JP2018066614A - Radiation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation detection device capable of detection with high sensitivity in a state regarding irradiation of radiation.SOLUTION: A radiation detection device 10 includes: a scintillator 16 for converting radiation R to visible light V; a TFT substrate 14 in which pixels 15 including a sensor part 30 for detecting the visible light V converted by the scintillator 16 are two-dimensionally arranged in a pixel region 25; a protection layer 18 through which the visible light V converted by the scintillator 16 transmits and which protects the scintillator 16; and a detection part 22 which includes photo diodes 23 for detecting the visible light V converted by the scintillator 16. The TFT substrate 14, the scintillator 16, the protection layer 18 and the detection part 22 are arranged in this order from an incident side of the radiation R.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a radiation detection apparatus.

  Conventionally, in a radiation detection device that detects irradiated radiation and outputs image data representing a radiation image, it detects visible light converted from the radiation by radiation or a conversion layer in order to detect a state related to radiation irradiation. There is known an apparatus including a detection unit that performs the above-described operation.

  For example, Patent Literature 1 describes a radiation detection apparatus including at least one detection unit that detects a radiation irradiation state. Further, for example, Patent Document 2 discloses a fluorescent plate that is a conversion layer that converts radiation into visible light, a photoelectric conversion element array that is a substrate in which photoelectric conversion elements that detect visible light are two-dimensionally arranged, and detection. A radiation detection device is described in which a photodetector as a unit is stacked in this order from the radiation incident side.

JP-A-11-151233 JP 2007-147370 A

  However, in the conventional technique, there is a case where sufficient sensitivity cannot be obtained for detection of a state related to radiation irradiation. For example, in the technique described in Patent Document 1, there is a concern that radiation cannot be detected when radiation is emitted outside the detection range of the detection unit. Further, in the technique described in Patent Document 2, the detection unit detects visible light that has been converted by the conversion layer and transmitted through the substrate, so that the substrate is shielded by the substrate, and the amount of visible light that reaches the detection unit is reduced. May end up.

  The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a radiation detection apparatus that enables highly sensitive detection of a state related to radiation irradiation.

  In order to achieve the above object, a radiation detection apparatus according to the present disclosure includes two pixels in a pixel region including a conversion layer that converts radiation into visible light and a first detection element that detects visible light converted by the conversion layer. A detection unit including a substrate arranged in a dimension, a protective layer that transmits visible light converted by the conversion layer and protects the conversion layer, and a second detection element that detects visible light converted by the conversion layer And a substrate, a conversion layer, a protective layer, and a detector are arranged in that order from the radiation incident side.

  The radiation detection apparatus of the present disclosure may further include a sealing member that has an opening at a location corresponding to the pixel region of the substrate and seals the end of the conversion layer.

  Moreover, the protective layer of the radiation detection apparatus of this indication may cover the edge part of the conversion layer.

  Moreover, the visible light converted by the conversion layer may be opaque to the region other than the region corresponding to the pixel region of the protective layer of the radiation detection apparatus of the present disclosure.

  Further, in the protective layer of the radiation detection apparatus of the present disclosure, a region corresponding to the position of the second detection element in the detection unit may transmit visible light converted by the conversion layer.

  In addition, the protective layer of the radiation detection apparatus of the present disclosure may be provided with a plurality of transmission regions that transmit visible light converted by the conversion layer.

  Further, the detection unit of the radiation detection apparatus of the present disclosure is provided at a position corresponding to a partial region of the surface of the protective layer opposite to the surface facing the conversion layer. The ratio may be different between some areas and some areas.

  Further, at least the end of the detection unit of the radiation detection apparatus of the present disclosure may be sealed.

  Further, in the radiation detection device of the present disclosure, visible light converted by the conversion layer is impermeable to the surface facing the detection unit of the protective layer, and in a region corresponding to the position of the second detection element in the detection unit, You may further provide the impervious member provided with the permeation | transmission part which permeate | transmits visible light.

  In the radiation detection apparatus of the present disclosure, the protective layer and the opaque member may be in a non-adhered state or in a state where a part thereof is adhered.

  In addition, the radiation detection apparatus of the present disclosure further includes a first light guide unit that is provided between the conversion layer and the opaque member and guides visible light converted by the conversion layer to the second detection element. Also good.

  In addition, the first light guide unit of the radiation detection device of the present disclosure may guide light from the end of the conversion layer toward the detection unit.

  In addition, the radiation detection apparatus of the present disclosure may include a non-transparent member that does not transmit visible light converted by the conversion layer on a surface opposite to the surface facing the protective layer of the detection unit.

  The radiation detection apparatus of the present disclosure further includes an opaque member that does not transmit visible light converted by the conversion layer, and a surface of the protective layer opposite to the surface facing the conversion layer faces the detection unit. And a region facing the impermeable member may be included.

  In addition, the opaque member of the radiation detection apparatus of the present disclosure may reflect or diffusely reflect visible light converted by the conversion layer.

  In the radiation detection apparatus of the present disclosure, the conversion layer and the protective layer may be in a non-adhered state or in a state where a part thereof is adhered.

  In addition, the radiation detection apparatus according to the present disclosure may further include a second light guide path that guides visible light converted by the conversion layer to the second detection element, between the conversion layer and the protective layer.

  Further, the second light guide path of the radiation detection apparatus of the present disclosure may guide visible light from the end of the conversion layer toward the second detection element.

  Moreover, the detection part of the radiation detection apparatus of this indication may be provided in the position corresponding to the center part of a pixel area.

  Moreover, the radiation detection apparatus of this indication may be provided with two or more detection parts.

  Moreover, the some detection part of the radiation detection apparatus of this indication may be provided in the position symmetrical with respect to the center part of a pixel area.

  In addition, the detection unit of the radiation detection apparatus of the present disclosure includes a plurality of second detection elements that output electric signals that increase as the visible light detected by detecting the visible light converted by the conversion layer increases, You may output the average value of the value which the electric signal output from each of the 2nd detection element represents as a detection result.

  In addition, the detection unit of the radiation detection apparatus of the present disclosure includes a plurality of second detection elements that output electric signals that increase as the visible light detected by detecting the visible light converted by the conversion layer increases, You may output the total value of the value which the electric signal output from each of the 2nd detection element represents as a detection result.

  The radiation detection apparatus according to the present disclosure may further include a detection unit that detects at least one of radiation irradiation start and radiation irradiation stop based on a detection result.

  In addition, the detection unit of the radiation detection apparatus of the present disclosure detects the irradiation start when the detection result exceeds the first threshold or is equal to or higher than the first threshold, and the detection result is equal to or lower than the second threshold or lower than the second threshold. In this case, the irradiation stop may be detected.

  Further, the first detection element of the radiation detection apparatus of the present disclosure converts the detected visible light into electric charge, and the pixel includes a switching element that outputs electric charge when turned on, and the detection result of the detection unit A control unit that controls switching of the ON state and the OFF state of the switching element may be further included.

  Moreover, the control part of the radiation detection apparatus of this indication may switch a switching element from an ON state to an OFF state, when a detection result shows having detected the irradiation start.

  According to the present disclosure, it is possible to detect a state relating to radiation irradiation with high sensitivity.

It is a block diagram which shows an example of a structure of the radiographic imaging system of 1st Embodiment. It is a block diagram (partial circuit diagram) showing an example of the principal part composition of the electric system of the radiation detector of a 1st embodiment. It is sectional drawing which shows an example of the radiation detection apparatus of 1st Embodiment. It is sectional drawing which shows an example of the lamination | stacking state of a scintillator and a TFT (Thin Film Transistor) board | substrate in case the composition of a scintillator contains GOS (gadolinium sulfide) as a main component. It is sectional drawing which shows the other example of the lamination | stacking state of a scintillator and a TFT substrate in case the composition of a scintillator contains GOS as a main component. It is sectional drawing which shows an example of the lamination | stacking state of a scintillator and a TFT substrate in case the composition of a scintillator contains CsI as a main component. It is sectional drawing which shows the other example of the lamination | stacking state of a scintillator and a TFT substrate in case the composition of a scintillator contains CsI as a main component. It is sectional drawing which shows the other example of the lamination | stacking state of a scintillator and a TFT substrate in case the composition of a scintillator contains CsI as a main component. It is sectional drawing which shows the other example of the lamination | stacking state of a scintillator and a TFT substrate in case the composition of a scintillator contains CsI as a main component. It is the top view which looked at the intermediate | middle board and detection part which were shown in FIG. 3 from the incident side of a radiation. It is the top view which looked at an example of the lamination | stacking state of the TFT substrate of 1st Embodiment, a scintillator, a protective layer, an intermediate | middle board, and several detection part from the opposite side to the side irradiated with a radiation. It is the top view which looked at an example of the laminated state of the TFT substrate of 1st Embodiment, a scintillator, a protective layer, an intermediate | middle board, and one detection part from the opposite side to the side irradiated with a radiation. It is a flowchart which shows an example of the flow of the imaging | photography process performed by the control part of the radiation detection apparatus of 1st Embodiment. It is sectional drawing which shows an example of the radiation detection apparatus of 2nd Embodiment. It is sectional drawing which shows the other example of the radiation detection apparatus of 2nd Embodiment. It is sectional drawing which shows an example of the radiation detection apparatus of 3rd Embodiment. It is sectional drawing which shows an example of the structure which provided the opaque part in the radiation detection apparatus of 3rd Embodiment. It is sectional drawing which shows the other example of the structure which provided the opaque part in the radiation detection apparatus of 3rd Embodiment. It is sectional drawing which shows the other example of the structure which provided the opaque part in the radiation detection apparatus of 3rd Embodiment. It is sectional drawing which shows an example of the radiation detection apparatus of 4th Embodiment. It is sectional drawing which shows the other example of the radiation detection apparatus of 4th Embodiment. It is sectional drawing which shows the other example of the radiation detection apparatus of 4th Embodiment. It is sectional drawing which shows an example of the radiation detection apparatus of 5th Embodiment. It is sectional drawing which shows an example of the radiation detection apparatus of 6th Embodiment. It is sectional drawing which shows the other example of the radiation detection apparatus of 6th Embodiment. It is sectional drawing which shows the other example of the radiation detection apparatus of 6th Embodiment. It is sectional drawing which shows the other example of a radiation detection apparatus. It is sectional drawing which shows the other example of a radiation detection apparatus. It is a flowchart which shows the other example of the flow of the imaging | photography process performed by the control part of a radiation detection apparatus.

  DETAILED DESCRIPTION Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, with reference to FIG. 1, the structure of the radiographic imaging system 1 provided with the radiation detection apparatus 10 of this embodiment is demonstrated. As shown in FIG. 1, the radiographic imaging system 1 includes a radiation irradiation device 2, a console 4, and a radiation detection device 10.

  The radiation irradiation apparatus 2 according to the present embodiment irradiates a subject W, which is an example of an imaging target, with a radiation R such as an X-ray (X-ray) from a radiation source (not shown). A method for instructing the radiation irradiation apparatus 2 to irradiate the radiation R is not particularly limited. For example, when the radiation irradiation apparatus 2 includes an irradiation button or the like, a user such as a doctor or a radiographer instructs the irradiation of the radiation R using the irradiation button, so that the radiation R is irradiated from the radiation irradiation apparatus 2. Also good. For example, the user may irradiate the radiation R from the radiation irradiating apparatus 2 by operating the console 4 and instructing the irradiation of the radiation R.

  When receiving the instruction to start the exposure of radiation R, the radiation irradiation device 2 irradiates the radiation R according to the exposure conditions such as the tube voltage, the tube current, and the irradiation period.

  The radiation detection apparatus 10 of the present embodiment captures a radiation image of the subject W by detecting the radiation R irradiated from the radiation irradiation device 2 and transmitted through the subject W.

  Next, with reference to FIG. 2, the principal part structure of the electric system of the radiation detection apparatus 10 of this embodiment is demonstrated. As shown in FIG. 2, the radiation detection apparatus 10 of this embodiment includes a TFT (Thin Film Transistor) substrate 14, a detection unit 22, a control unit 40, a gate wiring driver 42, and a signal processing unit 44.

  As shown in FIG. 2, the TFT substrate 14 is provided with a plurality of pixels 15 two-dimensionally in one direction (row direction in FIG. 2) and in an intersecting direction (column direction in FIG. 2) intersecting one direction. . The pixel 15 includes a sensor unit 30 and a field effect thin film transistor (TFT, hereinafter simply referred to as “thin film transistor”) 34. The TFT substrate 14 of the present embodiment is an example of the substrate of the present invention, and the sensor unit 30 is an example of the first sensing element of the present invention.

  The sensor unit 30 includes an upper electrode, a lower electrode, a photoelectric conversion film, and the like (not shown). The sensor unit 30 detects visible light converted by the scintillator 16 (see FIG. 3 and will be described in detail later), and generates and generates charges. Accumulate charge. The charge generated by the sensor unit 30 increases as the detected visible light increases. Accumulate charge. The thin film transistor 34 reads out and outputs the charge accumulated in the sensor unit 30 according to the control signal.

  In addition, the TFT substrate 14 is provided with a plurality of gate wirings 36 arranged in the one direction and for switching the thin film transistors 34 between the on state and the off state. The TFT substrate 14 is provided with a plurality of data wirings 38 that are arranged in the crossing direction and that output charges read by the thin film transistors 34 in the on state.

  A gate wiring driver 42 is disposed on one side of two adjacent sides of the TFT substrate 14, and a signal processing unit 44 is disposed on the other side. Each gate wiring 36 of the TFT substrate 14 is connected to a gate wiring driver 42, and each data wiring 38 of the TFT substrate 14 is connected to a signal processing unit 44.

  Each thin film transistor 34 on the TFT substrate 14 is turned on in turn for each gate wiring 36 (in the present embodiment, in units of rows) by a control signal supplied from the gate wiring driver 42 via the gate wiring 36. Is done. Then, the electric charge read by the thin film transistor 34 that is turned on is transmitted as an electric signal through the data wiring 38 and input to the signal processing unit 44. As a result, the charges are sequentially read out for each gate wiring 36 (in this embodiment, in units of rows shown in FIG. 2), and image data indicating a two-dimensional radiation image is acquired.

  The signal processing unit 44 includes an amplification circuit and a sample-and-hold circuit (both not shown) for amplifying an input electric signal for each individual data wiring 38, and the electric signal transmitted through each data wiring 38. Is amplified by the amplifier circuit and then held in the sample hold circuit. Further, a multiplexer and an A / D (Analog / Digital) converter (both not shown) are sequentially connected to the output side of the sample hold circuit. The electrical signals held in the individual sample and hold circuits are sequentially input to the multiplexer (serially), and the electrical signals sequentially selected by the multiplexer are converted into digital image data by the A / D converter, and the control unit 40 Is output.

  The control unit 40 includes a CPU (Central Processing Unit) 40A, a memory 40B including a ROM (Read Only Memory) and a RAM (Random Access Memory), and a non-volatile storage unit 40C such as a flash memory. An example of the control unit 40 is a microcomputer. The CPU 40A controls the overall operation of the radiation detection apparatus 10. The memory 40B stores various programs including a shooting processing program described later. The control unit 40 of the present embodiment is an example of the control unit and the detection unit of the present invention.

  The communication unit 46 is connected to the control unit 40, and transmits and receives various types of information including image data of radiographic images to and from external devices such as the radiation irradiation device 2 and the console 4 by at least one of wireless communication and wired communication. I do.

  Next, the configuration of the radiation detection apparatus 10 of the present embodiment will be further described with reference to FIGS. FIG. 3 is a cross-sectional view showing an example of the radiation detection apparatus 10 of the present embodiment.

  As shown in FIG. 3, in the radiation detection apparatus 10, the TFT substrate 14, the scintillator 16, the protective layer 18, the intermediate plate 20, and the detection unit 22 are disposed from the incident side of the radiation R in a housing 12 that transmits the radiation R. Are provided in this order. That is, the radiation detection apparatus 10 is a radiation detection apparatus of a surface reading method (so-called ISS (Irradiation Side Sampling) method) in which the radiation R is irradiated from the TFT substrate 14 side.

  The scintillator 16 of this embodiment converts the radiation R into visible light V. The scintillator 16 of this embodiment is an example of the conversion layer of the present invention. The protective layer 18 transmits the visible light V converted by the scintillator 16 and protects the scintillator 16.

  Here, the radiation detection apparatus 10 may be laminated in the order of the TFT substrate 14, the scintillator 16, and the protective layer 18 from the radiation R incident side, and the specific lamination state is not particularly limited. In the present embodiment, “lamination” refers to a state in which, when viewed from the radiation R incident side or emission side of the radiation detection apparatus 10, the layers are visually recognized. Each layer, for example, the TFT substrate 14 and the scintillator 16 may be overlapped in contact with each other, or may be overlapped with a space in the stacking direction.

  However, the laminated state of the TFT substrate 14, the scintillator 16, and the protective layer 18 is preferably a laminated state corresponding to the composition of the scintillator 16.

  For example, when the composition of the scintillator 16 includes GOS (gadolinium sulfate) as a main component, the film 17 in which the scintillator 16 and the protective layer 18 are integrated as shown in FIG. May be adhered to the TFT substrate 14.

  In this case, the scintillator 16 and the protective layer 18 are integrally formed as a film 17. As a method for forming the film 17, for example, on a base film such as PET (Poly Ethylene Terephthalate) that functions as the protective layer 18 and has a thickness of about several hundred μm, the film 17 has a thickness of about several tens of μm, and An example is a method in which an adhesive layer 52 that transmits visible light V is applied, and a GOS phosphor that functions as the scintillator 16 is applied thereon. Then, on the scintillator 16 of the film 17, as an example, an adhesive layer 50 having a thickness of about several μm to several tens of μm is formed and bonded to the TFT substrate 14, whereby the state shown in FIG. 4A can be obtained. it can.

  In addition, the film 17 may adhere | attach (adhere) the film 17 and the TFT substrate 14 by physical press, without providing the contact bonding layer 50 like the example shown to FIG. 4B.

  Further, when the composition of the scintillator 16 includes GOS as a main component, and the scintillator 16 itself has a function as an adhesive layer, directly on the base film that functions as the protective layer 18 as shown in FIG. The scintillator 16 may be applied and the scintillator 16 and the TFT substrate 14 may be directly bonded.

  Further, for example, when the composition of the scintillator 16 includes CsI (Tl) (cesium iodide to which thallium is added) as a main component, generally, the TFT substrate 14 has a thickness of about several hundred μm as an example by vapor deposition. The columnar CsI is formed as the scintillator 16. Therefore, as in the example shown in FIG. 5A, the scintillator 16 and the protective layer 18 deposited on the TFT substrate 14 have a thickness of about several μm to several tens of μm as an example, and transmit visible light V. The adhesive layer 54 may be bonded together. Since CsI is weaker than moisture than GOS and may be deliquescent even under a normal environment, when the scintillator 16 includes CsI as a main component, a protective layer 18 having a moisture-proof function is used.

  In this case, the sealing effect against moisture (humidity) may be improved by covering the end portion of the scintillator 16 with the protective layer 18 and the adhesive layer 54 as in the example shown in FIG. 5B. In the present embodiment, the “end portion” refers to a range including at least a side surface of itself and including a surface near the side surface to which the radiation R is irradiated and a surface opposite to the surface. For example, “the end portion of the scintillator 16” refers to a range including at least the side surface of the scintillator 16 and also including the surface on the side irradiated with the radiation R in the vicinity of the side surface and the surface opposite to the surface.

  When the composition of the scintillator 16 includes CsI as a main component, a highly moisture-proof member such as glass may be provided as the protective layer 18 as in the example illustrated in FIG. 5C. In this case, as in the example shown in FIG. 5C, the size (area) of the protective layer 18 when viewed from the side irradiated with the radiation R is made larger than the size (area) of the scintillator 16 to protect By making the end portion of the layer 18 outside the end portion of the scintillator 16, the moisture-proof effect is enhanced.

  When the composition of the scintillator 16 includes CsI as a main component, the entire TFT substrate 14 and scintillator 16 may be covered with a moisture-proof film such as a parylene film as the protective layer 18 as in the example shown in FIG. 5D. . In this case, it goes without saying that the protective layer 18 transmits visible light V and radiation R.

  On the other hand, the detection unit 22 of the present embodiment includes a plurality of photodiodes 23 that detect the visible light V converted by the scintillator 16 and output an electrical signal that increases as the detected visible light V increases. In the present embodiment, as an example, as illustrated in FIG. 6, the detection unit 22 includes nine photodiodes 23. 6 shows a plan view of the intermediate plate 20 and the detection unit 22 shown in FIG. 3 as viewed from the radiation R incident side.

  Note that the number of photodiodes 23 included in the detection unit 22 is not limited to the number of the present embodiment, and may be one or a plurality other than nine. The photodiode 23 of the present embodiment is an example of the second sensing element of the present invention.

  The detection unit 22 outputs a detection result based on the electrical signal output from each photodiode 23 to the control unit 40. In addition, although the detection part 22 of this embodiment derives | leads-out a detection result from the said electrical signal, and outputs the derived | led-out detection result, the derivation method of a detection result is not specifically limited. For example, the detection unit 22 derives and derives a total value of values (hereinafter simply referred to as “electrical signals”) represented by electric signals output from each of a plurality (nine in the present embodiment) of photodiodes 23. The total value may be output as the detection result. Further, for example, the detection unit 22 may derive an average value of the electrical signals output from each of the plurality of photodiodes 23 and output the derived average value as a detection result. In addition, for example, the detection unit 22 calculates a total value or an average value of other electric signals excluding one that is a singular point (for example, maximum or minimum) among electric signals output from each of the plurality of photodiodes 23. You may output as a detection result.

  Moreover, the radiation detection apparatus 10 of this embodiment is provided with the four detection parts 22, as shown in FIG. 7 as an example. Thus, when the radiation detection apparatus 10 includes a plurality of detection units 22, as illustrated in FIG. 7 as an example, the radiation detection apparatus 10, more specifically, a pixel region in which the pixels 15 of the TFT substrate 14 are provided. The detection units 22 are preferably arranged at point-symmetrical or line-symmetrical positions with respect to the central portion C of 25. By arranging the detection unit 22 in this way, the visible light V can be detected with higher sensitivity on the entire surface of the scintillator 16 (TFT substrate 14) irradiated with the radiation R.

  In addition, the number of the detection parts 22 with which the radiation detection apparatus 10 is provided is not limited to the number of this embodiment, One may be sufficient and plural other than four may be sufficient. When the radiation detection apparatus 10 includes one detection unit 22, as in the example illustrated in FIG. 8, the position corresponding to the central part C of the pixel region 25, specifically, the central part C or the central part. It is preferable to arrange in the vicinity of C. By arranging the detection unit 22 in this manner, the visible light V is detected on the entire surface of the scintillator 16 (TFT substrate 14) as compared with the case where the detection unit 22 is not arranged in the central part C or in the vicinity of the central part C. It can be performed with higher sensitivity.

  On the other hand, the intermediate plate 20 is substantially impermeable to visible light V converted by the scintillator 16 but has a region corresponding to the position of the photodiode 23 in the detection unit 22 (more specifically, the photodiode 23). In a region corresponding to the position of the light receiving portion, a transmissive portion 21 that transmits visible light V is provided. In the present embodiment, the visible light V being “non-transparent” is not limited to the case where the visible light V is not transmitted at all, but can be regarded as hardly transmitted (for example, the transmittance is less than 1%). Including cases. The middle plate 20 of this embodiment is an example of the impermeable member of the present invention. The intermediate plate 20 is supported by the support portion 13 on the side opposite to the side irradiated with the radiation R of the housing 12.

  The intermediate plate 20 of the present embodiment has a function of reflecting the visible light V on the surface on the incident side of the radiation R and a function of sealing the scintillator 16. Therefore, the material of the intermediate plate 20 is preferably a metal, such as aluminum (Al), magnesium (Mg), SUS (Steal Use Stainless), carbon, and alloys containing these. Moreover, as a material of the intermediate | middle board 20, you may use the carbon fiber laminated board described in Unexamined-Japanese-Patent No. 2012-73186, for example. Furthermore, the surface of the intermediate plate 20 may have a reflective layer for enhancing the reflective function with respect to the visible light V, and when including at least one of the protective layer 18 and the intermediate plate 20, or the adhesive layer 54, The adhesive layer or the like may include particles having a reflective function.

  Note that the reflection of the visible light V on the intermediate plate 20 may be either specular reflection or diffuse reflection.

  In this embodiment, as shown in FIG. 3 and FIG. 6 as an example, the transmission part 21 of the intermediate plate 20 is provided for each photodiode 23, and the opening 21 </ b> A of the transmission part 21 is received by the photodiode 23. Smaller than the area. In the present embodiment, as an example, the transmissive portion 21 is formed of a member that transmits visible light V (for example, polycarbonate or the like), but is not particularly limited as long as it transmits visible light V, but the scintillator 16 is not limited thereto. When the main component is CsI, it is preferable that the transmittance with respect to light (visible light V) in the vicinity of 540 nm, which is the central wavelength of the emission spectrum of the scintillator 16, is high. In the present embodiment, “transmitting” visible light V is not limited to the case where the transmittance of visible light V measured by a spectral transmittance meter (hereinafter simply referred to as “transmittance”) is 100%. Although the transmittance exceeds 10%, it is preferable that the transmittance exceeds 50%.

  Moreover, the transmission part 21 is not limited to this embodiment, A cavity (state with which air is filled) may be sufficient.

  In the present embodiment, the visible light V that has been converted by the scintillator 16 and transmitted through the protective layer 18 is transmitted through the protective layer 18, as shown in the example shown in FIG. 3, and the boundary surface between the scintillator 16 and the protective layer 18. In addition, reflection is repeated at the boundary surface between the protective layer 18 and the intermediate plate 20 and reaches the photodiode 23 via the transmission part 21.

  Next, a radiographic image capturing operation by the radiation detection apparatus 10 of the present embodiment will be described. In the radiographic image capturing system 1 of the present embodiment, when capturing a radiographic image, the user gives an instruction to start capturing from the console 4. Further, as described above, the user instructs the radiation irradiation apparatus 2 to start the radiation R exposure.

  In the control unit 40 of the radiation detection apparatus 10, when an imaging start instruction is received from the console 4, the imaging processing program is executed by the CPU 40A of the control unit 40, whereby the imaging process shown in FIG. 9 is executed. FIG. 9 is a flowchart illustrating an example of the flow of imaging processing executed by the control unit 40 of the radiation detection apparatus 10.

  In step S <b> 100 of FIG. 9, the control unit 40 acquires the detection result of each detection unit 22. In the present embodiment, the detection results of each of the four detection units 22 are acquired. As described above, when the radiation detection apparatus 10 is irradiated with the radiation R, the amount of the visible light V converted by the scintillator 16 increases in accordance with the increase in the dose of the irradiated radiation R, and the photo of the detection unit 22 is increased. The electrical signal output from the diode 23 increases.

  In the next step S102, the control unit 40 compares the detection result with a first threshold value that is predetermined for detecting the start of irradiation of the radiation R for each detection result of each detection unit 22, and the detection result is the first. By determining whether or not one threshold value has been exceeded, the irradiation start of the radiation R is detected. The first threshold value may be obtained in advance by an experiment using an actual machine, a computer simulation based on the design specifications of the radiographic imaging system 1, and the like, and stored in the storage unit 40C.

  In this embodiment, when all the detection results of the four detection units 22 are equal to or less than the first threshold value, the determination in step S102 is negative and the process returns to step S100. On the other hand, if even one of the four detection results of the detection unit 22 exceeds the first threshold, it means that the radiation R irradiation start has been detected, and the determination in step S102 is affirmative and the process proceeds to step S104. . Note that the number of the detection units 22 used for the determination condition is not limited to the present embodiment, and for example, when the detection results of all the detection units 22 exceed the first threshold, the irradiation start of the radiation R is detected. You may do it.

  In step S104, the control unit 40 shifts each pixel 15 of the TFT substrate 14 to the charge accumulation state. Specifically, the control unit 40 causes the gate wiring driver 42 to output a control signal that turns off all the thin film transistors 34 of each pixel 15. Thereby, in the sensor part 30 of each pixel 15, the electric charge generated according to the visible light V is accumulated.

  In the next step S106, the control unit 40 acquires the detection result of each detection unit 22 in the same manner as in step S100. In the present embodiment, the detection results of each of the four detection units 22 are acquired. When the irradiation of the radiation R is stopped, the amount of the visible light V converted by the scintillator 16 is reduced according to a decrease in the dose of the radiation R irradiated to the radiation detection device 10 and is output from the photodiode 23 of the detection unit 22. The electrical signal that is transmitted is reduced.

  In the next step S108, the control unit 40 compares the detection result with a second threshold value that is predetermined for detecting the radiation R irradiation stop for each detection result of each detection unit 22, and the detection result is the first. By determining whether or not it is equal to or less than two thresholds, the irradiation stop of the radiation R is detected. Note that the second threshold value may be obtained in advance through experiments or the like and stored in the storage unit 40C.

  In this embodiment, when all the detection results of the four detection units 22 exceed the second threshold value, the determination in step S108 is negative and the process returns to step S106. On the other hand, if at least one of the four detection results of the detection unit 22 is equal to or smaller than the second threshold, it means that the radiation R irradiation stop has been detected, and the determination in step S108 is affirmative and the process proceeds to step S110. Note that the present invention is not limited to this embodiment, and the number of detection units 22 used for the determination condition is arbitrary as in the determination of the start of radiation R irradiation. For example, the detection results of all the detection units 22 are equal to or less than the second threshold value. In this case, it may be detected that the irradiation stop of the radiation R is detected.

  In step S110, the control unit 40 shifts each pixel 15 of the TFT substrate 14 from the charge accumulation state to the charge readout state. Specifically, as described above, the control unit 40 causes the gate wiring driver 42 to output a control signal for sequentially switching the thin film transistor 34 of each pixel 15 from the off state to the on state. As a result, the charges accumulated in the sensor unit 30 of each pixel 15 for each gate wiring 36 are sequentially read out to the data wiring 38, and an electrical signal corresponding to the read out charges flows into the signal processing unit 44. As described above, the image data is output from the signal processing unit 44 to the control unit 40.

  In the next step S112, the control unit 40 performs predetermined image processing on the image data input from the signal processing unit 44. Here, the image processing performed on the image data by the control unit 40 is not particularly limited, and examples thereof include shading correction processing and defect correction processing for correcting image data that could not be obtained by defective pixels.

  In the next step S114, the control unit 40 stores the image data representing the radiographic image obtained by the above processing in the storage unit 40C and outputs it to the console 4, and then ends the main imaging processing.

  Thus, in the radiation detection apparatus 10 of the present embodiment, the pixel 15 including the scintillator 16 that converts the radiation R into the visible light V and the sensor unit 30 that detects the visible light V converted by the scintillator 16 includes the pixel region 25. A two-dimensionally arranged TFT substrate 14, a protective layer 18 that transmits the visible light V converted by the scintillator 16 and protects the scintillator 16, and a photo that detects the visible light V converted by the scintillator 16. And a detector 22 including a diode 23. In the radiation detection apparatus 10, the TFT substrate 14, the scintillator 16, the protective layer 18, and the detection unit 22 are arranged in order from the radiation R incident side. Further, in the radiation detection apparatus 10 of the present embodiment, the visible light V converted by the scintillator 16 is not transmitted through the surface of the protective layer 18 facing the detection unit 22, and is positioned at the position of the photodiode 23 in the detection unit 22. The intermediate plate 20 is further provided with a transmission portion 21 that transmits the visible light V in a corresponding region.

  In the present embodiment, the control unit 40 has described the form in which the irradiation start of the radiation R is detected when the detection result of the detection unit 22 exceeds the first threshold. However, the present invention is not limited to this form. It is good also as a form which detects the irradiation start of the radiation R, when the detection result of the part 22 becomes more than a 1st threshold value. Moreover, although this embodiment demonstrated the form which the control part 40 detects the irradiation stop of the radiation R when the detection result of the detection part 22 is below a 2nd threshold value, it is not limited to this form, A detection part It is good also as a form which detects the irradiation stop of the radiation R, when the detection result of 22 becomes less than a 2nd threshold value.

[Second Embodiment]
Since the radiation detection apparatus 10 of this embodiment differs in the structure of the radiation detection apparatus 10 and radiation detection apparatus 10 of 1st Embodiment, a different structure is demonstrated with reference to drawings. FIG. 10 is a cross-sectional view showing an example of the radiation detection apparatus 10 of the present embodiment.

  As shown in FIG. 10, the radiation detection apparatus 10 of the present embodiment includes the sealing member 60 that covers the end of the scintillator 16, and the radiation detection apparatus 10 (see FIG. 3) of the first embodiment. Is different.

  In the radiation detection apparatus 10 of the present embodiment, as shown in FIG. 10, a sealing member that has an opening at a location corresponding to the pixel region 25 of the TFT substrate 14 and covers the ends of the scintillator 16 and the protective layer 18. 60 is provided. In the radiation detection apparatus 10 of the present embodiment, the radiation R or the radiation R irradiated to the pixel region 25 is provided by providing the sealing member 60 having the opening at the location corresponding to the pixel region 25 of the TFT substrate 14 as described above. This prevents the sealing member 60 from blocking the visible light V. Note that the shape of the sealing member 60 when the radiation emitting detection device 10 is viewed from the incident side of the radiation R may be a shape that surrounds at least part of the periphery of the scintillator 16 and the protective layer 18.

  Note that, as in the example illustrated in FIG. 10, the sealing member 60 does not directly cover the ends of the scintillator 16 and the protective layer 18, but may indirectly cover the sealing member 60 by being provided at a separate position. . Further, unlike the example shown in FIG. 10, the sealing member 60 may directly cover the ends of the scintillator 16 and the protective layer 18 by being provided near the ends of the scintillator 16 and the protective layer 18.

  Thus, in the radiation detection apparatus 10 of this embodiment, since the protective layer 18 and the intermediate | middle board 20 are provided in the surface on the opposite side to the side into which the radiation R of the scintillator 16 injects, moisture-proof performance improves. Furthermore, in the radiation detection apparatus 10 of the present embodiment, moisture (moisture) entering from the side surface of the scintillator 16 can be suppressed by providing the sealing member 60 on the side surface of the scintillator 16. In particular, as described above in the first embodiment, when the composition of the scintillator 16 is mainly composed of CsI, since it is vulnerable to moisture, in order to improve the moisture-proof performance, like the radiation detection apparatus 10 of the present embodiment, It is preferable to provide the sealing member 60.

  As described above in the first embodiment, even when the end portion of the scintillator 16 is covered with the protective layer 18 (see FIGS. 5B and 5D), the scintillator 16 is sealed as in the radiation detection device 10 of the present embodiment. By providing the member 60, the moisture-proof effect can be further enhanced.

  Moreover, in the radiation detection apparatus 10 of this embodiment, although the sealing member 60 demonstrated the form which covers both the edge parts of the scintillator 16 and the protective layer 18, it is not restricted to the said form, The sealing member 60 is a scintillator at least. What is necessary is just to cover the 16 edge part. For example, FIG. 11 shows an example when the sealing member 60 is provided in the embodiment described with reference to FIG. 5C in the first embodiment. In the radiation detection apparatus 10 of the example shown in FIG. 11, a sealing member 60 that covers the scintillator 16 is provided between the TFT substrate 14 and the protective layer 18.

[Third Embodiment]
Since the radiation detection apparatus 10 of this embodiment differs in the structure of the radiation detection apparatus 10 and radiation detection apparatus 10 of 1st Embodiment, a different structure is demonstrated with reference to drawings. FIG. 12 is a cross-sectional view showing an example of the radiation detection apparatus 10 of the present embodiment.

  As shown in FIG. 12, the protective layer 18 of the radiation detection apparatus 10 of this embodiment is provided with a first protective layer 18A and a second protective layer 18B in this order from the radiation R incident side. Thus, it is different from the radiation detection apparatus 10 of the first embodiment (see FIG. 3). Furthermore, in the end portion of the second protective layer 18B, more specifically, in the region excluding the pixel region 25, an opaque portion 18C that does not transmit visible light V is provided. This is different from the radiation detection apparatus 10 (see FIG. 3).

  In the radiation detection apparatus 10 of the present embodiment, the protective layer 18 includes the first protective layer 18A and the second protective layer 18B, so that the first protective layer 18A and the second protective layer 18A are provided as shown in FIG. Each of the protective layers 18 </ b> B functions as a light guide that guides the visible light V from the end of the scintillator 16 toward the photodiode 23.

  FIG. 13 (FIGS. 13A to 13C) shows a configuration example in which the radiation detection apparatus 10 is provided with an opaque portion 18C. In FIG. 13, for convenience of illustration, the radiation R incident side is in the lower side of the figure, that is, the upper and lower sides are opposite to those in FIG. 12.

  The protective layer 18 illustrated in FIG. 13A is a single layer of the second protective layer 18B. The second protective layer 18B includes a non-transparent portion 18C that covers the end of the scintillator 16, and a transmissive portion 18D that covers the pixel region 25 and transmits visible light V.

  Further, the protective layer 18 illustrated in FIG. 13B is a two-layered structure including a first protective layer 18A and a second protective layer 18B. The first protective layer 18A covers the scintillator 16 and transmits the visible light V entirely. The second protective layer 18 </ b> B is an impermeable portion 18 </ b> C that is provided near the end of the scintillator 16 provided on the first layer and covers the end of the scintillator 16.

  Further, the protective layer 18 illustrated in FIG. 13C is a two-layered structure including a first protective layer 18A and a second protective layer 18B. The first protective layer 18A covers the scintillator 16 and transmits the visible light V entirely. The second protective layer 18B includes a non-transparent portion 18C that covers the end of the scintillator 16, and a transmissive portion 18D that covers the pixel region 25 and transmits visible light V.

  As described above, a colored material having a high moisture-proof performance can be generally applied to the impermeable portion 18C. For example, a metal such as aluminum can be used. According to the radiation detection apparatus 10 of this embodiment, since the edge part of the scintillator 16 is covered with the non-permeable part 18C having high moisture-proof performance, the moisture-proof performance can be increased.

  Therefore, in the radiation detection apparatus 10 of the present embodiment, the protective layer 18 includes the non-transmissive portion 18C provided in the region excluding the pixel region 25, so that the moisture proof performance is improved. In particular, as described above in the first embodiment, when the composition of the scintillator 16 is mainly composed of CsI, since it is vulnerable to moisture, in order to improve the moisture-proof performance, like the radiation detection apparatus 10 of the present embodiment, It is preferable that the protective layer 18 includes an impermeable portion 18C provided in a region excluding the pixel region 25.

  Further, in the radiation detection apparatus 10 of the present embodiment, the radiation R or the visible light V blocked by the opaque part 18C can be suppressed by providing the opaque part 18C in an area excluding the pixel area 25.

[Fourth Embodiment]
Since the radiation detection apparatus 10 of this embodiment differs in the structure of the radiation detection apparatus 10 and radiation detection apparatus 10 of 1st Embodiment, a different structure is demonstrated with reference to drawings. FIG. 14 is a cross-sectional view illustrating an example of the radiation detection apparatus 10 of the present embodiment.

  As shown in FIG. 14, the protective layer 18 of the radiation detection apparatus 10 of the present embodiment is provided in a region corresponding to the position of the opaque region 18 </ b> E that does not transmit visible light V and the photodiode 23 of the detection unit 22. Further, it differs from the radiation detection apparatus 10 of the first embodiment (see FIG. 3) in that it has a transmission region 18F that transmits visible light V.

  Note that the transmission region 18F may be filled with a member that transmits visible light V (for example, polycarbonate or the like), or may be, for example, a cavity (a state that is filled with air).

  As shown in FIG. 14, in the radiation detection apparatus 10 of the present embodiment, most of the protective layer 18 is a non-transparent region 18E, so that the space between the scintillator 16 and the protective layer 18 is exposed from the end of the scintillator 16 It functions as a light guide for guiding visible light V toward the diode 23. The visible light V guided by the light guide further guides the transmissive region 18F and the transmissive portion 21 and reaches the light receiving portion of the photodiode 23.

  As described above, the opaque region 18E can generally be made of a colored material having high moisture-proof performance, and for example, a metal such as aluminum can be used. As described above, according to the radiation detection apparatus 10 of the present embodiment, the surface of the scintillator 16 on the side opposite to the radiation R incident side is covered with the opaque region 18E except for the region corresponding to the position of the photodiode 23. Performance is improved. In particular, as described above in the first embodiment, when the composition of the scintillator 16 is mainly composed of CsI, since it is vulnerable to moisture, in order to improve the moisture-proof performance, like the radiation detection apparatus 10 of the present embodiment, It is preferable to cover most of the scintillator 16 with an impermeable region 18E.

  The number of transmission regions 18F provided is not limited to the form shown in FIG. For example, as shown in FIG. 15, a plurality of transmission regions 18 </ b> F may be provided on the surface opposite to the surface on which the radiation R of the scintillator 16 is incident with the space between the transmission regions 18 </ b> F uniform.

  Further, as shown in FIG. 16, the ratio of the transmissive region 18F is such that the partial region 74 of the protective layer 18 corresponding to the position of the light receiving unit of the detection unit 22, in particular the photodiode 23, and the partial region 75 outside. May be different. In this case, since the non-transparent region 18E increases as compared with the radiation detection apparatus 10 illustrated in FIG. 15, the moisture proof performance is higher than that of the radiation detection apparatus 10 illustrated in FIG.

[Fifth Embodiment]
Since the radiation detection apparatus 10 of this embodiment differs in the structure of the radiation detection apparatus 10 and radiation detection apparatus 10 of 1st Embodiment, a different structure is demonstrated with reference to drawings. FIG. 17 is a cross-sectional view showing an example of the radiation detection apparatus 10 of the present embodiment.

  As shown in FIG. 17, the detection unit 22 of the radiation detection apparatus 10 of the present exemplary embodiment is that the end part is sealed with a sealing member 62, and the radiation detection apparatus 10 of the first exemplary embodiment (FIG. 3). See).

  The detection unit 22 is not limited to the form shown in FIG. 17 as long as at least the end is sealed by the sealing member 62. For example, the sealing member 62 may cover the entire surface other than the surface in contact with the middle plate 20 of the detection unit 22.

[Sixth Embodiment]
Since the radiation detection apparatus 10 of this embodiment differs in the structure of the radiation detection apparatus 10 and radiation detection apparatus 10 of 1st Embodiment, a different structure is demonstrated with reference to drawings. 18-20 is sectional drawing which shows an example of the radiation detection apparatus 10 of this embodiment.

  As shown in FIGS. 18-19, the radiation detection apparatus 10 of this embodiment differs in the position in which the intermediate board 20 is provided from the radiation detection apparatus 10 (refer FIG. 3) of 1st Embodiment.

  In the example shown in FIG. 18, the intermediate plate 20 is provided on the surface opposite to the surface facing the protective layer 18 of the detection unit 22. In the radiation detection apparatus 10 shown in FIG. 18, the protective layer 18 functions as a light guide that guides the visible light V from the end of the scintillator 16 toward the photodiode 23. In the radiation detection apparatus 10 shown in FIG. 18, since the distance between the scintillator 16 and the detection unit 22 is shorter than the radiation detection apparatus 10 of each of the above embodiments, the visible light V can be detected with higher sensitivity.

  Further, the example shown in FIG. 19 is different from the radiation detection apparatus 10 shown in FIG. 18 in that a buffer material 19 is provided between the intermediate plate 20 and the protective layer 18. In the radiation detection apparatus 10 illustrated in FIG. 19, the protective layer 18 functions as a light guide that guides the visible light V from the end of the scintillator 16 toward the photodiode 23. Therefore, the material of the buffer material 19 is not particularly limited, but the surface facing the protective layer 18 preferably has a function of reflecting the visible light V. Further, in the radiation detection apparatus 10 shown in FIG. 19, the buffer material 19 can stabilize the space between the protective layer 18 and the intermediate plate 20 and can prevent the detection unit 22 from being damaged by an impact or the like.

  In the example shown in FIG. 20, the surface of the protective layer 18 opposite to the surface facing the scintillator 16 includes a region 70 facing the detection unit 22 and a region 71 facing the intermediate plate 20. Show. In the radiation detection apparatus 10 illustrated in FIG. 20, the protective layer 18 functions as a light guide that guides the visible light V from the end of the scintillator 16 toward the photodiode 23. In the radiation detection apparatus 10 shown in FIG. 20, since the distance between the scintillator 16 and the detection unit 22 is shorter than the radiation detection apparatus 10 of each of the above embodiments, the visible light V can be detected with higher sensitivity. Further, as shown in FIG. 20, since the detection unit 22 is embedded in the intermediate plate 20, the detection unit 22 can be prevented from being damaged by an impact or the like.

  As described above, the radiation detection apparatus 10 according to each of the above embodiments includes the scintillator 16 that converts the radiation R into the visible light V, and the pixel 15 that includes the sensor unit 30 that detects the visible light V converted by the scintillator 16. The TFT substrate 14 arranged two-dimensionally in the pixel region 25, the protective layer 18 that transmits the visible light V converted by the scintillator 16 and protects the scintillator 16, and the visible light V converted by the scintillator 16 And a detection unit 22 including a photodiode 23 to be detected. In the radiation detection apparatus 10, the TFT substrate 14, the scintillator 16, the protective layer 18, and the detection unit 22 are arranged in order from the radiation R incident side.

  Thus, since the TFT substrate 14 is provided on the opposite side of the detection unit 22 with respect to the scintillator 16, the visible light V converted by the scintillator 16 is used in the radiation detection apparatus 10 of each of the above embodiments. 14 reaches the detection unit 22 without being interrupted.

  Further, according to the radiation detection apparatus 10 of each of the embodiments described above, the light guide path that guides the visible light V from the end of the scintillator 16 toward the light receiving unit of the photodiode 23 of the detection unit 22 is provided. Therefore, the detection unit 22 can detect the visible light V (radiation R) obtained by converting the radiation R by the scintillator 16 over the entire surface of the scintillator 16 (TFT substrate 14).

  Therefore, according to the radiation detection apparatus 10 of each of the above embodiments, it is possible to detect the state relating to the irradiation of the radiation R with high sensitivity.

  Moreover, according to the radiation detection apparatus 10 of each said embodiment, the detection part 22 detects the visible light V. FIG. Therefore, for example, compared with the case where a part of the pixels 15 of the TFT substrate 14 is used as a pixel for detecting radiation R, the occurrence of defective pixels is suppressed, so that the image quality of the captured radiation image is degraded. Can be suppressed. Further, the configuration of the radiation detection apparatus 10 can be simplified.

  Further, according to the radiation detection device 10 of each of the above embodiments, the detection unit 22 is provided at a position farther from the incident side of the radiation R than the scintillator 16. Therefore, compared with the case where the detection unit 22 is provided on the radiation R incident side of the scintillator 16, the detection unit 22 can suppress the radiation R reaching the scintillator 16 from being attenuated, and the captured radiation It is possible to suppress the deterioration of the image quality.

  In addition, the radiation detection apparatus 10 of each said embodiment detects the radiation R based on the electric charge (electrical signal) which generate | occur | produced in the sensor part 30 according to irradiation of the radiation R, and starts the accumulation | storage of the electric charge in the pixel 15, or The present invention can also be applied to AEC (Automatic Exposure Control) in which stopping or the like is performed.

  The radiation R in each of the above embodiments is not particularly limited, and X-rays, γ-rays, and the like can be applied.

  In addition, the configurations and operations of the radiographic imaging system 1 and the radiation detection apparatus 10 described in the above embodiments are merely examples, and can be changed according to the situation without departing from the gist of the present invention. Needless to say.

  For example, the protective layer 18 and the intermediate plate 20 may be either in an adhesive (close contact) state or a non-adhesion state, or may be in a state in which a part thereof is adhered. As an example in this case, FIG. 21 shows the radiation detection apparatus 10 in which the protective layer 18 and the intermediate plate 20 are not bonded. In the radiation detection apparatus 10 shown in FIG. 21, the space (air layer) between the protective layer 18 and the intermediate plate 20 functions as the light guide path 28. The light guide path 28 in this case is an example of the first light guide unit of the present invention. Therefore, in the radiation detection apparatus 10 illustrated in FIG. 21, each of the protective layer 18 and the light guide path 28 functions as a light guide path that guides the visible light V from the end of the scintillator 16 toward the photodiode 23.

  In addition, for example, the scintillator 16 and the protective layer 18 may be either in an adhered (adherent) state or a non-adhered state, or may be in a partially adhered state. As an example of this case, FIG. 22 shows the radiation detection apparatus 10 in which the scintillator 16 and the protective layer 18 are not bonded. In the radiation detection apparatus 10 shown in FIG. 22, the space (air layer) between the scintillator 16 and the protective layer 18 functions as the light guide path 29. The light guide path 29 in this case is an example of the second light guide unit of the present invention. Therefore, in the radiation detection apparatus 10 illustrated in FIG. 22, each of the protective layer 18 and the light guide 29 functions as a light guide that guides the visible light V from the end of the scintillator 16 toward the photodiode 23.

  Moreover, although the said 1st Embodiment demonstrated the form which detects both irradiation start and the stop of irradiation of the radiation R based on the detection result of the detection part 22 about imaging | photography operation | movement of the radiographic image by the radiation detection apparatus 10, However, the present invention is not limited to this, and either one of irradiation start and irradiation stop may be detected. FIG. 23 is a flowchart illustrating an example of the flow of imaging processing executed by the control unit 40 of the radiation detection apparatus 10 when only the start of radiation R irradiation is detected. The imaging process shown in FIG. 23 is different in that a process of step S109 is provided instead of the processes of step S106 and step S108 of the imaging process (see FIG. 9) described in the first embodiment.

  In the imaging process shown in FIG. 23, in step S109, the control unit 40 determines whether or not the radiation R has been stopped by determining whether or not a predetermined time has elapsed. Here, the predetermined time includes, for example, an irradiation time for irradiating the radiation R from the radiation irradiation apparatus 2 to the radiation detection apparatus 10. If the predetermined time has not elapsed, the determination in step S109 is negative and this step is repeated. On the other hand, when a predetermined time has elapsed, the determination in step S109 is affirmative, and the process proceeds to step S110. In this case, the control unit 40 has detected that the radiation R has been stopped.

  Note that a member (for example, polycarbonate or the like) that transmits visible light V may be used for the light guide 28 shown in FIG. 21 and the light guide 29 shown in FIG.

DESCRIPTION OF SYMBOLS 1 Radiographic imaging system 2 Radiation irradiation apparatus 4 Console 10 Radiation detection apparatus 12 Case 13 Support part 14 TFT substrate 15 Pixel 16 Scintillator 17 Film 18 Protective layer 18A First protective layer 18B Second protective layer 18C Impervious part 18D Transmission part 18E Non-transmission area 18F Transmission area 19 Buffer material 20 Middle plate 21 Transmission part 21A Opening part 22 Detection part 23 Photodiode 25 Pixel area 28 Light guide path 29 Light guide path 30 Sensor part 34 Thin film transistor 36 Gate wiring 38 Data wiring 40 Control part 40A CPU
40B Memory 40C Storage unit 42 Gate wiring driver 44 Signal processing unit 46 Communication unit 50, 52 Adhesive layer 54 Adhesive layer 60 Sealing member 62 Sealing member 70, 71 Area 74 Partial area 75 Partial area C Central part R Radiation V Visible light W Subject

Claims (27)

A conversion layer that converts radiation into visible light;
A substrate in which pixels including first detection elements that detect visible light converted by the conversion layer are two-dimensionally arranged in a pixel region;
A protective layer that transmits visible light converted by the conversion layer and protects the conversion layer;
A detection unit including a second detection element that detects visible light converted by the conversion layer;
With
In order from the radiation incident side, the substrate, the conversion layer, the protective layer, and the detection unit are arranged,
Radiation detection device. A sealing member having an opening at a location corresponding to the pixel region of the substrate and sealing an end of the conversion layer;
The radiation detection apparatus according to claim 1. The protective layer covers an end of the conversion layer;
The radiation detection apparatus according to claim 1 or 2. In the region excluding the region corresponding to the pixel region of the protective layer, the visible light converted by the conversion layer is opaque.
The radiation detection apparatus of any one of Claims 1-3. In the protective layer, a region corresponding to the position of the second detection element in the detection unit transmits visible light converted by the conversion layer,
The radiation detection apparatus of any one of Claims 1-3. The protective layer is provided with a plurality of transmission regions that transmit visible light converted by the conversion layer.
The radiation detection apparatus of any one of Claims 1-5. The detection unit is provided at a position corresponding to a partial region of the surface of the protective layer opposite to the surface facing the conversion layer, and the protective layer has a ratio of the transmission region, Different in some areas and outside the some areas,
The radiation detection apparatus according to claim 6. The detection unit is sealed at least at an end.
The radiation detection apparatus of any one of Claims 1-7. Visible light converted by the conversion layer is impermeable to the surface of the protective layer facing the detection unit, and the visible light is transmitted to a region corresponding to the position of the second detection element in the detection unit. Further provided with a non-permeable member provided with a transmissive portion to
The radiation detection apparatus of any one of Claims 1-8. The protective layer and the impermeable member are in a non-adhered state or in a state where a part thereof is adhered,
The radiation detection apparatus according to claim 9. A first light guide portion provided between the conversion layer and the opaque member and configured to guide visible light converted by the conversion layer to the second detection element;
The radiation detection apparatus according to claim 10. The first light guide part guides light from an end part of the conversion layer toward the detection part,
The radiation detection apparatus according to claim 11. The surface of the detection unit opposite to the surface facing the protective layer is provided with an opaque member that is opaque to visible light converted by the conversion layer,
The radiation detection apparatus of any one of Claims 1-8. Further comprising an impermeable member that is impermeable to visible light converted by the conversion layer,
The surface of the protective layer opposite to the surface facing the conversion layer includes a region facing the detection unit and a region facing the impermeable member.
The radiation detection apparatus of any one of Claims 1-8. The opaque member reflects or diffusely reflects the visible light converted by the conversion layer,
The radiation detection apparatus of any one of Claim 9 to 14. The conversion layer and the protective layer are in a non-adhered state or in a state where a part thereof is adhered,
The radiation detection apparatus of any one of Claims 1-15. A second light guide path for guiding the visible light converted by the conversion layer to the second sensing element between the conversion layer and the protective layer;
The radiation detection apparatus according to claim 16. The second light guide guides the visible light from an end of the conversion layer toward the second sensing element;
The radiation detection apparatus according to claim 17. The detection unit is provided at a position corresponding to a central portion of the pixel region.
The radiation detection apparatus of any one of Claims 1-18. A plurality of the detection units are provided,
The radiation detection apparatus of any one of Claims 1-18. The plurality of detection units are provided at positions that are symmetric with respect to the central portion of the pixel region.
The radiation detection apparatus according to claim 20. The detection unit includes a plurality of the second detection elements that detect the visible light converted by the conversion layer and output an electric signal that increases as the detected visible light increases, and a plurality of the second detection elements The average value of the values represented by the electrical signals output from each is output as a detection result.
The radiation detection apparatus according to any one of claims 1 to 21. The detection unit includes a plurality of the second detection elements that detect the visible light converted by the conversion layer and output an electric signal that increases as the detected visible light increases, and a plurality of the second detection elements The total value of the values represented by the electrical signals output from each is output as a detection result.
The radiation detection apparatus according to any one of claims 1 to 21. Based on the detection result, further comprising a detection unit for detecting at least one of radiation irradiation start and radiation irradiation stop,
The radiation detection apparatus according to claim 22 or claim 23. The detection unit detects the irradiation start when the detection result exceeds a first threshold or is equal to or greater than the first threshold, and when the detection result is equal to or less than a second threshold or less than the second threshold. Detecting the irradiation stop,
The radiation detection apparatus according to claim 24. The first sensing element converts the detected visible light into a charge,
The pixel includes a switching element that outputs the charge when turned on.
Based on the detection result of the detection unit, further comprising a control unit that controls switching of the ON state and the OFF state of the switching element,
The radiation detection apparatus according to claim 24 or claim 25. The control unit switches the switching element from an on state to an off state when the detection result indicates that the irradiation start is detected,
The radiation detection apparatus according to claim 26.