WO1990012405A1

WO1990012405A1 - Accelerated phosphor plate and accelerated phosphor reader

Info

Publication number: WO1990012405A1
Application number: PCT/JP1990/000434
Authority: WO
Inventors: Shiro Takeda; Fumihiro Namiki; Yuuichi Sugiyama; Nobuhiro Iwase; Shinji Tadaki; Nagaaki Koshino
Original assignee: Fujitsu Limited
Priority date: 1989-04-03
Filing date: 1990-03-30
Publication date: 1990-10-18
Also published as: DE69024610T2; EP0426865B1; DE69024610D1; EP0426865A4; EP0426865A1

Abstract

An accelerated phosphor plate and a reader having high accuracy at the time of reading when the plate is irradiated with an excited beam and high spatial resolution. The plate is provided with micropores (26) each having a wall (2) impervious to excited light and filled with an accelerated phosphor (6), wherein the micropores are provided at each of the intersections of crossing directions.

Description

Specification

[Title of Invention]

Photostimulable phosphor plate and photostimulable phosphor reader [Technical field]

The present invention further _β about the excitation light or excitation light and bright尽螢light in the photostimulable尽螢light body plate using the scatter preventing means against its read-device, speaking For more information, such as X-ray images Radiation images are often used for disease diagnosis and the like. In order to obtain an X-ray image of this, the X-rays that have passed through the subject are irradiated onto the phosphor layer (fluorescent screen) to generate visible light, which is then converted into silver salt. A so-called radiographic image is used, which is developed by irradiating a film using a so-called photographic film, and the conventional silver salt sensitizer is directly or indirectly applied to the film coated on the sheet. A high-sensitivity, high-resolution X-ray imaging system has been developed as a system that can replace the X-ray imaging device that records two-dimensional G-ray images. Background technology

The high-sensitivity and high-resolution X-ray imaging device described above

This is a system that uses a sex fluorescent substance. The basic scheme for such a scheme is described in detail in U.S. Pat. No. 3,859,522. The fluorophores used in this system are sources of radiation such as X-rays. When it receives ruggy, it stores some of its energy. This condition is relatively stable and can be maintained for a long time or for a long time. When the phosphor in this state is irradiated with the first light that acts as the excitation light, the stored energy is emitted as the second light. At this time, the first light is not limited to visible light, but light of a wide wavelength range from infrared rays to ultraviolet rays is used. However, the choice depends on the phosphor material used. The second'lights also vary from infrared to ultraviolet. The difference also depends on the fluorescent material used. This second electromagnetic wave is received, converted into an electric signal by a photoelectric converter, and then converted into a digital signal to obtain digital image information. The photostimulable phosphor layer that has been conventionally used. Was not transparent to the first light, that is, the excitation light, or to the second light, that is, the stimulated emission light, and showed a strong scattering phenomenon. Therefore, even if the excitation light flux of the same size as or less than one pixel is applied to the photostimulable phosphor layer, the excitation light flux is scattered very widely, and, for example, a phosphor with a thickness of 0.3% is used. It has been observed that when a layer is irradiated with an excitation light beam with a diameter of 0.1, the surface opposite to the irradiation surface has a diameter of 1 yr or more and, in some cases, a diameter of 3 yr or more. ..

Figure 1 shows this. In the case of the above example, such excitation light scatters if the size of one pixel is 0.1 If the size is large, when one pixel is read, a part of the information of the adjacent 100 to 900 pixels is taken in as an error, and as a result, the spatial resolution of the obtained image is significantly degraded. It is natural that the image will be extremely sharp and unsharp. Several attempts have been made to mitigate this phenomenon of excitation light scattering. For example, a method of decomposing white fine particles in a fluorescent material layer as disclosed in JP-A-5-5-1464647 and JP-A-558-5850, or The method of adding a coloring agent capable of absorbing excitation light, which is disclosed in Japanese Laid-Open Patent Publication No. 61-170740, or the method disclosed in Japanese Laid-Open Patent Publication No. 6-21-211600. There is a method of forming a colorant or white fine particles on a supporting substrate of such a photostimulable phosphor. Although such a method is a method for improving the sharpness, which has been done for the intensifying screen of the conventional X-ray film, it is not a method for completely eliminating the excitation light scattering. Is clear. In addition, a method of forming cracks in a vertical direction in a layer of a photoluminescent material, such as disclosed in Japanese Patent Laid-Open No. 60-171500, or a method of forming a honeycomb structure or a substrate There are also attempts to prevent scattering by forming uneven patterns or mosaic patterns on the surface. However, these methods also do not completely prevent the excitation light from being scattered, and they give rise to the possibility of forming moire patterns in the obtained image. [Disclosure of Invention]

The present invention was created in view of such technical problems, and an object of the present invention is to provide a photostimulable phosphor body that does not scatter excitation light and photostimulable light.

As a first means for achieving the above-mentioned object, micro holes 2 6 in which a photostimulable phosphor 6 is embedded in a hole forming part 2 which is processed to be opaque to excitation light and has almost the same size are intersected. The hole forming part 2 is provided at each intersecting position in the difference direction, and the exciting light is impermeable to each other at each intersecting position in the intersecting direction. A light-transmissive encapsulant 4 disposed on the transmissive side; a encapsulant 5 disposed on a surface opposite to the light-transmissive side surface of the hole forming part forming substrate; and the light-transmissive encapsulant. This can be achieved by constructing a photostimulable phosphor 6 filled in the hole forming portion 2 sealed by the material 4 and the sealing material 5 _{; and} as a second means, meet each other. Each of the hole forming positions of the substrate, which is a regularly arranged position in which the hole forming positions are displaced by a predetermined value necessary to bring them closer to each other, has substantially the same size, and the inner wall surface 2 thereof is Micro holes 26 that are opaque to excitation light are provided, and photostimulable phosphors are embedded in each of the micro holes 26, and the hole forming positions for at least the eye contact are predetermined. Microholes 26 that are approximately equal in size and whose inner wall surface 2 is processed to be opaque to excitation light at each hole formation position of the substrate that is displaced by a value and has a regular array position, and the microholes. 2 6 A light-transmissive sealing material 4 arranged on the light-transmitting side surface of the forming substrate, and a sealing material 5 arranged on the surface opposite to the light-transmitting side surface of the 6-forming substrate. This is achieved by providing a photostimulable phosphor 6 filled in the minute holes 26 sealed by the light transmissive sealing material 4 and the sealing material 5.

Further, as a third means, the micro holes 16 are arranged in a grid pattern, and the micro holes 16 are arranged in the sub-scanning direction of the excitation light scanning, and in the main scanning direction. , The read line pitch, which is the size of the pixel in the secondary scanning direction, and the scanning efficiency of the excitation light scan? ? , Where Δ is the positional deviation between the starting and ending points of the micro hole 16 on one scanning line in the sub-scanning direction, it agrees with the straight line having the relationship of Δ = 1) — b (1 — ??). Is configured to be _c

Furthermore, as a fourth means, a latent image of the subject is formed as an energy distribution pattern using X-ray energy on the photoluminescent plate 105, and the latent image is read using excitation light. In the digital X-ray apparatus, when forming the latent image of the object, a stimulable phosphor is formed in the hole forming part 2 which is processed to the excitation light opaque substrate with the same size. One pixel of the subject image is formed in each of the corresponding integer holes of 1 or more of the photostimulable phosphor plate formed by forming the embedded micro holes 2 at each intersection position. Stored in an integer number of small holes This is achieved by reading out each of the stacked pixels and reproducing them.

Furthermore, as a fifth means, a digital X-ray device that uses X-ray energy to form a latent image energy distribution pattern of the subject on the photoluminescent body 105 and reads the latent image using excitation light is used. In, in the hole forming part (2) processed to be opaque to the excitation light, there is a micro hole in which a photostimulable phosphor is embedded, and the plate surface other than the micro hole is reflective to the excitation light. A means for scanning the excitation light in the array direction of the holes of the photostimulable phosphor plate; and a photostimulant for concentrating the photostimulable light excited by the excitation light from the photostimulable phosphors embedded in the minute holes. Fluorescence condensing means, reflection excitation light condensing means for condensing the light in which the excitation light is reflected from the photostimulable phosphor plate, and a signal obtained from the reflection excitation light condensing means Excitation light irradiation period determination means for determining the period during which the excitation light is irradiated to the microhole in which the photostimulable phosphor is embedded; and the excitation light irradiation period determination means for determining the period during which the excitation light irradiation period is determined. The purpose is achieved by sampling the photostimulable light obtained by the light collecting means as pixel information.

[Description of Drawings]

Figure 1 is an illustration of excitation light scattering in a conventional photostimulable phosphor,

FIG. 2 is a cross-sectional view of the photostimulable phosphor of the present invention, FIG. 3 is an explanatory diagram of excitation light scattering in the photostimulable phosphor of the present invention,

FIG. 4A is a diagram showing a manufacturing process of the photostimulable phosphor of the present invention,

FIG. 4B is a diagram showing a manufacturing process of the photostimulable phosphor of the present invention,

Fig. 5 is a diagram of a photostimulable phosphor plate with circular microholes, Fig. 6 is a diagram showing various planar shapes of microholes, Fig. 7 is a diagram showing various cross-sectional shapes of microholes, and Fig. 8 is a circle. Figure of a photostimulable phosphor in which micro holes are arranged in a close-packed manner,

FIG. 9 shows the photostimulable phosphor plate of the third embodiment,

Fig. 10 is a block diagram of a digital X-ray reader. Fig. 11 is a diagram showing the pixel formation form and the number of minute holes in it.

Fig. 12 shows the configuration of the digital X-ray that synchronizes the reflected excitation light.

Figure 13 is a circuit diagram for synchronizing the reflection excitation light, and Figure 14 is a timing chart of the circuit diagram for synchronizing the reflection excitation light.

〔Example〕

FIG. 2 shows the first embodiment of the present invention, and FIG. 2A shows that the photostimulable phosphor 6 is embedded in the hole forming portion 2 which is processed to be opaque to excitation light and has substantially the same size. Micro hole 2 It is a photostimulable phosphor plate with 6 provided at each intersection in the intersection direction.

Further, FIG. 2B shows, at each crossing position in the crossing direction, a hole forming part 2 which is processed to be opaque to excitation light and has a substantially equal size, and is arranged on the light transmitting side of the hole forming part 2. The light-transmissive sealing material 4, the sealing material 5 arranged on the surface opposite to the light-transmissive side surface of the hole forming portion forming substrate, the light-transmissive sealing material 4 and A photostimulable phosphor 6 filled in the hole forming portion 2 sealed by a sealing material 5.

The X-ray energy of the subject pattern, which is irradiated with X-rays and transmitted through the subject, is distributed to each of the photostimulable phosphors 6 in the micro holes 2 6 that are regularly arranged in the photostimulable phosphor plate. Accumulated. The excitation light beam is scanned on the photostimulable phosphor plate having this energy distribution pattern, and the subject pattern formed as an energy distribution pattern there is taken out as an electric signal pattern and used for its use. It

When the electric signal pattern is output, the excitation light is scanned through the regularly arranged micro holes 26 of the photostimulable phosphor plate along one of the intersecting directions. Since the photostimulable phosphor irradiated with the excitation light is contained in the hole wall 2 impermeable to the excitation light, it does not scatter. Therefore, it is possible to completely prevent the spatial resolution from being degraded. Figure 3 shows how this is prevented. C The method for producing the photostimulable phosphor plate of the present invention will be described below with reference to FIG. This manufacturing method is a method by etching.

First, a resist pattern (see Fig. 5) for forming micro holes in a thin stainless plate is manufactured using a known CAD technique. The size of the hole-corresponding part of the pattern should be smaller than the size of the micro holes. Masks 2 2 and 2 3 are formed on both sides of the stainless steel plate 20 using this resist pattern (see Fig. 4A). 2 4 is a mask hole of masks 2 2 and 2 3. An etching agent is applied to the stainless steel support 20 through the formed mask holes 24 to form micro holes 26 as shown in Fig. 4B. 2 8 is a hole wall. The adhesive 30 is applied to the hole wall plate surface area 29 by screen printing (Fig. 4C). As shown in Fig. 4D, this adhesive 30 © is applied to both sides of the stainless steel plate 2 0 z sandwiched between them, and to the stainless steel plates 20 0 ,, 2 0 3 sandwiched between them. , it applied only to the stearyl emissions less plate surface sandwiching the stearyl emissions less plate 2 0 _2. In Figure 4D, G 32 is a glass frame. After bonding process is completed, overlapping if I have been three stearyl emissions less plate 2 0, or 2 0 ₃ has been made form, the deeper Ku powder stimulable尽螢the light in summer and small holes 2 6 are After filling with 6 (BaFEr: Bu ^2- ) (see Fig. 4E), a protective layer of polyester "34 (see Fig. 4F) is formed on it to form a photostimulable phosphor coating. Made Made (see Figure 5).

The wall surface of the minute hole 26 has an optical surface and efficiently reflects excitation light and stimulated emission light. As a result, the excitation light does not pass through the walls of the microholes, and the excitation light emitted from the excitation phosphor by irradiation of the excitation light can be efficiently collected (3rd step). (See figure). Therefore, it is possible to prevent deterioration of the spatial resolution of the image. Further, by the above-mentioned superposition, it is possible to increase the amount of photostimulable light emitted from the photostimulable phosphor by the excitation light irradiation. There is no reduction in spatial resolution.

The thin stainless plate in the above embodiment may be another thin metal plate, a plastic plate, or the like. There are various methods for forming a large number of minute holes in a thin metal plate, a plastic plate, or the like, such as a method by etching: a method by machining, but the method is not limited.

The method of forming the micro holes is not limited, but the micro holes 26 formed can have various shapes depending on the material and the forming means (see FIGS. 6 and 7). For example, if a hole with a diameter of 0.08 thighs is formed on a stainless steel plate with a thickness of 0. I ran by etching with vertical and horizontal pitches of 0.1 thighs each, the shape of the holes is completely straight. However, if the etching is performed from only one side, the other side becomes larger, and if the etching is performed from both sides, the center has a narrowed shape. Or it can be a different shape depending on how the mask holes are formed. Alternatively, when a hole is formed by electric discharge machining, it can have various shapes such as a relatively straight shape, but it is possible to carry out the present invention regardless of the shape. The shape of the micropores is not particularly limited, but in practice, circles, ellipses, squares, rectangles, or polygons are used in manufacturing (see Fig. 6). If the wall surface of the micro hole formed in this way transmits the excitation light due to the property of the material, a material that does not transmit the excitation light may be applied to the wall surface of the micro hole or may be vapor-deposited to generate the excitation light. It is necessary to prevent penetration. Also, when the wall surface of the hole does not have surface accuracy in the optical sense, it is effective to apply resin to make it smooth and to form a highly reflective layer such as metal on it.

Also, the size of the microholes is not particularly limited-due to the technical difficulty of embedding the photostimulable phosphor in the microholes of a certain thickness, the lower limit of the size is 0.01 The upper limit is about 0.4 in terms of the spatial resolution required for X-ray image diagnosis. The direction of the minute holes with respect to the surface of the photostimulable phosphor plate is the vertical direction, but it may be completely vertical or oblique. For example, diagonal micro-holes can be formed by arranging a large number of capillaries whose inner diameter is the same as that of the micro-holes in a square array, or by stacking them one by one. It can be manufactured by cutting, polishing, and cleaning. Also, the shape of the inside of the hole may be _straight or the size of the top and bottom may be different. Any forest material that forms a hole may have any mechanical strength after forming the hole.

Further, in the above-mentioned embodiment, an example in which the glass plate is used on one side of the stainless plate after forming the micro holes is shown. It is also possible to use a force, ', a metal sheet or the like. , It is preferable that the sheet reflects excitation light and stimulated emission light. Alternatively, the excitation light may be reflected but the stimulated emission light may be transmitted, and in the opposite case, the usage method, that is, the direction of excitation light irradiation and the direction of collection of stimulated emission light Yes, depending on your choice. It is also effective to form a cover having a function of a selection mirror on both sides by adhesion or the like. The type of force par is not particularly limited, but in order to prevent X-ray backscattering rays, it is also effective to use, for example, lead glass that passes excitation light and stimulated emission light and absorbs X-rays. It is also effective to stick a board.

The photostimulable phosphor embedded in each microhole may be either opaque so that excitation light is scattered or transparent to excitation light or stimulated emission light. Any composition can be applied, and the composition is not limited, and the burying method is not limited, and the phosphor powder having a particle size of 5 m or less can be used. The powder is dispersed in the binder solution and poured, the phosphor powder is pressed into the microholes as it is, and then the binder is soaked in and the lift-off method is applied. It is possible to use various methods such as a method of forming a soluble layer later on the part, filling the inside of the hole by vapor deposition of the phosphor, and then removing the phosphor other than the hole. it can.

Next, referring to FIG. 8, a substrate having a regular array position, which is the second embodiment, is displaced by a predetermined value necessary to bring the adjacent hole forming positions closer to each other. Microholes 26 of approximately the same size and whose inner wall surface 2 are opaque to excitation light are provided at each hole formation position, and a photostimulable phosphor is embedded in each microhole 26. In addition, at least for each hole forming position of the substrate, which is a regular array position where the adjacent hole forming positions are displaced by a predetermined value, the size is almost equal and the inner wall surface 2 has no excitation light. A micro hole 26 processed to be transparent, a light-transmissive encapsulant 4 disposed on the light transmission side surface of the micro hole 26 forming substrate, and a light transmissive material of the micro hole 26 forming substrate. Inside the micro hole 2 S sealed by the sealing material 5 arranged on the surface opposite to the surface on the side, and the light-transmissive sealing material 4 and the sealing material (5). The photostimulable phosphor 6 and the photostimulable phosphor 6 will be described.

The micro holes in the photostimulable phosphor plate of Example 2 © are shown in Fig. 8. As shown in FIG.

That is, since the micro holes 26 are formed close to each other, the amount of the photostimulable phosphor plate embedded in the photostimulable phosphor plate is increased, and the amount of energy stored therein is increased. Helps prevent decline.

A side sectional view of this second embodiment is as shown in FIG.

Since the photostimulable phosphor irradiated with the excitation light is contained in the inner wall surface 2 which is impermeable to the excitation light as in the first embodiment, it is not scattered. Therefore, it is possible to completely prevent the spatial resolution from being lowered.

The manufacturing method of this photostimulable phosphor plate is the same as that of the first embodiment, and the resist pattern as shown in FIG. 8 may be used.

Next, a third embodiment will be described based on FIG. 9. In FIG. 9, the photostimulable phosphor plate I 0 is composed of a plurality of stainless sheets 12. And each stainless sheet 12 has a thickness of 0.1 and a size of 380, and there are several micro holes in the central area (3 5 6 mra angle) 14. 1 6 are arranged in a grid. When forming the minute holes 16, the size of one pixel is decided. For example, in the case of a photostimulable phosphor plate or sheet for the purpose of diagnosing breast cancer, the size of one pixel is approximately 50 m square. 87.5 m square or 17.5 m for chest radiographs The unreasonable size is generated because it handles digital information and is not essential, but if it has a spatial resolution of about that level, it achieves the diagnostic purpose. Therefore, it is necessary to change the size of the pixel depending on the target diagnosis site, and in the present invention, it is possible to use various types of pixel-sized photostimulable phosphor plates or sheets. The smallest feasible pixel size is determined by the achievable pumping light beam diameter, and is currently about 20 square. The maximum pixel size is not limited in terms of feasibility, but in most cases, the pixel size larger than 0.4 is not sufficient for the diagnostic purpose. Therefore, the range of the size of one pixel in the present invention is 20 m square to 0.4 mm square, and the shape of the pixel may be not only square but also rectangular.

Once the size of one pixel has been determined, this decision is followed-by forming four circular holes or square micro holes 16 with a diameter smaller than the size of one pixel on four stainless sheets 12. In this case, the vertical and horizontal pitches are 1 Ί 5 um-, the positional deviation Δ of the microholes 16 at the start and end points is 52.5 m, and the array of each microhole 16 is the sub-axis of the excitation light scan. In the scanning direction (longitudinal direction), it coincides with that direction, and in the main scanning direction (horizontal direction), the read line pitch, which is the size of the pixel in the sub-scanning direction, is set to b, and the scanning of excitation light scanning is performed. Efficiency? ? Then, it is formed so as to coincide with a straight line having the relation of A = b — b (I-V). Note that the scanning effect rate? ? Is expressed as (7: s / c where the reading line length is (:, the actual scanning length of the excitation light is s.

Etching is used to form the micro holes 16 in the stainless steel sheet 12, and the thermosetting epoxy resin is dissolved in an organic solvent to disperse the graphite powder. When the solution is applied to both sides excluding the minute holes by screen printing and then G is dried, minute holes 16 are formed in the stainless sheet 12. Micro holes ;! The stainless sheet 12 with 6 formed on it and the stainless sheet 12 coated with resin only on one surface are overlapped, and the thickness 0.2 without micro holes 16 is further Place the stainless steel sheet on one side, put a weight on it and set it at 180 and cure it. In addition, a reflective film for reflecting the excitation light is fixed to the wall of each microhole 16 _c

On the other hand, a phosphor powder consisting of BaClBr: Eu with a particle size of 5 m or less is dispersed in an organic solvent solution containing a binding agent, epoquine resin, and poured onto the above sheet under reduced pressure. Embed in the hole and dry. Repeat this operation 3 times to confirm that the photostimulable phosphor has been embedded up to the surface of the hole, and then wipe off the mixture of photostimulable phosphor and epoxy resin on the surface. It is then cured, and then a transparent polyester sheet is adhered to the surface as a protective layer.

The photostimulable phosphor plate 10 produced as described above is The laser beam system is fixed to the stage and consists of a semiconductor laser with a wavelength of 780-lens diameter, a galvanometer, etc., and a laser beam system with a scanning efficiency of 70% is used. When the 40 O laser was irradiated onto the photostimulable phosphor plate 10 in the scanning direction, the excitation light was transmitted through the photostimulable phosphors in the micro holes 16 and the other micro holes 16 It was confirmed that the particles were prevented from being scattered. That is, the surface of the photostimulable phosphor substrate 10 is irradiated with X-rays, and the photostimulable light emitted as a result of the excitation by the pulsed laser is condensed by the converging mirror and the glass fiber array and is in the normal state. The light is received, the signal is A / D converted, and then the digital signal processing is performed. A fiber array other than the fiber array collects the reflected light of the excitation light from the wall surface of the micro hole 16 and collects it from the fiber array! · The received light. The _e excitation light from the light receiving quantity is this Toga確IS is reflected from the wall surface also in this case is irradiated with X-ray of a standard dose, the standard output of each pixel It was possible to obtain a normal image by inputting it in the memory and correcting the change of the stimulated emission light amount over time and the correction 0 of the variation over time between each pixel.

In the present invention, when the excitation light beam is scanned on the photoluminescent substrate or sheet, the size of the excitation light beam on the fluorescence plate or the node is It must be smaller than the length of one pixel in the sub-scanning direction. The degree is determined from the degree of wobble. Main scanning direction It is desirable that the length of each pixel be smaller than the length of one pixel in the secondary scanning direction. The excitation light may be continuous light or pulsed light, but the length of the excitation light beam in the main scanning direction is preferably as small as possible. Needless to say, it is necessary to scan so that the excitation light beam does not pass over the pixel that is adjacent in the sub-scanning direction. By paying attention to these points, it is possible to read an image with a predetermined spatial resolution without being affected by excitation light scattering.

Whether the excitation light scanning system and the condensing light receiving system are fixed and the photostimulable phosphor plate or sheet is moved or vice versa, the photostimulable phosphor plate or sheet and the sub-scanning direction The angle of is uniquely determined in relation to the excitation light scanning efficiency and the size of one pixel.

The fourth embodiment will be described below.

Figure 1Q is a photostimulable phosphor reader. The latent image of the subject is formed by using X-ray energy and the latent image of the subject is formed as an energy distribution pattern on the photostimulable fluorescent plate 105 by using energy, and the latent image is read by using excitation light. It is a thing.

As shown in FIG. 10, the laser beam is scanned from the excitation light source 1 0 1 by the scanner 1 0 2 consisting of a galvanometer mirror or a polygon mirror. The scanned laser beam is composed of optical components such as an Θ lens for beam shape correction and a reflection mirror. The photostimulable phosphor 1 0 5 is scanned through 10 4 etc. _{c The} photostimulable light emitted from the photostimulable fluorescent plate 1 0 5 by being scanned with the laser beam having the above laser beam diameter. Fluorescent light is collected by a condenser of 10 Ί such as a fiber array. The condensed light does not pass the excitation light from the fiber array, etc. 107, but is received by the photoelectric converter, such as a photoelectron tube, through a filter that allows only stimulated emission light to pass. The quantity is converted into an electrical signal, amplified by an amplifier 1109 and then exchanged into a digital signal by an A / D converter 1109. Di Sita Le signal temporarily stored in the off Remume mode Li 1 1 1, Oh Rui after _¾ This stored without passing through the full Remume mode Li to the optical de-shrugging mode Li 1 1 2, the image processing at any time Processing such as gradation processing is performed in the processing unit 1 1 3 and displayed as an X-ray image on the image display unit 1 1 4 such as a CRT, or the X-ray film is displayed in a film writing device. It can be directly written and developed to obtain an X-ray image.

This example is for reading the photostimulable phosphors of the first to third examples.

The laser beam diameter on the surface of the photostimulable phosphor plate is the sub-scanning direction (the moving direction of the photostimulable phosphor) and the laser beam diameter is 70 m in the sub-scanning direction and 40 in the main scanning direction. 〃 m The size of the laser beam is generally larger than that of the sub-scanning direction of 1 pixel. It is desirable that the length is less than.

When the laser beam is used for scanning, one standard pixel focused on this is set to be 176 m square, and there are 16 holes in each pixel (see I in Fig. 11-1). ) Exists.

If one pixel is to be 1 3 2 / m square, there are 9 holes (see E in Fig. I 1) in one pixel. At this time, the laser beam diameter in the sub-scanning direction is 1 2 δ m, "5.

Further, assuming that one pixel is an 88 m square, if there are four holes (see ΠΙ in Fig. 11) in one pixel, one laser beam in the sub-scanning direction is used. Diameter

8 3 〃 m

If one pixel is 44 m square, there is one hole (see Fig. 1 1 © I) in each pixel, and the laser beam diameter in the sub-scanning direction is 39 m. Main scanning direction Is set to 20 〃 m.

The purpose of the present invention is achieved by setting the number of holes for one pixel to be 1 to 400.

In this way, the reason for using an integral number of small holes in one pixel is that if two pixels share a part of a certain small hole, the spatial resolution will decrease accordingly.

Furthermore, consider the case where multiple holes are set to one pixel. If, for example, the scanning line for the photostimulable phosphor is Assume that there is a deviation. That is, the holes located on a certain main scanning line are arranged on a certain straight line, but consider the case where the excitation light is slightly deviated from that line. Excitation light does not necessarily illuminate the entire surface of one hole. That is, a certain hole is irradiated with the exciting light only in a part of the hole. However, it is clear that the ratio of non-irradiation is relatively small when one pixel is formed by multiple holes compared to when one pixel is formed by one hole. Therefore, if a plurality of holes are set to one pixel, the reading accuracy will be improved and the reliability of the reading device will be increased.

The fifth embodiment will be described below with reference to FIGS. 12, 13, and 14.

In the above-mentioned Example, the light is condensed as shown in FIG. 10 in the scanning of the photostimulable phosphor plate. In this embodiment, a G-beam array or a plastic fiber concentrator separate from the F,., And I-arrays in FIG. The reflected wave of the excitation light from the wall surface that does not form the hole of the body is condensed, and the light and the light from the photostimulable phosphor are synchronized, and the light from the photostimulable phosphor is emitted. It collects light. The excitation light & reflection from the wall surface is the photostimulable phosphor plate of the first to third embodiments configured so as to reflect the surface other than forming the hole of the photostimulable phosphor plate. It is realized by using it.

5 Figure 12 shows the reflected excitation light pattern that collects the excitation light. The thing provided with the light guide path 113 is shown in figure. The same reference numerals as those in FIG. 10 are the same as those in FIG. 1 0 7 1 is an excitation light absorption filter. Since 10 7 collects photostimulable light, it must absorb the reflected wave of the excitation light. Excitation light absorption filter 10 * 71 absorbs light of 600 to 900 nm (wavelength of excitation light) and transmits light of 400 nm (wavelength of photostimulable light). Is. 1 15 is a condenser mirror that collects excitation light and photostimulable light so as not to scatter. 20 7 is a collection optical path for reflected excitation light. 2 0 7 1 is a photostimulable absorption filter, which absorbs light in the vicinity of 400 nm (wavelength of photostimulable light) and absorbs light of 600 to 900 nm (excitation light). Wavelengths). However, 208 is an optical sensor. This photosensor is a semiconductor sensor such as a photomultiplier tube or photo diode. The above photostimulable fluorescent absorption filter 2071 can be labor-saving by selecting an appropriate type of photomultiplier tube. Figure 12 is a picture of the timing of the sampling. In FIG. 12, reference numeral 108 is a photoelectric converter and reference numeral 208 is an optical sensor, which are the same as those in FIG. Photostimulation and excitation light are input to the photoelectric converter 1 0 8 and the optical sensor 2 0 8 through the fiber array 1 0 7 and the reflection excitation light condensing light guide 2 0 7, respectively. .. The photostimulable fluorescent light input from the photoelectric converter 108 described above is converted into an electric signal and is converted into an A / D signal through the amplifier 109. Input to converter 1 1 0. On the other hand, the pumping light converted into an electric signal by the optical sensor 208 is compared with the reference voltage by the comparison circuit 209. Figure 14 shows the signal timing output from the circuit in Figure 13. As shown in Fig. 13, the comparator circuit 209 outputs a signal when the electrical signal from the optical sensor is below the reference voltage. The optical sensor 208 receives the excitation light. Suppose that the excitation light scans line L in Fig. 11 1. At this time, in Fig. 11 1, the surface other than the holes (where the photostimulable fluorescent light is buried) strongly reflects the excitation light. At the hole where the photoluminescent material is embedded, the excitation light is absorbed and emits photoluminescent light, but there is some reflection. Therefore, the electric signal obtained from the excitation light received by the optical sensor 208 is as shown in 208 in Fig. 14 below. When the voltage is high, it is the excitation light from the reflection part, and when it is low, it is the reflection from the hole where the photostimulable phosphor is embedded. The reason for comparing the reference voltage in the comparative image path 209 is to distinguish the hole portion and the reflection portion.

The output of the comparator circuit 209 is input to the fly ':' flop loop 210, and the flip flop 210 is a signal synchronized with the clock input to itself. Is output.

The output of the above-mentioned frisotop flosc 210 is clocked and added at the address 211, and the operation clock is output to the α-D converter 1 110. Is entered. That is, encouragement When the electrical signal of the light (the output of the optical sensor 208) is lower than the reference voltage, the A / D converter 110 operates and the electrical signal of the fluorescent emission (the output of the amplifier 109) is generated. Digitally converted. The digitally converted value is added by an adder 2 17 while the output of the analog gate 2 11 is on, and a flip-flop 2 1 8 (this flip-flop is added). Is stored in multiple drawings and is omitted in the drawing).

While the adder 218 is performing the addition, the output of the aggregate 211 is input to the counter 216 and the number of clocks is counted. When the output of flip-flop 210 is turned off, the counter is cleared and its value is stored in flip-flop 211.

Finally, the divider 2 1 9 force ";, the flip-flop 2 1

The sum of the outputs of the 8 A / D converters is divided by the value of the power counter stored in the flyback flow knob 2 15 and the value is output to the memory 1 11 1. That is, by receiving the excitation light, the excitation light is sampled while the excitation light is passing through the hole in which the excitation light body is embedded. The outputs were added and the average was calculated, but the present invention is not limited to this. The added value may be simply obtained or integrated. By receiving the excitation light at the time when the addition timing or integration is performed at that time, the timing can be changed as described above. o 5 should be taken.

〔The invention's effect〕

As described above, according to the present invention, the excitation light opaque microscopic region is formed, and the photostimulable phosphor plate having a structure in which the photostimulable phosphor is embedded in the microscopic region is also provided. By reading the photostimulable phosphor with the above configuration, it is possible to completely prevent the deterioration of the spatial resolution.

Claims

The scope of the claims

1. Micro holes (2 6) in which photostimulable phosphors (6) are embedded in hole forming parts (2) of approximately the same size and processed to be opaque to excitation light are provided at each crossing position in the crossing direction. A bright phosphor plate.

2. The photostimulable phosphor plate according to claim 1, wherein the photostimulable phosphor has excitation light scattering properties.

3. The photostimulable phosphor plate according to claim 1, wherein a wall surface of the hole forming part (2) is reflective to excitation light and photostimulable light.

4. The photostimulable phosphor plate according to claim 1, wherein the plate surface other than the minute holes on the excitation light scanning side exhibits reflectivity for the excitation light.

5. At each crossing position in the crossing direction, a hole forming part (2) of approximately the same size is processed to be opaque to excitation light, and a light transmitting part arranged on the light passage side of the hole forming diagram (2). Sealing compound (4),

A sealing material (5) arranged on the surface opposite to the surface on the light transmission side of the hole forming part (2) forming substrate;

A luminescent material composed of the light-transmissive encapsulant (4) and a photostimulable phosphor (6) filled in the hole forming part (2) encapsulated by the encapsulant (5). Exciting plate.

6. The photostimulable phosphor plate according to claim 5, wherein the photostimulable phosphor plate (6) has an excitation light scattering property.

7. The wall of the hole forming part (2) has excitation light and 6. The photostimulable phosphor plate according to claim 5, which is reflective to light.

8. The photostimulable phosphor plate according to claim 5, wherein the plate surface other than the minute holes on the excitation scanning side exhibits reflectivity with respect to the excitation light.

9. The hole forming positions of the regularly arranged substrate, which are displaced by a predetermined value required to bring the adjacent hole forming positions closer to each other, have substantially the same size, and A photostimulable phosphor characterized in that the wall surface (2) is provided with micropores (2 6) that are impermeable to excitation light, and a photostimulable phosphor is embedded in each microhole (2 6). Board.

10. The photostimulable phosphor plate according to claim 9, wherein the photostimulable phosphor plate (6) has an excitation light scattering property.

11. The photostimulable phosphor plate according to claim 9, wherein the minute holes (36) have reflectivity for excitation light and photostimulable light.

12. The photostimulable phosphor plate according to claim 9, wherein the surface of the plate other than the minute holes on the excitation light scanning side exhibits reflectivity for the excitation light.

13. Each hole forming position of the substrate is a regular array position where at least adjacent hole forming positions are displaced by a predetermined value, and the size is almost equal and the inner wall surface is

(2) is a micro hole (36) processed to be opaque to excitation light, A light-transmissive encapsulant (4) arranged on the light-transmissive side surface of the microhole (36) formation substrate,

The light transmission side surface of the microhole (36) forming substrate is a sealing material (5) arranged on the reflection side surface,

δ consisting of the light-transmissive encapsulant (4) and a photostimulable phosphor (6) filled in the minute holes (3 6) encapsulated by the encapsulant (5). A bright phosphor plate.

14. The photostimulable phosphor plate according to claim 13, wherein the photostimulable phosphor (6) has an excitation light scattering property. 0

15. The photostimulable phosphor plate according to claim 13, wherein the minute holes (36) have reflectivity with respect to excitation light and photostimulable light.

16. The photostimulable phosphor plate according to claim 155, characterized in that the surface of the plate other than the minute holes on the optical scanning side exhibits reflectivity for excitation light.

17. A plurality of microholes (16) are isolated from each other, and a photostimulable phosphor is embedded in each microhole (16), and the microholes are arranged in a grid pattern. Is aligned with the sub-scanning direction of the excitation light scan, and 0 in the sub-scanning direction, which is the size of the pixel in the sub-scanning direction in the main scanning direction, and the scan line of the excitation light scan is b. When the efficiency is r / and the positional deviation in the sub-scanning direction between the starting point and the ending point of the minute hole (16) on one reading line is Δ, it should match the straight line with the relationship of Δ = b. Photoluminescent plate set to 5.

18. A latent image of the subject is formed on the photostimulable phosphor plate (1 0 5) as an energy distribution pattern using X-ray energy, and the latent image is read using excitation light. In the fluorescent reading device,

When forming the latent image of the subject, cross the micro holes (2) embedded with photostimulable fluorescent light in the hole forming part (2) of equal size and processed to be at least opaque to excitation light. The characteristic is that each pixel of the subject image is read out for reproduction by reading into each of the corresponding 1 or more small holes of the photostimulable phosphor plate formed at each crossing position in the direction. Exciting body reading device.

19. A digital X-ray device that uses X-ray energy to form a latent image of a subject on a photostimulable phosphor (1 0 5) as a distribution pattern and reads the latent image using excitation light. At

The hole forming part (2) processed to be opaque to the excitation light has microholes in which photostimulable phosphors are embedded, and the surface of the plate other than the microholes exhibits the reflectivity to the excitation light. Means (1 0 2) for scanning the excitation light in the direction of arrangement of the holes in the optical plate,

Photostimulable light collecting means (1 0 7, 1 0 7 1) for concentrating the photostimulable light excited by the excitation light from the photostimulable phosphor embedded in the minute hole, and

Reflection excitation light condensing means (2 0 7, 2 0 7 1) for collecting the light reflected from the photostimulable phosphor plate by the excitation light, and With the signal obtained from the reflected excitation light condensing means and the signal obtained from the photostimulable fluorescence condensing means, the excitation light is irradiated to the microholes embedded in the photostimulable phosphor plate. A photostimulable phosphor panel reader having a means for sampling the photostimulable light generated by the octopus in synchronization with the reflected excitation light.

20. A photostimulable phosphor plate reader that uses X-ray energy to form a latent image energy distribution pattern of a subject on a photostimulable phosphor (1 0 5) and reads the latent image using excitation light. ,

Reflection excitation light condensing means (207, 207 1) for concentrating the excitation light reflected from the photostimulable phosphor plate, and reflection excitation light condensing means (207, 2) Excitation light irradiation period determination means (209, 2) for obtaining the period during which excitation light is radiated to the microhole in which the photostimulable phosphor is embedded, from the signal obtained from 1 0, 2 1 1, 2 1 4, 2 1 5), A means for sampling the photostimulable light obtained by the photostimulable light condensing means as pixel information for the period of time determined by the excitation light irradiation period determination means (1 1 0, 2 1 8, 2 1 7, 2 1 9), and a photoluminescent plate reader.

21. Forming a through-hole by etching so that at least one integer number of at least one approximately equal hole in the metal sheet corresponds to one pixel, and light reflection on one side of the metal sheet A step of forming a layer, a step of embedding a phosphor in the hole of the metal sheet, and a step of forming a transparent protective film layer on the surface of the metal sheet opposite to the light reflecting surface. The method for manufacturing a photostimulable phosphor plate of paragraphs 1 to 17.

22. A step of forming through holes by etching so that at least one integer number of at least one uniform hole in the metal sheet corresponds to one pixel, and the through holes are formed. The step of adhering a plurality of metal sheets by screen printing, the step of forming a light-reflecting layer on one side of the plurality of adhered metal sheets, and the step of forming a photoluminescent material in the holes of the metal sheets. The method for producing a photostimulable phosphor plate according to any one of items 1 to 17, which comprises a step of embedding and a step of forming a transparent protective film layer on the surface of the metal sheet opposite to the light reflecting surface.