JP2017062210A - Radiation image imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation image imaging apparatus capable of suppressing generation of a noise, improving a characteristic such as contrast, resolution or detection resolution, and lowering an exposure dose.SOLUTION: In a radiation image imaging apparatus including a plurality of optical sensor parts (4A, 4B) and a plurality of scintillator parts (5A, 5B), an overlapping wavelength region between a detection wavelength band of the optical sensor part 4A and an emitted-light wavelength band of the scintillator part 5A is separated from an overlapping wavelength region between a detection wavelength band of the optical sensor part 4B and an emitted-light wavelength band of the scintillator part 5B, in mutually adjacent pixels.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiographic imaging apparatus that detects radiation and outputs an electrical signal corresponding to the intensity distribution of the radiation.

  A radiographic imaging apparatus 100 as shown in FIG. 12 is known. The radiographic image capturing apparatus 100 captures a subject using X-rays R that have passed through a subject (not shown). The radiographic imaging apparatus 100 includes a substrate 101, a thin film transistor (hereinafter referred to as TFT) circuit portion 102 provided on the substrate 101, a photodiode array 103, and a scintillator 104 disposed on the photodiode array 103. It is equipped with. The photodiode array 103 includes a large number of photodiodes arranged for each pixel. FIG. 12 shows five photodiodes S1 to S5 arranged adjacent to each other. The scintillator 104 has a function of converting incident X-rays into light (visible light). In the scintillator 104, it is known to increase the thickness of the scintillator in order to increase the efficiency of conversion from X-rays to light.

  As another conventional technique, for example, a radiation detection apparatus described in Patent Document 1 is known. This radiation detection apparatus includes upper and lower two-layer scintillators. These scintillators emit light in two different wavelength bands.

JP2013-127371A

  In the radiographic imaging device 100 shown in FIG. 12, when X-rays R are incident on a predetermined position in the scintillator 104, for example, above the photodiode S2, the X-rays are emitted at the light emitting point L located above the photodiode S2. R is converted to light. The light emitted from the light emitting point L diffuses in all directions. Therefore, light (converted light) also enters the photodiodes S1, S3, S4 and the like adjacent to the photodiode S2 immediately below the light emitting point L. In FIG. 12, light directed from the light emitting point L toward the photodiode S2 is denoted by F1, light directed toward the photodiode S1 is denoted by F2, light directed toward the photodiode S3 is denoted by F3, and light directed toward the photodiode S4 is denoted by F4. As shown in FIG. 12, high intensity light is detected by the photodiode S2 immediately below the light emitting point L. However, in this radiographic imaging apparatus 100, visible light is detected by the photodiodes S1, S3, S4, etc. in the vicinity of the photodiode S2, and so-called crosstalk occurs. When such crosstalk occurs, characteristics such as contrast, resolution, and detection resolution of the captured image deteriorate.

  A scintillator has been proposed in which a large number of columnar crystals having a function of guiding light to a photodiode are erected. However, even with such a scintillator, light scattered from the interface between the columnar crystals enters the adjacent pixels, preventing the occurrence of noise that degrades the contrast, resolution, detection resolution, and other characteristics of the captured image. Can not.

  When the thickness of the scintillator is increased in order to increase the efficiency of conversion from X-rays to light, the optical path length of the light becomes long before reaching the photodiode from the light emitting point in the scintillator. For this reason, there is a problem that the light is scattered before reaching the photodiode and the detection resolution is lowered. These problems similarly exist in the radiation detection apparatus disclosed in Patent Document 1 and the radiographic imaging apparatus including the columnar crystal scintillator.

  In order to prevent deterioration of characteristics such as the contrast, resolution, and detection resolution of the captured image described above, it is necessary to increase the irradiation output of the X-ray generation source. In this case, the problem that the radiation exposure dose at the time of imaging increases occurs.

  The present invention has been made in view of the above problems, suppresses the occurrence of noise in the vicinity of the location where radiation is incident, and improves characteristics such as contrast, resolution, and detection resolution of the captured image, An object of the present invention is to provide a radiographic imaging apparatus that can reduce the radiation exposure dose during imaging.

  In order to solve the above-described problems and achieve the object, an aspect of a radiographic imaging apparatus according to the present invention includes a substrate, a plurality of photosensor units that are arranged on the substrate and respectively constitute pixels, and each A plurality of scintillator units arranged to face the photosensor unit one by one, and a detection wavelength band of the photosensor unit and a light emission wavelength band of the scintillator unit facing the photosensor unit, Is characterized in that the overlapping wavelength regions are separated between adjacent pixels.

  As an aspect described above, the optical sensor unit includes a photoelectric conversion layer, and the photoelectric conversion layer performs photoelectric conversion with light in the emission wavelength band of the scintillator unit facing the optical sensor unit, and is adjacent to the optical sensor unit. It is preferable to set so that photoelectric conversion is not performed with light in the emission wavelength band of the scintillator unit facing the optical sensor unit.

  In the above-described aspect, the color filter unit is provided in the optical sensor unit, and the color filter unit transmits light in the emission wavelength band of the scintillator unit facing the optical sensor unit and is adjacent to the optical sensor unit. It is preferable to block the transmission of light in the emission wavelength band of the scintillator unit facing the optical sensor unit.

  In the above aspect, the photoelectric conversion layers of the photosensor units adjacent to each other may be a pair of different semiconductor layers.

  In the above aspect, one of the pair of semiconductor layers may be formed of amorphous silicon, and the other of the pair of semiconductor layers may be formed of polycrystalline silicon.

  As the above aspect, the semiconductor layer pair may have the same semiconductor material and different impurity doping amounts.

  In the above aspect, the optical sensor unit is disposed on the substrate, the scintillator unit is disposed on the optical sensor unit, and radiation is incident on the scintillator unit from a direction opposite to the optical sensor unit in the scintillator unit. The configuration is preferable.

  In the above aspect, the reflective film is formed on the substrate, the scintillator unit is disposed on the reflective film, the optical sensor unit is disposed on the scintillator unit, and radiation that has passed through the optical sensor unit is incident on the scintillator unit. It is good also as a structure to be made.

  According to the radiographic imaging device of the present invention, it is possible to suppress the occurrence of noise in neighboring pixels due to crosstalk, improve the characteristics of the captured image, such as contrast, resolution, detection resolution, and the like. The dose can be reduced.

FIG. 1 is an explanatory cross-sectional view of a main part of a radiographic image capturing apparatus according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the radiographic image capturing apparatus according to the first embodiment of the present invention. FIG. 3 is an explanatory plan view showing an arrangement configuration of the first photoelectric conversion layer and the second photoelectric conversion layer in the photoelectric conversion layer of the radiographic image capturing apparatus according to the first embodiment of the present invention. FIGS. 4-1 is process sectional drawing which shows the manufacturing process of the photoelectric converting layer in the radiographic imaging apparatus which concerns on the 1st Embodiment of this invention. FIGS. 4-2 is process sectional drawing which shows the manufacturing process (selective laser annealing process) of the photoelectric converting layer in the radiographic imaging apparatus which concerns on the 1st Embodiment of this invention. FIGS. FIG. 5 is a cross-sectional view of a main part showing a first modification of the radiographic imaging apparatus according to the first embodiment of the present invention. FIG. 6 is a plan explanatory view showing a second modification of the radiographic image capturing apparatus according to the first embodiment of the present invention and showing the arrangement of the first to fourth photoelectric conversion layers in the photoelectric conversion layer. FIG. 7 is an essential part cross-sectional view showing Modification 3 of the radiographic image capturing apparatus according to the first embodiment of the present invention. FIG. 8 is a cross-sectional explanatory view of a main part of a radiographic image capturing apparatus according to the second embodiment of the present invention. FIG. 9 is a cross-sectional explanatory view of a main part of a radiographic image capturing apparatus according to the third embodiment of the present invention. FIG. 10 is a diagram illustrating a setting example of the emission wavelength band and the detection wavelength band in the radiographic image capturing apparatus according to the first embodiment of the present invention. FIG. 11 is a diagram illustrating a setting example of the emission wavelength band and the detection wavelength band in the radiographic image capturing apparatus according to the first embodiment of the present invention. FIG. 12 is a cross-sectional explanatory view showing a conventional radiographic imaging apparatus.

  Below, the detail of the radiographic imaging apparatus which concerns on embodiment of this invention is demonstrated based on drawing. However, it should be noted that the drawings are schematic, and the dimensions, ratios and shapes of the members are different from actual ones. In addition, the drawings include portions having different dimensional relationships, ratios, and shapes.

[First Embodiment]
First, an outline of the configuration of the radiographic image capturing apparatus according to the first embodiment of the present invention will be described. The radiographic image capturing apparatus according to the present embodiment is a configuration example that does not include a color filter. The radiographic imaging device according to the present embodiment includes a substrate, a plurality of photosensor units arranged on the substrate, and a plurality of photosensor units arranged to face each photosensor unit one by one. A scintillator section.

  The radiographic imaging device is characterized by a substrate, a plurality of optical sensor units arranged on the substrate and constituting pixels, respectively, and arranged to face each of the optical sensor units one by one. A plurality of scintillator units, and a wavelength region where a detection wavelength band of the optical sensor unit and an emission wavelength band of the scintillator unit facing the optical sensor unit overlap is separated between adjacent pixels. is there. The detection wavelength band of the optical sensor unit is set so as not to detect light from the scintillator unit of the adjacent pixel. Note that the pixel in this embodiment is an area of one unit of light detection occupied by each optical sensor unit, and is arranged in a matrix on the substrate.

  Hereinafter, the configuration of the radiographic imaging apparatus 1 according to the present embodiment will be specifically described with reference to FIGS. As shown in FIG. 1, the radiographic image capturing apparatus 1 includes a glass substrate 2 as a substrate, a TFT circuit unit 3 formed on the surface of the glass substrate 2, and an optical sensor formed on the TFT circuit unit 3. An array 4 and a scintillator array 5 are provided.

(TFT circuit part)
As shown in FIG. 2, the TFT circuit unit 3 includes a TFT 31 as a switching element for each pixel. That is, these TFTs 31 are arranged in a matrix on the surface of the glass substrate 2. In addition, the TFT circuit section 3 includes a charge storage capacitor, a gate line, a data line, and the like (not shown).

  The TFT 31 includes a gate electrode 32 formed on the surface of the glass substrate 2, a gate insulating film 33 covering the gate electrode 32 and the surface of the glass substrate 2, a semiconductor layer 34 formed to face the gate electrode 32, A source electrode 35 disposed so as to be joined to one side of the semiconductor layer 34 across the gate electrode 32; and a drain electrode 36 disposed so as to be joined to the other side of the semiconductor layer 34 across the gate electrode 32. . Further, an interlayer insulating film 37 is formed on the TFT 31 and the gate insulating film 33.

(Optical sensor array)
As shown in FIG. 1, the optical sensor array 4 includes a first optical sensor unit 4A having a first detection wavelength band and a second optical sensor unit 4B having a second detection wavelength band. The rows are arranged alternately. The first optical sensor unit 4A and the second optical sensor unit 4B are configured by photodiodes.

  As shown in FIG. 2, the optical sensor array 4 includes a large number of pixel electrodes 41 patterned for each pixel region on the interlayer insulating film 37, and the entire imaging region on the pixel electrodes 41 and the interlayer insulating film 37. And a transparent electrode 43 formed on the photoelectric conversion layer 42. The pixel electrode 41 is made of a conductive material such as metal.

  As shown in FIGS. 1 and 2, the photoelectric conversion layer 42 includes a first photoelectric conversion layer 42A made of amorphous silicon and a second photoelectric conversion layer 42B made of polycrystalline silicon. The first photoelectric conversion layer 42 </ b> A and the second photoelectric conversion layer 42 </ b> B are arranged to overlap the pixel electrode 41 with substantially the same size as the pixel electrode 41. As shown in FIG. 3, in the photoelectric conversion layer 42, the first photoelectric conversion layer 42 </ b> A and the second photoelectric conversion layer 42 </ b> B are alternately arranged in columns and rows.

  In the present embodiment, the transparent electrode 43 is formed over the entire imaging region as a common electrode of the photosensor array 4. As shown in FIGS. 1 and 2, the first photosensor unit 4 </ b> A includes a pixel electrode 41, a first photoelectric conversion layer 42 </ b> A, and a transparent electrode 43. The second photosensor unit 4B includes a pixel electrode 41, a second photoelectric conversion layer 42B, and a transparent electrode 43. Each pixel electrode 41 is connected to the drain electrode 36 of the TFT 31 formed in the corresponding pixel region via the extraction electrode 38 embedded in the contact hole formed in the interlayer insulating film 37.

  Since the first photosensor unit 4A includes the first photoelectric conversion layer 42A made of amorphous silicon, the first photosensor unit 4A is set to have a predetermined first detection wavelength band (for example, 300 nm to 700 nm). Since the second photosensor unit 4B includes the second photoelectric conversion layer 42B made of polycrystalline silicon, the second photosensor unit 4B is set to have a predetermined second detection wavelength band (for example, 500 nm to 900 nm). The first detection wavelength band and the second detection wavelength band are set so as not to overlap.

(Scintillator array)
As shown in FIGS. 1 and 2, the scintillator array 5 is formed on the transparent electrode 43. In the scintillator array 5, the first scintillator portions 5A and the second scintillator portions 5B are alternately arranged in columns and rows. And the 1st scintillator part 5A is formed corresponding to 4 A of 1st optical sensor parts. The second scintillator section 5B is formed corresponding to the second photosensor section 4B.

In the present embodiment, the scintillator material constituting the scintillator array 5 can be selected from CsI: Tl, Gd ₂ O ₂ S: Tb, LaBr ₃ : Ce, and the like. From these materials, a material that becomes an emission wavelength band that falls within the first detection wavelength band of the first optical sensor unit 4A, and a material that becomes an emission wavelength band that falls within the second detection wavelength band of the second optical sensor unit 4B. Should be selected. The first scintillator portion 5A and the second scintillator portion 5B can be formed using these materials, for example, by vapor deposition or printing.

  The wavelength region where the detection wavelength band of the first optical sensor unit 4A overlaps the emission wavelength band of the first scintillator unit 5A facing the first optical sensor unit 4A is the detection wavelength of the second optical sensor unit 4B in the adjacent pixel. The band is separated from the overlapping wavelength region of the emission wavelength band of the second scintillator unit 5B facing the second optical sensor unit 4B.

  In other words, the first photoelectric conversion layer 42A performs photoelectric conversion with light in the emission wavelength band of the first scintillator unit 5A facing the first optical sensor unit 4A. The first photoelectric conversion layer 42A is set so as not to perform photoelectric conversion with light in the emission wavelength band of the second scintillator 5B portion facing the second photosensor unit 4B adjacent to the first photosensor unit 4A. Has been. The second photoelectric conversion layer 42B performs photoelectric conversion with light in the emission wavelength band of the second scintillator unit 5B facing the second photosensor unit 4B. The second photoelectric conversion layer 42B is set so as not to perform photoelectric conversion with light in the emission wavelength band of the first scintillator 5A portion facing the first photosensor portion 4A adjacent to the second photosensor portion 4B. Has been.

  In the radiographic image capturing apparatus 1 according to the present embodiment, the setting of the emission wavelength band and the detection wavelength band as shown in FIG. 10 or FIG. 11 can also be applied. That is, FIG. 10 shows a case where the emission wavelength bands of the first scintillator unit 5A and the second scintillator unit 5B partially overlap between adjacent pixels. In this case, if the detection wavelength band of the first photosensor unit 4A facing the first scintillator unit 5A and the detection wavelength band of the second photosensor unit 4B facing the second scintillator unit 5B do not overlap, The detection signal A and the detection signal B can be separated without crosstalk with each other.

  FIG. 11 shows a case where the detection wavelength bands of the first optical sensor unit 4A and the second optical sensor unit 4B partially overlap between adjacent pixels. In this case, the detection wavelength band of the first scintillator section 5A facing the first optical sensor section 4A and the detection wavelength band of the second scintillator section 5B facing the second optical sensor section 4B do not overlap. The detection signal a and the detection signal b can be separated without crosstalk with each other. Of course, the detection wavelength bands of the first optical sensor unit 4A and the second optical sensor unit 4B are separated from each other between adjacent pixels, and the emission wavelength bands of the first scintillator unit 5A and the second optical sensor unit 5B are separated from each other. It is good also as a separated structure. In this case, the detection wavelength band of the first optical sensor unit 4A and the emission wavelength band of the first scintillator unit 5A overlap, and the detection wavelength band of the second optical sensor unit 4B and the emission wavelength band of the second scintillator unit 5B overlap. If you do.

(Method for producing photoelectric conversion layer)
Here, the manufacturing method of the photoelectric converting layer 42 is demonstrated easily using FIGS. 4-1 and FIGS. 4-2. As shown in FIG. 4A, the glass substrate 2 on which the TFT circuit portion 3 and the pixel electrode 41 are formed is prepared. Then, the first photoelectric conversion layer 42A made of amorphous silicon is deposited to a predetermined thickness using, for example, a vacuum deposition method, a chemical vapor deposition method, or the like over the entire imaging region on the surface of the glass substrate 2. Let

  Next, as shown in FIG. 4B, annealing is performed by selectively performing laser irradiation (indicated by an arrow in the drawing) on the first photoelectric conversion layer 42A made of amorphous silicon. At this time, the portion selectively irradiated with laser is made to have a pattern as shown in FIG. That is, in the laser irradiated portion, the first photoelectric conversion layer 42A made of amorphous silicon is changed to polycrystalline silicon to become the second photoelectric conversion layer 42B.

(Operation and effect of the first embodiment)
The configuration of the radiographic image capturing apparatus 1 according to the first embodiment has been described above. Next, the operation and effect of the radiation image capturing apparatus 1 will be described.

  As shown in FIG. 1, in the radiographic imaging apparatus 1, when X-rays R are incident on the first scintillator unit 5A, the X-rays R are converted into light at a light emitting point L located above the first scintillator unit 5A. The The light emitted from the light emitting point L is light in the first emission wavelength band and diffuses in all directions. Therefore, light (converted light) also enters the second photosensor unit 4B adjacent to the first photosensor unit 4A immediately below the light emitting point L. In FIG. 1, light traveling from the light emitting point L toward the first optical sensor unit 4A is denoted by F5 and F7, and light traveling toward the second optical sensor units 4B on both sides is denoted by F6 and F8.

  As shown in FIG. 1, high intensity light is detected by the first optical sensor unit 4 </ b> A immediately below the light emitting point L. This is because the first optical sensor unit 4A is set to the first detection wavelength band, and thus the lights F5 and F7 contribute to photoelectric conversion. Lights F6 and F8 are incident on the second photosensor units 4B on both sides adjacent to the first photosensor unit 4A. However, the second photoelectric conversion layer 42B of the second optical sensor unit 4B on which the lights F6 and F8 are incident does not cause photoelectric conversion with light in the first emission wavelength band, and therefore does not detect light from the emission point L. For this reason, in the radiographic imaging apparatus 1, what is called crosstalk does not generate | occur | produce and the fall of characteristics, such as the contrast of a captured image, resolution, detection resolution, can be prevented.

  Thus, in the radiographic imaging device 1 according to the present exemplary embodiment, the emission wavelength band of the first scintillator unit 5A is associated with the detection wavelength band of the first photosensor unit 4A. In addition, the emission wavelength band of the second scintillator unit 5B is associated with the detection wavelength band of the second photosensor unit 4B. For this reason, by designing the detection wavelength bands between adjacent pixels so as not to overlap (different), it is possible to suppress the occurrence of noise due to the diffusion of light emission in the scintillator array 5.

  According to the radiographic image capturing apparatus 1 according to the present embodiment, the contrast and resolution of a captured image are improved by suppressing noise to adjacent pixels caused by crosstalk. For this reason, according to the radiographic imaging device 1 of this Embodiment, it becomes possible to reduce the irradiation amount of the X-ray R at the time of imaging | photography, and can suppress an exposure dose.

  In general, when the thickness of the scintillator array 5 is increased in order to increase the efficiency of conversion from X-rays R to light, the optical path length of the light from the light emitting point in the scintillator array 5 to the optical sensor array 4 side is reached. However, there is a problem that the detection resolution is lowered due to the increase in length. However, according to the radiographic image capturing apparatus 1 according to the present embodiment, it is possible to prevent the occurrence of crosstalk, and thus it is possible to suppress a decrease in detection resolution.

(Modification 1 of the first embodiment)
FIG. 5 shows a first modification of the radiographic image capturing apparatus 1 according to the first embodiment. In the radiographic image capturing apparatus 1 according to the first embodiment described above, the transparent electrode 43 constituting the photosensor array 4 is a common electrode. However, as in the radiographic image capturing apparatus 1A shown in FIG. The transparent electrode 43 may be separated. The other configuration in the first modification is the same as that of the radiographic image capturing apparatus 1 according to the first embodiment.

(Modification 2 of the first embodiment)
FIG. 6 shows a second modification of the radiographic image capturing apparatus 1 according to the first embodiment. In the radiographic imaging apparatus 1 according to the first embodiment described above, the photoelectric conversion layer 42 includes the first photoelectric conversion layer 42A and the second photoelectric conversion layer 42B, but as shown in FIG. The conversion layer 42 may include four photoelectric conversion layers including a first photoelectric conversion layer 42A, a second photoelectric conversion layer 42B, a third photoelectric conversion layer 42C, and a fourth photoelectric conversion layer 42D.

  In the second modification, the scintillator array 5 includes a first scintillator section 5A, a second scintillator section 5B, a third scintillator section (not shown), and a fourth scintillator (not shown) as the configuration of the photoelectric conversion layer 42 is changed. It is necessary to arrange the portion corresponding to the photoelectric conversion layer 42. In the second modification, the emission wavelength band of the first scintillator unit 5A and the detection wavelength band of the first photoelectric conversion layer 42A are made to correspond to each other, and the emission wavelength band of the second scintillator unit 5B and the detection wavelength of the second photoelectric conversion layer 42B. The light emission wavelength band of the third scintillator part (not shown) and the detection wavelength band of the third photoelectric conversion layer 42C are made to correspond to each other, and the light emission wavelength band of the fourth scintillator part (not shown) and the fourth photoelectric conversion layer 42D What is necessary is just to make it correspond with a detection wavelength band.

  According to the second modification, when attention is paid to one pixel, it is possible to further suppress the occurrence of crosstalk to the four pixels of the pixel and the four diagonally adjacent four pixels. That is, in FIG. 6, when focusing on the first photoelectric conversion layer 42A, the fourth photoelectric conversion layer 42D is disposed on both sides in the vertical direction in the figure, and the second photoelectric conversion layer 42B is disposed on both sides in the left-right direction. The configuration is such that the third photoelectric conversion layer 42 </ b> C is disposed adjacent to four diagonal lines, and the occurrence of crosstalk can be further suppressed.

(Modification 3 of the first embodiment)
FIG. 7 shows a radiographic image capturing apparatus 1B that is a third modification of the radiographic image capturing apparatus 1 according to the first embodiment. In the radiographic imaging apparatus 1 according to the first embodiment described above, laser annealing was selectively performed on the first photoelectric conversion layer 42A in which the photoelectric conversion layer 42 was formed of amorphous silicon, and changed to polycrystalline silicon. A second photoelectric conversion layer 42B was formed. In the radiographic image capturing apparatus 1B according to Modification 3, the first photoelectric conversion layer 42E and the second photoelectric conversion layer 42F are separately manufactured from different materials.

  Examples of different materials include single crystal silicon, polycrystalline silicon, and amorphous silicon as silicon (Si) -based semiconductor materials, and CdTe (cadmium telluride) and GaAs (gallium arsenide) as compound semiconductor-based semiconductor materials. ), CuInGaSe (a compound of copper, indium, gallium, and selenium) and various semiconductor materials such as organic semiconductor materials can be applied. In this way, by separately forming the first photoelectric conversion layer 42A and the second photoelectric conversion layer 42B using different materials, the detection wavelength bands of the first photoelectric conversion layer 42A and the second photoelectric conversion layer 42B can be reliably separated. Easy to do.

[Second Embodiment]
Next, a radiographic imaging device 10 according to a second exemplary embodiment of the present invention will be described. FIG. 8 shows a cross section of the main part of the radiographic imaging apparatus 10 according to the present exemplary embodiment. The radiographic image capturing apparatus 10 is a configuration example including a reflective film. In the configuration of the radiographic imaging apparatus 10 according to the present embodiment, the same members as those in the radiographic imaging apparatus 1 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 8, the radiographic imaging device 10 includes a glass substrate 2, a reflective film 6 formed over the entire imaging region on the surface of the glass substrate 2, a scintillator array 5, and a photosensor array 4. TFT circuit portion 3. As the material of the reflective film 6, Al, Ag, Ni, Au, or the like can be used. The first scintillator section 5A and the second scintillator section 5B constituting the scintillator array 5 are stacked so as to correspond to the first optical sensor section 4A and the second optical sensor section 4B of the optical sensor array 4.

  In this radiographic imaging apparatus 10, X-rays R are incident from the TFT circuit unit 3 side. The X-ray R is not detected by the TFT circuit unit 3 or the optical sensor unit 4 but is converted into light after entering the scintillator array 5. Since the light converted by the first scintillator section 5A and the second scintillator section 5B of the scintillator array 5 is reflected by the reflective film 6 and enters the photosensor array 4 side, the light collection function is high, and the captured image Contrast can be improved. The other operations and effects of the radiographic imaging apparatus 10 according to the present embodiment are the same as those of the radiographic imaging apparatus 1 according to the first embodiment.

[Third Embodiment]
Next, a radiographic imaging device 20 according to a third exemplary embodiment of the present invention will be described using FIG. The radiographic image capturing apparatus 20 according to the present embodiment is a configuration example including a color filter. In the configuration of the radiographic image capturing apparatus 20 according to the present embodiment, the same members as those in the radiographic image capturing apparatus 1 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 9, the radiographic image capturing device 20 according to the present embodiment includes a TFT circuit unit 3, a photosensor array 4, a color filter array 7, and a scintillator array 8 on a glass substrate 2. ing. The photosensor array 4 includes a pixel electrode 41 patterned for each pixel region, a photoelectric conversion layer 42, and a transparent electrode 43 as a common electrode.

  In the present embodiment, the photoelectric conversion layer 42 is formed as a single layer. That is, the photoelectric conversion layer 42 is formed of a semiconductor film common to the entire imaging region.

(Color filter array)
The color filter array 7 includes an arrangement in which the first color filter unit 7A and the second color filter unit 7B are alternately arranged. The first color filter unit 7A is set to block transmission of light in a second emission wavelength band to be described later. The second color filter unit 7B is set to block light in a first emission wavelength band to be described later. The first color filter unit 7A and the second color filter unit 7B are alternately arranged in the vertical and horizontal rows of the array.

(Scintillator array)
As shown in FIG. 9, the scintillator array 8 is disposed on the color filter array 7. The scintillator array 8 includes a first scintillator unit 8A and a second scintillator unit 8B that separate (different) emission wavelength bands from each other. The first scintillator unit 8A has a predetermined first emission wavelength band. The second scintillator unit 8B has a predetermined second emission wavelength band. The first scintillator portions 8A and the second scintillator portions 8B are alternately arranged in the vertical and horizontal rows of the array. The first scintillator portion 8A is formed on the first color filter portion 7A. The second scintillator portion 8B is formed corresponding to the second color filter portion 7B.

  The scintillator material constituting the scintillator array 8 of the radiographic imaging apparatus 20 according to the present embodiment is the same as the material of the scintillator array 5 in the radiographic imaging apparatus 1 according to the first embodiment described above. The first scintillator portion 8A and the second scintillator portion 8B are formed in a hemispherical lens structure. As shown in FIG. 9, X-rays R enter the second scintillator unit 8B, and light diffuses in all directions at the light emitting point L in the second scintillator unit 8B. For example, when attention is focused on the light F15 shown in FIG. 9, the light F15 is reflected by the surface of the second scintillator portion 8A (boundary surface with air) and enters the photoelectric conversion layer 42 directly below the second scintillator portion 8B. Thus, due to the hemispherical lens structure of the first scintillator portion 8A and the second scintillator portion 8B, the photoelectric conversion layer 42 directly below the first scintillator portion 8A and the second scintillator portion 8B. Light can be incident and condensed.

  When attention is paid to the light F16 shown in FIG. 9, the light F16 passes through the second scintillator portion 8B to the outside and enters the adjacent pixel side. In this case, on the adjacent pixel side, the first color filter unit 7A blocks the light of the second wavelength band incident from the second scintillator unit 8B, and light detection is not performed on the adjacent pixel side. For this reason, in the radiographic imaging device 20, the occurrence of crosstalk can be suppressed, and characteristics such as the contrast, resolution, and detection resolution of the captured image can be improved. Other actions and effects of the radiographic image capturing apparatus 20 according to the present embodiment are the same as those of the radiographic image capturing apparatus 1 according to the first embodiment described above. In the radiographic image capturing apparatus 20 according to the present embodiment, in the optical sensor array 4, a first sensor unit in which the photoelectric conversion layer 42 is made of amorphous silicon and a second sensor unit made of polycrystalline silicon are set. May be. In this case, the first detection wavelength band of the first sensor unit can be set to 300 to 500 nm, and the second detection wavelength band of the second sensor unit can be set to 700 to 900 nm.

[Other embodiments]
Although the first to third embodiments have been described above, it should not be understood that the description and the drawings, which form part of the disclosure of these embodiments, limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the above embodiment, the photosensor array 4 is configured using a photodiode (silicon photodiode), but various photodetection elements such as a CCD sensor and a CMOS sensor may be applied.

  Further, the photoelectric conversion layers in adjacent pixel regions may be semiconductor layers of different material types, or may be semiconductor layers having the same semiconductor material type and different impurity concentrations. In the radiographic imaging apparatus 20 according to the third embodiment, the photoelectric conversion layer 42 is formed of a single semiconductor layer. However, like the radiographic imaging apparatus 1 according to the first embodiment, they are adjacent to each other. Alternatively, the photoelectric conversion layer 42 having a different detection wavelength band may be used in the pixel region to be processed.

  In the first to third embodiments, each scintillator portion is formed by a single member, but each scintillator portion may be formed by a plurality of columnar crystals.

1,1A, 1B, 10,20 Radiographic imaging device 2 Glass substrate (substrate)
DESCRIPTION OF SYMBOLS 3 TFT circuit part 4 Photosensor array 4A 1st photosensor part 4B 2nd photosensor part 5 Scintillator array 5A 1st scintillator part 5B 2nd scintillator part 6 Reflective film 7 Color filter array 7A 1st color filter part 7B 2nd color Filter unit 8 Scintillator array 8A First scintillator unit 8B Second scintillator unit 31 TFT
42 photoelectric conversion layer 42A first photoelectric conversion layer 42B second photoelectric conversion layer

Claims (8)

A substrate,
A plurality of photosensors each disposed on the substrate to constitute a pixel;
A plurality of scintillator units arranged to face each of the photosensor units one by one;
With
A radiographic imaging apparatus, wherein a wavelength region where a detection wavelength band of the optical sensor unit and an emission wavelength band of the scintillator unit facing the optical sensor unit overlap is separated between adjacent pixels. The optical sensor unit includes a photoelectric conversion layer,
The photoelectric conversion layer performs photoelectric conversion with light in the emission wavelength band of the scintillator unit facing the photosensor unit, and the scintillator unit facing the photosensor unit adjacent to the photosensor unit. The radiographic image capturing apparatus according to claim 1, wherein photoelectric conversion is not performed with light in an emission wavelength band. A color filter portion is provided in the optical sensor portion,
The color filter unit transmits light in the emission wavelength band of the scintillator unit facing the optical sensor unit, and the emission wavelength of the scintillator unit facing the optical sensor unit adjacent to the optical sensor unit The radiographic imaging apparatus according to claim 1, wherein transmission of light in a band is blocked. The radiographic image capturing apparatus according to claim 2, wherein the photoelectric conversion layers of the optical sensor units adjacent to each other are pairs of different semiconductor layers. The radiographic imaging device according to claim 4, wherein one of the pair of semiconductor layers is formed of amorphous silicon and the other is formed of polycrystalline silicon. The radiographic imaging apparatus according to claim 4, wherein the pair of semiconductor layers have the same semiconductor material and different impurity concentrations. The optical sensor unit is disposed on the substrate,
The scintillator portion is disposed on the optical sensor portion,
The radiation image capturing apparatus according to claim 1, wherein radiation is incident on the scintillator unit from a direction opposite to the optical sensor unit in the scintillator unit. A reflective film is formed on the substrate;
The scintillator portion is disposed on the reflective film,
The optical sensor unit is disposed on the scintillator unit,
The radiation image capturing apparatus according to claim 1, wherein radiation that has passed through the optical sensor unit is incident on the scintillator unit.

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