Radiation imaging panel, radiation imaging device, radiation imaging system, method for manufacturing radiation imaging panel, and scintillator plate

Abstract

To provide a technique advantageous for improving an MTF in a radiation imaging panel.SOLUTION: A radiation imaging panel includes a substrate in which a plurality of pixels each including a photoelectric conversion element are arranged on a principal surface, a scintillator that includes a plurality of columnar crystals arranged on the principal surface, and a protective layer that includes a resin layer arranged to cover the scintillator. An area between the principal surface and a top face of the resin layer includes first areas that are areas between the adjacent columnar crystals of the plurality of columnar crystals, and a second area that is an area between the plurality of columnar crystals and the first areas and the top face and in which the resin layer is arranged. Particles of a metal compound are arranged in the first areas. The particles of the metal compound are arranged in the second area at a lower concentration than that of the first areas, or the particles of the metal compound are not arranged in the second area.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radiation imaging panel, a radiation imaging apparatus, a radiation imaging system, a method for manufacturing a radiation imaging panel, and a scintillator plate. [Background technology]

[0002] As a flat panel detector (FPD) used for radiography in medical image diagnosis and non-destructive testing, there is an indirect conversion type FPD in which radiation passing through a subject is converted into light by a scintillator, and the light emitted by the scintillator is detected by a photoelectric conversion element. For the scintillator that converts radiation into light, columnar crystals of alkali metal halide compounds such as cesium iodide are widely used in order to efficiently transmit the light converted from radiation to the photoelectric conversion element. Since the alkali metal halide compounds deteriorate due to moisture absorption, a protective layer having a moisture-proof function may be arranged on the scintillator. In addition, a reflective layer having a light-reflecting function may be arranged on the opposite side of the scintillator from the photoelectric conversion element so that the light converted from radiation by the scintillator is efficiently detected by the photoelectric conversion element. Patent Document 1 shows a radiation detection device in which a phosphor protective layer having a light-reflecting function and a moisture-proof function, which is made of a resin containing light-reflective fine particles and has a light-reflecting function, is formed on a phosphor layer in a shape embedded between the columns of the phosphor columnar crystals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-052980 A Summary of the Invention [Problem to be solved by the invention]

[0004] The concentration distribution of the light-reflective particles shown in Patent Document 1 needs to be examined. Specifically, between each columnar crystal of the scintillator, light-reflective particles must be arranged so that light does not enter adjacent columnar crystals in order to improve the MTF (Modulation Transfer Function). On the other hand, when light-reflective particles are present at the top of the columnar crystal, the light emitted upward from the columnar crystal of the scintillator is reflected by the light-reflective particles and re-enters the columnar crystal, thereby improving the DQE (Detective Quantum Efficiency). However, the light emitted upward from the columnar crystal may be diffused by the light-reflective particles, and the effect of improving the MTF may not be obtained.

[0005] An object of the present invention is to provide a technique that is advantageous for improving the MTF in a radiation imaging panel. [Means for solving the problem]

[0006] In view of the above problems, a radiation imaging panel according to an embodiment of the present invention comprises: A scintillator plate for detecting radiation, comprising: a scintillator having a plurality of columnar crystals that convert the radiation into visible light; a plate-shaped substrate; and a thermoplastic resin material that covers tip sides of adjacent columnar crystals among the plurality of columnar crystals to position metal particles in a first region between the adjacent columnar crystals, and that is positioned in a second region between the scintillator and the substrate to bond the scintillator to the substrate, The first territory The area is ,gold genus grain Children are distributed This is an area where , the second area The area is The gold is at a lower concentration than the first region. genus grain Children are distributed This is an area where , or the second area The area is , said gold genus grain No children assigned It is an area It is characterized by: Effect of the Invention

[0007] The above-mentioned means provides a technique that is advantageous for improving the MTF in a radiation imaging panel. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view showing an example of the configuration of a radiation imaging panel according to the present embodiment. [Diagram 2] FIG. 2 is a diagram showing the configuration of the radiation imaging panel shown in FIG. [Diagram 3] FIG. 2 is a diagram showing the configuration of a comparative example of the radiation imaging panel of FIG. [Figure 4] FIG. 2 is a diagram showing the configuration of the radiation imaging panel shown in FIG. [Diagram 5] FIG. 2 is a diagram showing the configuration of a comparative example of the radiation imaging panel of FIG. [Figure 6] 2 is a graph showing characteristics of the radiation imaging panel of FIG. 1; [Figure 7] 2 is a diagram showing an example of the configuration of a radiation imaging apparatus and a radiation imaging system using the radiation imaging panel of FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] Furthermore, radiation in the present invention may include α-rays, β-rays, γ-rays, and the like, which are beams produced by particles (including photons) emitted by radioactive decay, as well as beams having the same or greater energy, such as X-rays, particle beams, and cosmic rays.

[0011] The configuration and manufacturing method of the radiation imaging panel according to this embodiment will be described with reference to Figs. 1 to 7. Fig. 1 is a diagram showing a cross-sectional structure of a radiation imaging panel 100 in this embodiment. The radiation imaging panel 100 includes a substrate 101 including a pixel region 110 in which a plurality of pixels, each including a photoelectric conversion element, are arranged on a main surface 109, a scintillator 107 including a plurality of columnar crystals 102 arranged on the main surface 109 of the substrate 101, and a protective layer 108 including a resin layer 103 arranged so as to cover the scintillator 107. A planarization layer 105 for reducing steps due to transistors, wiring layers, and the like formed on the main surface 109 of the substrate 101 may be arranged between the substrate 101 and the scintillator 107.

[0012] In the pixel region 110, a plurality of pixels may be arranged in a two-dimensional array. For example, 3300×2800 pixels may be arranged on a substrate 101 of 550 mm×445 mm. Ten pixels arranged on the outer periphery of the 3300×2800 pixels may be a dummy pixel region, and an effective pixel region of the pixel region 110 may be constituted by 3280×2780 pixels arranged inside the dummy pixels. The number of pixels arranged in the pixel region 110 and the number of pixels arranged in the effective pixel region of the pixel region 110 may be appropriately set according to the size of the substrate 101, the subject to be imaged, and the like.

[0013] Further, in the pixel region 110 provided on the substrate 101, column signal lines for extracting signals generated in each pixel, row signal lines for driving each element including the pixels arranged in the pixel region 110, and the like may be arranged. The column signal lines and row signal lines may be electrically connected to a readout circuit board and a drive circuit board via a flexible wiring board, or the like. In order to connect the column signal lines and row signal lines to the readout circuit board and the drive circuit board, the substrate 101 may be provided with a connection terminal portion (not shown). A signal generated in each pixel of the pixel region 110 may be output from the radiation imaging panel 100 via the connection terminal portion.

[0014] Here, an example is shown in which the readout circuit and the drive circuit are disposed outside the radiation imaging panel 100, but the readout circuit and the drive circuit may be disposed in the radiation imaging panel 100. Even in this case, a connection terminal portion (not shown) is disposed on the substrate 101, and a signal generated in each pixel of the pixel region 110 can be output from the radiation imaging panel 100 via the connection terminal portion (not shown).

[0015] In this embodiment, the protective layer 108 includes a base 106 disposed on the side of the resin layer 103 opposite to the scintillator 107, and a metal layer disposed between the resin layer 103 and the base 106. For example, the protective layer 108 may be produced by forming a metal layer 104 of aluminum on the base 106, and forming the resin layer 103 on the metal layer 104.

[0016] The scintillator 107 converts radiation incident on the scintillator 107 into light detectable by a photoelectric conversion element provided on the substrate 101. For example, the scintillator 107 can convert radiation into visible light. For the scintillator 107, an alkali metal halide compound such as cesium iodide (CsI) that grows columnar crystals can be used. When CsI is used as the scintillator 107, thallium iodide (TlI) can be used as an activator.

[0017] The scintillator 107 can be formed by, for example, a vapor deposition method. The substrate 101 is placed in a vapor deposition apparatus so that the planarization layer 105 becomes the vapor deposition surface, and CsI and TlI are filled in cell containers so that the Tl concentration is 1 mol % relative to CsI, and co-deposition is performed by heating. In this way, the scintillator 107 including a plurality of columnar crystals 102 is formed.

[0018] A resin layer 103 is formed on the scintillator 107. The scintillator 107, which is composed of a plurality of columnar crystals 102 containing an alkali metal halide compound, deteriorates due to moisture absorption. Therefore, the resin layer 103 may also function as a moisture-proof layer for the scintillator 107. By providing the resin layer 103 that covers the scintillator 107 with the function of a moisture-proof layer, it becomes possible to prevent the scintillator 107 from deteriorating due to moisture absorption.

[0019] FIG. 2(a) is an enlarged view of a portion 111 in FIG. 1. A hot melt resin mainly composed of a polyolefin resin may be used for the resin layer 103. The hot melt resin is defined as an adhesive resin that does not contain water or solvent, is solid at room temperature, and is composed of 100% non-volatile thermoplastic material (Thomas P. Flanagan, Adhesives Age, vol. 9, No. 3, pp. 28 (1966)). The hot melt resin has a property of melting when the resin temperature rises and solidifying when the resin temperature drops, and is adhesive to other organic materials and inorganic materials in a heated and molten state, but is in a solid state at room temperature and has no adhesiveness. In addition, since the hot melt resin does not contain a polar solvent, a solvent, or water, even if it comes into contact with the scintillator 107 having the columnar crystals 102 of an alkali halide, the scintillator 107 does not dissolve, so it can also have the function of a protective layer.

[0020] Hot melt resins are classified according to the type of base polymer (base material) that is the main component, and polyolefin-based, polyester-based, polyamide-based, etc. When a hot melt resin is used in resin layer 103 as protective layer 108 for scintillator 107, it is important that the resin layer 103 has high moisture resistance and high optical transparency for transmitting visible light generated from scintillator 107.

[0021] The material used for the resin layer 103 is not limited to hot melt resin. For example, a resin having a pressure-sensitive adhesive action due to intermolecular forces, a so-called adhesive material, may be used for the resin layer 103. In this case, a urethane resin or an acrylic resin may be used for the resin layer 103. For example, a polymethyl methacrylate resin, which is an acrylic resin, may be used for the resin layer 103.

[0022] The region between the main surface 109 of the substrate 101 and the upper surface 203 of the resin layer 103 shown in Fig. 1 and Fig. 2(a) is defined as follows. A region between adjacent columnar crystals 102 of the scintillator 107 is defined as a first region 211. A region between the plurality of columnar crystals 102 and the first region 211 and the upper surface 203 of the resin layer 103, in which the resin layer 103 is disposed, is defined as a second region 212. Here, the first region 211 is defined as a region in which the proportion of the plurality of columnar crystals 102 of the scintillator 107 in a plane parallel to the main surface 109 of the substrate 101 is 75% or more and 98% or less. In the first region 211, as shown in Fig. 2(a), particles 201 of a metal compound are disposed.

[0023] 3 shows a cross-sectional view of a radiation imaging panel 300 of the comparative example. In the radiation imaging panel 300 of the comparative example, since metal compound particles are not arranged in the first region 211, the light emitted from the columnar crystals 102 of the scintillator 107 may spread in the lateral direction of the drawing in the first region 211. As a result, repeated reflection and refraction in the first region 211 may promote light scattering and attenuation of light that occurs at the same time, and the MTF may decrease.

[0024] 2(a), in the present embodiment, metal compound particles 201 are disposed in the first region 211. By disposing the metal compound particles 201, the light emitted from the columnar crystals 102 is more likely to be reflected by the columnar crystals 102 from which it was emitted again. As a result, scattering of light in the first region 211 can be suppressed, and the MTF can be improved.

[0025] The metal compound particles 201 may be metal oxide particles. A material having a higher refractive index than the scintillator 107 may be used for the metal compound particles 201. For example, when the above-mentioned CsI (refractive index (n): 1.78 to 1.84 (depending on the type of activator, etc.)) is used as the scintillator 107 of the alkali metal halide compound, a material having a higher refractive index than CsI may be used. For example, the metal compound particles 201 may be white lead (2PbCo3·Pb(OH)2) (n: 1.94 to 2.09), zinc oxide (n: 2.0), yttrium oxide (n: 1.91), zirconium oxide (n: 2.20), titanium oxide (n: 2.50 to 2.72), etc. For example, the refractive index of the metal compound particles 201 may be 1.94 or more and 2.72 or less. Also, for example, rutile type titanium dioxide particles, which have a high refractive index among titanium oxides, may be used as the metal compound.

[0026] Furthermore, the metal compound particles 201 may have a higher refractive index than the resin constituting the resin layer 103. By increasing the difference between the refractive index of the metal compound particles 201 and the refractive index of the resin layer 103, light is more likely to be reflected on the surface of the metal compound particles 201 in the first region 211. The refractive index of the above-mentioned hot melt resin is about 1.52, the refractive index of the urethane resin is about 1.49, and the refractive index of the acrylic resin is about 1.49 to 1.53.

[0027] The average particle size of the metal compound particles 201 may be 200 nm or more and 500 nm or less. Generally, the sensitivity characteristic of a photoelectric conversion element is 500 nm to 800 nm, but if the particle is 1 / 2 the wavelength of light or less, the effect of Rayleigh scattering appears, and the probability of reflection in the direction of the light incidence increases. For example, if the average particle size is 250 nm and the particle size distribution is 10% diameter D 10 = 195 nm, 50% diameter (median diameter) D 50 =245nm, 90% diameter D 90 Rutile titanium dioxide particles having a diameter of 275 nm may be used as the metal oxide particles 201 .

[0028] In the configuration shown in FIG. 2(a), a part of the resin layer 103 is disposed in the first region 211. In addition, in the first region 211, the metal compound particles 201 are disposed in the resin layer 103. However, as shown in FIG. 2(b), the resin layer 103 may not be disposed in the first region 211. Since the resin layer 103 is not disposed in the first region 211, the refractive index of the space (air layer) in the first region 211 is lowered. This increases the refractive index difference between the air layer and the columnar crystals 102 in the first region 211, making it difficult for light to be emitted from the columnar crystals 102. In addition, the refractive index difference between the air layer and the metal compound particles 201 in the first region 211 increases, and the light that has been emitted from the columnar crystals 102 can be more efficiently reflected by the metal compound particles 201. This can further improve the MTF.

[0029] 2(a) and 2(b), the metal compound particles 201 are not disposed in the second region 212. However, as shown in Fig. 4, the metal compound particles 201 may be disposed in the second region 212. In this case, the metal compound particles 201 may be dispersed in the portion of the resin layer 103 that is disposed in the second region 212, as shown in Fig. 4.

[0030] Here, the concentration of the metal compound particles 201 in the second region 212 relative to the resin layer 103 will be considered. FIG. 4 shows the radiation imaging panel 100 of this embodiment in which the metal compound particles 201 are added to the second region 212 at a concentration lower than that of the first region 211. FIG. 5 shows a radiation imaging panel 500 of a comparative example in which the concentration of the metal compound particles 201 in the second region 212 is equal to or higher than the concentration of the metal compound particles 201 in the first region 211. When the concentration of the metal compound particles 201 in the second region 212 is high, scattering in the film thickness direction of the resin layer 103 (the vertical direction in FIG. 5) increases. Therefore, the amount of light returning to the columnar crystals 102 increases. However, the light reflected by the metal compound particles 201 in the second region 212 may be incident on other columnar crystals 102 without being reflected by the columnar crystals 102 that emitted the light. In other words, the light is diffused, which may cause a decrease in MTF.

[0031] FIG. 6 shows the MTF value at 2 lp / mm of a radiographic imaging panel manufactured by changing the concentration of the metal compound particles 201 in the resin layer 103 in the second region 212. Since it is difficult to mix the metal compound particles 201 exceeding 90 vol% in the resin constituting the resin layer 103, the maximum concentration of the metal compound particles 201 in the resin layer 103 is 90 vol%. The MTF value was measured by irradiating X-rays conforming to the radiation quality RQA5 of the international standard. Also, FIG. 6 shows a case where the metal compound particles 201 are arranged at the same concentration in the first region 211 and the second region 212 (radiographic imaging panel 500 of the comparative example) and a case where the metal compound particles 201 are arranged at a lower concentration in the second region 212 than in the first region 211 (radiographic imaging panel 100 of the present embodiment).

[0032] As shown in FIG. 6, the radiation imaging panel 100 of this embodiment, in which the metal compound particles 201 are added to the second region 212 at a lower concentration than the first region 211, has an improved MTF value compared to the radiation imaging panel 500 of the comparative example, in which the metal compound particles 201 are added to the first region 211 and the second region 212 at the same concentration.

[0033] Furthermore, from FIG. 6, it can be seen that in the second region 212, when the concentration of the metal compound particles 201 in the resin layer 103 is increased from 0 vol%, the MTF improves, and at an appropriate concentration, the optimum value is shown, and when the concentration is further increased, the MTF decreases. More specifically, when the concentration of the metal compound particles 201 in the resin layer 103 in the second region 212 is 0.15 vol% or more and less than 7.5 vol%, the MTF value improves. When the concentration of the metal compound particles 201 in the second region 212 is low, the possibility of light reflection by the metal compound particles 201 in the second region 212 of the resin layer 103 is lower than when the concentration is high, and scattering is suppressed. In addition, by the presence of an appropriate amount of the metal compound particles 201, the light reflected by the metal compound particles 201 is attenuated while being diffused, and does not return to the columnar crystals 102. As a result, the radiation imaging panel 100 of this embodiment can improve the MTF.

[0034] That is, as shown in Fig. 4, when the metal compound particles 201 are arranged in the second region 212, the metal compound particles 201 may be arranged in the second region 212 at a lower concentration than in the first region 211. This can improve the MTF in the radiation imaging panel 100. Furthermore, in this case, the concentration of the metal compound particles 201 in the second region 212 in the resin layer 103 may be 0.15 vol% or more and less than 7.5 vol%. This can further improve the MTF in the radiation imaging panel 100.

[0035] In this manner, the MTF can be improved when the metal compound particles 201 are arranged in the first region 211 and the metal compound particles 201 are arranged in the second region 212 at a concentration lower than that in the first region 211, or when the metal compound particles 201 are not arranged in the second region 212. This makes it possible to realize a radiation imaging panel 100 with high spatial resolution.

[0036] Next, a method for manufacturing the radiation imaging panel 100 in which the concentration of the metal compound particles 201 differs between the first region 211 and the second region 212 will be described. First, for example, an alkali-free glass having a size of 550 mm×445 mm and a thickness of 500 μm is prepared as the substrate 101. The substrate 101 is not limited to glass, and may be a resin substrate or a semiconductor substrate such as silicon. The pixel region 110 is formed by repeatedly performing a film formation process for forming a semiconductor layer such as silicon (e.g., amorphous silicon) and a metal (e.g., aluminum) constituting a wiring layer, a photolithography process, an etching process, and the like on the glass substrate 101. The pixel region 110 includes a plurality of pixels each including a photoconversion element that generates a charge according to the light emitted by the scintillator 107 and a switching element that outputs a signal according to the generated charge. In addition, a connection terminal portion (not shown) for driving the pixel and sending the obtained signal to an external circuit may be formed in the pixel region 110.

[0037] After forming the pixel region 110, an array test may be performed to check the operation of the pixels formed in the pixel region 110. After confirming that the operation is good and there are no or only a few missing pixels in the array test, the periphery of the substrate 101 may be masked with a masking film to protect the connection terminal portion (not shown), and the planarization layer 105 may be formed. The planarization layer 105 may be formed, for example, by placing the substrate 101 in a spray spin coater, spinning at a rotation speed of about 100 rpm while spraying a polyimide solution, and then drying and dry annealing at a temperature of 220°C. For example, the planarization layer 105 may have a thickness of about 2 μm.

[0038] After preparing the substrate 101 on which the pixel region 110 is formed, the scintillator 107 is then formed. First, a deposition mask is set on the region of the substrate 101 on which the planarization layer 105 is formed where the scintillator 107 is not to be formed, and then the substrate 101 is placed on a deposition apparatus so that the planarization layer 105 is the deposition surface. Then, CsI and TlI are respectively filled in a cell container so that the Tl concentration is 1 mol % relative to CsI, and co-deposition is performed by heating. The scintillator 107 may have a thickness of, for example, 380 μm and a film filling rate of 75%. At this time, the outer edge of the scintillator 107 may be disposed outside the outer edge of the pixel region 110. In addition, when depositing the scintillator 107, the deposition apparatus is set at 100° C. -3 After exhausting to a pressure in the Pa range, the substrate surface may be heated to 175° C. using a lamp heater.

[0039] After the scintillator 107 is formed, the particles 201 of the metal compound are scattered from above the scintillator 107 so that the particles 201 of the metal compound get into the spaces between the columnar crystals 102 of the scintillator 107. Next, a sheet of hot-melt resin that constitutes the resin layer 103 is placed on the scintillator 107 and bonded together using a vacuum thermal transfer device or the like, thereby producing the radiation imaging panel 100 shown in Fig. 2(b). For example, the scintillator 107 and the sheet of hot-melt resin are first brought into contact with each other at 30°C, and then the sheet is bonded to the scintillator 107 at 10°C. -1 The pressure is reduced to 1 Pa to remove air bubbles. Furthermore, pressure is applied between substrate 101 and the hot melt resin sheet constituting resin layer 103, and the sheet is heated to 70 to 100° C. and held for an appropriate period of time, whereby substrate 101 on which scintillator 107 has been formed and resin layer 103 constituting protective layer 108 are bonded together.

[0040] Also, for example, after the scintillator 107 is formed, a resin to which metal compound particles 201 are added may be applied so as to cover the scintillator 107, thereby forming a portion of the resin layer 103 to be disposed in the first region 211. Next, a sheet of hot melt resin or a sheet containing a urethane resin or an acrylic resin, which is called an adhesive having a pressure-sensitive adhesive action due to the above-mentioned intermolecular force, is attached onto the resin formed by the coating method. In this way, a portion of the resin layer 103 to be disposed in the second region 212 is formed. At this time, the resin attached onto the resin formed by the coating method may contain metal compound particles 201 added at a lower concentration than the resin formed by the coating method. In this way, the radiation imaging panel 100 shown in FIG. 4 can be produced. In addition, the resin attached onto the resin formed by the coating method may not contain metal compound particles 201. In this way, the radiation imaging panel 100 shown in FIG. 2(a) can be produced.

[0041] The portion of the first region 211 of the resin layer 103 is not limited to being formed by using a coating method. The portion of the resin layer 103 in the first region 211 that contacts the columnar crystals 102 may be formed by laminating a resin to which particles 201 of a metal compound have been added, using a vacuum thermal transfer device or the like.

[0042] After forming the resin layer 103, a metal layer 104 such as aluminum or a base 106 may be formed on the resin layer 103. The above-mentioned hot melt resin sheet or a sheet containing a urethane resin or an acrylic resin called an adhesive may be produced by forming a metal layer 104 such as aluminum on the base 106 and forming a resin on the metal layer 104. A PET substrate or the like may be used for the base 106. For example, a metal layer 104 made of aluminum having a thickness of 12 μm may be formed on a base 106 made of PET having a thickness of 30 μm, and the resin layer 103 or a part of the resin layer 103 may be formed on the metal layer 104. The resin layer 103 formed on the base 106 may be bonded to the scintillator 107 to produce the radiation imaging panel 100 having the protective layer 108 shown in FIG. 1.

[0043] In addition, in the present embodiment, a case has been described in which the substrate 101 having the pixel region 110 in which a plurality of pixels are arranged is used, but the present invention is not limited to this. For example, the substrate 101 may not have the pixel region 110. In this case, the reference numeral 100 may be called a scintillator plate. For example, by mounting this scintillator plate on a sensor substrate having a pixel region in which a plurality of pixels are arranged, the substrate 101 may function as a radiation imaging panel. Therefore, when the substrate 101 does not have the pixel region 110, the substrate 101 may be a transparent substrate that transmits light emitted by the scintillator 107.

[0044] Hereinafter, a radiation imaging apparatus incorporating the above-described radiation imaging panel 100 and a radiation imaging system 800 using the radiation imaging apparatus incorporating the radiation imaging panel 100 will be described with reference to FIG.

[0045] The radiation imaging system 800 is configured to electrically capture an optical image formed by radiation and obtain an electrical radiation image (i.e., radiation image data). The radiation imaging system 800 includes, for example, a radiation imaging device 801, an exposure control unit 802, a radiation source 803, and a computer 804.

[0046] A radiation source 803 for irradiating radiation to a radiation imaging device 801 starts irradiating radiation in accordance with an exposure command from an exposure control unit 802. The radiation emitted from the radiation source 803 passes through a subject (not shown) and is irradiated to the radiation imaging device 801. The radiation source 803 stops emitting radiation in accordance with a stop command from the exposure control unit 802.

[0047] The radiation imaging apparatus 801 includes the above-mentioned radiation imaging panel 100, a control unit 805 for controlling the radiation imaging panel 100, and a signal processing unit 806 for processing a signal output from the radiation imaging panel 100. The signal processing unit 806 may, for example, perform A / D conversion of the signal output from the radiation imaging panel 100 and output the signal as radiation image data to a computer 804. The signal processing unit 806 may also generate a stop signal for stopping the irradiation of radiation from the radiation source 803 based on the signal output from the radiation imaging panel 100. The stop signal is supplied to the exposure control unit 802 via the computer 804, and the exposure control unit 802 sends a stop command to the radiation source 803 in response to the stop signal.

[0048] The control unit 805 can be configured, for example, by a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit), or a general-purpose computer with a built-in program, or a combination of all or part of these.

[0049] In addition, in the present embodiment, the signal processing unit 806 is shown as being disposed in the control unit 805 or as a part of the function of the control unit 805, but is not limited thereto. The control unit 805 and the signal processing unit 806 may each have a different configuration. Furthermore, the signal processing unit 806 may be disposed separately from the radiation imaging device 801. For example, the computer 804 may have the function of the signal processing unit 806. For this reason, the signal processing unit 806 may be included in the radiation imaging system 800 as a signal processing device that processes a signal output from the radiation imaging device 801.

[0050] The computer 804 can control the radiation imaging apparatus 801 and the exposure control unit 802, receive radiation image data from the radiation imaging apparatus 801, and perform processing for displaying the data as a radiation image. The computer 804 can also function as an input unit for a user to input conditions for capturing a radiation image.

[0051] As an example, the exposure control unit 802 has an exposure switch, and when the exposure switch is turned on by the user, it sends an exposure command to the radiation source 803 and also sends a start notification indicating the start of radiation emission to the computer 804. In response to the start notification, the computer 804 notifies the control unit 805 of the radiation imaging device 801 of the start of radiation irradiation. In response to this, the control unit 805 causes the radiation imaging panel 100 to generate a signal corresponding to the incident radiation.

[0052] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0053] 100: radiation imaging panel, 101: substrate, 102: columnar crystals, 103: resin layer, 107: scintillator, 108: protective layer, 109: main surface, 201: metal compound particles, 203: upper surface, 211: first region, 212: second region

Claims

1. A scintillator plate for detecting radiation, comprising: a scintillator having a plurality of columnar crystals for converting the radiation into visible light; A plate-shaped substrate; a thermoplastic resin material that covers tip sides of adjacent columnar crystals among the plurality of columnar crystals to position metal particles in a first region between the adjacent columnar crystals, and that is positioned in a second region between the scintillator and the base material to bond the scintillator to the base material, the first region is a region in which the metal particles are arranged, A scintillator plate characterized in that the second region is a region in which the metal particles are arranged at a lower concentration than the first region, or the second region is a region in which the metal particles are not arranged.

2. 2. The scintillator plate according to claim 1, wherein the resin material is not disposed in the first region.

3. 2. The scintillator plate according to claim 1, wherein a portion of the resin material is disposed in the first region.

4. 4. The scintillator plate according to claim 1, wherein the concentration of the metal particles added to the resin material in the second region is equal to or greater than 0.15 vol % and less than 7.5 vol %.

5. 5. The scintillator plate according to claim 1, wherein the metal particles are dispersed in a portion of the resin material that is disposed in the second region.

6. 6. The scintillator plate according to claim 1, wherein the metal particles have a refractive index higher than a refractive index of a resin constituting the resin material.

7. 7. The scintillator plate according to claim 1, wherein the metal particles contain a metal oxide as a material.

8. 8. The scintillator plate according to claim 1, wherein the metal particles contain rutile titanium dioxide as a material.

9. 9. The scintillator plate according to claim 1, wherein the plurality of columnar crystals contain an alkali metal halide compound as a material.

10. A scintillator plate as described in any one of claims 1 to 9, characterized in that the resin material contains at least one of a resin composed of a non-volatile thermoplastic material and a resin having a pressure-sensitive adhesive effect due to intermolecular forces.

11. 11. The scintillator plate according to claim 1, wherein the first region is located at a position where the cross section of the plurality of columnar crystals occupies 75% or more and 98% or less of the cross section.

12. 12. The scintillator plate according to claim 1, wherein the average particle size of the metal particles is 200 nm or more and 500 nm or less.

13. 13. A scintillator plate according to any one of the preceding claims, wherein the substrate comprises a metal layer.

14. A scintillator plate as claimed in any one of claims 1 to 13, characterized in that the substrate comprises a PET layer.

15. A radiation imaging panel comprising the scintillator plate according to any one of claims 1 to 14; a control unit for controlling the radiation imaging panel; 13. A radiation imaging apparatus comprising:

16. The radiation imaging apparatus according to claim 15 , a signal processing device for processing a signal output from the radiation imaging device; 1. A radiation imaging system comprising:

17. A method of manufacturing a scintillator comprising the steps of: providing a scintillator having a plurality of columnar crystals for converting radiation into visible light; disposing metal particles between the plurality of columnar crystals; a step of bringing a thermoplastic resin into contact with the scintillator and heating the thermoplastic resin to cover tip sides of adjacent columnar crystals among the plurality of columnar crystals, thereby positioning metal particles in a first region between the adjacent columnar crystals and in a second region between the scintillator and the substrate, thereby bonding the scintillator and the substrate, the first region is a region in which the metal particles are arranged, A method for manufacturing a scintillator plate, characterized in that the second region is a region in which the metal particles are arranged at a lower concentration than the first region, or the second region is a region in which the metal particles are not arranged.

18. A substrate having a plurality of photoelectric conversion elements arranged on a main surface side thereof; a scintillator disposed on the main surface side and including a plurality of columnar crystals for converting radiation into visible light; A plate-shaped substrate; a thermoplastic resin material that covers tip sides of adjacent columnar crystals among the plurality of columnar crystals to position metal particles in a first region between the adjacent columnar crystals, and that is positioned in a second region between the scintillator and the base material to bond the scintillator to the base material, the first region is a region in which the metal particles are arranged, The second region is a region in which the metal particles are arranged at a lower concentration than the first region, or the second region is a region in which the metal particles are not arranged.

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