EP0426865A1 - Phosphorplatte und methode zu deren herstellung - Google Patents

Phosphorplatte und methode zu deren herstellung Download PDF

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Publication number
EP0426865A1
EP0426865A1 EP90905637A EP90905637A EP0426865A1 EP 0426865 A1 EP0426865 A1 EP 0426865A1 EP 90905637 A EP90905637 A EP 90905637A EP 90905637 A EP90905637 A EP 90905637A EP 0426865 A1 EP0426865 A1 EP 0426865A1
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EP
European Patent Office
Prior art keywords
light beam
photostimulable phosphor
excited light
phosphor plate
fine holes
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Application number
EP90905637A
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English (en)
French (fr)
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EP0426865A4 (en
EP0426865B1 (de
Inventor
Shiro Takeda
Fumihiro Namiki
Yuuichi Sugiyama
Nobuhiro Iwase
Shinji Tadaki
Nagaaki Koshino
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Fujitsu Ltd
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Fujitsu Ltd
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Publication date
Priority claimed from JP8425389A external-priority patent/JPH02262100A/ja
Priority claimed from JP1130739A external-priority patent/JPH02308238A/ja
Priority claimed from JP13557389A external-priority patent/JPH032599A/ja
Priority claimed from JP14434989A external-priority patent/JPH039300A/ja
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Publication of EP0426865A1 publication Critical patent/EP0426865A1/de
Publication of EP0426865A4 publication Critical patent/EP0426865A4/en
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Publication of EP0426865B1 publication Critical patent/EP0426865B1/de
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens

Definitions

  • the present invention relates to a photostimulable phosphor plate and a reader thereof utilizing excited light beam and a scattering preventing means for the excited light beam and photostimulable fluorescent light.
  • a radiation image such as an X-ray image is often used for medical diagnosis.
  • a radiation photograph has been used.
  • a phosphor layer fluorescent screen
  • a visible light beam is generated therefrom
  • a film using silver salt is then irradiated with such visible light beam for the purpose of development.
  • a high sensitive and high resolution X-ray imaging apparatus explained above is designed as a system utilizing photostimulable phosphor.
  • the basis system of this apparatus has been described in detail in the U.S. Patent No. 3,859,527.
  • the phosphor used in this system stores a part of energy, upon reception of energy of radiation such as X-ray. This condition is comparatively stable and is therefore maintained for a while or for a long period of time.
  • the phosphor under this condition is irradiated with the first light beam working as the excited light beam, the stored energy is emitted as the second light beam.
  • the first light beam the light having the wavelength in the wider range from the infrared beam to ultraviolet beam can also be used as well as the visible light beam.
  • the second light is also emitted through wide selection from the infrared beam to ultraviolet beam. Selection of such light also depends on the phosphor material used.
  • the second electromagnetic beam is received, it is converted to an electrical signal by a photoelectric converter, it is then converted to a digital signal and thereby digital image information can be obtained.
  • the photostimulable phosphor layer which has been used in the prior art is not transparent for the first light beam, namely the excited light beam and the second light, namely photostimulable emitted light beam and showed distinctive scattering phenomenon. Therefore, even when the photostimulable phosphor layer is irradiated with the excited light beam flux in such a size as is equal to one pixel or is smaller than such pixel, the excited light beam flux is scattered very widely and it has also been observed that when the phosphor layer, for example, in the thickness of 0.3 mm is irradiated with the excited light beam flux in diameter of 0.1 mm, the flux is scattered, at the surface opposed to the irradiation surface, up to the size larger than 1 mm in diameter, in some cases, up to the size larger than 3 mm in diameter.
  • Fig. 1 shows such scattering condition.
  • the one pixel is sized in the 0.1 mm square in this case, a part of information of the adjacent 100 to 900 pixels is detected as an error when the one pixel is read, thereby the space resolution of image obtained is remarkably deteriorated and the image is naturally defocused.
  • several methods have been proposed. For instance, a method for decomposing white fine particles in the phosphor layer described in the Japanese Laid-open Patents Nos. 55-146447 and 58-58500, a method for adding a coloring agent which absorbs the excited light beam is described in the Japanese Laid-open Patent No.
  • the present invention has been proposed, under the technical background as explained above, to provide a photostimulable phosphor plate which does not show any scattering for the emitted fluorescent light.
  • the first means for attaining this object is constituted so that fine holes 26 burying photostimulable phosphour 6 within the hole forming portions 2 which are processed in almost the same size and does not penetrate the excited light beam are provided at respective crossing positions in the crossing direction, comprising the hole forming portions 2 which are processed in almost the same size at respective crossing positions in the crossing direction and does not allow transmission of excited light beam, the light transmissivity sealing material 4 provided in the light penetrating side of the hole fomring portions 2, the sealing materials 5 provided at the surface opposed to the surface in the light penetrating side of the hole foming portion forming substrate, and the phosphor 6 imbeded in the hole forming portion 2 sealed by the light transmissivity sealing material 4 and sealing material 5.
  • the second means is constituted so that the fine holes 26 which are almost the same in size and does not penetrate the excited light beam at the internal side wall 2 thereof are provided at the hole forming positions of the substrate in the regular positional layout wherein the adjacent hole foming positions are deviated only by the value required for approximation and the photostimulable phoshor is buried within such fine holes 2, comprising the fine holes in almost the same size which does not penetrate the excited light beam at the internal side wall 2 thereof at the hole forming positions of the substrate in the regular positional layout wherein the adjacent hole foming positions are deviated only by the value required for approximation, the light transmissivity sealing material 4 provided in the surface of light penetrating side of the fine hole 2 foming substraste, the sealing material 5 provided in the surface opposed to the light penetrating side of the fine hole 26 forming substraste, and the photostimulable phosphor 6 filling the fine holes 26 sealed by the light transmissivity sealing material 4 and sealing material 5.
  • the fourth means is constituted in a digital X-ray apparatus which forms a latent image of object on the photostimulable phosphor plate 105 as an energy distribution pattern using the X-ray energy and reads such latent image using the excited light beam so that one pixel of the specimen is individually formed, on the occasion of forming latent image of the object, in the corresponding one and larger integer number of fine holes of the photostimulable phosphor plate forming, in each crossing positions in the crossing direction, the fine holes 2 of almost the same size burying the photostimulable phosphor in the hole foming portion 2 processed at least on the substrate which does not penetrate the excited light beam and respective pixels accumulated in the one or larger integer number of fine holes are read out for recovery of the image data.
  • the fifth means is constituted in a digital X-ray apparatus which forms a latent image of specimen on the photostimulable phosphor plate 105 as an energy distribution pattern using the X-ray energy and reads such latent image using the excited light beam; comprising a means for scanning the photostimulable phosphor plate, which is provided with fine holes burying photostimulable phosphor in the hole fomring portion (2) which does not penetrate the excited light beam and shows reflectivity for the excited light beam at the plate surface other than the fine holes portions, in the direction of hole arrangement with the excited light beam; an emitted fluorescent light gathering means for gathering the emitted fluorescent light with the excited light beam from the photostimulable phosphor buried in the fine holes; a reflected excited light beam gathering means for gathering the excited light beam reflected from the photostimulable phosphor plate; an excited light beam irradiation period detecting means for detecting the period of excited light beam irradiated on the fine holes buried by the photostimulable phosphor from the signal
  • Fig. 2 is the first embodiment of the present invention.
  • Fig. 2A is a photostimulable phosphor plate providing, at the crossing positions of crossing direction, the fine holes 26 of almost the same size burying the extincitve phosphor 6 in the hole forming portions processed not to penetrate the excited light beam.
  • Fig. 2B shows the hole forming portions which is formed almost in the same size and processed not to penetrate the excited light beam at respective crossing positions in the crossing direction, a light transmissivity sealing material 4 provided in the light penetrating side of the hole forming portion 2, a sealing material 5 provided in the surface opposed to the light penetrating side of the hole forming portion forming substrate, and a photostimulable phosphor 6 buried in the hole forming portion 2 sealed by the light transmissivity sealing material 4 and sealing material 5.
  • the X-ray energy of object pattern which has been obtained therethrough when the specimen is irradiated with the X-ray is distributed and stored in the fine holes 26 regularly arranged on the photostimulable phosphor plate.
  • the photostimulable phosphor plate having such energy distribution pattern is scanned with the excited light beam and thereby the object pattern formed as the energy distribution pattern thereon may be extracted as the electrical signal pattern.
  • the fine holes 26 regularly arranged on the photostimulable phosphor plate are scanned along the one direction of crossing directions with the excited beam. Since the photostimulable phosphor irradiated with the excited beam is provided within the hole wall 2 which does not penetrate the excited light beam, the excited light beam is never scattered. Therefore, reduction of space resolution can be prevented perfectly.
  • Fig. 3 shows the profile of preventing reduction of space resolution.
  • a manufacturing method of photostimulable phosphor plate of the present invention will be explained hereunder with reference to Fig. 4. This manufacturing method utilizes the etching.
  • a resist pattern (refere to Fig. 5) to form fine holes on a thin stainless steel plate is produced by the well known CAD techinique.
  • the diameter of the part corresponding to the hole of the pattern is set smaller than the diameter of the fine hole.
  • the masks 22, 23 are formed to both surfaces of the stainless steel plate 20 (refer to Fig. 4A).
  • the reference numeral 24 designates mask hole of the masks 22, 23.
  • the fine holes 26 are formed as shown in Fig. 4B by effectuating etching agent to the stainless steel plate 20 through the mask hole 24 formed.
  • the reference numeral 28 designates hole wall.
  • the hole wall area 29 of the plate surface is coated with an adhesive agent 30 by the screen printing method (Fig. 4C).
  • both surfaces are coated with the bonding agent 30 as shown in Fig. 4D, while in the case of the stainless steel plates 201, 203, only the surfaces in contact with the stainless steel plate 202 are coated with the agent.
  • the reference numeral 32 designates glass plate.
  • the deeper fine holes 25 formed on the stacked three sheets of stainless steel plates 201 to 203 are filled with the photostimulable phosphor powder 6 (BaFBr:Bu2+) (refer to Fig.f4E) and a polyester protection layer 34 (refer to Fig. 4F) is formed thereon, thereby completing the manufacture of photostimulable phosphor plate (refer to Fig. 5).
  • the wall surface of fine hole 26 has the optical surface and efficiently reflects the excited light beam and emitted fluorescent light. Therefore, the excited light beam does not penetrate through the wall surface of fine hole and the emitted fluorescent light from the photostimulable phosphor due to irradiation of excited light beam can be collected efficiently (refer to Fig. 3). Accordingly, reduction of space resolution of image can be prevented. Moreover, quantity of photostimulable fluorescent light emitted from the photostimulable phosphor due to irradiation of excited light beam can be increased by stacking the stainless steels as explained previously. In this case, reduction of space resolution is not increased thereby.
  • the thin stainless steel plate used in this embodiment may be replaced with other thin metal plate or plastic plate.
  • Many fine holes may be formed on a thin metal plate or plastic plate by various methods including the etching method and mechanical processing method. Here, there is no limitation on such fine hole forming method.
  • the fine holes 26 formed show various shapes depending on material and forming method (refer to Fig. 6 and Fig. 7).
  • the shape of hole will never become straight.
  • the etching is made only to the single side, only the single side becomes larger.
  • the etching is made to both sides, the center is narrowed. Otherwise, other shape appears depending on the method of forming the holes of mask. In case the holes are foremd by the electrospark machining method, the shape become straight comparatively.
  • the holes take various shapes but it is possible to execute the present invention without relation to the shape of hole.
  • the shape of fine hole is not particularly restricted, the circular, elliptical, square, rectangular or polygonal shapes are actually introduced for the convenience of manufacture (refer to Fig. 6).
  • the wall surface of the fine holes thus formed penetrates the excited light beam due to the property of material, the wall surfaces better to be coated or evaporated with the material which does not penetrate the excited light beam in order to prevent penetration of excited light beam.
  • the wall surface of hole does not have surface accuracy from the optical view point, it is effective to make smooth the surface by coating it with resin and forme thereon a layer such as metal having a high reflectivity.
  • the size of fine hole is not particularly restricted, the lower limit lies in about 0.01 mm because of technical difficulty of burying the photostimulable phosphor in the fine holes of a certain thickness and moreover the upper limit lies in about 0.4 mm from the viewpoint of the space resolution required for X-ray image diagnosis.
  • the fine holes are provided in perpendicular to the surface of photostimulable phosphor plate but these may formed prefectly in perpendicular or with inclination.
  • the hole with inclination may be formed, for example, by the process that many capillaries of the same internal diameter as the diameter of fine hole are bundled in the square arrangement or bundled in layer by layer, the space between the capillaries is filled with adhesive agent, this adhesive agent is hardened, thereafter these capillaries are cut with inclination and ground and washed.
  • the shape of hole may be straight or the sizes of upper and lower portions of hole may be different.
  • any kind of material may be selected from those having a certain mechanical strength even after formation of hole.
  • a glass plate is used for the single surface of stainless steel plate after formation of the fine holes, but it is also possible to use a metal sheet.
  • the sheet used reflects the excited light beam and emitted fluorescent light.
  • the sheet which reflects the excited light beam but penetrates the emitted fluorescent light may also be used and the sheet having the inverse property may also be used depending on the way of use, namely, depending on the selection of the irradiating direction of the excited light beam or collecting direction of the emitted fluorescent light.
  • a cover functions as a selection mirror may also be effectively formed to both sides using adhesive agent.
  • Althouth not particularly limited, it is effective to use a material, as the cover, such as lead glass which penetrates the excited light beam and photostimulable emitted light and absorbs the X-ray in order to prevent the back scattering beam of X-ray. Or, it is also effective to attach a lead plate.
  • a material such as lead glass which penetrates the excited light beam and photostimulable emitted light and absorbs the X-ray in order to prevent the back scattering beam of X-ray.
  • it is also effective to attach a lead plate.
  • the photostimulable phosphor buried in the fine holes those which does not penetrate the excited light beam to show the scattering or penetrate the excited light beam or emitted fluorescent light in any composition may be used without restriction, and the burying method is also not restricted. Namely, the method where the photostimulable phosphor powder of the grain size of 5 um or less is dispered into the solution of binder and the solution is then supplied inot the holes, or the where where the photostimulable phosphor powder is put in direct into the fine holes and thereafter the binder is then soaked thereto, or the method where a layer which may be dissolved later is formed to the part other than the holes by the lift-off method, the holes are filled with the photostimulable phosphor by the evaporation and thereafter the photostimulable phosphor is removed from the part other than the holes, may be used.
  • the fine holes 26 which are almost same in the size and provides the internal wall surface 2 which does not penetrate the excited light beam are provided at respective hole forming positions of the substrate providing the regular arrangement positions wherein the adjacent hole fomring positions are displaced by the value required for approximating the hole forming positions like the second embodiment and the photostimulable phosphor is buried in the fine holes 26.
  • the photostimulable phosphor comprising fine holes 26 of almost the same size providing the wall surface 2 which does not penetrate the excited light beam processed at the respective hole forming positions of the substrate having the regular hole arrangement where at least adjacent hole forming positions are previously deviated by the predetermined value, the light transmissivity sealing material 4 arranged at the surface in the light penetrating side of the fine hole fomring substrate, the sealing material 5 arranged in the surface opposed to the light penetrating side of the fine hole forming substrate and the photostimulable phosphor 6 burying the fine holes 26 sealed by the light beam transmissivity sealing material 4 and sealing material 5.
  • the fine holes of photostimulable phosphor plate of the second embodiment are arranged in the highest density as shown in Fig. 8.
  • FIG. 2 The cross sectional view of the second embodiment is shown in Fig. 2.
  • the photostimulable phosphor irradiated with the excited light beam is buried in the internal wall surface 2 which does not penetrate the excited light beam, the light beam is never scattered. Accordingly, reduction of space resolution can be prevented perfectly.
  • the method of manufacturing the photostimulable phosphor plate is similar to that of the first embodiment and the resist pattern as shown in Fig. 8 is used.
  • a photostimulable phosphor plate 10 is formed by a plurality sheets of stainless sheet 12.
  • Each stainless sheet 12 is in the thickness of 0.1 mm and in the size of 380 mm square.
  • the center area thereof (356 mm square) 14 is provided with a plurality of fine holess 15 arranged in the form of lattice.
  • the size of one pixel is determined. For example, the size of one pixel of the photostimulable phosphor plate or sheet for diagnosing breast cancer is set to almost 50 ⁇ m square.
  • the one pixel size is set to 87.5 ⁇ m square to 175 ⁇ m square in order to process the digital information. Although this size is not essential, diagnosis may be realized with such space resolution. Therefore, the size of pixel must be changed depending on the object tissue and in the case of the present invention, the photostimulable phosphor plate or sheet in various kinds of pixel sizes may be used.
  • the possible minimum pixel size is determined by the possible excited light beam diameter.
  • the current minimum size of pixel is about 20 ⁇ m square.
  • the maximum pixel size is not limited from the viewpoint of possibility in realization and the diagnostic purpose is not attained when the pixel size is 0.4 mm square or more. Therefore, in the present invention, the one pixel size is ranged from 20 ⁇ m square to 0.4 mm square and the pixel is capable of taking the square shape and rectangular shape.
  • the circular or square fine holes 15 which are smaller than the diameter of one pixel size are formed on the four sheets of stainless sheets 12 depending on such determination.
  • the lateral and vertical pitches are set to 175 ⁇ m and positional deviation of fine holes 15 between the starting and ending points is set to 52.5 ⁇ m.
  • the etching process has been employed.
  • the thermosetting type epoxy resin is dissolved into an organic agent, the both sides of sheets are coated with the solution, obtained by dispersing the graphite powder, by the screen printing method except for the fine hole portions and thereafter the coated area is dried up, forming the fine holes 15 on the stainless sheet 12.
  • the stainless sheet 12 forming the fine holes 16 and the stainless sheet 12 coated with the resin only at the single surface are stacked with each.
  • the stainless sheet not forming the fine holes 16 in the thickness of 0.2 mm is placed on the single surface.
  • the three sheets of stainless sheet are pressurized with a weight and bonded through thermosetting at 180°C
  • a reflective film is fitted to the wall surface of fine holes 16 in order to reflect the excited light beam.
  • the phosphor powder consisting of BaC Br:Eu in the grain size of 5 ⁇ m or less is dispersed into the organic solvent including epoxy resin as the binder, it is then poured onto the sheet under the reduced pressure condition and the phosphor buried in the holes is dried up. This process is repeated for three times. After confiming that the holes are filled with the photostimulable phosphor up to the surface thereof, the mixture of photostimulable phosphor and epoxy resin at the surface is wiped out. The sheets are hardened at 180°C and moreover a transparent polyester sheet is bonded to the surface as the protection layer.
  • the photostimulable phosphor plate 10 manufactured as explained above is fixed on a stage and is irradiated with the laser beam of 100 ⁇ m in the scanning direction and 40 ⁇ m in the main scanning direction using the laser scanning system having the scanning efficiency of 70% consisting of the semiconductor laser with wavelength of 780 nm, lens and galvano mirror. Thereby it has been confirmed that the excited light beam penetrates through the photostimulable phosphor in the fine holes 16 and scattering to the other fine holes 16 can be prevented.
  • the emitted fluorescent light which is emitted by irradiating the surface of photostimulable phosphor plate 10 with the X-ray to excite the phosphor with the pulse laser is gathered by a condenser mirror and glass fiber array and is received by the photomultiplier.
  • the converted electrical signal is then converted into the digital signal through the analog to digital conversion.
  • the sheet is irradiated with the X-ray of the reference dose
  • the reference output of each pixel is input to the memory
  • normal image can be obtained through compensation for change by aging of quantity of photostimulable light beam and compensation for fluctuation in change by aging of pixels.
  • size of excited beam on the phospghor plate or sheet must be smaller in such a degree determined by the degree of wobble.
  • the length of main scanning direction is smaller than the leng of one pixel in the subscanning direction.
  • the excited light beam used may be a continuous light or pulse beam but the length of excited light beam in the main scanning direction will be better as short as possible.
  • the scanning must be made in such a manner that the excited light beam does not pass on the adjacent pixels in the subscanning direciton.
  • the image of the predetermined space resolution can be read without influence of scatting of excited light beam by paying attension to these conditions.
  • the angle between the photostimulable phosphor plate or sheet and subscanning direction may be determined uniquely in relation to the efficiency of the scanning by the excited light beam and size of the one pixel.
  • Fig. 10 is a photostimulable phosphor reader. Using the X-ray energy, a latent image of object is formed as an energy distribution pattern on the photostimulable phosphor plate 105 and such latent image is read using the excited light beam.
  • the laser beam output from the excited light beam source 101 is used for the scanning through the scanner 102 consisting of a galvano mirror or polygon mirror.
  • the photostimulable phosphor 105 is scanned by such laser beam through an optical part 103 for compensating for the shape of beam such as f0 lens, etc. and a reflection mirror 104.
  • the emitted fluorescent light from the photostimulable phosphor plate 105 when the plate is scanned by the laser beam from the laser beam system is gathered by a gathering means such as a fiber array 107.
  • the gathered light beam is converted as the quantity of light received into the electrical signal in the photoelectric converter 108 such as a photoelectron multiplier through a filter which does not transmit the excited light beam from the fiber array 107 but transmits only the photostimulable light beam and is then amplified by an amplifier 109. Thereafter, the signal is converted to the digital signal by an A/D converter 110.
  • the digital signal is once stored in the frame memory 111 or stored in the optical disk memory 112 without passing through the frame memory.
  • the processing such as gradation process is carried out as required in the image processing part 113.
  • the image is displayed as the X-ray image on the image display part 114 such as CRT or written in direct on the X-ray film through the film writing apparatus and it is then developed to obtain the X-ray image.
  • This embodiment is used for reading the photostimulable phosphor as the first to third embodiment.
  • the laser beam diameter at the surface of photostimulable phosphor plate is set to 170 ⁇ m in the subscanning direction (in which the photostimulable phosphor moves) or to 40 ⁇ m in the main scanning direction.
  • the laser beam diameter in the main scanning direction is preferably smaller than the length of main scanning direction of the one pixel.
  • the standard one pixel to which the light is gathered has the size of 176 ⁇ m square and 16 holes in total (refer to I of Fig. 11) are provided in the one pipxel.
  • the one pixel has the size of 132 ⁇ m square, nine holes (refer to II of Fig. 11) exist within the one pixel.
  • the laser beam diameter in the subscanning direction is 125 um.
  • the one pixel has the size of 88 ⁇ m square, four holes (refer to III of Fig. 11) exist in the one pixel.
  • the laser beam diameter in the subscanning direction is 83 ⁇ m.
  • the one pixel has the size of 44 ⁇ m square, only one hole (refer to IV of Fig. 11) exits in the one pixel and the laser beam diameter in the subscanning direction is 39 ⁇ m or 20 ⁇ m in the main scanning direction.
  • the hole located on a certain main scanning line is allocated on a certain straight line but it is also assumed here that the excited light beam is a little deviated.
  • a certain hole is not always irradiated with the excited light beam at the entire part thereof. Namely, a certain hole is irradiated with the excited light beam only at a part thereof.
  • the one pixel is formed with several holes, it is apparent the part not irradiated with the light beam relatively increases in comparison with the case where the one pixel is formed by one hole. Accordingly, when one pixel is formed by several holes, the read accuracy can be improved and realiability of reader can also be enhanced.
  • the light beam is gathered as shown in Fig. 10 for the scanning of the photostimulable phosphor plate.
  • the excited light beam reflected from the wall surface not forming the holes of photostimulable phosphor is gathered by the fiber array different from that of Fig. 10 or plastic light receiver and the light from the photostimulable phosphor is received through synchronizaiton between such gathered light beam and the light from the photostimulable phosphor.
  • the excited light beam from the wall surface is reflected by utilizing the photostimulable phosphor plate of the first to third embodiments which are formed to reflect the light at the surface other than the hole fomring portion of the estinctive phosphor plate.
  • Fig. 12 shows a structure wherein reflected excited light beam gathering optical guide path 113 for gathering the excited light beam is provided.
  • the elements like those in Fig. 10 are designated by the like reference numerals.
  • the reference numeral 1071 designates an excited light beam absorbing filter; 107, gathers the photostimulable flurescent light and therefore it must absorb the reflected wave of excited light beam.
  • the excited light beam absorbing filter 1071 absorbs the light of 600 ⁇ 900 nm (wavelength of excited light beam) and transmits the light of 400 nm (wavelength of photostimulable fluorescent beam).
  • Ther reference numeral 115 designates a gathering mirror and gathers the light beam so that the excited light beam and emitted fluorescent light are not scattered.
  • the numeral 207 designates a reflected excited light gathering and guiding path; 2071, emitted fluorescent light absorbing filter which absorbs the light in the vicinity of 400 nm (wavelength of emitted fluorescent light) and transmits the light of 600 ⁇ 900 nm (wavelength of excited light beam).
  • the reference 208 designates a photosenser.
  • This photosensor is a semiconductor sensor such as a photoelectron multiplier or photodiode.
  • the emitted fluorescent light absorbing filter 2071 realizes power saving through selection of a kind of photoelectron multiplier.
  • Fig. 12 indicates a circuit for determining the timing of sampling. In Fig.
  • the numeral 108 designates a photoelectric converter; 208, a photosensor which is similar to that shown in Fig. 11.
  • the emitted flluorescent light and excited beam are input to the photoelectric converter 108 and photosensor 208 respectively through the fiber array 107 and reflected and excited light beam gathering and guiding path 207.
  • the emitted fluorescent light input from the photoelectric converter 108 is converted into the electrical signal and input to the A/D converter 110 through the amplifier 109.
  • the excited light beam converted to the electrical signal in the photosensor 208 is compared with the reference voltage in the comparison circuit 209.
  • Fig. 14 shows a timechart of the signals output from the circuit shown in Fig. 13. As shown in Fig.
  • the comparison circuit 209 outputs signals.
  • the photosensor 208 receives the excited light beam. If the line L in Fig. 11 is scanned by the excited light beam, the surface other than the hole portions (the photostimulable phosphor is buried therein) intensively reflects the excited light in the case of Fig. 1. The excited light beam is absorbed by the hole portions in which the photostimulable phosphor is buried and the emitted fluorescent light is output therefrom through a certain degree of reflection. Therefore, an electrical signal indicated as 208 in Fig. 14 can be obtained from the excited light beam received by the photosensor 208.
  • the excited light beam reflected from the reflecting part shows a high voltage
  • the excited light beam reflected from the hole portion where the photostimulable phosphor is buried shows a low voltage. Comparison is carried out with reference to the reference voltage in the comparison circuit 209 in order to discriminate the hole portion and reflecting portion.
  • An output of comparison circuit 209 is input to the flipflop 210 which outputs a signal synchronized with the input signal thereto.
  • An output of the flipflop 210 is ANDed with the clock in the AND gate 211 and is then input to the A/D converter 110 as the operation clock. Namely, when an electrical signal of excited light beam (output of photosensor 208) is lower than the reference voltage, the A/D converter 110 operates and electrical signal of emitted fluorescent light (output of amplifier 109) is converted to a digital signal. The converted digital value is added by the adder 217 while an output of AND gate 211 is ON, and the added value is stored in the flipflop 218 (this flipflop is provided as many as the plural bits but is not illustrated in the drawings).
  • a divider 219 outputs a value obtained by dividing a sum of outputs of A/D converter of flipflop 218 with a value of counter stored in the flipflop 215 to the memory 111. Namely, the emitted fluoresent light is sampled while the excited light beam passes the holes filled with the photostimulable phosphor by receiving the excited light beam.
  • outputs of the A/D converter are added and an average value of these outputs is obtained.
  • the present invention is not limited thereto. It is also possible that only addition or integration may also be carried out. Here, it is important to select the timing of such addition and the time for integration by receiving the excited light beam.
  • the present invention is capable of perfectly preventing deterioration of space resolution with the photostimulable phophor plate having the structure that the fine regions which does not penetrate the excited light beam are formed and the photostimulable phophor is buried in such fine regions and by reading the photostimulable phosphor with such structure.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Conversion Of X-Rays Into Visible Images (AREA)
  • Measurement Of Radiation (AREA)
EP90905637A 1989-04-03 1990-03-30 Phosphorplatte und methode zu deren herstellung Expired - Lifetime EP0426865B1 (de)

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
JP8425389A JPH02262100A (ja) 1989-04-03 1989-04-03 輝尽蛍光体板
JP84253/89 1989-04-03
JP1130739A JPH02308238A (ja) 1989-05-24 1989-05-24 ディジタルｘ線撮像装置の画像読取り方式
JP130739/89 1989-05-24
JP135573/89 1989-05-29
JP13557389A JPH032599A (ja) 1989-05-29 1989-05-29 輝尽蛍光体板
JP14434989A JPH039300A (ja) 1989-06-07 1989-06-07 輝尽蛍光体板
JP144349/89 1989-06-07
PCT/JP1990/000434 WO1990012405A1 (fr) 1989-04-03 1990-03-30 Plaque a substance fluorescente acceleree et lecteur prevu a cet effet

Publications (3)

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EP0426865A1 true EP0426865A1 (de) 1991-05-15
EP0426865A4 EP0426865A4 (en) 1991-08-07
EP0426865B1 EP0426865B1 (de) 1996-01-03

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EP (1) EP0426865B1 (de)
DE (1) DE69024610T2 (de)
WO (1) WO1990012405A1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995030236A1 (en) * 1994-04-29 1995-11-09 Minnesota Mining And Manufacturing Company Method for fabricating a pixelized phosphor
EP0760520A1 (de) * 1995-08-29 1997-03-05 Hewlett-Packard Company Verbesserung der Resolution von aufgenommenen Bildern mit Speicherphosphoren
WO2001003146A1 (de) * 1999-07-02 2001-01-11 Rainer Kassing Herstellungsverfahren für eine wiederverwendbare bildplatte mit einem speicherleuchtstoff zur speicherung von röntgenstrahlbildern

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5534702A (en) * 1994-08-08 1996-07-09 Hewlett-Packard Company Resolution improvement of images recorded using storage phosphors

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DE2347923A1 (de) * 1973-01-17 1974-07-18 Winnek Douglas Fredwill Hochaufloesender verstaerkungsfilm fuer strahlung
DE2638114A1 (de) * 1975-08-29 1977-03-10 Rca Corp Verfahren zum fuellen von oeffnungen mit kristallinem werkstoff
FR2462020A1 (fr) * 1979-07-23 1981-02-06 Siemens Ag Ecran luminescent a structure en forme de trame et utilisation de ce dernier
DE3325035A1 (de) * 1983-07-11 1985-01-24 Siemens AG, 1000 Berlin und 8000 München Roentgenleuchtschirm
EP0242024A2 (de) * 1986-03-10 1987-10-21 Picker International, Inc. Strahlungsbildverstärkerröhre
JPS643599A (en) * 1987-06-25 1989-01-09 Seiko Instr & Electronics Fluorescent screen and its production
EP0372395A2 (de) * 1988-12-02 1990-06-13 Kabushiki Kaisha Toshiba Röntgenbildverstärker und dessen Herstellungsverfahren
DE3909450A1 (de) * 1989-03-22 1990-09-27 Kernforschungsz Karlsruhe Verfahren zur herstellung von leuchtschirmen, verstaerkungs- oder speicherfolien fuer die roentgendiagnostik
FR2644927A1 (fr) * 1989-03-22 1990-09-28 Kernforschungsz Karlsruhe Procede de realisation d'ecrans lumineux, de feuilles d'amplification ou d'enregistrement pour la radiographie aux rayons x

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JPS59202100A (ja) * 1983-04-30 1984-11-15 コニカ株式会社 放射線画像変換パネル及びその製造方法
JPH0664195B2 (ja) * 1986-03-11 1994-08-22 コニカ株式会社 亀裂界面間が遮蔽された蛍光体層を有する放射線画像変換パネル
JP3348452B2 (ja) * 1993-02-09 2002-11-20 ソニー株式会社 磁気記録再生装置

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US2827571A (en) * 1955-05-23 1958-03-18 Philips Corp Intensifying screen for making x-ray registrations
DE2347923A1 (de) * 1973-01-17 1974-07-18 Winnek Douglas Fredwill Hochaufloesender verstaerkungsfilm fuer strahlung
DE2638114A1 (de) * 1975-08-29 1977-03-10 Rca Corp Verfahren zum fuellen von oeffnungen mit kristallinem werkstoff
FR2462020A1 (fr) * 1979-07-23 1981-02-06 Siemens Ag Ecran luminescent a structure en forme de trame et utilisation de ce dernier
DE3325035A1 (de) * 1983-07-11 1985-01-24 Siemens AG, 1000 Berlin und 8000 München Roentgenleuchtschirm
EP0242024A2 (de) * 1986-03-10 1987-10-21 Picker International, Inc. Strahlungsbildverstärkerröhre
JPS643599A (en) * 1987-06-25 1989-01-09 Seiko Instr & Electronics Fluorescent screen and its production
EP0372395A2 (de) * 1988-12-02 1990-06-13 Kabushiki Kaisha Toshiba Röntgenbildverstärker und dessen Herstellungsverfahren
DE3909450A1 (de) * 1989-03-22 1990-09-27 Kernforschungsz Karlsruhe Verfahren zur herstellung von leuchtschirmen, verstaerkungs- oder speicherfolien fuer die roentgendiagnostik
FR2644927A1 (fr) * 1989-03-22 1990-09-28 Kernforschungsz Karlsruhe Procede de realisation d'ecrans lumineux, de feuilles d'amplification ou d'enregistrement pour la radiographie aux rayons x

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PATENT ABSTRACTS OF JAPAN vol. 13, no. 165 (P-860)(3513) 20 April 1989, & JP-A-1 3599 (SEIKO) 09 January 1989, *
See also references of WO9012405A1 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995030236A1 (en) * 1994-04-29 1995-11-09 Minnesota Mining And Manufacturing Company Method for fabricating a pixelized phosphor
EP0760520A1 (de) * 1995-08-29 1997-03-05 Hewlett-Packard Company Verbesserung der Resolution von aufgenommenen Bildern mit Speicherphosphoren
WO2001003146A1 (de) * 1999-07-02 2001-01-11 Rainer Kassing Herstellungsverfahren für eine wiederverwendbare bildplatte mit einem speicherleuchtstoff zur speicherung von röntgenstrahlbildern

Also Published As

Publication number Publication date
EP0426865A4 (en) 1991-08-07
WO1990012405A1 (fr) 1990-10-18
DE69024610T2 (de) 1996-05-15
DE69024610D1 (de) 1996-02-15
EP0426865B1 (de) 1996-01-03

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