EP0426865B1 - Plaque a substance fluorescente et methode pour produire une telle plaque - Google Patents

Plaque a substance fluorescente et methode pour produire une telle plaque Download PDF

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Publication number
EP0426865B1
EP0426865B1 EP90905637A EP90905637A EP0426865B1 EP 0426865 B1 EP0426865 B1 EP 0426865B1 EP 90905637 A EP90905637 A EP 90905637A EP 90905637 A EP90905637 A EP 90905637A EP 0426865 B1 EP0426865 B1 EP 0426865B1
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EP
European Patent Office
Prior art keywords
plate
holes
excitation light
light beam
photostimulable phosphor
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP90905637A
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German (de)
English (en)
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EP0426865A1 (fr
EP0426865A4 (en
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/fr
Publication of EP0426865A4 publication Critical patent/EP0426865A4/en
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Publication of EP0426865B1 publication Critical patent/EP0426865B1/fr
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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 method of manufacturing a photostimulable phosphor plate and a photostimulable phosphor plate so manufactured.
  • Radiation images such as X-ray images are often used for medical diagnosis.
  • a so-called 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.
  • an "indirect" radiation image is obtained, using visible light generated from X-rays.
  • a highly sensitive and high resolution X-ray imaging apparatus as mentioned above is designed as a system utilising photostimulable phosphor.
  • the basis system of this apparatus has been described in detail in U.S. Patent No.US-A-3,859,527.
  • the phosphor used in this system stores a part of energy which it receives in the form of radiation, such as X-rays. This condition is comparatively stable and can therefore be maintained for a while or for a long period of time. However, when the phosphor under this condition is irradiated with a first light beam, working as an excitation light beam, the stored energy is emitted as a second light beam.
  • the first light beam For the first light beam, light having a wavelength in a wide range from infrared to ultraviolet can be used as well as visible light, depending on the phosphor material used.
  • the light of the second light beam may also occur over a wide range of wavelengths from infrared to ultraviolet, again depending on the phosphor material used.
  • the terms 'light' and 'light beam' as used herein thus comprehend not only visible light but also light outside the visible range.
  • the second light beam can be received and converted into an electrical signal by a photoelectric converter, and then converted into a digital signal and thereby digital image information can be obtained.
  • a photostimulable phosphor layer which has been used in the prior art is not transparent for the first light beam, namely the excitation light beam, and the second light beam, namely the photostimulated emitted light beam, and a distinctive scattering phenomenon has been manifest.
  • the excitation light beam flux is scattered very widely.
  • Fig. 1 shows such scattering conditions.
  • one pixel has a size of 0.1 mm square in this case, a part of the information from 100 to 900 adjacent pixels is undesirably detected when the one pixel is read, and thereby the space resolution of the image obtained suffers significant deterioration and the image is naturally defocused.
  • the present invention has been proposed, under the technical background as explained above, to provide a photostimulable phosphor plate which exhibits no substantial scattering effects with regard to emitted, fluorescent/photostimulated light generated in response to an excitation light beam.
  • a photostimulable phosphor plate having therein an array of fine holes, all of substantially the same size and with photostimulable phosphor therein, which phosphor is stimulable by excitation light to emit stimulated light, the wall surfaces of the holes being non-transmissive for or not penetrable by such excitation light, the method comprising:-
  • a photostimulable phosphor plate which has fine holes with photostimulable phosphor buried in the holes, between remaining portions of the plate which surround and, hence, form the holes.
  • These hole forming portions 2 of the plate are such as not to be penetrated by an excitation light beam.
  • the holes are regularly positioned, at respective crossing positions of arrays of imaginary lines extending in crossing directions, and are all of substantially the same size.
  • Light transmissive sealing material may be provided at the light penetrating side of the hole forming portions (i.e. at the side towards which the excitation light beam will be directed), and sealing material provided at the opposed side. Phosphor embedded in the hole forming portions is sealed by the sealing materials.
  • the positions of adjacent holes may be deviated only by the value required for approximation.
  • a digital X-ray apparatus wich forms a latent image of an object on a photostimulable phosphor plate as an energy distribution pattern using X-ray energy, and which reads such latent image using an excitation light beam, such that each pixel is individually formed, when forming the latent image of the object, and corresponds to one or a larger integer number of fine holes of a photostimulable phosphor plate, which plate has, at crossing positions in crossing directions, such fine holes, of almost the same size, burying photostimulable phosphor in hole forming portions processed at least on a substrate which is not penetrated by an excitation light beam, and respective pixels, accumulated in one or more such fine holes, are read out for recovery of the image data.
  • a digital X-ray apparatus which forms a latent image of a specimen on a photostimulable phosphor plate as an energy distribution pattern using the X-ray energy, and which reads such latent image using an excitation light beam may comprise a means for scanning the photostimulable phosphor plate, which is provided with fine holes burying photostimulable phosphor in a hole forming portion which is not penetrated by the excitation light beam and exhibits reflectivity for the excitation light beam at the plate surface, other than where the fine holes are formed, in the direction of hole arrangement with the excitation light beam; an emitted fluorescent light gathering means for gathering the fluorescent light emitted in response to the excitation light beam from the photostimulable phosphor buried in the fine holes; a reflected excitation light beam gathering means for gathering the excitation light beam reflected from the photostimulable phosphor plate; an excitation light beam irradiation period detecting means, for detecting periods when the excitation light beam is being irradiated on to the fine holes with the
  • Fig. 2A shows a photostimulable phosphor plate having therein fine holes 26 of substantially the same size.
  • the fine holes are regularly positioned, at the crossing points of two imaginary arrays of lines which extend in mutually crossing directions.
  • Extinctive phosphor 6, in the holes is surrounded by portions of the plate (hole forming portions 2) which are not penetrable by excitation light beam used to stimulate the phosphor.
  • Fig. 2B shows hole forming portions 2, of substantially the same size, which are processed so as not to be penetrable by the excitation light beam, with a light transmissive sealing material 4 provided at the light penetrating side of the hole forming portions 2 (the side from which excitation light is directed at the plate), a sealing material 5 provided on the surface opposite to the light penetrating side of the hole forming portions, and photostimulable phosphor 6 in the fine holes 26, surrounded by the hole forming portions 2 and sealed by the light transmissive sealing material 4 and sealing material 5.
  • a light transmissive sealing material 4 provided at the light penetrating side of the hole forming portions 2 (the side from which excitation light is directed at the plate)
  • a sealing material 5 provided on the surface opposite to the light penetrating side of the hole forming portions
  • photostimulable phosphor 6 in the fine holes 26, surrounded by the hole forming portions 2 and sealed by the light transmissive sealing material 4 and sealing material 5.
  • X-ray energy in accordance with an object pattern obtained when a specimen is irradiated with X-rays is distributed and stored in the fine holes 26 regularly arranged on the photostimulable phosphor plate.
  • the photostimulable phosphor plate with such a stored energy distribution pattern is scanned with an excitation light beam and thereby the object pattern, stored as the energy distribution pattern in the plate, may be extracted as an electrical signal pattern.
  • the fine holes 26 regularly arranged on the photostimulable phosphor plate are scanned, in one direction of the two crossing directions mentioned above, with an excitation beam. Since the photostimulable phosphor irradiated with the excitation beam is provided within the fine holes separated by portions 2 which are not penetrated by the excitation light beam, the excitation light beam is not subject to scattering. Therefore, reduction of space resolution can be prevented.
  • Fig. 3 illustrates how scattering is prevented or restricted, to avoid reduction of space resolution.
  • a method of manufacturing a photostimulable phosphor plate in accordance with an embodiment of the present invention will be explained hereunder with reference to Figs. 4A to 4F and Figs. 5A and 5B. This manufacturing method utilises etching.
  • a resist pattern suitable for forming fine holes (see Fig. 5A) in a thin stainless steel plate is produced by well-known CAD technique.
  • the diameter of a part of the pattern corresponding to a hole is set smaller than the desired diameter of a fine hole to be formed.
  • masks 22, 23 are formed on both surfaces of a stainless steel plate 20, as shown in Fig. 4A.
  • 24 designates mask holes in the masks 22, 23.
  • Fine holes 26 are formed as shown in Fig. 4B by applying etching agent to the stainless steel plate 20 through the mask holes 24.
  • 28 designates hole walls.
  • the photostimulable phosphor plate in this case is built up of three steel plates 20, as shown at 201, 202 and 203 in Fig. 4D.
  • hole wall areas 29 of a plate surface are coated with an adhesive agent 30 by a screen printing method, as shown in Fig. 4C.
  • both surfaces are coated with the bonding agent 30, whilst in the cases of stainless steel plates 201, 203, only the surfaces which come into contact with the stainless steel plate 202 are coated with the agent.
  • Fig. 4D 32 is a glass plate.
  • the deep fine holes 26, formed through the three stacked stainless steel plates 201 to 203, are filled with photostimulable phosphor powder 6 (BaFBr:Bu+), as shown in Fig. 4E, and a polyester protection layer 34, as shown in Fig. 4F, is formed thereon, thereby completing the manufacture of the photostimulable phosphor plate, which is schematically illustrated in Figs. 5A and 5B.
  • photostimulable phosphor powder 6 (BaFBr:Bu+)
  • a polyester protection layer 34 as shown in Fig. 4F
  • the wall surfaces of fine holes 26 are optical surfaces and efficiently reflect the excitation light beam and emitted fluorescent light. Therefore, the excitation light beam does not penetrate through the wall surfaces of the fine holes and emitted fluorescent light, arising from the photostimulable phosphor due to irradiation with the excitation light beam can be collected efficiently (refer to Fig. 3). Accordingly, reduction of the space resolution of an image can be prevented.
  • the quantity of photostimulable fluorescent light emitted from the photostimulable phosphor due to irradiation with the excitation light beam is increased by stacking stainless steel plates as described above, and space resolution is not thereby reduced.
  • the thin stainless steel plates used in this embodiment may be replaced by other thin metal plates.
  • Many fine holes may be formed in thin metal plates by various methods including etching methods and mechanical processing methods. In relation to the present invention, there is no limitation on the methods by which fine holes may be formed.
  • the fine holes 26 formed may exhibit various shapes, depending on the materials and forming methods used.
  • the holes can take various sectional shapes but it is possible to execute the present invention regardless of the shape of hole.
  • the flat or plan shapes of the fine holes may vary, for example as shown in Fig. 6.
  • the shapes may be circular, elliptical, square, rectangular or polygonal. These are not restrictive examples, but can be used for convenience of manufacture.
  • wall surfaces of the fine holes formed may be penetrated by the excitation light beam, due to the properties of the material used, it is better that wall surfaces be coated or evaporated with material which does not allow penetration by the excitation light beam, in order to prevent penetration by the excitation light beam.
  • the wall surfaces of the holes do not have sufficient surface accuracy from an optical viewpoint, it is effective to smooth the surface by coating it with resin and form thereon a layer such as metal having a high reflectivity.
  • the present size lower limit lies at about 0.01 mm diameter because of technical difficulties in burying photostimulable phosphor in fine holes of a certain thickness.
  • the upper visual limit lies at about 0.4 mm diameter from the viewpoint of space resolution required for X-ray image diagnosis.
  • the fine holes may be perpendicular to the surface of the photostimulable phosphor plate but they may also be formed at an inclination.
  • the shape of a hole may be straight or the sizes of upper and lower portions of hole may be different.
  • any kind of material may be used, provided it has sufficient mechanical strength after hole formation.
  • a glass plate is provided on one surface of the stainless steel plate (201, 202, 203) after formation of the fine holes. It is, however, also possible to use a metal sheet.
  • the sheet used reflects the excitation light beam and emitted fluorescent light.
  • a sheet which reflects the excitation light beam but is penetrated by the emitted fluorescent light may be used, as may a sheet having the inverse properties, depending on the manner of use; namely, depending on selection of the direction from which the excitation light beam is irradiated or the direction in which the emitted fluorescent light is collected.
  • a cover which functions as a selection mirror may also be effectively formed to both sides using adhesive agent.
  • a material as the cover, such as lead glass which is penetrated by excitation light beam and the photostimulable emitted light and which absorbs X-rays in order to prevent the back scattering of an X-ray beam.
  • a lead plate may be attached.
  • photostimulable phosphors which may be buried in the fine holes those which are not penetrated by the excitation light beam to show the scattering may be used, or those which are penetrated by the excitation light beam or the emitted fluorescent light in any combination may be used, without restriction.
  • the method of burying the phosphor may be freely chosen.
  • a method in which photostimulable phosphor powder of a grain size of 5 ⁇ m or less is dispersed into a solution of binder and the solution is then supplied into the holes may be used.
  • a method may be used in which the photostimulable phosphor powder is put directly into the fine holes and thereafter binder soaked into the powder, as may a method in which a layer which may be dissolved later is formed at parts other than the holes by a lift-off method, the holes are filled with the photostimulable phosphor by evaporation and thereafter the photostimulable phosphor is removed from the parts other than the holes.
  • fine holes 36 which are almost the same in size, and are provided with internal wall surfaces 2 (not indicated) not penetrated by the excitation light beam, are provided at respective hole forming positions affording a regular arrangement of positions wherein adjacent hole forming positions are displaced by amounts required for approximating or bringing together the hole forming positions.
  • Photostimulable phosphor is buried in the fine holes 36.
  • a photostimulable phosphor plate comprising fine holes 26 of almost the same size, providing wall surfaces 2 which are not penetrated by the excitation light beam, formed at respective hole forming positions of the substrate giving a regular hole arrangement where at least adjacent hole forming positions are previously deviated by a predetermined value.
  • Light transmissive sealing material 4 is arranged at the surface on the light penetrating side of the fine hole forming substrate, and sealing material 5 is arranged at the surface opposed to the light penetrating side of the fine hole forming substrate.
  • Photostimulable phosphor 6 fills the fine holes 26 sealed by the light beam transmissivity sealing material 4 and sealing material 5.
  • the fine holes of the photostimulable phosphor plate of the second embodiment of the present invention are thus arranged with the highest density as shown in Fig. 8.
  • the fine holes 36 are formed close to each other, the quantity of photostimulable phosphor buried in the photostimulable phosphor plate is increased and the phosphor effectively prevents reduction of energy to be stored therein.
  • a cross-sectional view of the second embodiment resembles Fig. 2.
  • the photostimulable phosphor irradiated with the excitation light beam is buried between internal wall surfaces 2 which are not penetrated by the excitation light beam, the light beam is not subject to scattering. Accordingly, reduction of space resolution can be prevented.
  • the method of manufacturing the photostimulable phosphor plate is similar to that of the first embodiment and a resist pattern corresponding to Fig. 8 is used.
  • a photostimulable phosphor plate 10 is formed by a plurality of stainless sheets 12.
  • Each stainless sheet 12 has a thickness of 0.1 mm and a size of 380 mm square.
  • the centre area 14 thereof (356 mm square) is provided with a plurality of fine holes 16 arranged in the form of a lattice.
  • the size of one pixel is considered.
  • the size of one pixel of a photostimulable phosphor plate or sheet for use in diagnosing breast cancer is set to approximately 50 ⁇ m square.
  • the pixel size is set from 87.5 ⁇ m square to 175 ⁇ m square in order to process the digital information. Although such sizes are not essential, diagnosis may be realised with such space resolution. Therefore, the pixel size must be changed depending on the object tissue and in the case of embodiments of the present invention, the photostimulable phosphor plates or sheets may be used to provide various pixel sizes.
  • the possible minimum pixel size is determined by the possible excitation light beam diameter.
  • the current minimum pixel size is about 20 ⁇ m square.
  • the maximum pixel size is not limited from the viewpoint of the possibility of realisation, but the diagnostic purpose is not attained when the pixel size is 0.4 mm square or more. Therefore, in embodiments of the present invention, pixel size ranges from 20 ⁇ m square to 0.4 mm square, the pixel being capable of taking a square shape and rectangular shape.
  • circular or square fine holes 16 which are smaller in diameter than the pixel size are formed on, for example, four stainless sheets 12.
  • the lateral and vertical (as seen in Fig. 9) pitches of the lattice of fine holes are set to 175 ⁇ m and positional deviation of fine holes 16 between the starting and ending points is set to 52.5 ⁇ m.
  • the holes 16 are, of course, to be scanned by an excitation light beam when the plate is in use.
  • the fine holes 16 are formed so that the arrangement of fine hole matches with a subscanning direction (vertical direction in Fig.
  • the etching process is employed for example.
  • a thermosetting type epoxy resin is dissolved into an organic agent, both sides of the sheet are coated with the solution, obtained by dispersing the graphite powder, by a screen printing method (except for the fine hole portions) and thereafter the coated area is dried up.
  • Such a stainless sheet 12 and a stainless sheet 12 coated with the resin only at one single surface are stacked with each other.
  • a stainless sheet without fine holes 16 and having a thickness of 0.2 mm is placed on one surface.
  • the three stainless sheets are placed under pressure, 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 excitation light beam.
  • a phosphor powder consisting of BaC Br:Eu with a grain size of 5 ⁇ m or less is dispersed into organic solvent including epoxy resin as binder, it is then poured on to the sheet under a reduced pressure condition and the phosphor buried in the holes is dried up. This process is repeated three times. After confirming 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 away.
  • the sheets are hardened at 180°C and moreover a transparent polyester sheet is bonded to the surface as the protection layer.
  • a photostimulable phosphor plate 10 manufactured as explained above was fixed on a stage and irradiated with the laser beam of 100 ⁇ m extent in the subscanning direction and 40 ⁇ m extent in the main scanning direction using a laser scanning system having a scanning efficiency of 70% consisting of the semiconductor laser with a wavelength of 780 nm, a lens and a galvano mirror. Thereby, it was confirmed that the excitation light beam penetrates through the photostimulable phosphor in the fine holes 16 and that scattering from one hole to other fine holes 16 can be prevented.
  • the emitted fluorescent light which is emitted, as a consequence of irradiation of the surface of photostimulable phosphor plate 10 with X-rays, when the phosphor is excited with a pulse laser was gathered by a condenser mirror and glass fibre array and received by a photomultiplier. The converted electrical signal was then converted into the digital signal through the analog to digital conversion.
  • the sheet was irradiated with a reference dose of X-rays, and a reference output of each pixel input to a memory.
  • a normal image can be obtained in which changes in the quantity of photostimulated light beam produced, resulting from aging, is compensated and fluctuation or changes due to aging of pixels is compensated.
  • the size of the excitation beam on the phosphor plate or sheet must be smaller than it could otherwise be, by a factor determined by the degree of wobble which arises.
  • the length of the beam in the main scanning direction is smaller than the length of one pixel in the subscanning direction.
  • the excitation light beam used may be a continuous light or pulse beam but the length of excitation light beam in the main scanning direction is best as short as possible.
  • the scanning must be made in such a manner that the excitation light beam does not pass over pixels adjacent in the subscanning direction. An image of a predetermined space resolution can be read without influence of scattering of the excitation light beam by paying attention to these conditions.
  • the angle between the photostimulable phosphor plate or sheet and a subscanning direction may be determined uniquely in relation to the efficiency of the scanning by the excitation light beam and the size of one pixel.
  • Fig. 10 shows a photostimulable phosphor reader.
  • a latent image of an object is formed as an energy distribution pattern on the photostimulable phosphor plate 105 and such latent image is read using an excitation light beam.
  • a laser beam output from an excitation light beam source 101 is used for scanning, through the scanner 102 consisting of a galvano mirror or polygon mirror.
  • the photostimulable phosphor plate 105 is scanned by the laser beam through an optical part 103 for compensating the shape of the beam (for example an f0 lens, etc.) and a reflection mirror 104.
  • the fluorescent light emitted 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 fibre array 107.
  • the gathered light beam is converted into an electrical signal, corresponding to the quantity of the light received, in a photoelectric converter 108, such as a photoelectron multiplier, through a filter which does not transmit the excitation light beam as received from the fibre array 107 but transmits only the photostimulated light beam and is then amplified by an amplifier 109. Thereafter, the signal is converted to a digital signal by an A/D converter 110.
  • the digital signal is first stored in a frame memory 111 or stored in an optical disk memory 112 without passing through the frame memory.
  • an image processing part 113 Thereafter, processing such as a gradation process is carried out as required in an image processing part 113.
  • the image is displayed as an X-ray image on the image display part 114 such as a CRT, or is written direct on an X-ray film through film writing apparatus and the film is then developed to obtain the X-ray image.
  • a reader of this kind can be used for reading a photostimulable phosphor plate as described in relation to any of the first to third embodiments of the present invention.
  • 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 plate 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 one pixel in the main scanning direction.
  • a standard single pixel from which light is gathered has a size of 176 ⁇ m square and includes 16 holes in total (refer to I of Fig. 11).
  • the laser beam diameter in the subscanning direction is 125 ⁇ m.
  • 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) exists 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 number of holes corresponding to one pixel may range from 1 to 400.
  • fine holes may be provided in one pixel, but if two pixels use in common a part of certain fine hole, space resolution is reduced.
  • a situation may be considered in which several holes are used as one pixel but that scanning line used for reading the photostimulable phosphor is deviated at the time of the reading operation. Namely, a situation may be considered in which a hole located on a certain main scanning line corresponding to a certain straight line but that the excitation light beam deviates slightly from this line. This may mean that a certain hole is not always irradiated by the excitation light beam over its entire extent. In other words, only a part of a certain hole may be irradiated by the excitation light beam only.
  • a light beam is gathered for the scanning of the photostimulable phosphor plate.
  • light of the excitation light beam reflected from the wall surface not forming the holes of the photostimulable phosphor plate is gathered by a fibre array different from that of Fig. 10, or by a plastic light receiver, and light from the photostimulable phosphor is received with synchronisation between such gathered light beam and the light from the photostimulable phosphor.
  • the excitation light beam from the wall surface is reflected by utilising the photostimulable phosphor plate of any of the first to third embodiments described above which are formed to reflect the light from that surface, other than at hole forming portions of the extinctive phosphor plate.
  • Fig. 12 shows a structure wherein a reflected excitation light beam gathering optical guide path 113, for gathering the excitation light beam, is provided. Elements similar to those in Fig. 10 are designated by like reference signs.
  • 1071 designates an excitation light beam absorbing filter; 107 gathers photostimulated fluorescent light and therefore it must absorb reflections of the excitation light beam.
  • the excitation light beam absorbing filter 1071 absorbs light of 600 to 900 nm wavelength (wavelength of the excitation light beam) and transmits light of 400 nm wavelength (wavelength of the photostimulated fluorescent beam).
  • 115 is a gathering mirror which gathers light so that the excitation light beam and emitted fluorescent light are not scattered.
  • 207 is a reflected excitation light gathering and guiding path; 2071 is an emitted fluorescent light absorbing filter which absorbs light in the vicinity of 400 nm (wavelength of emitted fluorescent light) and transmits light of 600 to 900 nm wavelength (wavelength of the excitation light beam).
  • 208 is a photosensor. This photosensor is a semiconductor sensor such as a photoelectron multiplier or photodiode.
  • the emitted fluorescent light absorbing filter 2071 realises power saving through selection of a kind of photoelectron multiplier.
  • Fig. 13 illustrates a circuit for determining the timing of sampling. In Fig. 13, 108 designates a photoelectric converter and 208 designates a photosensor similar to that shown in Fig. 12.
  • the emitted fluorescent light and light of the excitation light beam are input to the photoelectric converter 108 and photosensor 208 respectively through the fibre array 107 and reflected and excited light beam gathering and guiding path 207 as shown in Fig. 12.
  • the emitted fluorescent light input to the photoelectric converter 108 is converted into an electrical signal and input to the A/D converter 110 through the amplifier 109.
  • the light of the excitation light beam converted to the electrical signal in the photosensor 208 is compared with a reference voltage in a comparison circuit 209.
  • Fig. 14 shows a timechart of signals output from the circuit shown in Fig. 13. As shown in Fig. 13, when the electrical signal from the photosensor 208 is lower than the reference voltage, the comparison circuit 209 outputs signals.
  • the photosensor 208 receives the light of the excitation light beam. If the line L in Fig. 11 is scanned by the excitation light beam, the surface other than the hole portions (the photostimulable phosphor is buried therein) intensively reflects the excitation light. The excitation light beam is absorbed in 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 light of the excitation light beam received by the photosensor 208.
  • An output of comparison circuit 209 is input to a flipflop 210 which outputs a signal synchronised with the input signal thereto.
  • An output of the flipflop 210 is ANDed with an original clock in an AND gate 211 and is then input to an A/D converter 110 as an operation clock. Namely, when an electrical signal corresponding to light of the excitation light beam (output of photosensor 208) is lower than the reference voltage, the A/D converter 110 operates and an electrical signal corresponding to emitted fluorescent light (output of amplifier 109) is converted to a digital signal. The converted digital value is added by an adder 217 whilst an output of AND gate 211 is ON, and the added value is stored in a flipflop 218 (such flipflops are provided in a number corresponding to the number of bits of the digital signal, but this is not illustrated in the drawings).
  • a divider 219 outputs a value, obtained by dividing a sum of outputs of the A/D converter from flipflop 218 with a value from the counter stored in the flipflop 215, to the memory 111. Namely, the emitted fluorescent light is sampled while the excited light beam passes the holes filled with the photostimulable phosphor by receiving the excited light beam.

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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)

Abstract

Sont décrits une plaque à substance fluorescente accélérée et un lecteur possédant une haute précision au moment de la lecture lors de l'irradiation de la plaque avec un faisceau excité, ainsi qu'une résolution spatiale élevée. La plaque comporte des micropores (26) présentant chacun une paroi (2) imperméable à la lumière excitée et remplie d'une substance fluorescente accélérée (6), les micropores étant disposés au niveau de chacune des intersections de directions de croisement.

Claims (7)

  1. Procédé de fabrication d'une plaque luminescente photostimulable ayant une grille de trous fins (26 ; 16 ; 36) ayant tous pratiquement la même dimension et contenant une matière luminescente photostimulable (6), cette matière luminescente pouvant être stimulée par une lumière d'excitation et pouvant alors émettre de la lumière par stimulation, les surfaces des parois des trous ne transmettant pas la lumière d'excitation ou ne pouvant pas être traversée par cette lumière, le procédé comprenant :
    l'attaque de trous fins (26 ; 16 ; 36) dans plusieurs feuilles métalliques (20₁, 20₂, 20₃),
    l'empilement de plusieurs feuilles métalliques (20₁, 20₂, 20₃) pour la formation du corps de la plaque, les trous attaqués dans les feuilles étant alignés afin qu'ils forment la grille de trous fins (26 ; 16 ; 36),
    l'incorporation d'une matière luminescente photostimulable dans les trous attaqués,
    la réalisation d'une surface du corps de la plaque afin qu'elle soit réfléchissante, et
    la réalisation d'une couche protectrice transparente à la surface opposée du corps de la plaque.
  2. Procédé de fabrication selon la revendication 1, comprenant le collage des feuilles métalliques (20₁, 20₂, 20₃) par un procédé de sérigraphie.
  3. Plaque luminescente photostimulable fabriquée par le procédé selon la revendication 1 ou 2, dans laquelle la grille de trous fins (26 ; 16 ; 36) est sous forme d'un réseau, des lignes de trous étant alignés dans une première direction du réseau qui correspond à une direction de balayage auxiliaire de la plaque par un faisceau de lumière d'excitation lorsque la plaque est utilisée, et des lignes de trous étant alignées dans une seconde direction du réseau qui correspond à la direction de balayage principal de ce balayage, la seconde direction du réseau faisant un certain angle avec une direction orthogonale à la première direction du réseau d'une manière telle que, d'une extrémité à l'autre d'une ligne de trous (26 ; 16 ; 36) disposée dans la seconde direction du réseau, les extrémités soient décalées les unes par rapport aux autres dans la première direction du réseau d'une distance △ = b.η, b étant le pas de lecture ou de balayage dans la direction de balayage auxiliaire qui correspond à la dimension d'un élément d'image dans la direction d'une image qui doit être formée d'après la lumière obtenue par stimulation, et η étant le rendement de balayage de la plaque par le faisceau de lumière d'excitation.
  4. Plaque selon la revendication 3, dans laquelle les surfaces de paroi des trous sont réfléchissantes pour la lumière d'excitation et la lumière obtenue par stimulation.
  5. Plaque selon la revendication 3 ou 4, dans laquelle les trous sont placés dans la grille de manière qu'ils soient très proches les uns des autres et soient bien tassés ou approximativement bien tassés.
  6. Plaque selon la revendication 3, 4 ou 5, ayant une matière (4) d'étanchéité qui transmet la lumière, placée sur la plaque d'un côté de celle-ci vers lequel la lumière d'excitation est destinée à être dirigée lorsque la plaque est utilisée, et une matière d'étanchéité (5) placée de l'autre côté de la plaque et enfermant la matière luminescente dans les trous (26 ; 16 ; 36).
  7. Plaque selon la revendication 3, 4, 5 ou 6, dans laquelle la surface de la plaque du premier côté de la plaque vers lequel doit être dirigée la lumière d'excitation lorsque la plaque est utilisée est réfléchissant pour la lumière d'excitation aux endroits où les trous (26 ; 16 ; 36) ne sont pas présents.
EP90905637A 1989-04-03 1990-03-30 Plaque a substance fluorescente et methode pour produire une telle plaque Expired - Lifetime EP0426865B1 (fr)

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
JP130739/89 1989-05-24
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
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)

Publication Number Publication Date
EP0426865A1 EP0426865A1 (fr) 1991-05-15
EP0426865A4 EP0426865A4 (en) 1991-08-07
EP0426865B1 true EP0426865B1 (fr) 1996-01-03

Family

ID=27466943

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90905637A Expired - Lifetime EP0426865B1 (fr) 1989-04-03 1990-03-30 Plaque a substance fluorescente et methode pour produire une telle plaque

Country Status (3)

Country Link
EP (1) EP0426865B1 (fr)
DE (1) DE69024610T2 (fr)
WO (1) WO1990012405A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0797835A1 (fr) * 1994-04-29 1997-10-01 Minnesota Mining And Manufacturing Company Procede de fabrication de phosphore a pixels
US5534702A (en) * 1994-08-08 1996-07-09 Hewlett-Packard Company Resolution improvement of images recorded using storage phosphors
EP0760520A1 (fr) * 1995-08-29 1997-03-05 Hewlett-Packard Company Amélioration de la résolution d'images enregistrées utilisant des matériaux phosphorescents à mémoire
DE19930645A1 (de) * 1999-07-02 2001-01-11 Rainer Kassing Wiederverwendbare Bildplatte mit einem Speicherleuchtstoff zur Speicherung von Röntgenstrahlbildern und Herstellungsverfahren für eine wiederverwendbare Bildplatte

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2827571A (en) * 1955-05-23 1958-03-18 Philips Corp Intensifying screen for making x-ray registrations
DE2347923C2 (de) * 1973-01-17 1983-11-24 Douglas F. Los Altos Hills Calif. Winnek Hochauflösender Strahlenverstärkerfilm für Strahlung
US4059707A (en) * 1975-08-29 1977-11-22 Rca Corporation Method of filling apertures with crystalline material
DE2929745C2 (de) * 1979-07-23 1986-03-27 Siemens AG, 1000 Berlin und 8000 München Verfahren zur Herstellung eines Eingangsleuchtschirms eines Röntgenbildverstärkers
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
DE3325035A1 (de) * 1983-07-11 1985-01-24 Siemens AG, 1000 Berlin und 8000 München Roentgenleuchtschirm
US4730107A (en) * 1986-03-10 1988-03-08 Picker International, Inc. Panel type radiation image intensifier
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
JPS643599A (en) * 1987-06-25 1989-01-09 Seiko Instr & Electronics Fluorescent screen and its production
JPH02152143A (ja) * 1988-12-02 1990-06-12 Toshiba Corp Ｘ線イメージ管及びその製造方法
DE3909450A1 (de) * 1989-03-22 1990-09-27 Kernforschungsz Karlsruhe Verfahren zur herstellung von leuchtschirmen, verstaerkungs- oder speicherfolien fuer die roentgendiagnostik
DE3909449A1 (de) * 1989-03-22 1990-11-22 Kernforschungsz Karlsruhe Verfahren zur herstellung von leuchtschirmen, verstaerkungs- oder speicherfolien fuer die roentgendiagnostik
JP3348452B2 (ja) * 1993-02-09 2002-11-20 ソニー株式会社 磁気記録再生装置

Also Published As

Publication number Publication date
DE69024610T2 (de) 1996-05-15
EP0426865A1 (fr) 1991-05-15
EP0426865A4 (en) 1991-08-07
WO1990012405A1 (fr) 1990-10-18
DE69024610D1 (de) 1996-02-15

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