel region 102 was formed on the back surface 110 of the substrate 101. In this embodiment, the thickness t1 of the central region of the substrate 101 is 200 μm. In addition, the thickness t2 of the peripheral region 112 in the substrate 101 was set to 500 μm, which is the thickness of the prepared substrate 101. The width of the peripheral region 112, that is, the distance between the recess 115 and the end of the substrate 101 was 46.5 mm on the short side of the substrate 101 and 61.0 mm on the long side. When the width of the peripheral region 112 is narrow, the above-described beam structure cannot be realized and the substrate 101 may be bent. On the other hand, when the peripheral region 112 is wide, the pixel region 102 in which a plurality of pixels are arranged becomes narrow. Therefore, the distance between the recess 115 and the end of the substrate 101 when forming the radiation imaging panel 100 may be in the range of, for example, 40 mm or more and 100 mm or less. In this embodiment, the recess 115 is formed by wet etching. However, the method for forming the recess 115 is not limited to this. For example, the recess 115 may be formed by polishing.
 凹部115を形成した後、波長変換部114を形成した。まず、基板101の凹部115内にシンチレータ106が形成されるように、シンチレータ106を形成する領域を除く周辺部分を覆う蒸着マスクをセットした後、凹部115が蒸着面となるように基板101を蒸着装置に載置した。次いで、タリウム添加ヨウ化セシウム(CsI:Tl)を蒸着し、図2Cに示すように、膜厚250μmのシンチレータ106を形成した。基板101の表面109に対する正射影において、シンチレータ106の外縁は、画素領域102の外縁よりも外側に配されうる。 After forming the recess 115, the wavelength converter 114 was formed. First, after setting a vapor deposition mask that covers a peripheral portion excluding a region where the scintillator 106 is formed so that the scintillator 106 is formed in the concave portion 115 of the substrate 101, the substrate 101 is vapor deposited so that the concave portion 115 becomes a vapor deposition surface. Placed on the device. Next, thallium-added cesium iodide (CsI: Tl) was deposited to form a scintillator 106 with a thickness of 250 μm as shown in FIG. 2C. In the orthogonal projection with respect to the surface 109 of the substrate 101, the outer edge of the scintillator 106 can be arranged outside the outer edge of the pixel region 102.
 シンチレータ106を形成した後、蒸着装置から基板101を取り出す。取り出した基板101の表面109の画素領域102が覆われる範囲にシンチレータ104が形成されるように、シンチレータ104を形成する領域を除く周辺部分を覆う蒸着マスクをセットした。その後、蒸着マスクがセットされた表面109が蒸着面となるように基板101を再び蒸着装置に載置した。この状態でCsI:Tlを蒸着し、図2Cに示すように、膜厚350μmのシンチレータ104を形成した。基板101の表面109に対する正射影において、シンチレータ104の外縁は、画素領域102の外縁よりも外側に配されうる。 After forming the scintillator 106, the substrate 101 is taken out from the vapor deposition apparatus. A vapor deposition mask that covers the peripheral portion excluding the region where the scintillator 104 is formed is set so that the scintillator 104 is formed in a range where the pixel region 102 of the surface 109 of the substrate 101 taken out is covered. Thereafter, the substrate 101 was placed again on the vapor deposition apparatus so that the surface 109 on which the vapor deposition mask was set became the vapor deposition surface. In this state, CsI: Tl was vapor-deposited to form a scintillator 104 having a thickness of 350 μm as shown in FIG. 2C. In the orthogonal projection with respect to the surface 109 of the substrate 101, the outer edge of the scintillator 104 can be arranged outside the outer edge of the pixel region 102.
 続いて、基板101を蒸着装置から取り出し、速やかに基板101の裏面110が上向きになるように転写装置にセットした。転写装置において、30μm厚のホットメルト樹脂がコーティングされている20μm厚のアルミニウム薄膜をシンチレータ106の上に熱転写することによって、反射層107を形成した。このとき、シンチレータ106と反射層107とによって構成される波長変換部114の厚さを厚さt3とすると、厚さt3は300μmとなった。 Subsequently, the substrate 101 was taken out from the vapor deposition apparatus, and immediately set on the transfer apparatus so that the back surface 110 of the substrate 101 faced upward. In the transfer device, the reflective layer 107 was formed by thermally transferring a 20 μm-thick aluminum thin film coated with a 30 μm-thick hot melt resin onto the scintillator 106. At this time, when the thickness of the wavelength conversion unit 114 constituted by the scintillator 106 and the reflective layer 107 is defined as the thickness t3, the thickness t3 is 300 μm.
 厚さt3が、凹部115の深さよりも厚くなった場合、裏面110を下にして基板101を置いた場合、波長変換部114が突出し、基板101の周辺領域112が浮いてしまう。周辺領域112が浮いた状態で、後述する接続端子部103に配線を接続する工程を行った場合、配線を接続する工程の間、基板101が不安定となって歩留まりが低下するなどの問題が発生する可能性がある。また、周辺領域112が浮いた状態の基板101を安定させるためには、冶具などが必要となり、製造コストが上昇してしまう可能性がある。 When the thickness t3 is thicker than the depth of the recess 115, when the substrate 101 is placed with the back surface 110 facing down, the wavelength conversion unit 114 protrudes and the peripheral region 112 of the substrate 101 floats. When a process of connecting a wiring to the connection terminal portion 103 to be described later is performed in a state where the peripheral region 112 is floating, there is a problem that the substrate 101 becomes unstable and the yield decreases during the process of connecting the wiring. May occur. In addition, in order to stabilize the substrate 101 in a state where the peripheral region 112 is floated, a jig or the like is required, which may increase the manufacturing cost.
 このため、波長変換部114の厚さt3は、凹部115の深さ、換言すると基板101の周辺領域の厚さt2から中央領域108の厚さt1を減じた厚さ以下である必要がある。つまり、基板101のうち中央領域108の厚さをt1[μm]、基板101のうち周辺領域112の厚さをt2[μm]、波長変換部114の厚さをt3[μm]としたとき、
t3≦t2-t1 … (1)
である必要がある。本実施例において、厚さt1=500[μm]、厚さt2=200[μm]、厚さt3=300[μm]であるため、上述の(1)式を満たす。また、本実施例において、波長変換部114と基板101の裏面110の周辺領域112との間には殆ど段差がない状態となった。
For this reason, the thickness t3 of the wavelength converter 114 needs to be equal to or less than the depth of the recess 115, in other words, the thickness t2 of the peripheral region of the substrate 101 minus the thickness t1 of the central region 108. That is, when the thickness of the central region 108 of the substrate 101 is t1 [μm], the thickness of the peripheral region 112 of the substrate 101 is t2 [μm], and the thickness of the wavelength conversion unit 114 is t3 [μm],
t3 ≦ t2-t1 (1)
Need to be. In this embodiment, since the thickness t1 = 500 [μm], the thickness t2 = 200 [μm], and the thickness t3 = 300 [μm], the above formula (1) is satisfied. In this embodiment, there is almost no step between the wavelength converter 114 and the peripheral region 112 of the back surface 110 of the substrate 101.
 次に、基板101の表面109が上向きになるように転写装置にセットし、反射層107と同じ材料を熱転写することによって反射層105を形成した。これら反射層105、107は、シンチレータ104、106で生じた光を効果的に画素領域102に向かわせる効果のみだけでなく、シンチレータ104、106として用いるCsI:Tlの防湿層としての機能も備えうる。 Next, the reflective layer 105 was formed by setting the transfer device so that the surface 109 of the substrate 101 faced upward and thermally transferring the same material as the reflective layer 107. These reflective layers 105 and 107 not only have the effect of effectively directing the light generated by the scintillators 104 and 106 toward the pixel region 102, but can also have a function as a moisture-proof layer of CsI: Tl used as the scintillators 104 and 106. .
 本実施例において、シンチレータ104、106にCsI:Tlを用いたが、これに限られることはない。例えば、テルビウム添加酸硫化ガドリニウム(GOS:Tb)などの粒子状のシンチレータの厚膜シートを転写することによってシンチレータ106を形成してもよい。 In this embodiment, CsI: Tl is used for the scintillators 104 and 106, but the present invention is not limited to this. For example, the scintillator 106 may be formed by transferring a thick film sheet of a particulate scintillator such as terbium-added gadolinium oxysulfide (GOS: Tb).
 波長変換部113、114の形成後、基板101の不必要な領域を、例えば、スクライブ装置など用いて除去し、面取りを実施した後、実装装置にセットした。本実施例において、スクライブ装置による基板101の不必要な領域の除去および面取りの後の、凹部115と基板101の端部との距離は、6.2mmとした。凹部115と基板101の端部との距離は、十分に実装の工程に耐えられる強度を保つためには少なくとも5.0mm以上が必要である。また、基板101の端部から画素領域102までの距離を鑑みると、凹部115と基板101の端部の距離は、50mm以下であってもよい。つまり、放射線撮像装置に実装された放射線撮像パネル100の基板の凹部115と基板101の端部との距離が、5.0mm以上かつ50mm以下の範囲であってもよい。その後、実装装置において、列信号線、行信号線のそれぞれを放射線撮像パネル100の外部と接続させるために、接続端子部103にフレキシブル配線基板を接続する外周配線接続(OLB:Outer Lead Bonding)を行った。 After forming the wavelength converters 113 and 114, unnecessary regions of the substrate 101 were removed using, for example, a scribing device, chamfered, and then set on a mounting device. In this example, the distance between the recess 115 and the end of the substrate 101 after removing unnecessary regions of the substrate 101 and chamfering by the scribing device was set to 6.2 mm. The distance between the recess 115 and the end of the substrate 101 needs to be at least 5.0 mm in order to maintain sufficient strength to withstand the mounting process. In view of the distance from the end of the substrate 101 to the pixel region 102, the distance between the recess 115 and the end of the substrate 101 may be 50 mm or less. That is, the distance between the concave portion 115 of the substrate of the radiation imaging panel 100 mounted on the radiation imaging apparatus and the end portion of the substrate 101 may be in a range of 5.0 mm or more and 50 mm or less. Thereafter, in the mounting apparatus, in order to connect each of the column signal lines and the row signal lines to the outside of the radiation imaging panel 100, an outer peripheral wiring connection (OLB: Outer | Lead | Bonding) that connects the flexible wiring board to the connection terminal portion 103 is performed. went.
 このとき、接続端子部103は、十分な強度を担保できており、基板101が割れるなどのトラブルは発生しなかった。一方、比較例として基板の裏面に凹部を備えず、厚さが260μmの同じ無アルカリガラスを基板として用い同様の試作を行った。比較例では、反射層107の形成時とOLBの工程とにおいて、それぞれ基板が割れるなどの破損が発生した。また、基板の全体が260μmと薄いため、通常の把持方法では基板に大きい反り、撓みが発生し、アレイ検査によって一部の画素など素子の破壊が確認された。一方、本実施例の基板101は、周辺領域112が厚いため、基板101の反りが抑制され、基板101の変形に起因する素子の破壊は確認されなかった。 At this time, the connection terminal portion 103 was able to secure sufficient strength, and troubles such as breakage of the substrate 101 did not occur. On the other hand, as a comparative example, the same trial manufacture was performed using the same non-alkali glass having a thickness of 260 μm as a substrate without providing a recess on the back surface of the substrate. In the comparative example, damage such as cracking of the substrate occurred during the formation of the reflective layer 107 and the OLB process. In addition, since the entire substrate was as thin as 260 μm, the substrate was warped and bent by a normal gripping method, and destruction of elements such as some pixels was confirmed by array inspection. On the other hand, since the peripheral region 112 of the substrate 101 of this example is thick, the warpage of the substrate 101 is suppressed, and element destruction due to deformation of the substrate 101 was not confirmed.
 上述の工程によって、図1Aに示される放射線撮像パネル100が得られた。この放射線撮像パネル100を、フレキシブル配線基板を介して回路基板に接続し、筐体の中に配置組み立てることによって、本実施例の放射線撮像装置が得られた。回路基板は、放射線撮像パネル100を制御するための制御部と、放射線撮像パネル100から出力される信号を処理するための信号処理部と、を含む。 The radiation imaging panel 100 shown in FIG. 1A was obtained by the above-described steps. The radiation imaging panel 100 of this example was obtained by connecting the radiation imaging panel 100 to a circuit board via a flexible wiring board and arranging the radiation imaging panel 100 in a housing. The circuit board includes a control unit for controlling the radiation imaging panel 100 and a signal processing unit for processing a signal output from the radiation imaging panel 100.
 得られた放射線撮像装置をRQA5の線質条件で駆動し、検出量子効率(DQE:Detective Quantum Efficiency)と光学伝達係数(MTF:Modulation Transfer Function)を測定した。図1Aに示すように、放射線111は、基板101の表面109の側から放射線撮像パネル100に入射させた。空間周波数2lp/mmの条件において、DQEは0.70、MTFは0.40であった。 The obtained radiation imaging apparatus was driven under the quality condition of RQA5, and the detection quantum efficiency (DQE: Detect Quantum Efficiency) and the optical transfer coefficient (MTF: Modulation Transfer Function) were measured. As shown in FIG. 1A, the radiation 111 was incident on the radiation imaging panel 100 from the surface 109 side of the substrate 101. Under the condition of the spatial frequency of 2 lp / mm, the DQE was 0.70 and the MTF was 0.40.
 比較例として波長変換部113を備え、波長変換部114を備えていない放射線撮像パネルを含む放射線撮像装置について同様の測定を行った。比較例の放射線撮像装置のDQEは0.610、MTFは0.40であった。 As a comparative example, the same measurement was performed on a radiation imaging apparatus including a radiation imaging panel including the wavelength conversion unit 113 and not including the wavelength conversion unit 114. The DQE of the comparative radiation imaging apparatus was 0.610, and the MTF was 0.40.
 このように、本実施例の放射線撮像パネル100は、基板101の表面109および裏面110の両方に配されたシンチレータ104、106で放射線から変換される光を画素領域102に入射させることによって、高いDQEを示すことが確認できた。また、基板101の裏面110の側に配されるシンチレータ106からの光は、基板101を介して画素領域102に入射するが、基板101の裏面110に凹部115を形成し、凹部115にシンチレータ106を配することによって、光路長の増加を抑制した。これによって、MTFの劣化が抑制され、本実施例の放射線撮像パネル100を含む放射線撮像装置において、比較例の放射線撮像パネルを含む放射線撮像装置と同等のMTFが実現できた。 As described above, the radiation imaging panel 100 according to the present embodiment is high by making light converted from radiation by the scintillators 104 and 106 arranged on both the front surface 109 and the back surface 110 of the substrate 101 enter the pixel region 102. It was confirmed that DQE was shown. Further, light from the scintillator 106 disposed on the back surface 110 side of the substrate 101 enters the pixel region 102 through the substrate 101, but a recess 115 is formed in the back surface 110 of the substrate 101, and the scintillator 106 is formed in the recess 115. By suppressing the increase in the optical path length, it was suppressed. As a result, the degradation of the MTF was suppressed, and in the radiation imaging apparatus including the radiation imaging panel 100 of the present example, an MTF equivalent to the radiation imaging apparatus including the radiation imaging panel of the comparative example could be realized.
 第2の実施形態
 図3A~5Bを参照して、本発明の実施形態による放射線撮像パネル100の構成について説明する。本実施形態において、上述の放射線撮像パネル100を用いてエネルギサブトラクション画像を取得する。エネルギサブトラクションとは、高エネルギと低エネルギとの異なるエネルギの放射線を用いた放射線画像(高エネルギ画像および低エネルギ画像と呼ぶ場合がある。)を取得し、これらの差分などから、エネルギ吸収率の異なる物質を分離し、表示する方法である。例えば、骨と骨以外の組織との分離などを行うことが可能であり、診断能の向上が期待されている。高エネルギ画像および低エネルギ画像は、2回の放射線の照射によって容易に取得することが可能である。しかしながら、本実施形態の放射線撮像パネル100は、後述するように1回の放射線照射によってエネルギサブトラクション画像が取得可能である。つまり、被曝線量を抑制可能な放射線撮像パネル100が実現できる。
Second Embodiment A configuration of a radiation imaging panel 100 according to an embodiment of the present invention will be described with reference to FIGS. 3A to 5B. In this embodiment, an energy subtraction image is acquired using the radiation imaging panel 100 described above. Energy subtraction is the acquisition of radiation images (sometimes called high energy images and low energy images) using radiation with different energies between high energy and low energy. It is a method of separating and displaying different substances. For example, it is possible to separate bones from tissues other than bones, and improvement of diagnostic ability is expected. A high energy image and a low energy image can be easily acquired by two irradiations of radiation. However, the radiation imaging panel 100 of this embodiment can acquire an energy subtraction image by one-time radiation irradiation as will be described later. That is, the radiation imaging panel 100 capable of suppressing the exposure dose can be realized.
 図3A~3Cは、本発明の第2の実施形態による放射線撮像パネル100の画素領域102の2種類の画素300、301の配置を示す平面図および断面図である。画素300には、上述の第1の実施形態と同様に、基板101の表面109の側に配されたシンチレータ104で生じた光と、基板101の裏面110の側に配されたシンチレータ106で生じた光との両方の光が入射する。一方、画素301には、図3Bに示されるように、シンチレータ104と画素301との間に、シンチレータ104で放射線から変換された光が画素301の光電変換素子に入射することを抑制する遮光層302が設けられる。つまり、画素301には、シンチレータ106で生じた光は入射するが、シンチレータ104で生じた光は遮光層302によって遮光されるため、シンチレータ104で生じた光の一部が入射する。シンチレータ104で生じた光のすべてが遮光層302によって遮光され、画素301には、シンチレータ106で生じた光だけが入射してもよい。このため、画素301は、遮光画素とも呼ばれうる。本実施形態において、遮光層302は、シンチレータ104と画素301との間に、シンチレータ104で放射線から変換された光が画素301に入射することを抑制するように設けられるが、これに限られることはない。遮光層302は、シンチレータ106と画素301との間に、シンチレータ106で放射線から変換された光が画素301に入射することを抑制するように設けられてもよい。本実施形態の放射線撮像パネル100は、この遮光層302が一部の画素に設けられることが上述の第1の実施形態と異なる。これ以外の放射線撮像パネル100の構成は、上述の第1の実施形態と同様であってもよい。 3A to 3C are a plan view and a cross-sectional view showing the arrangement of two types of pixels 300 and 301 in the pixel region 102 of the radiation imaging panel 100 according to the second embodiment of the present invention. In the pixel 300, similarly to the first embodiment described above, light generated by the scintillator 104 disposed on the front surface 109 side of the substrate 101 and light generated by the scintillator 106 disposed on the back surface 110 side of the substrate 101 are generated. Both light and incident light are incident. On the other hand, as shown in FIG. 3B, the pixel 301 includes a light shielding layer that prevents light converted from radiation by the scintillator 104 from entering the photoelectric conversion element of the pixel 301 between the scintillator 104 and the pixel 301. 302 is provided. That is, although the light generated by the scintillator 106 is incident on the pixel 301, the light generated by the scintillator 104 is blocked by the light blocking layer 302, and thus a part of the light generated by the scintillator 104 is incident. All of the light generated by the scintillator 104 may be blocked by the light blocking layer 302, and only the light generated by the scintillator 106 may enter the pixel 301. For this reason, the pixel 301 can also be referred to as a light-shielded pixel. In the present embodiment, the light shielding layer 302 is provided between the scintillator 104 and the pixel 301 so as to suppress the light converted from the radiation by the scintillator 104 from entering the pixel 301, but is not limited thereto. There is no. The light shielding layer 302 may be provided between the scintillator 106 and the pixel 301 so as to prevent light converted from radiation by the scintillator 106 from entering the pixel 301. The radiation imaging panel 100 of this embodiment is different from the first embodiment described above in that the light shielding layer 302 is provided in some pixels. Other configurations of the radiation imaging panel 100 may be the same as those in the first embodiment.
 図1Aに示されるように、放射線111が、放射線撮像パネル100の基板101の表面109の側から入射する場合、シンチレータ106には、シンチレータ104よりも高エネルギの放射線が入射する。つまり、シンチレータ104では低エネルギの放射線が光に変換され、シンチレータ106では高エネルギの放射線が光に変換される。画素300は、シンチレータ104およびシンチレータ106で放射線から変換された光、つまり高エネルギおよび低エネルギの両方の放射線に起因する信号を取得できる。また、画素301は、シンチレータ106で放射線から変換された光、つまり高エネルギの放射線に起因する信号を取得できる。これによって、本実施形態の放射線撮像パネル100は、ワンショットで高エネルギと低エネルギとの2種類にエネルギの放射線画像を取得し、エネルギサブトラクション画像を取得することができる。本実施形態では、放射線撮像パネル100の基板101の表面109の側から放射線が入射する場合を説明するが、放射線は基板101の裏面110の側から入射させてもよい。 As shown in FIG. 1A, when the radiation 111 is incident from the surface 109 side of the substrate 101 of the radiation imaging panel 100, radiation having higher energy than that of the scintillator 104 is incident on the scintillator 106. That is, the scintillator 104 converts low energy radiation into light, and the scintillator 106 converts high energy radiation into light. Pixel 300 can acquire light converted from radiation at scintillator 104 and scintillator 106, that is, signals resulting from both high energy and low energy radiation. Further, the pixel 301 can acquire light converted from radiation by the scintillator 106, that is, a signal resulting from high-energy radiation. Thereby, the radiation imaging panel 100 of this embodiment can acquire the radiation image of energy in two types, high energy and low energy, and can acquire the energy subtraction image by one shot. In this embodiment, the case where radiation enters from the front surface 109 side of the substrate 101 of the radiation imaging panel 100 will be described, but the radiation may be incident from the back surface 110 side of the substrate 101.
 遮光画素である画素301の配置パターンは、図3Aに示される限りではなく、適宜設定すればよい。しかしながら、画素301の比率が高くなると、画素300の画素ピッチが広がってしまい、得られる放射線画像の画質の低下を招いてしまう可能性がある。画素301は、周辺の画素と著しく異なる信号を出力する欠陥画素と同様に、画像補てん技術によって補うことができるが、画素301の比率が高くなった場合、補てん後の画質の低下が大きくなりうる。そこで、例えば、複数の画素301の数が、複数の画素の全体(画素300と画素301との合計)の1/2以下となるように画素300と画素301との配置を調整してもよい。また、画素301の数が、例えば、画素全体の1/3以下になるようにしてもよいし、1/4以下になるようにしてもよいし、1/5以下になるようにしてもよい。 The arrangement pattern of the pixels 301 that are light-shielding pixels is not limited to that shown in FIG. However, when the ratio of the pixels 301 is increased, the pixel pitch of the pixels 300 is increased, and there is a possibility that the quality of the obtained radiation image is deteriorated. The pixel 301 can be compensated by image compensation technology, as is the case with a defective pixel that outputs a signal that is significantly different from the surrounding pixels. However, when the ratio of the pixels 301 increases, the image quality after compensation can be greatly reduced. . Therefore, for example, the arrangement of the pixels 300 and the pixels 301 may be adjusted so that the number of the plurality of pixels 301 is equal to or less than ½ of the total of the plurality of pixels (the sum of the pixels 300 and 301). . Further, the number of pixels 301 may be, for example, 1/3 or less of the entire pixels, 1/4 or less, or 1/5 or less. .
 また、本実施形態では、画素領域102に配される画素のうち一部の画素301に遮光層302が配されるが、これに限られることはない。例えば、図3Cに示されるように、画素領域102に配される複数の画素が画素310と画素311との2種類の遮光画素を含んでいてもよい。画素310において、シンチレータ106と画素310との間に、シンチレータ106で放射線から変換された光が画素310に入射することを抑制する遮光層302aが配される。また、画素311において、シンチレータ104と画素311との間に、シンチレータ104で放射線から変換された光が画素311に入射することを抑制する遮光層302bが配される。この構成によって、放射線が基板101の表面109の側から入射する場合、ワンショットで、画素310は低エネルギ、画素311は高エネルギのそれぞれ放射線画像を生成するための信号を取得し、エネルギサブトラクション画像を取得することができる。 In the present embodiment, the light shielding layer 302 is disposed in some of the pixels 301 among the pixels disposed in the pixel region 102, but is not limited thereto. For example, as illustrated in FIG. 3C, a plurality of pixels arranged in the pixel region 102 may include two types of light-shielding pixels, a pixel 310 and a pixel 311. In the pixel 310, between the scintillator 106 and the pixel 310, a light shielding layer 302 a that suppresses the light converted from the radiation by the scintillator 106 from entering the pixel 310 is disposed. Further, in the pixel 311, a light shielding layer 302 b that suppresses the light converted from the radiation by the scintillator 104 from entering the pixel 311 is disposed between the scintillator 104 and the pixel 311. With this configuration, when radiation is incident from the surface 109 side of the substrate 101, a signal for generating a radiation image of low energy and a pixel 311 of the pixel 310 is acquired in one shot, and an energy subtraction image is obtained. Can be obtained.
 次に、本実施形態の遮光画素(画素301)を含む放射線撮像パネル100の製造方法について、本実施形態の実施例を説明する。 Next, an example of the present embodiment will be described with respect to a method for manufacturing the radiation imaging panel 100 including the light-shielding pixels (pixels 301) of the present embodiment.
 まず、上述の第1の実施形態の実施例と同様に、基板101に、画素領域102および接続端子部103を形成した。次いで、遮光層302を基板101に形成した。本実施例では、予めフォトレジストを塗布し、パターニングすることによって、画素301の上に開口を有するマスクパターンを形成した。次いで、スピンコートによって低反射率クロム分散液を塗布し、現像することによって、画素301を覆うように遮光層302を形成した。本実施例において、遮光層302の膜厚は約1.2μm、可視光透過率は約1.0%であった。 First, similarly to the example of the first embodiment described above, the pixel region 102 and the connection terminal portion 103 were formed on the substrate 101. Next, a light shielding layer 302 was formed on the substrate 101. In this embodiment, a mask pattern having an opening is formed on the pixel 301 by applying a photoresist in advance and patterning. Next, a light-reflective layer 302 was formed so as to cover the pixels 301 by applying and developing a low-reflectance chromium dispersion by spin coating. In this example, the thickness of the light shielding layer 302 was about 1.2 μm, and the visible light transmittance was about 1.0%.
 その後、上述の第1の実施例と同様に、図2A~2Cに示されるそれぞれの工程を行うことによって、放射線撮像パネル100を作製した。この放射線撮像パネル100を、フレキシブル配線基板を介して回路基板に接続し、筐体の中に配置組み立てることによって、本実施例の放射線撮像装置が得られた。ただし、本実施例において、基板101の中央領域108の厚さt1は250μm、周辺領域112の厚さt2は500μm、シンチレータ104の厚さは400μm、シンチレータ106の厚さは200μm、反射層105、107の厚さは50μmとした。したがって、上述の波長変換部114の厚さt3は250μmであり、上述の(1)式を満たしている。また、本実施例においても、上述の第1の実施形態の実施例と同様に、基板101であるガラスの破損、撓み、反りなどの問題は発生しなかった。また、比較例として、基板の厚さが500μmで、凹部115を有さないこと以外、本実施例と同様の放射線撮像パネルを作製し、この放射線撮像パネルを搭載した比較例の放射線撮像装置を得た。 Thereafter, similarly to the first embodiment described above, the radiation imaging panel 100 was manufactured by performing the respective steps shown in FIGS. 2A to 2C. The radiation imaging panel 100 of this example was obtained by connecting the radiation imaging panel 100 to a circuit board via a flexible wiring board and arranging the radiation imaging panel 100 in a housing. However, in this embodiment, the thickness t1 of the central region 108 of the substrate 101 is 250 μm, the thickness t2 of the peripheral region 112 is 500 μm, the thickness of the scintillator 104 is 400 μm, the thickness of the scintillator 106 is 200 μm, the reflective layer 105, The thickness of 107 was 50 μm. Therefore, the thickness t3 of the wavelength conversion unit 114 is 250 μm, which satisfies the above-described expression (1). Also in this example, similarly to the example of the first embodiment described above, problems such as breakage, bending, and warping of the glass serving as the substrate 101 did not occur. Moreover, as a comparative example, a radiation imaging panel similar to that of this example except that the substrate thickness is 500 μm and the recess 115 is not provided, and a radiation imaging apparatus of a comparative example equipped with this radiation imaging panel is prepared. Obtained.
 ここで、複数の成分を含む物質を放射線が透過した際のそれぞれの画素から出力される信号値は以下の式(2)で表される。 Here, the signal value output from each pixel when radiation passes through a substance containing a plurality of components is expressed by the following equation (2).
Figure JPOXMLDOC01-appb-M000001
ここでEは放射線のエネルギ、μは成分iの線減弱定数、tは成分iの厚み、N(E)は照射した放射線のエネルギ分布である。
Figure JPOXMLDOC01-appb-M000001
Here, E is the energy of radiation, μ i is the linear attenuation constant of component i, t i is the thickness of component i, and N (E) is the energy distribution of the irradiated radiation.
 式(2)に高エネルギおよび低エネルギのそれぞれ観測された信号値を用い、積分方程式を解くことによって、各成分の厚みtを計算することができる。本実施例において、高エネルギおよび低エネルギのそれぞれの信号値は以下の通りに求めた。
高エネルギの信号値=画素301で観測された信号値
低エネルギの信号値=(画素301を取り囲む周辺8つの画素300の信号値のメジアン平均値)-(画素301で観測された信号値)
Using each observed signal value of the high-energy and low-energy equation (2), by solving the integral equation, it is possible to calculate the thickness t i of each component. In this example, the signal values of high energy and low energy were determined as follows.
High energy signal value = signal value observed at pixel 301 Low energy signal value = (median average of signal values of eight neighboring pixels 300 surrounding pixel 301) − (signal value observed at pixel 301)
 図4は、シンチレータ104の厚さが400μm、シンチレータ106の厚さが200μmの場合の、中央領域108の基板101の厚さt1とシンチレータ106の発光についての空間周波数2lp/mmの条件でのMTFとの関係を示す。図1Aに示されるように、放射線111が、波長変換部113の側から入射し、波長変換部114のシンチレータ106で光に変換され、この光が基板101を透過し、画素領域102に届くまでのMTFである。このとき、シンチレータ104の発光についてのMTF(放射線111が、波長変換部113の側から入射し、波長変換部113のシンチレータ104で光に変換され、この光が画素領域102に届くまでのMTF。)は、基板101の厚さt1が0μmの場合と同じ値、つまり、0.35となる。 FIG. 4 shows an MTF under the condition that the thickness t1 of the substrate 101 in the central region 108 and the spatial frequency of light emission of the scintillator 106 are 2 lp / mm when the thickness of the scintillator 104 is 400 μm and the thickness of the scintillator 106 is 200 μm. Shows the relationship. As shown in FIG. 1A, radiation 111 enters from the wavelength conversion unit 113 side, is converted into light by the scintillator 106 of the wavelength conversion unit 114, and the light passes through the substrate 101 and reaches the pixel region 102. The MTF. At this time, the MTF for light emission of the scintillator 104 (the MTF until the radiation 111 enters from the wavelength conversion unit 113 side, is converted into light by the scintillator 104 of the wavelength conversion unit 113, and this light reaches the pixel region 102. ) Is the same value as when the thickness t1 of the substrate 101 is 0 μm, that is, 0.35.
 高エネルギ画像と低エネルギ画像とのMTFの差が広がると、エネルギサブトラクション処理を行った際に、特に高周波の成分が強調され、結果として不必要にエッジが強調された違和感のある画像となってしまう場合がある。図4に示されるように、基板101の厚さt1が500μm以上となると、計算上、MTFがほぼ0になる。このため、シンチレータ104の発光に対するMTFとの差が広がり、エネルギサブトラクション画像の画像品位が著しく低下することが予想される。また、図4から、基板101のうち中央領域108の厚さt1が250μmである本実施例の放射線撮像装置において、MTFの差は0.2以下であることがわかる。一方、比較例の基板の厚さが500μmで凹部を有さない放射線撮像装置において、MTFの差は約0.35であることがわかる。 When the difference in MTF between the high-energy image and the low-energy image widens, when the energy subtraction process is performed, particularly high-frequency components are emphasized, resulting in an uncomfortable image in which edges are unnecessarily enhanced. May end up. As shown in FIG. 4, when the thickness t1 of the substrate 101 is 500 μm or more, the MTF is almost 0 in calculation. For this reason, the difference with MTF with respect to light emission of the scintillator 104 is widened, and it is expected that the image quality of the energy subtraction image is remarkably lowered. Further, it can be seen from FIG. 4 that in the radiation imaging apparatus of the present example in which the thickness t1 of the central region 108 of the substrate 101 is 250 μm, the MTF difference is 0.2 or less. On the other hand, it can be seen that the MTF difference is about 0.35 in the radiation imaging apparatus having a substrate thickness of 500 μm and no recesses in the comparative example.
 図5Aに、放射線源の管電圧80kVをとして撮影された手ファントムの透過画像を用い、上述の式(2)を用いて取得した本実施例の放射線撮像パネル100を備える放射線撮像装置の骨分離画像を示す。図5Bは、同様の条件で比較例の放射線撮像パネルを備える放射線撮像装置を用いて取得した骨分離画像である。図5Aから、シンチレータ104の発光についてのMTFとシンチレータ106の発光についてのMTFとの差が0.2以下である本実施例の放射線撮像装置において、十分に高品位な骨分離画像が得られていることがわかる。一方、MTFの差が0.35である比較例の放射線撮像装置では、エッジが強調され違和感が強い骨分離画像であることがわかる。 FIG. 5A shows a bone separation of a radiation imaging apparatus including the radiation imaging panel 100 of the present embodiment, which is obtained by using the transmission image of a hand phantom photographed with a tube voltage of 80 kV of the radiation source and using the above-described equation (2). An image is shown. FIG. 5B is a bone separation image acquired using a radiation imaging apparatus including the radiation imaging panel of the comparative example under the same conditions. From FIG. 5A, a sufficiently high-quality bone separation image is obtained in the radiation imaging apparatus of the present embodiment in which the difference between the MTF for the light emission of the scintillator 104 and the MTF for the light emission of the scintillator 106 is 0.2 or less. I understand that. On the other hand, in the radiation imaging apparatus of the comparative example in which the difference in MTF is 0.35, it can be seen that the bone is an isolated bone image with a strong edge and a strong sense of discomfort.
 以上より、良好なエネルギサブトラクション画像を得るためには、シンチレータ104の発光に応じて得られるMTFとシンチレータ106の発光に応じて得られるMTFとの差を0.2以下にすることが必要であることがわかった。また、MTFの差を0.2以下にするために、図4から、基板101の中央領域108の厚さt1を300μm以下にする必要がある。また、よりエネルギサブトラクション画像の画質を向上するために、例えば、本実施例のように基板101の中央領域108の厚さが、250μm以下であってもよい。さらに、例えば、基板101の中央領域108の厚さが、200μm以下であってもよい。ただし、基板101の中央領域108の厚さt1が薄くなりすぎると、基板101の強度が保てなくなる可能性がある。このため、例えば、基板101の中央領域108の厚さは、50μm以上であってもよい。 As described above, in order to obtain a good energy subtraction image, it is necessary to make the difference between the MTF obtained according to the light emission of the scintillator 104 and the MTF obtained according to the light emission of the scintillator 106 to 0.2 or less. I understood it. Further, in order to make the MTF difference 0.2 or less, it is necessary from FIG. 4 that the thickness t1 of the central region 108 of the substrate 101 is 300 μm or less. In order to further improve the image quality of the energy subtraction image, for example, the thickness of the central region 108 of the substrate 101 may be 250 μm or less as in the present embodiment. Further, for example, the thickness of the central region 108 of the substrate 101 may be 200 μm or less. However, if the thickness t1 of the central region 108 of the substrate 101 becomes too thin, the strength of the substrate 101 may not be maintained. Therefore, for example, the thickness of the central region 108 of the substrate 101 may be 50 μm or more.
 以下、上述の各実施形態および各実施例の放射線撮像パネル100が組み込まれた放射線撮像装置の応用例として、放射線撮像パネル100が組み込まれた放射線撮像装置を用いた放射線撮像システム600について図6を用いて説明する。 Hereinafter, as an application example of the radiation imaging apparatus in which the radiation imaging panel 100 of each embodiment and each example described above is incorporated, FIG. 6 illustrates a radiation imaging system 600 using the radiation imaging apparatus in which the radiation imaging panel 100 is incorporated. It explains using.
 放射線撮像システム600は、放射線で形成される光学像を電気的に撮像し、電気的な放射線画像(すなわち、放射線画像データ)を得るように構成される。放射線撮像システム600は、例えば、放射線撮像装置601、曝射制御部602、放射線源603、コンピュータ604を含む。 The radiation imaging system 600 is configured to electrically capture an optical image formed by radiation and obtain an electrical radiation image (ie, radiation image data). The radiation imaging system 600 includes, for example, a radiation imaging apparatus 601, an exposure control unit 602, a radiation source 603, and a computer 604.
 放射線撮像装置601に放射線を照射するための放射線源603は、曝射制御部602からの曝射指令に従って放射線の照射を開始する。放射線源603から放射された放射線は、不図示の被険体を通って放射線撮像装置601に照射される。放射線源603は、曝射制御部602からの停止指令に従って放射線の放射を停止する。 The radiation source 603 for irradiating the radiation imaging apparatus 601 starts irradiation according to the exposure command from the exposure control unit 602. The radiation emitted from the radiation source 603 is irradiated to the radiation imaging apparatus 601 through an unillustrated object. The radiation source 603 stops radiation emission in accordance with a stop command from the exposure control unit 602.
 放射線撮像装置601は、上述の放射線撮像パネル100と、放射線撮像パネル100を制御するための制御部605と、放射線撮像パネル100から出力される信号を処理するための信号処理部606と、を含む。信号処理部606は、例えば、放射線撮像パネル100から出力される信号のA/D変換し、コンピュータ604に放射線画像データとして出力してもよい。また、信号処理部606は、例えば、放射線撮像パネル100から出力される信号に基づいて、放射線源603からの放射線の照射を停止させるための停止信号を生成してもよい。停止信号は、コンピュータ604を介して曝射制御部602に供給され、曝射制御部602は、停止信号に応答して放射線源603に対して停止指令を送る。 The radiation imaging apparatus 601 includes the radiation imaging panel 100 described above, a control unit 605 for controlling the radiation imaging panel 100, and a signal processing unit 606 for processing a signal output from the radiation imaging panel 100. . For example, the signal processing unit 606 may perform A / D conversion of a signal output from the radiation imaging panel 100 and output the signal to the computer 604 as radiation image data. Further, the signal processing unit 606 may generate a stop signal for stopping irradiation of radiation from the radiation source 603 based on a signal output from the radiation imaging panel 100, for example. The stop signal is supplied to the exposure control unit 602 via the computer 604, and the exposure control unit 602 sends a stop command to the radiation source 603 in response to the stop signal.
 制御部605は、例えば、FPGA(Field Programmable Gate Arrayの略。)などのPLD(Programmable Logic Deviceの略。)、または、ASIC(Application Specific Integrated Circuitの略。)、または、プログラムが組み込まれた汎用コンピュータ、または、これらの全部または1部の組み合わせによって構成されうる。 The control unit 605 includes, for example, PLD (abbreviation of Programmable Logic Device) such as FPGA (abbreviation of Field Programmable Gate Array), or ASIC (Application Specific Integrated, an abbreviation of General Integrated Circuit). It can be constituted by a computer, or a combination of all or part thereof.
 また、本実施形態において、信号処理部606は、制御部605の中に配される、または制御部605の一部の機能であるように示されているが、これに限られるものではない。制御部605と信号処理部606とは、それぞれ別の構成であってもよい。 In the present embodiment, the signal processing unit 606 is shown as being disposed in the control unit 605 or a part of the function of the control unit 605, but is not limited thereto. The control unit 605 and the signal processing unit 606 may have different configurations.
 コンピュータ604は、放射線撮像装置601および曝射制御部602の制御や、放射線撮像装置601から放射線画像データを受信し、放射線画像として表示するための処理を行いうる。また、コンピュータ604は、ユーザが放射線画像の撮像を行う条件を入力するための入力部として機能しうる。 The computer 604 can perform processing for controlling the radiation imaging apparatus 601 and the exposure control unit 602 and receiving radiation image data from the radiation imaging apparatus 601 and displaying it as a radiation image. The computer 604 can function as an input unit for the user to input conditions for capturing a radiographic image.
 一例として、曝射制御部602は、曝射スイッチを有し、ユーザによって曝射スイッチがオンされると、曝射指令を放射線源603に送るほか、放射線の放射の開始を示す開始通知をコンピュータ604に送る。開始通知を受けたコンピュータ604は、開始通知に応答して、放射線の照射の開始を放射線撮像装置601の制御部605に通知する。これに応じて、制御部605は、放射線撮像パネル100において、入射する放射線に応じた信号を生成させる。 As an example, the exposure control unit 602 includes an exposure switch. When the exposure switch is turned on by the user, the exposure control unit 602 sends an exposure command to the radiation source 603 and sends a start notification indicating the start of radiation emission to the computer. Send to 604. Receiving the start notification, the computer 604 notifies the start of radiation irradiation to the control unit 605 of the radiation imaging apparatus 601 in response to the start notification. In response to this, the control unit 605 causes the radiation imaging panel 100 to generate a signal corresponding to the incident radiation.
 本発明は上記実施の形態に制限されるものではなく、本発明の精神及び範囲から離脱することなく、様々な変更及び変形が可能である。従って、本発明の範囲を公にするために、以下の請求項を添付する。 The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.
 本願は、2018年2月27日提出の日本国特許出願特願2018-033675を基礎として優先権を主張するものであり、その記載内容の全てを、ここに援用する。 This application claims priority based on Japanese Patent Application No. 2018-033675 filed on Feb. 27, 2018, the entire contents of which are incorporated herein by reference.

Claims (13)

  1.  基板と、前記基板の第1の面に配された複数の画素と、前記複数の画素を覆うように前記第1の面に配された第1のシンチレータと、前記基板の前記第1の面とは反対側の第2の面を覆うように配された第2のシンチレータと、を含む放射線撮像パネルであって、
     前記第1の面に対する正射影において、前記基板は、前記複数の画素が配された画素領域を含む中央領域と、前記中央領域の外縁と前記基板の外縁との間の周辺領域とを含み、
     前記中央領域が前記周辺領域よりも前記基板の厚さが薄くなるように、前記第2の面は凹部を備え、
     前記第2のシンチレータが、前記凹部に配されることを特徴とする放射線撮像パネル。
    A substrate; a plurality of pixels disposed on a first surface of the substrate; a first scintillator disposed on the first surface so as to cover the plurality of pixels; and the first surface of the substrate. And a second scintillator arranged so as to cover the second surface on the opposite side of the radiation imaging panel,
    In the orthogonal projection with respect to the first surface, the substrate includes a central region including a pixel region in which the plurality of pixels are arranged, and a peripheral region between an outer edge of the central region and an outer edge of the substrate,
    The second surface includes a recess so that the central region is thinner than the peripheral region.
    The radiation imaging panel, wherein the second scintillator is disposed in the recess.
  2.  前記第1のシンチレータを含む第1の波長変換部と、前記第2のシンチレータを含む第2の波長変換部と、を更に含み、
     前記基板のうち前記中央領域の厚さをt1[μm]、前記基板のうち前記周辺領域の厚さをt2[μm]、前記第2の波長変換部の厚さをt3[μm]としたとき、
    t3≦t2-t1
    であることを特徴とする請求項1に記載の放射線撮像パネル。
    A first wavelength conversion unit including the first scintillator; and a second wavelength conversion unit including the second scintillator;
    When the thickness of the central region of the substrate is t1 [μm], the thickness of the peripheral region of the substrate is t2 [μm], and the thickness of the second wavelength conversion unit is t3 [μm]. ,
    t3 ≦ t2-t1
    The radiation imaging panel according to claim 1, wherein:
  3.  前記複数の画素は、複数の遮光画素を含み、
     前記第1のシンチレータと前記複数の遮光画素のそれぞれとの間に、前記第1のシンチレータで放射線から変換された光が前記複数の遮光画素のそれぞれに入射することを抑制する遮光層、または、前記第2のシンチレータと前記複数の遮光画素のそれぞれとの間に、前記第2のシンチレータで放射線から変換された光が前記複数の遮光画素のそれぞれに入射することを抑制する遮光層が設けられることを特徴とする請求項1または2に記載の放射線撮像パネル。
    The plurality of pixels include a plurality of light shielding pixels,
    A light-shielding layer that suppresses light converted from radiation by the first scintillator from being incident on each of the plurality of light-shielding pixels, between the first scintillator and each of the plurality of light-shielding pixels; or A light-shielding layer is provided between the second scintillator and each of the plurality of light-shielding pixels to suppress light converted from radiation by the second scintillator from entering each of the plurality of light-shielding pixels. The radiation imaging panel according to claim 1 or 2.
  4.  前記複数の遮光画素の数が、前記複数の画素の全体の1/2以下であることを特徴とする請求項3に記載の放射線撮像パネル。 The radiation imaging panel according to claim 3, wherein the number of the plurality of light-shielding pixels is ½ or less of the whole of the plurality of pixels.
  5.  前記複数の画素は、複数の第1の画素と複数の第2の画素とを含み、
     前記第2のシンチレータと前記複数の第1の画素のそれぞれとの間に、前記第2のシンチレータで放射線から変換された光が前記複数の第1の画素のそれぞれに入射することを抑制する遮光層、および、前記第1のシンチレータと前記複数の第2の画素のそれぞれとの間に、前記第1のシンチレータで放射線から変換された光が前記複数の第2の画素のそれぞれに入射することを抑制する遮光層が、それぞれ設けられることを特徴とする請求項1または2に記載の放射線撮像パネル。
    The plurality of pixels include a plurality of first pixels and a plurality of second pixels,
    Light shielding that prevents light converted from radiation by the second scintillator from entering each of the plurality of first pixels between the second scintillator and each of the plurality of first pixels. Light converted from radiation by the first scintillator is incident on each of the plurality of second pixels between the layer and each of the first scintillator and the plurality of second pixels. The radiation imaging panel according to claim 1, wherein a light shielding layer that suppresses light is provided.
  6.  前記第1のシンチレータの発光についてのMTF(Modulation Transfer Function)と、前記第2のシンチレータの発光についてのMTFと、の差が、空間周波数2lp/mmの条件において0.2以下であることを特徴とする請求項3乃至5の何れか1項に記載の放射線撮像パネル。 The difference between the MTF (Modulation Transfer Function) for the light emission of the first scintillator and the MTF for the light emission of the second scintillator is 0.2 or less under the condition of a spatial frequency of 2 lp / mm. The radiation imaging panel according to any one of claims 3 to 5.
  7.  前記基板のうち前記中央領域の厚さが、50μm以上かつ300μm以下であることを特徴とする請求項1乃至6の何れか1項に記載の放射線撮像パネル。 The radiation imaging panel according to any one of claims 1 to 6, wherein a thickness of the central region of the substrate is not less than 50 µm and not more than 300 µm.
  8.  前記基板のうち前記中央領域の厚さが、250μm以下であることを特徴とする請求項7に記載の放射線撮像パネル。 The radiation imaging panel according to claim 7, wherein a thickness of the central region of the substrate is 250 μm or less.
  9.  前記第1の面が、前記中央領域と前記周辺領域との間で段差を有さないことを特徴とする請求項1乃至8の何れか1項に記載の放射線撮像パネル。 The radiation imaging panel according to any one of claims 1 to 8, wherein the first surface has no step between the central region and the peripheral region.
  10.  前記第1の面に対する正射影において、前記画素領域の外縁が、前記中央領域の外縁の内側に配されることを特徴とする請求項1乃至9の何れか1項に記載の放射線撮像パネル。 10. The radiation imaging panel according to claim 1, wherein an outer edge of the pixel region is arranged inside an outer edge of the central region in orthogonal projection with respect to the first surface.
  11.  前記凹部と前記基板の端部との距離が5.0mm以上かつ50mm以下であることを特徴とする請求項1乃至10の何れか1項に記載の放射線撮像パネル。 The radiation imaging panel according to any one of claims 1 to 10, wherein a distance between the concave portion and an end portion of the substrate is 5.0 mm or more and 50 mm or less.
  12.  請求項1乃至11の何れか1項に記載の放射線撮像パネルと、
     前記放射線撮像パネルを制御するための制御部と、
     前記放射線撮像パネルから出力される信号を処理するための信号処理部と、
    を含む放射線撮像装置。
    The radiation imaging panel according to any one of claims 1 to 11,
    A control unit for controlling the radiation imaging panel;
    A signal processing unit for processing a signal output from the radiation imaging panel;
    A radiation imaging apparatus including:
  13.  請求項12に記載の放射線撮像装置と、
     前記放射線撮像装置に放射線を照射するための放射線源と、
    を含む放射線撮像システム。
    A radiation imaging apparatus according to claim 12,
    A radiation source for irradiating the radiation imaging apparatus with radiation;
    A radiation imaging system including:
PCT/JP2018/048506 2018-02-27 2018-12-28 Radiation imaging panel, radiation imaging device, and radiation imaging system WO2019167424A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080011960A1 (en) * 2006-07-14 2008-01-17 Eastman Kodak Company Apparatus for asymmetric dual-screen digital radiography
US20100140484A1 (en) * 2007-04-12 2010-06-10 Koninklijke Philips Electronics N.V. Reducing trap effects in a scintillator by application of secondary radiation
US20110303849A1 (en) * 2010-06-09 2011-12-15 Tredwell Timothy J Dual screen radiographic detector with improved spatial sampling
JP2012233781A (en) * 2011-04-28 2012-11-29 Fujifilm Corp Radiation image detector and radiographic device
JP2013127371A (en) * 2011-12-16 2013-06-27 Canon Inc Radiation detector
JP2017200522A (en) * 2016-05-02 2017-11-09 キヤノン株式会社 Radiation imaging device and radiation imaging system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080011960A1 (en) * 2006-07-14 2008-01-17 Eastman Kodak Company Apparatus for asymmetric dual-screen digital radiography
US20100140484A1 (en) * 2007-04-12 2010-06-10 Koninklijke Philips Electronics N.V. Reducing trap effects in a scintillator by application of secondary radiation
US20110303849A1 (en) * 2010-06-09 2011-12-15 Tredwell Timothy J Dual screen radiographic detector with improved spatial sampling
JP2012233781A (en) * 2011-04-28 2012-11-29 Fujifilm Corp Radiation image detector and radiographic device
JP2013127371A (en) * 2011-12-16 2013-06-27 Canon Inc Radiation detector
JP2017200522A (en) * 2016-05-02 2017-11-09 キヤノン株式会社 Radiation imaging device and radiation imaging system

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