JP2018061763A - Radiographic imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic imaging device which can suppress mutual interference between a first radiation detector and a second radiation detector.SOLUTION: A radiographic imaging device 10 includes: a first radiation detector 20A which images a first radiation image with an electric charge accumulated in each of a plurality of pixels 32 in accordance with irradiated radiation R; and a second radiation detector 20B which is arranged in a lamination manner on the side opposite to the incident side of the radiation R in the first radiation detector 20A and images a second radiation image with the electric charge accumulated in each of the plurality of pixels 32 in accordance with the irradiated radiation R. The radiographic imaging device 10 includes: a first imaging circuit 26A which is driven with the power supplied from a first power source 74A and causes the first radiation detector 20A to image the first radiation image; and a second imaging circuit 26B which is driven with the power supplied from a second power source 74B insulated from the first power source 74A and causes the second radiation detector 20B to image the second radiation image.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a radiographic image capturing apparatus.

  Conventionally, a first radiation detector including a plurality of pixels that accumulates charges corresponding to the irradiated radiation, and the first radiation detector that is stacked and disposed on the side through which radiation is transmitted and emitted. 2. Description of the Related Art A radiation image capturing apparatus including a second radiation detector including a plurality of pixels that accumulate charges corresponding to the received radiation is known (see Patent Document 1 and Patent Document 2).

  This radiographic imaging device includes a first imaging circuit that causes a first radiation detector to capture a first radiation image, and a second imaging circuit that causes a second radiation detector to capture a second radiation image.

Japanese Patent No. 5376897 Japanese Patent No. 5567614

  By the way, in the radiographic imaging apparatus provided with the first radiation detector and the second radiation detector as described above, the first radiation detector and the second radiation image are included in at least one of the first radiographic image and the second radiographic image to be captured. In some cases, the two radiation detectors interfere with each other. In this case, for example, there is a concern that an artifact may occur in at least one of the first radiation image captured by the first radiation detector and the radiation image captured by the second radiation detector.

  This indication is made in view of the above situation, and provides a radiographic imaging device which can control that the 1st radiation detector and the 2nd radiation detector mutually interfere. Objective.

  In order to achieve the above object, a radiographic imaging device of the present disclosure includes a first radiation detector that captures a first radiographic image with charges accumulated in each of a plurality of pixels in accordance with irradiated radiation, A second radiation detector that is disposed on the opposite side of the radiation incident side in one radiation detector and that captures a second radiation image by charges accumulated in each of a plurality of pixels in accordance with the irradiated radiation. And a first imaging circuit that is driven by the power supplied from the first power source and causes the first radiation detector to capture the first radiation image, and is driven by the power supplied from the second power source that is insulated from the first power source. And a second imaging circuit that causes the second radiation detector to capture a second radiation image.

  In addition, the radiographic imaging device of the present disclosure may further include a mechanism that increases the impedance between the ground of the first imaging circuit and the ground of the second imaging circuit.

  In the radiographic imaging device of the present disclosure, the substrate of the first imaging circuit and the substrate of the second imaging circuit are mounted on the conductive member, and the mechanism is mounted on the substrate of the first imaging circuit. A dividing unit that divides the conductive member into the first region and the second region on which the substrate of the second imaging circuit is mounted may be used.

  In the radiographic imaging device of the present disclosure, the substrate of the first imaging circuit and the substrate of the second imaging circuit are mounted on the conductive member, and the mechanism is the substrate of the first imaging circuit of the conductive member. The slit provided between the 1st area | region mounted and the 2nd area | region where the board | substrate of the 2nd imaging circuit was mounted may be sufficient.

  In the radiographic imaging device of the present disclosure, the substrate of the first imaging circuit and the substrate of the second imaging circuit may be mounted on a conductive member having a conductivity lower than a predetermined conductivity.

  In addition, the conductive member of the radiographic imaging device of the present disclosure may have a shape surrounding each of the substrate of the first imaging circuit and the substrate of the second imaging circuit.

  The conductive member of the radiographic imaging device of the present disclosure may be a metal chassis.

  The radiographic imaging device of the present disclosure may further include a main power source and a power distribution unit that distributes the main power source to generate the first power source and the second power source.

  Moreover, the radiographic imaging device of this indication may further be provided with the 1st power supply and the 2nd power supply.

  Further, the first power source and the second power source of the radiographic imaging device of the present disclosure may be configured separately from the own device.

  In the radiographic imaging device of the present disclosure, at least a part of the driving period of the first imaging circuit may overlap with the driving period of the second imaging circuit.

  Moreover, the radiographic imaging device of this indication may further be provided with the housing | casing which accommodates the 1st radiation detector and the 2nd radiation detector in the laminated state.

  According to the present disclosure, it is possible to suppress the first radiation detector and the second radiation detector from interfering with each other.

It is a block diagram which shows an example of a structure of the radiographic imaging system of 1st Embodiment. It is side surface sectional drawing which shows an example of a structure of the radiographic imaging apparatus of 1st Embodiment. It is a block diagram (part circuit diagram) which shows an example of the principal part structure of the electric system of the radiographic imaging apparatus of 1st Embodiment. It is side surface sectional drawing which shows an example of the detailed structure inside the radiographic imaging apparatus of 1st Embodiment. FIG. 5 is a plan view illustrating a schematic configuration when the inside of the radiographic image capturing apparatus illustrated in FIG. 4 is viewed from the opposite side (upper side in FIG. 4) of the imaging surface. It is a circuit diagram which shows an example of the insulated power supply distribution part of 1st Embodiment. It is a circuit diagram which shows an example of the insulated power supply distribution part of 2nd Embodiment. It is a circuit diagram which shows an example of the insulated power supply distribution part of 3rd Embodiment. It is a circuit diagram which shows the other example of an insulated power supply distribution part. It is a top view corresponding to Drawing 5 showing other examples of a chassis. It is a circuit diagram which shows the insulated power supply distribution part of a comparative example.

  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 radiographic imaging apparatus 10 of this embodiment is demonstrated. As shown in FIG. 1, the radiographic image capturing system 1 includes a radiation irradiating device 2, a console 4, and a radiographic image capturing device 10.

  The radiation irradiation apparatus 2 of this embodiment includes a radiation irradiation apparatus 2 that irradiates a subject W, which is an example of an imaging target, with radiation R such as X-rays (X-rays). 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 radiographic imaging device 10 of the present embodiment includes a first radiation detector 20A and a second radiation detector that respectively detect radiation R irradiated from the radiation irradiation device 2 and transmitted through the subject W and incident on the imaging surface 11. 20B is provided.

  The first radiation detector 20 </ b> A captures a first radiation image with charges accumulated in each of a plurality of pixels 32 (details will be described later) according to the irradiated radiation R. The second radiation detector 20B is stacked on the opposite side of the radiation R incidence side of the first radiation detector 20A and arranged on each of a plurality of pixels 32 (details will be described later) according to the irradiated radiation R. A second radiation image is picked up by the accumulated charge.

  In addition, in this embodiment, “lamination” means a state in which the radiation R is viewed from the incident side or the exit side of the radiation R in the radiographic imaging apparatus 10 and is overlapped in a state of being in contact with each other. Alternatively, they may overlap with a space in the stacking direction.

  Next, with reference to FIG. 2, an outline of an example of the configuration of the radiographic imaging apparatus 10 of the present embodiment will be described. As an example, as shown in FIG. 2, the radiographic imaging apparatus 10 of the present embodiment includes a flat casing 21 that transmits radiation R at least on the imaging surface 11, and has waterproofness, antibacterial properties, and sealing properties. It is made into the structure which has. In the housing 21, a first radiation detector 20A, a second radiation detector 20B, a radiation limiting member 24, a first imaging circuit 26A, and a second imaging circuit 26B are provided.

  The first radiation detector 20A is arranged on the radiation R incident side of the radiographic imaging apparatus 10, and the second radiation detector 20B is stacked on the side through which the radiation R of the first radiation detector 20A is transmitted and emitted. Has been placed. Further, the first radiation detector 20A includes a TFT (Thin Film Transistor) substrate 30A and a scintillator 22A that emits light (visible light) according to the dose of the irradiated radiation R when irradiated with the radiation R. ing. Further, the TFT substrate 30A and the scintillator 22A are stacked in the order of the TFT substrate 30A and the scintillator 22A from the radiation R incident side.

  The second radiation detector 20B includes a TFT substrate 30B and a scintillator 22B. The TFT substrate 30B and the scintillator 22B are stacked in the order of the TFT substrate 30B and the scintillator 22B from the radiation R incident side.

  That is, the first radiation detector 20A and the second radiation detector 20B are radiation detectors of a surface reading method (so-called ISS (Irradiation Side Sampling) method) in which the radiation R is irradiated from the TFT substrates 30A and 30B side.

  In the radiographic imaging device 10 of this embodiment, the scintillator 22A of the first radiation detector 20A and the scintillator 22B of the second radiation detector 20B may have different or the same scintillator composition. Good. The composition of each scintillator may be determined according to the imaging purpose of the radiation image capturing apparatus 10. For example, when capturing a so-called energy subtraction image (ES (Energy Subtraction) image) or a DXA image for deriving the bone density of the subject W by the DXA (Dual-energy X-ray Absorptiometry) method, the scintillator is used. It is preferable that 22A and the scintillator 22B have different compositions. As an example in this case, the composition of the scintillator 22A includes CsI (Tl) (cesium iodide added with thallium) as a main component, and the composition of the scintillator 22B includes GOS (gadolinium sulfate) as a main component. The case where it contains is mentioned. However, the composition of the scintillator 22A and the scintillator 22B is not limited to the above example even in the radiation image capturing apparatus 10 for capturing an ES image or a DXA image, and may be a combination of other compositions or the same composition A combination of

  A radiation limiting member 24 that limits transmission of the radiation R is provided between the first radiation detector 20A and the second radiation detector 20B. An example of the radiation limiting member 24 is a metal plate such as copper or tin. Further, the radiation limiting member 24 preferably has a thickness variation of 1% or less in the incident direction of the radiation R in order to make the radiation limitation (transmittance) uniform.

  The first imaging circuit 26A is provided corresponding to the first radiation detector 20A, and an electronic circuit including a gate wiring driver 52A, a signal processing unit 54A, an image memory 56A, a control unit 58A and the like, which will be described later, is formed on the substrate. Has been. The second imaging circuit 26B is provided corresponding to the second radiation detector 20B, and an electronic circuit including a gate wiring driver 52B, a signal processing unit 54B, an image memory 56B, a control unit 58B, and the like, which will be described later, is provided on the substrate. Is formed. Although details will be described later, the first imaging circuit 26A and the second imaging circuit 26B are disposed on the opposite side of the radiation R incident side in the second radiation detector 20B.

  Next, with reference to FIG. 3, the principal part structure of the electric system of the radiographic imaging apparatus 10 of this embodiment is demonstrated.

  As shown in FIG. 3, on the TFT substrate 30A, a plurality of pixels 32 are provided two-dimensionally in one direction (row direction in FIG. 3) and in an intersecting direction (column direction in FIG. 3) intersecting one direction. . The pixel 32 includes a sensor unit 33, a capacitor 34, and a field effect thin film transistor (TFT, hereinafter simply referred to as “thin film transistor”) 35.

  The sensor unit 33 includes an upper electrode, a lower electrode, a photoelectric conversion film, and the like (not shown), and absorbs light emitted from the scintillator 22A to generate charges. The capacitor 34 accumulates electric charges generated by the sensor unit 33. The thin film transistor 35 reads out and outputs the electric charge accumulated in the capacitor 34 according to the control signal.

  The TFT substrate 30 </ b> A is provided with a plurality of gate wirings 36 arranged in the one direction and for switching the thin film transistors 35 between the on state and the off state. The TFT substrate 30A is provided with a plurality of data wirings 38 that are arranged in the intersecting direction and that output charges read by the thin-film transistors 35 in the on state.

  Each gate wiring 36 of the TFT substrate 30A is connected to a gate wiring driver 52A, and each data wiring 38 of the TFT substrate 30A is connected to a signal processing unit 54A.

  The thin film transistors 35 on the TFT substrate 30A are turned on in turn for each gate wiring 36 (in the present embodiment, in units of rows) in accordance with a control signal supplied from the gate wiring driver 52A via the gate wiring 36. Is done. Then, the electric charge read by the thin film transistor 35 which is turned on is transmitted as an electric signal through the data wiring 38 and input to the signal processing unit 54A. As a result, the electric charges are sequentially read for each gate wiring 36 (in this embodiment, in units of rows shown in FIG. 3), and image data indicating a two-dimensional radiation image is acquired.

  The signal processing unit 54A includes an amplification circuit and a sample-and-hold circuit (both not shown) for amplifying an input electric signal for each data wiring 38, and the electric signal transmitted through the individual 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 electric signals held in the individual sample and hold circuits are sequentially input to the multiplexer (serially), and the electric signals sequentially selected by the multiplexer are converted into digital image data by the A / D converter.

  An image memory 56A is connected to the signal processing unit 54A, and image data output from the A / D converter of the signal processing unit 54A is sequentially stored in the image memory 56A. The image memory 56A has a storage capacity capable of storing a predetermined number of image data, and each time a radiographic image is captured, the image data obtained by the imaging is sequentially stored in the image memory 56A. The image memory 56A is also connected to the control unit 58A.

  The control unit 58A includes a CPU (Central Processing Unit) 60, a memory 62 including a ROM (Read Only Memory) and a RAM (Random Access Memory), and a nonvolatile storage unit 64 such as a flash memory. A microcomputer etc. are mentioned as an example of 58 A of control parts.

  The communication unit 66 is connected to the control unit 58A, and transmits and receives various types of information 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.

  The first power supply 74A supplies power to the various circuits and elements (gate wiring driver 52A, signal processing unit 54A, image memory 56A, control unit 58A, and the like) described above. In FIG. 3, in order to avoid complications, illustration of wirings for connecting the first power source 74 </ b> A to various circuits and elements is omitted.

  The components of the TFT substrate 30B, the gate wiring driver 52B, the signal processing unit 54B, the image memory 56B, the control unit 58B, and the second power source 74B of the second radiation detector 20B are respectively the first radiation detector 20A. Since this is the same as the corresponding component, the description is omitted here.

  Furthermore, with reference to FIGS. 4-6, an example of a structure of the radiographic imaging apparatus 10 of this embodiment is demonstrated further in detail. FIG. 4 is a side sectional view showing an example of a detailed configuration inside the radiographic image capturing apparatus 10 of the present embodiment. In FIG. 4, the imaging surface 11 (the side on which the radiation R is incident) is illustrated so as to be on the lower side of the drawing. FIG. 5 is a plan view showing a schematic configuration when the radiographic image capturing apparatus 10 shown in FIG. 4 is viewed from the opposite side (upper side in FIG. 4) of the imaging surface 11.

  As shown in FIG. 4, in the radiographic imaging apparatus 10 of the present embodiment, the first radiation detector 20A, the radiation limiting member 24, and the second radiation detector 20B are stacked in this order from the imaging surface 11 side. Is as described above. Furthermore, as shown in FIG. 4, in the radiographic image capturing apparatus 10 of the present embodiment, the shielding plate 29 and the chassis 80 are laminated in this order on the opposite side of the imaging surface 11 in the second radiation detector 20B.

  The shielding plate 29 malfunctions in the first imaging circuit 26A and the second imaging circuit 26B when the radiation R transmitted through the first radiation detector 20A, the radiation limiting member 24, and the second radiation detector 20B arrives. It has a function to suppress this. Therefore, the shielding plate 29 is preferably a metal material that hardly transmits the radiation R, and is particularly preferably formed of a copper material having excellent thermal conductivity.

  The chassis 80 is electrically connected to the housing 21, and has a function as a so-called chassis ground that applies a ground potential to the first imaging circuit 26A, the second imaging circuit 26B, and the like mounted on the chassis 80. . The chassis 80 is preferably made of a light metal material such as aluminum from the viewpoint of portability, and more preferably made of a light alloy material such as an aluminum alloy from the viewpoint of durability.

  As shown in FIGS. 4 and 5, the chassis 80 according to the present embodiment includes a first area in which a substrate of the first imaging circuit 26 </ b> A (hereinafter simply referred to as “first imaging circuit 26 </ b> A”) is mounted by the dividing unit 81. 80A and a second region 80B on which a substrate of the second imaging circuit 26B (hereinafter simply referred to as “second imaging circuit 26B”) is mounted.

  The first imaging circuit 26A is mounted in the first region 80A of the chassis 80 via a support member 90, and is connected to the first radiation detector 20A via a connector 92 by a connection wiring 94A. The second imaging circuit 26B is mounted in the second region 80B of the chassis 80 via a support member 90, and is connected to the second radiation detector 20B via a connector 92 via a connection wiring 94B. .

  Further, the insulated power distribution unit 70 is provided via the support member 90 across the boundary between the first region 80A and the second region 80B of the chassis 80. For example, as shown in FIG. 6, the insulated power distribution unit 70 of the present embodiment supplies power from the first power source 74A to the first radiation detector 20A and detects power from the second power source 74B to the second radiation detection. A function of supplying to the container 20B. The insulated power distribution unit 70 of this embodiment is an example of the power distribution unit of the present invention.

  As shown in FIG. 6 as an example, the insulated power distribution unit 70 of the present embodiment includes a main power source 72, a first power source 74A having an insulating transformer including a primary winding 75A and a secondary winding 76A, and a primary winding. And a second power source 74B having an insulating transformer including 75B and the secondary winding 76B.

  In the insulated power distribution unit 70, the voltage applied from the main power source 72 is distributed to the first power source 74A and the second power source 74B. The first power supply 74A and the first imaging circuit 26A include a signal line (hereinafter referred to as “power supply line”) 78A for supplying driving power and a signal line (hereinafter referred to as “ground”) for applying a ground potential. 79A)). The second power supply 74B and the second imaging circuit 26B are connected by a power supply line 78B and a ground line 79B having the same role as the power supply line 78A and the ground line 79B, respectively.

  Next, the operation of the radiographic image capturing apparatus 10 of this embodiment will be described with reference to FIG. When the first imaging circuit 26A is driven, power is supplied to the first imaging circuit 26A from the first power source 74A of the insulated power distribution unit 70, and when the second imaging circuit 26B is driven, the power of the insulated power distribution unit 70 is driven. Electric power is supplied from the second power source 74B to the second imaging circuit 26B.

  Here, in the radiographic image capturing apparatus 10 of the present embodiment, the first power supply 74A and the second power supply 74B are insulated from each other by the insulated power distribution unit 70. Therefore, the return current I generated in the first imaging circuit 26A is Then, it flows into the first power supply 74A through the ground line 79A. On the other hand, the return current I generated in the second imaging circuit 26B flows into the second power source 74B via the ground line 79B.

  In the radiographic imaging apparatus 10 of the present embodiment, the chassis 80 is divided into the first area 80A and the second area 80B by the dividing unit 81, and therefore the ground of the first imaging circuit 26A and the second imaging circuit 26B. Impedance between the ground and the ground is high. Therefore, it is difficult for the return current I generated in one of the first imaging circuit 26A and the second imaging circuit 26B to flow into the other imaging circuit.

  Therefore, according to the radiographic imaging device 10 of the present embodiment, the return current I flowing from one imaging circuit of the first radiation detector 20A and the second radiation detector 20B to the other imaging circuit can be suppressed.

[Second Embodiment]
Since the radiographic imaging apparatus 10 of this embodiment differs from the radiographic imaging apparatus 10 of 1st Embodiment about the insulated power supply distribution part 70, a different structure is demonstrated with reference to drawings. FIG. 7 is a circuit diagram showing an example of the insulated power distribution unit 70 of the present embodiment.

  As shown in FIG. 7, the insulated power distribution unit 70 of this embodiment is configured separately from the radiographic image capturing apparatus 10. The insulated power distribution unit 70 of the present embodiment may be incorporated into an AC adapter, for example. Generally, when power is supplied to the main power supply 72 of the radiographic imaging apparatus 10 from an external device (for example, a commercial power supply), AC power is converted into AC (Alternating Current) adapter DC power, and the converted DC current is converted. Is supplied to the main power source 72 of the radiographic imaging apparatus 10. Therefore, the insulated power distribution unit 70 according to the present embodiment may be incorporated in the AC adapter, and power may be supplied from the first power source 74A and the second power source 74B of the insulated power distribution unit 70 to the radiographic imaging apparatus 10. Good.

  Also in the radiographic imaging apparatus 10 of the present exemplary embodiment, the first power source 74A and the second power source 74B are insulated by the insulated power distribution unit 70, as in the first embodiment. Therefore, as shown in FIG. 7, the return current I generated in the first imaging circuit 26A flows into the first power supply 74A through the ground line 79A. On the other hand, as shown in FIG. 7, the return current I generated in the second imaging circuit 26B flows into the second power source 74B via the ground line 79B.

  Also in the radiographic imaging apparatus 10 of the present embodiment, the chassis 80 is divided into the first area 80A and the second area 80B by the dividing unit 81 as in the radiographic imaging apparatus 10 of the first embodiment. Therefore, the impedance between the ground of the first imaging circuit 26A and the ground of the second imaging circuit 26B is high. Therefore, it is difficult for the return current I generated in one of the first imaging circuit 26A and the second imaging circuit 26B to flow into the other imaging circuit.

  Therefore, according to the radiographic image capturing apparatus 10 of the present embodiment, as with the radiographic image capturing apparatus 10 of the first embodiment, the imaging circuit from one of the first radiation detector 20A and the second radiation detector 20B to the other. The return current I flowing through the imaging circuit can be suppressed.

[Third Embodiment]
The radiographic image capturing apparatus 10 according to the present embodiment is different from the radiographic image capturing apparatus 10 according to the first embodiment in the configuration for supplying power for driving to the first imaging circuit 26A and the second imaging circuit 26B. Will be described with reference to the drawings. FIG. 8 is a circuit diagram showing an example of the insulated power distribution unit 70 of the present embodiment.

  As shown in FIG. 8, the radiation imaging apparatus 10 of the present embodiment includes the first power supply 74 </ b> A and the second power supply 74 </ b> B itself instead of the insulated power distribution unit 70, and the radiation of the first embodiment. It is different from the image capturing device 10.

  In the radiographic imaging apparatus 10 of this embodiment, electric power is supplied from an external device (for example, a commercial power supply) to each of the first power supply 74A and the second power supply 74B via an AC adapter. The first power supply 74A supplies power to the first imaging circuit 26A through the power supply line 78A and the ground line 79A, and the second power supply 74B supplies the second imaging circuit 26B through the power supply line 78B and the ground line 79B. Is supplied with power.

  As described above, in the radiographic imaging device 10 of the present embodiment, each of the first imaging circuit 26A and the second imaging circuit 26B includes the first power supply 74A and the second power supply 74B as individual internal power supplies. Similar to the radiographic imaging apparatus 10 of each embodiment, the first power source 74A and the second power source 74B are insulated. Therefore, also in the radiographic imaging apparatus 10 of the present embodiment, as shown in FIG. 8, the return current I generated in the first imaging circuit 26A flows into the first power source 74A via the ground line 79A. On the other hand, as shown in FIG. 8, the return current I generated in the second imaging circuit 26B flows into the second power supply 74B via the ground line 79B.

  Also in the radiographic imaging apparatus 10 of the present embodiment, the chassis 80 is divided into the first area 80A and the second area 80B by the dividing unit 81, as in the radiographic imaging apparatus 10 of each of the above embodiments. Therefore, the impedance between the ground of the first imaging circuit 26A and the ground of the second imaging circuit 26B is high. Therefore, it is difficult for the return current I generated in one of the first imaging circuit 26A and the second imaging circuit 26B to flow into the other imaging circuit.

  Therefore, according to the radiographic image capturing apparatus 10 of the present embodiment, as with the radiographic image capturing apparatuses 10 of the above-described embodiments, the imaging circuit of one of the first radiation detector 20A and the second radiation detector 20B is changed to the other. The return current I flowing in the imaging circuit can be suppressed.

  As described above, the radiographic imaging device 10 of each of the above embodiments includes the first radiation detector that captures the first radiographic image with the electric charges accumulated in each of the plurality of pixels 32 according to the irradiated radiation R. 20A and the second radiation image by the charge accumulated in each of the plurality of pixels 32 according to the irradiated radiation R, which is stacked on the opposite side of the incident side of the radiation R in the first radiation detector 20A. And a second radiation detector 20B for imaging. The radiographic image capturing apparatus 10 is driven by the power supplied from the first power supply 74A, and is insulated from the first imaging circuit 26A that causes the first radiation detector 20A to capture the first radiographic image, and the first power supply 74A. And a second imaging circuit 26B that is driven by power supplied from the second power supply 74B and causes the second radiation detector 20B to capture a second radiation image.

  Thus, in the radiographic imaging device 10 of each of the above embodiments, the first power source 74A and the second power source 74B are insulated, so that the return current I generated in the first imaging circuit 26A is supplied to the first power source 74A. The return current I generated by the second imaging circuit 26B flows into the second power source 74B.

  Therefore, according to the radiographic imaging device 10 of the present embodiment, the return current I flowing from one imaging circuit of the first radiation detector 20A and the second radiation detector 20B to the other imaging circuit can be suppressed.

  Here, a case where the first power source 74A and the second power source 74B are not insulated, unlike the radiographic imaging device 10 of each of the above embodiments, will be described as a comparative example with reference to FIG. FIG. 11 is a circuit diagram illustrating an example of the power distribution unit 170 in the radiographic imaging apparatus 100 of the comparative example, unlike the radiographic imaging apparatus 10 of the present embodiment, in which the first power supply 174A and the second power supply 174B are not insulated. It is. The radiographic imaging apparatus 100 of the comparative example shown in FIG. 11 includes a power distribution unit 170 that distributes a main power source 172 and serves as a first power source 174A and a second power source 174B. In the radiographic imaging apparatus 100, driving power is supplied from the first power source 174A of the insulated power distribution unit 70 to the first imaging circuit 126A of the first radiation detector 120A, and the second radiation detector is supplied from the second power source 174B. Driving power is supplied to the second imaging circuit 126B of 120B.

  In the radiographic imaging apparatus 100 of the comparative example, since the first power source 174A and the second power source 174B are not insulated, for example, the return current I generated in the first imaging circuit 126A flows into the second imaging circuit 26B, and the ground The line 179B may flow to the power distribution unit 170. As described above, in the radiographic image capturing apparatus 100 of the comparative example, the return current I generated in one of the first imaging circuit 126A and the second imaging circuit 126B may flow to the other imaging circuit.

  Thus, in the radiographic imaging device 100 of the comparative example, the return current I generated in one imaging circuit flows into the other imaging circuit, whereby the first radiation detector 20A and the second radiation detector 20B are connected. Interfere with each other. In particular, when the driving period of the first imaging circuit 126A and the driving period of the second imaging circuit 126B overlap, they strongly interfere with each other.

  For example, when the above-described ES image or DXA image is intended for imaging, the first radiation image is captured by the first radiation detector 120A and the second radiation detector 120B is used to capture the first radiation image by one exposure by the radiation irradiation device 2. 2 Radiation images may be taken. In this case, the drive periods of the same kind of electronic circuits in the first radiation detector 20A and the second radiation detector 20B such as the gate wiring driver (52A) and the gate wiring driver (52B) may overlap. When the return current I generated in one imaging circuit of the first imaging circuit 126A and the second imaging circuit 126B flows to the other imaging circuit, the imaging circuit into which the return current I flows has a ground potential serving as a reference potential. Potential is likely to fluctuate. As described above, when the first radiation detector 120A and the second radiation detector 120B interfere with each other and the ground potential serving as a reference fluctuates, at least one of them may cause artifacts in the captured radiation image, resulting in image quality. Decreases.

  Thus, in the radiographic imaging device 100 of the comparative example, when the first imaging circuit 126A and the second imaging circuit 126B are driven simultaneously, the return current I may flow from one imaging circuit to the other imaging circuit. there were. In this case, the first radiation detector 120A and the second radiation detector 120B interfere with each other due to the influence of the return current I, and an artifact is generated in at least one of the captured first radiation image and second radiation image. There was concern.

  Here, as an example of interference between the first radiation detector 120A and the second radiation detector 120B due to the flow of the return current I, at least one reference of the first imaging circuit 126A and the second imaging circuit 126B is used. It has been described that the ground potential fluctuates. However, the present invention is not limited to this.

  On the other hand, according to the radiographic imaging device 10 of each of the embodiments described above, the return current I flowing from one imaging circuit of the first radiation detector 20A and the second radiation detector 20B to the other imaging circuit is suppressed. be able to. Therefore, according to the radiographic imaging apparatus 10 of the present embodiment, it is possible to suppress the first radiation detector 20A and the second radiation detector 20B from interfering with each other. Thereby, according to the radiographic imaging device 10 of each said embodiment, it suppresses that an artifact generate | occur | produces in the image | photographed radiographic image (1st radiographic image and 2nd radiographic image), and suppresses that image quality falls. can do.

  Further, in the radiographic imaging device 10 of each of the above embodiments, the chassis 80 is divided into the first area 80A and the second area 80B by the dividing unit 81, so the ground of the first imaging circuit 26A and the second imaging circuit. Impedance with the ground of 26B is high. Therefore, even when the return current I generated in one of the first imaging circuit 26A and the second imaging circuit 26B flows to the chassis 80, it is difficult to flow into the other imaging circuit.

  Therefore, according to the radiographic imaging apparatus 10 of the present embodiment, the return current I flowing from one imaging circuit of the first radiation detector 20A and the second radiation detector 20B to the other imaging circuit can be further suppressed. .

  In particular, the effect of the radiographic image capturing apparatus 10 of each of the above embodiments is prominent in a form in which at least a part of the driving period of the first imaging circuit 26A and the driving period of the second imaging circuit 26B described above overlap.

  The configurations and operations of the radiographic image capturing system 1 and the radiographic image capturing apparatus 10 described in the above embodiments are examples, and can be changed according to the situation without departing from the gist of the present invention. Needless to say.

  Another example of the insulated power distribution unit 70 will be described. For example, the insulated power distribution unit 70 may be configured as shown in FIG. The first power source 74A of the insulated power distribution unit 70 shown in FIG. 9 has an insulating transformer including a primary winding 75A and a secondary winding 76A, as in the above embodiments. On the other hand, the second power source 74B is a power source directly distributed from the main power source 72. Therefore, the power source line 78B and the ground line 79B are connected to the main power source 72. Even when only one of the first power supply 74A and the second power supply 74B is insulated from the main power supply 72 as in the radiographic imaging apparatus 10 shown in FIG. 9, the description will be given with reference to FIG. Since the insulation effect between the first power source 74A and the second power source 74B is higher than that of the conventional radiographic image capturing apparatus 100, the imaging circuit of one of the first radiation detector 20A and the second radiation detector 20B is used. The return current I flowing through the other imaging circuit can be further suppressed.

  Furthermore, the first power source 74A and the second power source 74B of the insulated power distribution unit 70 may have a predetermined time constant and may include a filter that artificially cuts high frequencies.

  Other examples of the chassis 80 will be described. In each of the above embodiments, the dividing unit 81 divides the first imaging circuit 26A into the first area 80A in which the first imaging circuit 26A is mounted and the second area 80B in which the second imaging circuit 26B is mounted. Although the embodiment in which the impedance between the ground and the ground of the second imaging circuit 26B is increased has been described, the embodiment in which the impedance is increased in this way is not particularly limited.

  For example, as shown in FIG. 10, a slit 82 may be provided in the chassis 80. When the slits 82 are provided in this way, as shown in FIG. 10, between the insulated power distribution unit 70 and the first imaging circuit 26A of the chassis 80 and between the insulated power distribution unit 70 and the first imaging circuit 26A. It is preferable to provide it. Moreover, it is preferable to provide a plurality of slits 82. By providing the slits 82 in this way, the return current I flowing in the chassis 80 flows around the slits 82, so that the impedance can be increased.

  Further, for example, the impedance of the chassis 80 may be increased by forming the chassis 80 with a material whose conductivity is lower than a predetermined conductivity. The predetermined conductivity in this case is not particularly limited, but as described above, considering the function as the chassis ground, computer simulation based on experiments using an actual machine, design specifications of the radiographic imaging system 1 and the like in advance It is sufficient to obtain it.

  Further, the shape and the like of the chassis 80 may be any shape that surrounds each of the first imaging circuit 26A and the second imaging circuit 26B, and it goes without saying that the above embodiments are not limited. In addition, as in the radiographic imaging apparatus 10 of each of the above embodiments, the shape of the dividing unit 81 when the chassis 80 is divided into the first region 80A and the second region 80B by the dividing unit 81, that is, how the chassis 80 is formed. There is no particular limitation on whether to divide.

  Furthermore, although the radiation image capturing apparatus 10 of each of the above embodiments has been described with respect to the form in which the first imaging circuit 26A and the second imaging circuit 26B are mounted on the chassis 80, the present invention is not limited to this form. For example, instead of the chassis 80, the first imaging circuit 26A and the second imaging circuit 26B may be mounted on other conductive members.

  In the above embodiment, a surface reading type radiation detector in which radiation R is incident from the TFT substrate 30A, 30B side is applied to both the first radiation detector 20A and the second radiation detector 20B. Although described, it is not limited to this. For example, a radiation detector of a back side reading method (so-called PSS (Penetration Side Sampling) method) in which the radiation R is incident on the scintillators 22A, 22B from at least one of the first radiation detector 20A and the second radiation detector 20B It is good also as a form to apply.

  In each of the above embodiments, an indirect conversion type radiation detector that converts radiation once into light and converts the converted light into electric charge is applied to both the first radiation detector 20A and the second radiation detector 20B. However, the present invention is not limited to this. For example, a direct conversion type radiation detector that directly converts radiation into electric charge may be applied to at least one of the first radiation detector 20A and the second radiation detector 20B.

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

DESCRIPTION OF SYMBOLS 1 Radiation imaging system 2 Radiation irradiation apparatus 4 Console 10, 100 Radiation imaging apparatus 11 Imaging surface 20A, 120A 1st radiation detector 20B, 120B 2nd radiation detector 21 Case 22A, 22B Scintillator 24 Radiation restriction member 26A, 126A First imaging circuit 26B, 126B Second imaging circuit 29 Shield plate 30A, 30B TFT substrate 32 Pixel 33 Sensor unit 34 Capacitor 35 Thin film transistor 36 Gate wiring 38 Data wiring 52A, 52B Gate wiring drivers 54A, 54B Signal processing units 56A, 56B Image memory 58A, 58B Control unit 60 CPU
62 Memory 64 Storage unit 66 Communication unit 70 Insulated power distribution unit 72, 172 Main power source 74A, 174A First power source 74B, 174B Second power source 75A, 75B Primary winding 76A, 76B Secondary winding 78A, 78B, 178A, 178B Power line 79A, 79B, 179A, 179B Ground line 80 Chassis 80A First area 80B Second area 81 Dividing part 82 Slit 90 Support member 92 Connector 94A, 94B Connection wiring 170 Power distribution part I Return current R Radiation W Subject

Claims (12)

A first radiation detector that captures a first radiation image with charges accumulated in each of the plurality of pixels in accordance with the irradiated radiation;
Second radiation that is disposed on the opposite side of the radiation incident side in the first radiation detector and that captures a second radiation image by charges accumulated in each of the plurality of pixels according to the irradiated radiation. A detector;
A first imaging circuit that is driven by power supplied from a first power source and causes the first radiation detector to capture the first radiation image;
A second imaging circuit that is driven by power supplied from a second power source that is insulated from the first power source, and causes the second radiation detector to capture the second radiation image;
A radiographic imaging apparatus comprising: A mechanism for increasing the impedance between the ground of the first imaging circuit and the ground of the second imaging circuit;
The radiographic imaging device according to claim 1. The substrate of the first imaging circuit and the substrate of the second imaging circuit are mounted on a conductive member,
The mechanism is a dividing unit that divides the conductive member into a first region where the substrate of the first imaging circuit is mounted and a second region where the substrate of the second imaging circuit is mounted.
The radiographic imaging apparatus according to claim 2. The substrate of the first imaging circuit and the substrate of the second imaging circuit are mounted on a conductive member,
The mechanism is a slit provided between a first region where the substrate of the first imaging circuit of the conductive member is mounted and a second region where the substrate of the second imaging circuit is mounted.
The radiographic imaging apparatus according to claim 2. The substrate of the first imaging circuit and the substrate of the second imaging circuit are mounted on a conductive member having a lower conductivity than a predetermined conductivity.
The radiographic imaging apparatus of any one of Claims 1-4. The conductive member has a shape surrounding each of the substrate of the first imaging circuit and the substrate of the second imaging circuit.
The radiographic imaging apparatus of any one of Claims 3-5. The conductive member is a metal chassis,
The radiographic imaging apparatus of any one of Claims 3-6. A main power supply,
A power distribution unit that distributes the main power to generate the first power and the second power;
Further equipped with,
The radiographic imaging device of any one of Claims 1-7. The apparatus further comprises the first power source and the second power source,
The radiographic imaging device of any one of Claims 1-7. The first power source and the second power source are configured separately from their own devices.
The radiographic imaging device of any one of Claims 1-7. The driving period of the first imaging circuit and the driving period of the second imaging circuit are at least partially overlapped.
The radiographic imaging apparatus of any one of Claims 1-10. A housing for storing the first radiation detector and the second radiation detector in a stacked state;
The radiographic imaging apparatus of any one of Claims 1-11.