JPWO2010010725A1 - Scintillator panel and radiation image detection apparatus having the same - Google Patents

Abstract

Provided are a scintillator panel capable of improving image quality such as granularity of a radiographic image, and a radiographic image detection apparatus including the scintillator panel. The scintillator panel of the present invention is a scintillator panel having a phosphor layer containing phosphor columnar crystals on a substrate, wherein a plurality of recesses are formed on the phosphor layer surface of the scintillator panel. .

Description

  The present invention relates to a scintillator panel used when forming a radiographic image of a subject and a ray image detection apparatus including the scintillator panel.

  Conventionally, radiographic images such as X-ray images have been widely used for diagnosis of medical conditions in the medical field. In particular, radiographic images using intensifying screen-film systems have been developed as an imaging system that combines high reliability and excellent cost performance as a result of high sensitivity and high image quality over the long history. Used in the medical field. However, these pieces of image information are so-called analog image information, and free image processing and instantaneous electric transmission cannot be performed like digital image information that has been developing in recent years.

  In recent years, digital radiological image detection apparatuses represented by computed radiography (CR), flat panel type radiation detectors (FPD), and the like have appeared. Since a digital radiographic image can be directly obtained and an image can be directly displayed on an image display device such as a cathode tube or a liquid crystal panel, it is not always necessary to form an image on a photographic film. As a result, these digital X-ray image detection devices reduce the need for image formation by the silver halide photography method, and greatly improve the convenience of diagnosis work in hospitals and clinics.

  Computed radiography (CR) is currently accepted in the medical field as one of the digital technologies for X-ray images. However, the image quality level of the screen film system has not been reached because the sharpness is insufficient and the spatial resolution is insufficient. Further, as new digital X-ray imaging techniques, for example, the magazine Physics Today, November 1997, page 24, John Laurans's paper “Amorphous Semiconductor User in Digital X-ray Imaging”, magazine SPIE Vol. 32, 1997. A flat-plate X-ray detector using a thin film transistor (TFT) developed in a paper by El Antonuk on “Development of a High Resolution, Active Matrix, Flat-Panel Imager with Enhanced Fill Factor”, etc. Has been.

  In order to convert radiation into visible light, a scintillator made of an X-ray phosphor having a characteristic of emitting light by radiation is used. In order to improve the S / N ratio in low-dose imaging, the luminous efficiency is improved. It becomes necessary to use a high scintillator. In general, the light emission efficiency of a scintillator is determined by the thickness of the phosphor layer and the X-ray absorption coefficient of the phosphor. The thicker the phosphor layer, the more scattered the emitted light in the phosphor layer. However, sharpness decreases. Therefore, when the sharpness necessary for the image quality is determined, the layer thickness is determined.

  In particular, cesium iodide (CsI) has a relatively high rate of change from X-rays to visible light, and phosphors can be easily formed into a columnar crystal structure by vapor deposition. Therefore, it was possible to increase the thickness of the phosphor layer.

  However, since CsI alone has low luminous efficiency, for example, a method in which CsI and sodium iodide (NaI) are mixed at an arbitrary molar ratio as described in Japanese Patent Publication No. 54-3560 is used by vapor deposition. Deposited as sodium-activated cesium iodide (CsI: Na) on the substrate, and recently mixed with any molar ratio of CsI and thallium iodide (TlI) on the substrate using vapor deposition Visible conversion efficiency is improved by performing heat treatment at a temperature of 200 ° C. to 500 ° C. on the material deposited as cesium (CsI: Tl) and used as an X-ray phosphor.

  As another means for increasing the light output, a method of making a substrate on which the scintillator panel is formed reflective (for example, see Patent Document 1), a method of providing a reflective layer on the substrate (for example, see Patent Document 2), A reflective metal thin film provided on a substrate and a method of forming a phosphor layer on a transparent organic film covering the metal thin film (see, for example, Patent Document 3) have been proposed. These methods can be obtained. Although the amount of light increases, there is a disadvantage that sharpness is remarkably lowered because the light emission intensity from the phosphor layer portion at a position away from the TFT which is a planar light receiving element is increased.

  In order to arrange the scintillator panel on the surface of the planar light receiving element, a method of fixing the scintillator panel and the planar light receiving element with an adhesive is generally used. For example, the method described in JP-A-6-331749, Japanese Laid-Open Patent Publication No. 2002-243859 describes a method of removing the unevenness on the scintillator surface, and in the contact method using these adhesives, if the scintillator panel or the planar light receiving element is defective, the scintillator Both the panel and the planar light receiving element are lost. On the other hand, there can be considered a method in which the scintillator panel is brought into close contact with the plane light receiving element surface only by pressure without using an adhesive.

  There are a plurality of light receiving pixels arranged two-dimensionally on the light receiving element surface, but each pixel has different characteristics, and it is difficult to obtain a good image with the output as it is, so the scintillator panel is placed in a state where the scintillator panel is arranged. Calibration is performed so that the output from each pixel with respect to incident X-rays is the same, including uneven emission intensity of the panel. When the positional deviation between the scintillator panel and the planar light receiving element occurs, calibration of each pixel becomes inappropriate and a good image cannot be obtained. In particular, the granularity of the obtained image is lowered.

  Conventionally, as a manufacturing method of a scintillator panel by a gas layer method, a phosphor layer is generally formed on a rigid substrate such as aluminum or amorphous carbon, and the entire surface of the scintillator panel is covered with a protective film on the phosphor layer. (For example, refer to Patent Document 4). However, when a phosphor layer is formed on these substrates that cannot be bent freely, the scintillator panel is affected by deformation of the substrate and warpage during vapor deposition when the scintillator panel and the planar light receiving element surface are brought into close contact with each other. If the planar light-receiving element is not fixed with an adhesive, the scintillator panel and the planar light-receiving element are easily misaligned due to temperature changes and impacts. In order to solve this problem, a method of forming a scintillator panel by vapor deposition on a flexible substrate such as a polymer film may be considered. In this method, the scintillator panel is deformed into a shape that matches the shape of the planar light-receiving element surface, and a uniform contact state is obtained over the entire light-receiving surface of the flat panel detector. Since there are many on the surface of the scintillator panel, these convex portions serve as slip points, and the scintillator panel and the planar light receiving element are likely to be misaligned due to temperature change, impact, and the like.

  The “splash” means that when the phosphor layer is formed by vapor deposition, before the raw material is completely vaporized (in a solid state), it jumps out into the vacuum chamber and the solid matter adheres to the vapor deposition surface. It is a convex part.

  In order to avoid this problem, it is common to use a medical intensifying screen having low sharpness but having flexibility as a substitute for the scintillator panel. In addition, an example is shown in which a flexible protective layer such as polyparaxylylene is used as the protective layer to ensure adhesion with a planar light receiving element (see, for example, Patent Document 5). However, the protective layer is used as a substrate. Aluminum, amorphous carbon, etc. are rigid, and in order to ensure a uniform contact state only by pressure without fixing the scintillator panel and flat light receiving element with adhesive due to the influence of unevenness and warpage of the substrate, the substrate Excessive pressure that can correct the unevenness and warpage of the flat light receiving element is necessary, leading to the destruction of the planar light receiving element.

From this situation, the coupling method has little loss of scintillator panels and flat photo detectors in the process, but it has excellent sharpness, and the graininess deteriorates due to the displacement of the scintillator panels and flat photo detectors due to temperature changes and impacts. It is desired to develop a radiological image detection apparatus that does not have any.
Japanese Patent Publication No. 7-21560 Japanese Patent Publication No. 1-240887 JP 2000-356679 A Japanese Patent No. 3669926 JP 2002-116258 A

  The present invention has been made in view of the above-described problems and situations, and a solution to the problem is to provide a scintillator panel capable of improving the image quality such as the granularity of the radiographic image and a radiographic image detection apparatus including the scintillator panel. It is.

  That is, while the scintillator panel and the planar light receiving element are arranged in an easily replaceable state, the scintillator panel and the planar light receiving element surface can be contacted uniformly in the surface, and the scintillator panel due to temperature change and impact To provide a scintillator capable of improving image quality such as granularity of a radiographic image by a method capable of preventing the positional deviation of a planar light receiving element, and a radiographic image detection apparatus including the scintillator.

  As a result of intensive studies to solve the above problems, the present inventor has controlled the scintillator surface shape without adhering the scintillator panel and the planar light receiving element, so that the coupling between the scintillator and the planar light receiving element can be performed even in the case of coupling only by pressure. The present inventors have found that no positional deviation occurs and that the in-plane characteristics of the planar light-receiving element surface are uniform by making the substrate on which the scintillator is formed flexible.

  That is, the said subject which concerns on this invention is solved by the following means.

  1. A scintillator panel having a phosphor layer containing phosphor columnar crystals on a substrate, wherein a plurality of recesses are formed on the phosphor layer surface of the scintillator panel.

  2. 2. The scintillator panel according to 1 above, wherein a diameter of the concave portion is 30 μm or more and 1/2 or less of a thickness of the phosphor layer.

  3. 3. The scintillator panel according to 1 or 2, wherein the recess is formed by removing a part of the phosphor from the surface of the phosphor layer.

  4). 3. The scintillator panel as described in 1 or 2 above, wherein the concave portion is formed by partially pressing and denting the surface of the phosphor layer.

  5. 3. The scintillator panel according to 1 or 2, wherein the recess is formed by removing the phosphor on the surface of the phosphor layer by a laser ablation method.

  6). The scintillator panel according to any one of 1 to 5, wherein the phosphor layer is formed using an additive containing cesium iodide and thallium as a raw material.

  7). The scintillator panel according to any one of 1 to 6, wherein the substrate is made of a flexible polymer film having a thickness of 50 to 500 µm.

  8). 8. The scintillator panel as described in 7 above, wherein the polymer film is a polymer film containing polyimide or polyethylene naphthalate.

  9. A radiation image detection apparatus comprising the scintillator panel according to any one of 1 to 8 above, wherein a light receiving element (hereinafter referred to as a plurality of light receiving pixels) is arranged two-dimensionally with the phosphor layer side of the scintillator panel. A radiographic image detection apparatus characterized by being in close contact with a "planar light receiving element" by pressure.

  10. A protective cover disposed on the radiation incident side of the scintillator panel on the side opposite to the phosphor layer through the substrate, and a foam material is filled between the protective cover and the substrate, and the scintillator panel and the flat surface 10. The radiological image detection apparatus according to 9, wherein the contact with the light receiving element is due to the pressure of the foam material.

  11. 11. The radiological image detection apparatus according to 10, wherein the foam material is a silicon-based, urethane-based, polyethylene-based, or polypropylene-based foam material.

  12 Any of 9 to 11 above, wherein the scintillator panel and the planar light receiving element are sealed, and the scintillator panel and the planar light receiving element are in close contact with each other by depressurizing the sealed portion. The radiographic image detection apparatus as described in any one of the above.

  13. The scintillator panel is disposed on the radiation incident side of the scintillator panel on the opposite side of the phosphor layer through the substrate and is fixed to the housing of the radiation image detection device or the planar light receiving element. The radiographic image detection apparatus according to any one of 9 to 12, wherein the scintillator panel and the light receiving element are brought into close contact with each other by being pressed against the light receiving element.

  14 14. The radiological image detection apparatus according to 13, wherein the auxiliary plate is a protective cover on the radiation incident side of the radiological image detection apparatus.

  By the above-mentioned means of the present invention, it is possible to provide a scintillator panel capable of improving the image quality such as the granularity of the radiation image and a radiation image detection apparatus including the scintillator panel.

  The effect of the present invention is that an adhesive is formed by forming a plurality of recesses having a diameter of 30 μm or more and a range of 1/2 or less of the phosphor layer thickness on the surface of a scintillator panel arranged on a light receiving pixel. Even in optical couplings that are not used, the scintillator panel and the light receiving element are not misaligned by temperature or impact, and the use of a flexible polymer film as the substrate for forming the scintillator panel allows light reception. The scintillator contact with the element is uniform over the entire surface of the light receiving element and the characteristics are uniform, and the contact area is increased due to the entire surface contact, so that it is difficult for the scintillator panel and the light receiving element to be misaligned. The effect of preventing the positional deviation by forming a plurality of recesses on the surface of the scintillator panel is that the recesses act as suction points on the light receiving element surface.

Conceptual diagram showing columnar crystal anomalous growth that starts from splash or foreign matter A method in which a compressed foam material is filled in a gap between a protective cover on a radiation incident side of a radiation detection device and a substrate of a scintillator panel, and the rebound force of the foam material is used to make a close contact A method of closely attaching the scintillator panel and the light receiving element by sealing between the scintillator panel and the light receiving element and depressurizing the sealed portion. (A) An example of a method in which pressure is applied by a radiation transmissive auxiliary plate to make close contact, the auxiliary plate being fixed to the housing 14 of the radiation image detection apparatus 1. (B) An example in which the auxiliary plate also serves as a protective cover on the radiation incident side of the ray image detector (A) Cross-sectional view showing schematic configuration of scintillator panel, example using resin film as protective layer covering scintillator panel, (b) Example of forming polyparaxylylene film by CVD method as protective layer covering scintillator panel (C) Enlarged sectional view of the scintillator panel The conceptual diagram which shows the example which removes the abnormal growth part on the surface of a fluorescent substance layer, and forms a recessed part with the roller which has adhesiveness Conceptual diagram showing an example of forming a recess by pressure in the phosphor layer Conceptual diagram showing an example of forming recesses on the phosphor surface by laser ablation Schematic configuration diagram of vapor deposition equipment Partially broken perspective view showing schematic configuration of radiographic image detection apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Splash 1b Foreign material 11 Columnar crystal 11a Abnormal growth part 12 Scintillator panel 13 Light receiving element 14 Case 15 Protective cover 21 Foam material layer 31 Sealing plate 32 Adhesive 33 Adhesive 41 Auxiliary plate 61 Roller 121 Substrate 122 Phosphor layer 123 Protective layer 124 Polyparaxylylene film 521 Concave part 611-616 Abnormally grown part 617 Convex part 810 Processing apparatus 811 XY stage 812 High power laser head 813 Microscope optical system 814 Optical axis 819 CCD camera 820 Reflective mirror 821 Lens 961 Deposition apparatus 962 Vacuum Container 963 boat (filled member)
964 Holder 965 Rotating mechanism 966 Vacuum pump 100 Radiation image detection device

  The scintillator panel of the present invention is a scintillator panel having a phosphor layer containing phosphor columnar crystals on a substrate, wherein a plurality of recesses are formed on the phosphor layer surface of the scintillator panel. . This feature is a technical feature common to the inventions according to claims 1 to 14.

  As an embodiment of the present invention, it is preferable that the diameter of the concave portion is 30 μm or more and is a half or less of the layer thickness of the phosphor layer. The recess is formed by removing a part of the phosphor from the surface of the phosphor layer, formed by partially pressing and denting the phosphor layer surface, or It is preferable that the phosphor is formed by removing the phosphor on the surface of the phosphor layer by a laser ablation method.

  Furthermore, the phosphor layer according to the present invention is preferably formed using an additive containing cesium iodide and thallium as a raw material.

  The substrate according to the present invention is preferably made of a flexible polymer film having a thickness of 50 to 500 μm. In this case, it is preferable that the polymer film is a polymer film containing polyimide or polyethylene naphthalate.

  The radiation image detection apparatus provided with the scintillator panel of the present invention includes a phosphor layer side of the scintillator panel and a light receiving element (hereinafter referred to as a “planar light receiving element”) in which a plurality of light receiving pixels are arranged two-dimensionally. It is preferable that the radiographic image detection apparatus is in a state of being closely attached by pressure. In this case, a foaming material is filled between the protective cover disposed on the radiation incident side of the scintillator panel on the side opposite to the phosphor layer through the substrate, and between the protective cover and the substrate. The close contact between the panel and the planar light receiving element is preferably due to the pressure of the foam material. The foam material is preferably a silicon-based, urethane-based, polyethylene-based or polypropylene-based foam material.

  Further, it is also preferable that the scintillator panel and the planar light receiving element are hermetically sealed, and the radiation image detecting apparatus has a mode in which the scintillator panel and the planar light receiving element are in close contact with each other by reducing the pressure of the sealed portion. .

  Further, the scintillator is disposed on the radiation incident side of the scintillator panel through the substrate and is arranged on the radiation incident side of the scintillator panel, and is fixed to the housing or the planar light receiving element of the radiation image detection device. It is also preferable that the scintillator panel and the light receiving element are in close contact with each other by pressing the panel against the planar light receiving element. In this case, it is also preferable that the auxiliary plate is a protective cover on the radiation incident side of the radiation image detection apparatus.

  Hereinafter, the present invention, its components, and the best mode and mode for carrying out the present invention will be described in detail.

(Characteristics of scintillator panel and radiation image detection apparatus of the present invention)
The scintillator panel of the present invention is a scintillator panel in which a phosphor layer made of a phosphor columnar crystal is provided on a substrate, and the surface of the phosphor layer has a diameter of 30 μm or more and 1/2 or less of the phosphor layer thickness. It is characterized in that a plurality of recesses in the range are formed.

  In addition, in this application, the "diameter of a recessed part" means the diameter at the time of calculating backward, assuming the maximum area of the opening part of a recessed part when a recessed part is observed from an upper surface as a perfect circle area. In general, the diameter of the columnar crystals forming the scintillator is usually 3 to 15 μm, and the columnar crystal gap is about 0.102 to 2.00 μm. The concave portion referred to in the present invention does not include the gap between the columnar crystals.

  The depth of the recess is not limited. However, since the amount of light from the phosphor to the light receiving element is reduced in the recess, the thickness of the phosphor layer is preferable, although it depends on the calibration capability on the light receiving element side. Within 1/2 of

The number of recesses formed on the phosphor surface is not particularly limited, but about 0.1 to 50 per 1.0 cm ² is more preferable from the viewpoint of preventing the displacement of the scintillator panel and the light receiving element.

  Hereinafter, further detailed description will be given with reference to the drawings.

  FIG. 1 shows an abnormally grown portion 11a of the columnar crystal 11 generated from the splash 1a and the foreign matter 1b as a starting point, and is a convex portion on the surface of the scintillator panel 12. FIG. In the columnar crystal formation process by the vapor phase method (evaporation), it usually occurs at a high frequency. The closer the starting point of abnormal growth is to the substrate, the larger the area of the convex portion on the scintillator panel surface. The convex part due to abnormal growth of the crystal has a weak binding force with the normal part at the starting point of the abnormal growth, and can be easily removed by cleaning the surface of the scintillator panel with an adhesive roller or the like. A recessed portion suitable for the present invention is formed in the removed portion. As a result of intensive studies, the present inventors have found that the diameter of the concave portion formed after cleaning is almost the same as the diameter of the convex portion before cleaning, and the diameter of the convex portion on the surface of the scintillator panel is 1 / th of the layer thickness of the phosphor layer. If it is 2 or less, it has been found that the depth of the recess after removing the abnormally grown portion is 1/2 or less of the phosphor layer thickness.

  In addition, it has also been found that the convex portion on the surface of the scintillator panel becomes a slip point in the coupling between the scintillator panel and the flat light receiver only by pressure, and promotes the positional shift between the scintillator panel and the flat light receiver due to temperature change, impact, etc. . Changing the convexity on the surface of the scintillator panel to concave corresponds to changing the slip point to the suction point, resulting in a further enhancement of the effect of the present invention.

  In the present invention, as an example of means for achieving close contact between the scintillator panel and the planar light receiving element by pressure, a compressed foam material is filled in the gap between the radiation incident side protective cover of the radiation detection device and the scintillator panel substrate, A method using the repulsive force of the foam material (FIG. 2), a method in which the scintillator panel and the light receiving element are closely sealed by reducing the pressure between the scintillator panel and the light receiving element (FIG. 3), and radiation transmission Although there is a method (FIG. 4) in which pressure is applied by using an auxiliary plate of FIG.

  FIG. 2 shows an example in which a foam material is used. As the foam material used, for example, a silicon-based, urethane-based, polyethylene-based, or polypropylene-based foam material that absorbs little radiation can be used. In this configuration, the pressure of the scintillator panel 12 against the light receiving element 13 is adjusted by the thickness of the foam material layer 21. In this configuration, the protective layer 123 is a film.

  FIG. 3 shows an example of a method of sealing between the scintillator panel and the light receiving element, and making contact by reducing pressure, and the radiation transmitting property to the substrate 121 side of the scintillator panel 12 through the adhesive 32 at the peripheral edge of the light receiving element 13. The sealing plate 31 is disposed to form a sealed space 33 in the scintillator panel and the light receiving element. In this configuration, the sealed space 33 is depressurized so that the scintillator panel and the light receiving element are in close contact with each other. The adhesion pressure of the scintillator panel 12 to the light receiving element 13 is adjusted by the degree of pressure reduction of the sealed space 33.

  FIG. 4A is an example of a method of applying pressure by using a radiation transmissive auxiliary plate, and the adhesion force can be easily adjusted by the rigidity of the auxiliary plate 41 and the method of attaching the auxiliary plate 41. In the example of FIG. 4A, the auxiliary plate is fixed to the housing 14 of the radiation image detection apparatus 1.

  FIG. 4B is an example in which the auxiliary plate 41 also serves as the protective cover 15 on the radiation incident side of the ray image detection apparatus 1.

  FIG. 5A shows a cross-section of the scintillator panel according to the present invention. The phosphor layer 122 made of columnar crystals inside the protective layer 123 made of a resin film covering the scintillator panel 12 has a diameter of 30 μm or more and a phosphor layer thickness. There is a recess 521 of ½ or less.

  FIG. 5B shows an example in which a polyparaxylylene film 124 is formed by a CVD method as a protective layer covering the scintillator panel 12.

  The method for forming the concave portion of the present invention in the phosphor layer 122 is not particularly limited, but there are many convex portions due to abnormal growth generated from splash or foreign matter on the phosphor surface formed by the gas phase. The convex portion due to the abnormal growth has a weak binding force with the normal portion at the starting point of the abnormal growth, and can be easily removed from the surface of the scintillator panel, and becomes a concave portion suitable for the present invention.

  FIG. 6 shows an example in which the abnormally grown portions 611 to 616 on the surface of the phosphor layer 122 are removed by the adhesive roller 61 to form concave portions.

FIG. 7 shows an example in which a recess is formed in the phosphor layer 122 by pressure. A recess is formed on the surface of the phosphor layer 122 by a needle-point holder 71 provided with a plurality of metallic needles having a diameter of 100 μm. The number and position of the concave portions are not particularly limited, but 0.1 to 50, more preferably 1 to 30 per 1.0 cm ² is more preferable from the viewpoint of preventing the positional deviation between the scintillator panel and the light receiving element.

  FIG. 8 shows an example in which concave portions are formed on the phosphor surface by laser ablation. The processing apparatus 810 includes an XY stage 811 that supports the scintillator panel 12 so as to be movable in the XY direction. Above the XY stage 811 is provided a microscope optical system 813 provided with a high power laser head 812 for irradiating a laser for processing. Here, the optical axis of the laser irradiated from the high power laser head 812 is shown as an optical axis 814. The microscope optical system 813 includes a CCD camera 819 that observes the surface of the scintillator panel 12. The CCD camera 819 includes a reflection mirror 820 that is coaxial with the optical axis 814 and disposed at a predetermined angle with respect to the optical axis 814 so that an image of the surface of the scintillator panel 12 can be captured, and a lens 821. Is provided. With this apparatus, the convex portion 617 due to abnormal growth can be specified, and the concave and convex portion can be effectively formed by laser irradiation. As a method for processing the phosphor surface by the laser ablation method, for example, a method described in JP-A-2006-343123 can be suitably used.

  Hereinafter, the present invention, components, and the like will be described in detail.

(Configuration of scintillator panel)
The scintillator panel of the present invention is preferably a scintillator panel in which a phosphor layer made of columnar crystals is provided on a polymer film substrate, and more preferably has an undercoat layer between the substrate and the phosphor layer. Alternatively, a reflective layer may be provided on the substrate, and the reflective layer, the undercoat layer, and the phosphor layer may be configured. Hereinafter, each constituent layer and constituent elements will be described.

(Phosphor layer: scintillator layer)
The phosphor layer according to the present invention is a phosphor layer composed of phosphor columnar crystals. Further, the phosphor layer has a plurality of recesses on the surface thereof.

  Various known phosphor materials can be used as the material for forming the phosphor layer, but the rate of change from X-ray to visible light is relatively high, and the phosphor is easily formed into a columnar crystal structure by vapor deposition. Therefore, cesium iodide (CsI) is preferable because scattering of the emitted light in the crystal can be suppressed by the light guide effect and the thickness of the phosphor layer can be increased.

  However, since only CsI has low luminous efficiency, various activators are added. For example, as shown in Japanese Patent Publication No. 54-35060, a mixture of CsI and sodium iodide (NaI) at an arbitrary molar ratio can be mentioned. Further, for example, CsI as disclosed in Japanese Patent Application Laid-Open No. 2001-59899 is deposited, and thallium (Tl), europium (Eu), indium (In), lithium (Li), potassium (K), rubidium (Rb) ), CsI containing an activating substance such as sodium (Na) is preferred. In the present invention, thallium (Tl) and europium (Eu) are particularly preferable. Furthermore, thallium (Tl) is preferred.

  In the present invention, it is particularly preferable to use an additive containing one or more types of thallium compounds and cesium iodide as raw materials. That is, thallium activated cesium iodide (CsI: Tl) is preferable because it has a wide emission wavelength from 400 nm to 750 nm.

  As the thallium compound as an additive containing one or more types of thallium compounds according to the present invention, various thallium compounds (compounds having oxidation numbers of + I and + III) can be used.

In the present invention, a preferred thallium compound is thallium bromide (TlBr), thallium chloride (TlCl), thallium fluoride (TlF, TlF ₃ ), or the like.

  The melting point of the thallium compound according to the present invention is preferably in the range of 400 to 700 ° C. If the temperature exceeds 700 ° C., the additives in the columnar crystals exist non-uniformly, resulting in a decrease in luminous efficiency. In the present invention, the melting point is a melting point at normal temperature and pressure.

  In the phosphor layer according to the present invention, the content of the additive is desirably an optimal amount according to the target performance, etc., but 0.001 mol% to 50 mol% with respect to the content of cesium iodide, Furthermore, it is preferable that it is 0.1-10.0 mol%.

  Here, when the additive is 0.001 mol% or more with respect to cesium iodide, the emission luminance obtained by using cesium iodide alone is improved, which is preferable in terms of obtaining the target emission luminance. Moreover, it is preferable that it is 50 mol% or less because the properties and functions of cesium iodide can be maintained.

  In addition, it is preferable that the thickness of a scintillator layer (phosphor layer) is 100-800 micrometers, and it is more preferable that it is 120-700 micrometers from the point from which the characteristic of a brightness | luminance and sharpness is acquired with sufficient balance.

  In the present invention, a phosphor layer is formed on a polymer film by vapor deposition of a phosphor (scintillator) raw material, and then a plurality of recesses are formed on the phosphor surface.

  As a result, the adhesion between the scintillator panel and the light receiving element can be sufficiently secured only by pressure, and the scintillator panel and the light receiving element are not misaligned due to temperature change or impact. Therefore, in the present invention, it is not necessary to fix the scintillator panel and the light receiving element with an adhesive, simplifying the assembly process of the radiation image detecting apparatus, and reducing the loss of the scintillator panel and the light receiving element. In addition, by using a flexible substrate, the image characteristics over the entire surface of the light receiving element are made uniform.

  Accordingly, it is possible to realize a radiation detection apparatus that is a close contact method in which the scintillator panel and the planar light receiving element can be easily exchanged and that does not cause a positional shift between the scintillator panel and the planar light receiving element due to a temperature change or an impact.

(Reflective layer)
In the present invention, it is preferable to provide a reflective layer on the polymer substrate, in order to reflect the light emitted from the phosphor (scintillator) and increase the light extraction efficiency. The reflective layer is preferably formed of a material containing any element selected from the element group consisting of Al, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au. In particular, it is preferable to use a metal thin film made of the above elements, for example, an Ag film, an Al film, or the like. Two or more such metal thin films may be formed. When the metal thin film has two or more layers, the lower layer is preferably a layer containing Cr from the viewpoint of improving the adhesion to the substrate. Further, a layer made of a metal oxide such as SiO ₂ or TiO ₂ may be provided in this order on the metal thin film to further improve the reflectance.
In addition, it is preferable from a viewpoint of emitted light extraction efficiency that the thickness of a reflection layer is 0.005-0.3 micrometer, More preferably, it is 0.01-0.2 micrometer.

(Undercoat layer)
In the present invention, it is preferable to provide an undercoat layer between the substrate and the phosphor layer or between the reflective layer and the phosphor layer from the viewpoint of attaching a film. The undercoat layer preferably contains a polymer binder (binder), a dispersant and the like. The thickness of the undercoat layer is preferably 0.5 to 4 μm, and if it is 4 μm or more, light scattering in the undercoat layer increases and sharpness deteriorates. If the thickness of the undercoat layer is larger than 5 μm, columnar crystallinity is disturbed by the heat treatment. Hereinafter, components of the undercoat layer will be described.

<Polymer binder>
The undercoat layer according to the present invention is preferably formed by applying and drying a polymer binder (hereinafter also referred to as “binder”) dissolved or dispersed in a solvent. Specific examples of the polymer binder include polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer. Polymer, polyamide resin, polyvinyl butyral, polyester, cellulose derivative (nitrocellulose, etc.), styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, melamine resin, phenoxy resin, silicone resin , Acrylic resins, urea formamide resins, and the like. Of these, polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, and nitrocellulose are preferably used.

  As the polymer binder according to the present invention, polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, nitrocellulose and the like are particularly preferable in terms of close contact with the phosphor layer. Moreover, it is preferable that the glass transition temperature (Tg) is a polymer having a temperature of 30 to 100 ° C. in terms of attaching a film between the deposited crystal and the substrate. From this viewpoint, a polyester resin is particularly preferable.

  Solvents that can be used to prepare the undercoat layer include lower alcohols such as methanol, ethanol, n-propanol and n-butanol, hydrocarbons containing chlorine atoms such as methylene chloride and ethylene chloride, acetone, methyl ethyl ketone, and methyl isobutyl ketone. Such as ketones, toluene, benzene, cyclohexane, cyclohexanone, xylene and other aromatic compounds, methyl acetate, ethyl acetate, butyl acetate and other lower fatty acid and lower alcohol esters, dioxane, ethylene glycol monoethyl ester, ethylene glycol monomethyl ester And ethers thereof and mixtures thereof.

  The undercoat layer according to the present invention may contain a pigment or a dye in order to prevent scattering of light emitted from the phosphor (scintillator) and improve sharpness.

(Protective layer)
The protective layer according to the present invention focuses on protecting the phosphor layer. That is, cesium iodide (CsI) absorbs water vapor in the air and deliquesces when exposed to a high hygroscopic property, and therefore the main purpose is to prevent this.

  The protective layer can be formed using various materials. For example, a polyparaxylylene film is formed by a CVD method. That is, a polyparaxylylene film can be formed on the entire surface of the phosphor (scintillator) and the substrate to form a protective layer.

  In addition, as another protective layer, a polymer film can be provided on the phosphor layer. As the material for the polymer film, the same film as the polymer film as a substrate material described later can be used.

  The thickness of the polymer film is preferably 12 μm or more and 120 μm or less, more preferably 20 μm or more and 80 μm or less, taking into consideration the formation of voids, the protective properties of the phosphor layer, sharpness, moisture resistance, workability and the like. Is preferred. The haze ratio is preferably 3% or more and 40% or less, more preferably 3% or more and 10% or less in consideration of sharpness, radiation image unevenness, production stability, workability, and the like. The haze ratio can be measured, for example, by Nippon Denshoku Industries Co., Ltd. NDH5000W. The required haze ratio is appropriately selected from commercially available polymer films and can be easily obtained.

  The light transmittance of the protective film is preferably 70% or more at 550 nm in consideration of photoelectric conversion efficiency, phosphor (scintillator) emission wavelength, etc., but a film having a light transmittance of 99% or more is commercially available. Since it is difficult, substantially 99% to 70% is preferable.

The moisture permeability of the protective film is preferably 50 g / m ² · day (40 ° C., 90% RH) (measured according to JIS Z0208) or less, more preferably 10 g / m ² taking into account the protective property and deliquescence of the phosphor layer. m ² · day (40 ° C, 90% RH) (measured according to JIS Z0208) or less is preferable, but a film with a water vapor transmission rate of 0.01 g / m ² · day (40 ° C, 90% RH) or less is industrial. Is practically 0.01 g / m ² · day (40 ° C, 90% RH) or more, 50 g / m ² · day (40 ° C., 90% RH) (measured according to JIS Z0208) ) Or less, more preferably 0.1 g / m ² · day (40 ° C./90% RH) or more, 10 g / m ² · day (40 ° C./90% RH) (measured according to JIS Z0208) or less .

(substrate)
The scintillator panel of the present invention preferably uses a polymer film as the substrate. Polymer film (plastic film) such as cellulose acetate film, polyester film, polyethylene terephthalate (PEN) film, polyamide film, polyimide (PI) film, triacetate film, polycarbonate film, carbon fiber reinforced resin sheet, etc. Can be used. In particular, a polymer film containing polyimide or polyethylene naphthalate is suitable when a phosphor columnar crystal is formed by a vapor phase method using cesium iodide as a raw material.

  The polymer film as the substrate according to the present invention is preferably a polymer film having a thickness of 50 to 500 μm and further having flexibility.

Here, the “substrate having flexibility” means a substrate having an elastic modulus (E120) at 120 ° C. of 1000 to 6000 N / mm ² , and a polymer film containing polyimide or polyethylene naphthalate as such a substrate. Is preferred.

  Note that the “elastic modulus” refers to the slope of the stress with respect to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS C 2318 and the corresponding stress have a linear relationship using a tensile tester. Is what we asked for. This is a value called Young's modulus, and in the present invention, this Young's modulus is defined as an elastic modulus.

The substrate used in the present invention preferably has an elastic modulus (E120) at 120 ° C. of 1000 to 6000 N / mm ² as described above. More preferably, it is 1200-5000 N / mm < ² >.

Specifically, polyethylene naphthalate ^{(E120 = 4100N / mm 2)} , polyethylene terephthalate ^{(E120 = 1500N / mm 2)} , polybutylene naphthalate ^{(E120 = 1600N / mm 2)} , polycarbonate (E120 = 1700N / ^mm 2) , Syndiotactic polystyrene (E120 = 2200 N / mm ² ), polyetherimide (E120 = 1900 N / mm ² ), polyarylate (E120 = 1700 N / mm ² ), polysulfone (E120 = 1800 N / mm ² ), polyethersulfone And a polymer film made of (E120 = 1700 N / mm ² ).

  These may be used singly or may be laminated or mixed. Among them, as a particularly preferable polymer film, a polymer film containing polyimide or polyethylene naphthalate is preferable as described above.

  In addition, when bonding the scintillator panel and the planar light receiving element surface, due to the influence of deformation of the substrate and warping during vapor deposition, uniform image quality characteristics cannot be obtained within the light receiving surface of the flat panel detector, By making the substrate into a polymer film having a thickness of 50 to 500 μm, the scintillator panel is deformed into a shape that matches the shape of the planar light receiving element surface, and uniform sharpness is obtained over the entire light receiving surface of the flat panel detector.

(Production method of scintillator panel)
A typical example of a method for manufacturing a scintillator panel according to the present invention will be described with reference to the drawings. FIG. 5A is a cross-sectional view showing a schematic configuration of the scintillator panel 12 for radiation. FIG. 5C is an enlarged cross-sectional view of the radiation scintillator panel 12 of the present invention, in which the substrate 121, the reflective layer 121a, the undercoat layer 121b, and the phosphor layer 122 are formed in this order. A recess 521 is present on the surface of the phosphor layer 122.

  In FIG. 6, the abnormally grown portions 611 to 616 on the surface of the phosphor layer 122 are removed by an adhesive roller to form concave portions.

<Vapor deposition equipment>
As shown in FIG. 9, the vapor deposition apparatus 961 has a box-shaped vacuum vessel 962, and a vacuum vapor deposition boat 963 is arranged inside the vacuum vessel 962. The boat 963 is a member to be deposited as an evaporation source, and an electrode is connected to the boat 963. When current flows through the electrode to the boat 963, the boat 963 generates heat due to Joule heat. At the time of manufacturing the radiation scintillator panel 12, a mixture containing cesium iodide and an activator compound is filled in the boat 963, and an electric current flows through the boat 963 so that the mixture can be heated and evaporated. It has become.

  As the member to be filled, an alumina crucible around which a heater is wound may be applied, or a refractory metal heater may be applied.

  A holder 64 for holding the substrate 121 is disposed inside the vacuum vessel 962 and immediately above the boat 963. The holder 964 is provided with a heater (not shown), and the substrate 1 mounted on the holder 964 can be heated by operating the heater. When the substrate 121 is heated, the adsorbate on the surface of the substrate 121 is removed and removed, and an impurity layer is prevented from being formed between the substrate 121 and the phosphor layer 122 formed on the surface. In addition, the adhesion between the substrate 121 and the phosphor layer 122 formed on the surface of the substrate 121 can be strengthened, and the film quality of the phosphor layer 2 formed on the surface of the substrate 121 can be adjusted. ing.

  The holder 964 is provided with a rotation mechanism 965 that rotates the holder 964. The rotating mechanism 965 includes a rotating shaft 65a connected to the holder 64 and a motor (not shown) as a driving source for the rotating shaft 65a. When the motor is driven, the rotating shaft 965a rotates to disengage the holder 964 from the boat. It can be rotated in a state facing 963.

  In the vapor deposition apparatus 961, a vacuum pump 966 is disposed in the vacuum vessel 962 in addition to the above configuration. The vacuum pump 966 exhausts the inside of the vacuum vessel 962 and introduces gas into the inside of the vacuum vessel 962. By operating the vacuum pump 966, the inside of the vacuum vessel 962 has a gas atmosphere at a constant pressure. Can be maintained below.

<Scintillator panel>
Next, a method for manufacturing the scintillator panel 12 according to the present invention will be described.

  In the method for manufacturing the radiation scintillator panel 12, the above-described evaporation apparatus 961 can be used preferably. A method of manufacturing the radiation scintillator panel 12 using the evaporation device 961 will be described.

<Formation of reflective layer>
A metal thin film (Al film, Ag film, etc.) as a reflective layer is formed on one surface of the substrate 1 by sputtering. Various types of films in which an Al film is sputter-deposited on a polymer film are available on the market, and these can also be used as the substrate of the present invention.

<Formation of undercoat layer>
The undercoat layer is formed by applying and drying a composition in which a polymer binder is dispersed and dissolved in an organic solvent. The polymer binder is preferably a hydrophobic resin such as a polyester resin or a polyurethane resin from the viewpoint of adhesiveness and corrosion resistance of the reflective layer.

<< Formation of phosphor layer >>
The substrate 121 provided with the reflective layer and the undercoat layer as described above is attached to the holder 964, and a plurality of (not shown) boats 963 are filled with a powdery mixture containing cesium iodide and thallium iodide ( Preparation step). In this case, the distance between the boat 963 and the substrate 121 is set to 100 to 1500 mm, and the vapor deposition process described later is performed while remaining within the set value range. More preferably, the distance between the boat 963 and the substrate 121 is set to 400 mm or more and 1500 mm or less, and the plurality of boats 963 are heated at the same time for vapor deposition. Thereby, the abnormal growth due to the splash occurs from the latter half of the deposition, and the diameter of the convex portion generated by the splash can be controlled to ½ or less of the phosphor layer thickness.

  When the preparation process is completed, the vacuum pump 966 is operated to evacuate the inside of the vacuum vessel 962, and the inside of the vacuum vessel 962 is brought to a vacuum atmosphere of 0.1 Pa or less (vacuum atmosphere forming step). Here, “under vacuum atmosphere” means under a pressure atmosphere of 100 Pa or less, and preferably under a pressure atmosphere of 0.1 Pa or less.

  Next, an inert gas such as argon is introduced into the vacuum vessel 962, and the inside of the vacuum vessel 962 is maintained in a vacuum atmosphere of 0.001 to 5 Pa, more preferably 0.01 to 2 Pa. Thereafter, the heater of the holder 964 and the motor of the rotation mechanism 965 are driven, and the substrate 121 attached to the holder 964 is rotated while being heated while facing the boat 963. The temperature of the substrate 121 on which the phosphor layer is formed is preferably set to a room temperature of 25 to 50 ° C. at the start of vapor deposition, and is preferably set to 100 to 300 ° C., more preferably 150 to 250 ° C. during the vapor deposition. .

  In this state, a current is passed from the electrode to the boat 963, and the mixture containing cesium iodide and thallium iodide is heated at about 700 ° C. for a predetermined time to evaporate the mixture. As a result, innumerable columnar crystals are sequentially grown on the surface of the substrate 121 to obtain crystals with a desired thickness (evaporation process). Thereafter, the substrate on which cesium iodide is deposited is taken out, and the phosphor surface is cleaned by an adhesive roller, thereby removing abnormally grown portions and forming a large number of recesses on the phosphor surface.

  In addition, in the said description matter, you may make various improvement and design change in the range which does not deviate from the main point of this invention.

  As one improvement / design change matter, although the resistance heating method is used in the vapor deposition process, the process in each process may be an electron beam process or a high frequency induction process. In the present embodiment, as described above, it is preferable to apply the heat treatment by the resistance heating method because it is easy to handle with a relatively simple configuration, is inexpensive, and can be applied to a very large number of substances. When the heat treatment by the resistance heating method is executed, both the heat treatment and the vapor deposition treatment of the mixture of cesium iodide and thallium iodide can be achieved in the same boat 963.

  As another improvement / design change item, a shutter (not shown) that blocks the space from the boat 963 to the holder 964 may be disposed between the boat 963 and the holder 964 of the vapor deposition apparatus 961. In this case, it is possible to prevent substances other than the target substance attached to the surface of the mixture on the boat 963 by the shutter from evaporating in the initial stage of the vapor deposition process, and to prevent the substances from adhering to the substrate 121. Abnormal growth of columnar crystals due to the generated foreign matter can be prevented.

(Radiation image detector)
Hereinafter, the configuration of the radiation image detection apparatus 100 including the radiation scintillator panel 12 will be described with reference to FIG. FIG. 10 is a partially broken perspective view showing a schematic configuration of the radiation image detection apparatus 100.

  A polyurethane foam (foam) 150 is disposed in the gap between the scintillator panel 12 and the protective cover 155 (a) installed on the radiation incident side of the housing 155.

  As shown in FIG. 10, the radiation image detection apparatus 100 includes a scintillator panel 12, a control unit 152 that controls the operation of the radiation image detection apparatus 100, a rewritable dedicated memory (for example, a flash memory), and the like. A memory unit 153 that is a storage unit that stores the output image signal, a power supply unit 154 that is a power supply unit that supplies power necessary to obtain the image signal by driving the radiation image detection apparatus, and the like are included in the housing. It is provided inside the body 155. The housing 155 includes a communication connector 156 for performing communication from the radiological image detection apparatus 100 to the outside as necessary, an operation unit 157 for switching the operation of the radiographic image detection apparatus 100, and completion of preparation for radiographic image capturing. And a display unit 158 indicating that a predetermined amount of image signal has been written in the memory unit 153.

  Here, if the radiographic image detection apparatus 100 is provided with a power supply unit 154 and a memory unit 153 that stores an image signal of the radiographic image, and the radiographic image detection apparatus 100 is detachable via the connector 156, the radiographic image detection apparatus is provided. It can be set as the portable structure which can carry 100.

  The radiation scintillator panel 12 is disposed on the radiation irradiation surface side, and is configured to emit an electromagnetic wave corresponding to the intensity of incident radiation.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

(Production of substrate 1)
A reflective layer (0.10 μm) was formed by sputtering aluminum onto a 125 μm thick, 250 × 200 mm size polyimide film (glass transition temperature: 285 ° C.) (Upilex manufactured by Ube Industries).
(Preparation of substrate 2)
A mirror-finished aluminum plate having a thickness of 0.5 mm was cut into a size of 250 × 200 mm.

(Preparation of undercoat layer)
Byron 20SS (Toyobo Co., Ltd .: polymer polyester resin) 300 parts by weight Methyl ethyl ketone (MEK) 200 parts by weight Toluene 300 parts by weight Cyclohexanone 150 parts by weight The above formulation is mixed and dispersed in a bead mill for 15 hours, for undercoating coating. A coating solution was obtained. This coating solution was applied to the reflective layer side of the substrate with a spin coater so that the dry layer thickness was 1.0 μm, and then dried at 100 ° C. for 8 hours to prepare an undercoat layer.

(Formation of phosphor layer)
A phosphor (CsI: 0.03 Tl mol%) was deposited on the undercoat layer side of the substrate using the deposition apparatus shown in FIG. 9 to form a 500 μm phosphor layer on the entire surface of the substrate. A shutter (not shown) was disposed between the boat 963 and the holder 964 to prevent substances other than the target substance from adhering to the phosphor layer at the start of vapor deposition.

  That is, first, a resistance heating crucible was filled as a phosphor raw material as a vapor deposition material, a substrate was placed on a rotating support holder, and the distance between the substrate and the evaporation source was adjusted to 500 mm.

  Subsequently, the inside of the vapor deposition apparatus was once evacuated, Ar gas was introduced and the degree of vacuum was adjusted to 0.5 Pa, and then the substrate temperature was maintained at 200 ° C. while rotating the substrate at a speed of 10 rpm. Next, the resistance heating crucible was heated to deposit a phosphor, thereby forming a phosphor layer having the layer thickness shown in (1) Layer thickness of Table 1.

  Five boats 963A to 963E (not shown) are used for vapor deposition, the timing of supplying power to each boat is controlled, and the vapor deposition pattern is adjusted as shown in the following AC to form on the phosphor surface. The size and number of abnormally grown parts due to splash were controlled.

Deposition pattern A Deposition at the same time in boats 963A to 963E B Deposition at boats 963A to 963C, followed by deposition at boats 963D to 963E in the order of deposition C boat 963A → 963B → 963C → 963D → 963E.

(Observation of abnormal growth part)
The surface of the phosphor layer obtained above is irradiated with light from an oblique direction, shaded to identify the position of the abnormally grown portion, and the position is photographed with a CCD camera to classify the size and number of protrusions due to abnormal growth. did. The location of the abnormally grown part and the CCD camera photographing were performed by a PC-controlled automatic inspection device (developed in-house). The size and number of convex portions of each sample are shown in (2) Number of surface convex portions in Table 1.

(Formation of recesses on phosphor surface)
After cleaning the surface of the phosphor sheet of the sample with an adhesive roller, the projections on the phosphor surface were observed using the same apparatus as described above, and the number of surface projections after cleaning in Table 1 is shown. . The amount of the decrease is the number of concave portions formed on the phosphor surface by removing abnormally grown portions by the adhesive roller. As a comparative example, a sample without cleaning with an adhesive roller was also produced.

(Formation of protective layer)
Next, a protective layer was formed by sealing the sample with a resin film. As the protective film on the phosphor layer side, a laminated film of PET (polyethylene terephthalate film) 12 μm and CPP (casting polypropylene) 20 μm was used. The lamination method of the laminated film was dry lamination, and the thickness of the adhesive layer was 1 μm. The adhesive used was a two-component reaction type urethane adhesive. The protective film on the substrate side was the same as the protective film on the phosphor surface side.

  The protective film was placed above and below the phosphor sheet (25 cm × 20 cm) obtained above, and the periphery was sealed with an impulse sealer under reduced pressure. In addition, it fused so that the distance from a fusion | melting part to a fluorescent substance sheet peripheral part might be set to 1 mm. The impulse sealer heater used for the fusion was 8 mm wide.

(Radiation detector)
The scintillator panel obtained above is set on the light-receiving element surface of PaxScan (Varian FPD: 2520) in turn, with a foam member made of urethane foam having a thickness of 12 mm, and a protective cover made of a carbon plate. Attached. At this time, the scintillator panel is pressed against the light receiving element at a pressure of 100 gf / cm ² (0.98 N / cm ² ) by the pressure of the compressed foam member.

The X-ray of 3.0 mR is irradiated at a tube voltage of 70 kVp on the radiation incident surface side of the radiation detection apparatus on which the scintillator panel is set, and the output from each pixel with respect to the incident X-ray including the emission intensity unevenness of the scintillator panel is output. Calibration (Gain correction) was performed so as to be the same. Next, 1.0 mR X-rays were irradiated at a tube voltage of 70 kVp, and the obtained digital signal was recorded on a hard disk. Next, the recording on the hard disk is analyzed by a computer, the average value of the electrical signal of the image signal is set as S, and the signal (noise) deviating from this average intensity S is set as the square root value N of the mean square.
20 x log10 (S / N) dB
And the graininess was evaluated based on the calculated value.

(Vibration temperature cycle test)
Next, fix the radiation detector to the vibration tester, give a vibration of 25Hz (2.5G) for 1 hour with the vibration tester, install it in the environmental tester, and change the temperature from -10 ℃ to 60 ℃ for 10 cycles. Gave.

(Evaluation)
After the vibration temperature cycle test, 1.0 mR X-rays were irradiated again at a tube voltage of 70 kVp to evaluate the graininess. The calibration (Gain correction) data used at this time is the same as that used for the graininess measurement before the vibration temperature cycle test.

  The granularity before and after the vibration temperature cycle test is shown in (c) Granularity in Table 1. Note that the graininess was 1.0 as the value before the vibration temperature cycle test, and the graininess after the vibration temperature cycle test was expressed as a ratio.

  If the light receiving element and the scintillator panel are misaligned by the vibration temperature cycle test, the calibration of each pixel becomes inappropriate and the graininess deteriorates.

  In Table 1, it means that the position shift between the light receiving element and the scintillator panel is smaller as the graininess value after the vibration temperature cycle test is closer to 1.0.

  The evaluation results are shown in Table 1.

  As apparent from the results shown in Table 1, it can be seen that the granularity of the examples of the present invention is superior to that of the comparative examples. That is, while the scintillator panel is installed on the planar light receiving element in an easily replaceable manner, the scintillator panel and the planar light receiving element surface can be contacted uniformly in the surface, and the scintillator panel and planar light receiving due to temperature change and impact are possible. It is possible to provide a scintillator capable of improving image quality such as granularity of a radiographic image and a radiographic image detection apparatus including the scintillator by a method capable of preventing the displacement of the element.

Claims (14)

A scintillator panel having a phosphor layer containing phosphor columnar crystals on a substrate, wherein a plurality of recesses are formed on the phosphor layer surface of the scintillator panel. 2. The scintillator panel according to claim 1, wherein a diameter of the recess is 30 μm or more and 1/2 or less of a thickness of the phosphor layer. The scintillator panel according to claim 1 or 2, wherein the concave portion is formed by removing a part of the phosphor from the surface of the phosphor layer. 3. The scintillator panel according to claim 1, wherein the concave portion is formed by partially pressing and denting the surface of the phosphor layer. 4. 3. The scintillator panel according to claim 1, wherein the recess is formed by removing the phosphor on the surface of the phosphor layer by a laser ablation method. 4. The scintillator panel according to any one of claims 1 to 5, wherein the phosphor layer is formed using an additive containing cesium iodide and thallium as a raw material. The scintillator panel according to any one of claims 1 to 6, wherein the substrate is made of a flexible polymer film having a thickness of 50 to 500 µm. The scintillator panel according to claim 7, wherein the polymer film is a polymer film containing polyimide or polyethylene naphthalate. A radiological image detection apparatus comprising the scintillator panel according to any one of claims 1 to 8, wherein a plurality of light receiving pixels are two-dimensionally arranged on the phosphor layer side of the scintillator panel. A radiation image detecting apparatus, wherein the received light receiving element (hereinafter referred to as “planar light receiving element”) is brought into close contact with pressure. A protective cover disposed on the radiation incident side of the scintillator panel on the side opposite to the phosphor layer through the substrate, and a foam material is filled between the protective cover and the substrate, and the scintillator panel and the flat surface The radiographic image detection apparatus according to claim 9, wherein the close contact with the light receiving element is due to the pressure of the foam material. The radiographic image detection apparatus according to claim 10, wherein the foam material is a silicon-based, urethane-based, polyethylene-based, or polypropylene-based foam material. The space between the scintillator panel and the planar light receiving element is hermetically sealed, and the scintillator panel and the planar light receiving element are in close contact with each other by reducing the pressure of the sealed portion. The radiation image detection apparatus as described in any one of Claim 11 thru | or 11. The scintillator panel is disposed on the radiation incident side of the scintillator panel on the opposite side of the phosphor layer through the substrate and is fixed to the housing of the radiation image detection device or the planar light receiving element. The radiographic image detection apparatus according to any one of claims 9 to 12, wherein the scintillator panel and the light receiving element are brought into close contact with each other by being pressed against the light receiving element. The radiographic image detection apparatus according to claim 13, wherein the auxiliary plate is a protective cover on a radiation incident side of the radiographic image detection apparatus.