JP2017143114A - Radiation imaging device and radiation imaging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique useful for reducing influence due to a grid for detecting radiation irradiation or a position in which radiation transmittance is low.SOLUTION: A radiation imaging device includes an imaging region arranged so that a plurality of pixels detecting a radial ray constructs a plurality of rows and a plurality of columns. Each of the plurality of pixels includes a first photoelectric conversion part. The radiation imaging device comprises a plurality of irradiation detection parts detecting irradiation of a radial ray for the imaging region. Each of the plurality of irradiation detection parts includes a second photoelectric conversion part. The second photoelectric conversion part is arranged at a gap of the plurality of first photoelectric conversion parts. The maximum dimension in a first direction along the plurality of rows is larger than an arrangement pitch in a first direction constructing one row of the plurality of pixels. The maximum dimension in a second direction along the plurality of columns is larger than the arrangement pitch in the second direction of the pixels constructing one row of the plurality of pixels.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a radiation imaging apparatus and a radiation imaging system that capture a radiation image.

  Radiation imaging apparatus having an array in which pixels in which a combination of a switch such as a TFT (thin film transistor) and a conversion element such as a photoelectric conversion element is arranged as a radiographic apparatus used for medical image diagnosis and nondestructive inspection using radiation such as X-rays Has been put to practical use. In the radiation imaging apparatus, in order to detect the start of radiation irradiation or to detect the timing for ending radiation irradiation, an element for detecting radiation irradiation is provided separately from the pixels. There is something to prepare.

  Patent Document 1 discloses a radiation imaging apparatus having a plurality of first conversion elements for imaging and a second conversion element disposed between adjacent first conversion elements for detecting radiation irradiation. Is described. The second conversion element has an elongated shape having a width narrower than the pixel pitch. Patent Document 2 describes a radiographic imaging apparatus in which a radiation image capturing pixel and a radiation detection pixel are provided at an intersection of a scanning wiring and a signal wiring.

Japanese Patent No. 4217506 JP 2012-075077 A

  In the radiation imaging apparatus described in Patent Document 1, the second conversion element for detecting radiation irradiation has only a width narrower than the pixel pitch. Therefore, for example, the second conversion element is located under a portion having a low radiation transmittance, such as a grid for removing scattered radiation (hereinafter simply referred to as “grid”) or a rib of the subject. In some cases, the accuracy of radiation detection can be reduced. In other words, a large difference occurs in the output from the second conversion element depending on whether the second conversion element is positioned below the grid or the portion having low radiation transmittance. Also, in the radiographic image capturing apparatus described in Patent Document 2, since the radiation detection pixels are arranged in a portion where the radiographic image capturing pixels are missing, the same problem as in the radiographic image capturing apparatus of Patent Document 1 Can occur.

  The present invention has been made with the above problem recognition as an opportunity, and it is an object of the present invention to provide an advantageous technique for reducing the influence of the position of a grid or a portion having a low radiation transmittance on the detection of radiation irradiation. .

  One aspect of the present invention has an imaging region in which a plurality of pixels that detect radiation includes a plurality of rows and a plurality of columns, and each of the plurality of pixels includes a first photoelectric conversion unit. A radiation imaging apparatus having a plurality of irradiation detection units for detecting radiation irradiation to the imaging region, wherein each of the plurality of irradiation detection units includes a second photoelectric conversion unit, and the second photoelectric conversion unit Is arranged in the gap between the plurality of first photoelectric conversion units, and the maximum dimension in the first direction along the plurality of rows is an arrangement in the first direction of pixels constituting one row of the plurality of pixels. The maximum dimension in the second direction along the plurality of columns is larger than the pitch, and is larger than the arrangement pitch in the second direction of pixels constituting one column among the plurality of pixels.

  According to the present invention, an advantageous technique is provided to reduce the influence of the position of a grid or a portion having a low radiation transmittance on detection of radiation irradiation.

The figure which shows the structure of the radiation imaging device of one embodiment of this invention. The figure which expanded a part of imaging region of the radiation imaging device of FIG. FIG. 9 illustrates a configuration example of a reading circuit. The timing chart which shows operation | movement of the radiation imaging device of one Embodiment of this invention. FIG. 2 is a schematic plan view of one pixel. FIG. 6 is a schematic cross-sectional view (a) taken along line A-A ′ of FIG. 5 and a schematic cross-sectional view taken along line B-B ′ of FIG. 5. The typical top view showing a plurality of pixels and the irradiation detection part arranged between them. FIG. 8 is a schematic cross-sectional view taken along line C-C ′ in FIG. 7. The figure which shows the example of arrangement | positioning of several irradiation detection part. The top view which shows typically the structure of the pixel and irradiation detection part in the radiation imaging device of 2nd Embodiment of this invention. The top view which shows typically the structure of the pixel and irradiation detection part in the radiation imaging device of 3rd Embodiment of this invention. The figure which shows the structure of the radiation imaging system of one Embodiment of this invention.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

  In this specification, the concept of radiation includes, in addition to α-rays, β-rays, γ-rays, and the like, which are beams produced by particles (including photons) emitted by radiation decay, For example, X-rays, particle beams, cosmic rays, and the like are included.

  FIG. 1 shows the configuration of the radiation imaging apparatus DR according to the first embodiment of the present invention. The radiation imaging apparatus DR has an imaging region IR in which a plurality of pixels 1 that detect radiation are arranged to form a plurality of rows and a plurality of columns. FIG. 2 shows an enlarged view of a part of the imaging region IR of the radiation imaging apparatus DR. Each pixel 1 has a first photoelectric conversion unit 2. The 1st photoelectric conversion part 2 may be comprised so that radiation may be directly converted into an electric charge, and may be comprised so that the light converted from the radiation by the scintillator may be converted into an electric charge. Each pixel 1 may have a first switch 2 as a circuit that outputs a signal detected by the first photoelectric conversion unit 2 to the first readout signal line 7.

  The radiation imaging apparatus DR includes a plurality of irradiation detection units S that detect radiation irradiation on the imaging region IR for exposure control. The exposure control can include, for example, detecting the start of radiation irradiation to the radiation imaging apparatus DR (imaging region IR) and starting accumulation of signals (charges converted from radiation) by the plurality of pixels 1. Further, the exposure control can include stopping radiation irradiation by the radiation source at a timing when the radiation dose to the radiation imaging apparatus DR (imaging region IR) reaches a specified value.

  Each irradiation detection unit S includes a second photoelectric conversion unit 5, and the second photoelectric conversion unit 5 is disposed in a gap between the plurality of first photoelectric conversion units 2. The second photoelectric conversion unit 5 may be configured to directly convert radiation into electric charge, or may be configured to convert light converted from radiation by the scintillator into electric charge. In the latter, the scintillator can be shared by the plurality of first photoelectric conversion units 2 and the plurality of second photoelectric conversion units 5. Each irradiation detection unit S may include a second switch 4 as a circuit that outputs a signal detected by the second photoelectric conversion unit 5 to the second readout signal line 9.

  The first photoelectric conversion unit 2 of the pixel 1 can be configured as, for example, a PIN sensor or a MIS sensor. Further, the second photoelectric conversion unit 5 of the irradiation detection unit S can be configured as, for example, a PIN type sensor or an MIS type sensor.

  In addition to the above, the radiation imaging apparatus DR may include a control unit 31, a bias power supply 32, and a reading unit 20. The bias power supply 32 supplies a bias voltage to the plurality of pixels 1 and the plurality of irradiation detection units S. The readout unit 20 reads out signals from the plurality of pixels 1 through the first readout signal line 7 and also reads out signals from the plurality of irradiation detection units S through the second readout signal line 9. The reading unit 20 includes a plurality of first reading circuits 21 that read signals from the pixels 1 via the first reading signal lines 7, and a plurality of second readings that read signals from the irradiation detection unit S via the second reading signal lines 9. Circuit 22 is included. The reading unit 20 can include a multiplexer 23, an ADC (AD converter) 24, and a signal processing unit 25. The multiplexer 23 selects an arbitrary signal from a plurality of signals from the plurality of readout circuits 22 and outputs it to the ADC 24 at the time of exposure control. Further, the multiplexer 23 sequentially selects a plurality of signals from the plurality of readout circuits 21 and outputs them to the ADC 24 at the time of image readout for reading out signals from the plurality of pixels 1. The ADC 24 converts the input signal into a digital signal and supplies it to the signal processing unit 25. The signal processing unit 25 processes the signal supplied from the ADC 24 (for example, offset correction, γ correction, etc.) and outputs the processed signal. The signal processing unit 25 can be configured to perform the above-described operation for exposure control. Specifically, the signal processing unit 25 detects the start of radiation irradiation to the radiation imaging apparatus DR (imaging region IR), and starts accumulation of signals (charges converted from radiation) by the plurality of pixels 1. In this way, the control unit 31 can be controlled. In addition, the signal processing unit 25 can be configured to stop the radiation irradiation by the radiation source at a timing when the radiation dose to the radiation imaging apparatus DR (imaging region IR) reaches a specified value.

  As illustrated in FIG. 3, the first readout circuit 21 and the second readout circuit 22 include, for example, a differential amplifier 201, a reference voltage source 202, a feedback capacitor 203, a short-circuit switch 204, a write switch 205, and a storage capacitor 206. May be included. The read signal line 7 or 9 can be connected to the inverting input terminal of the differential amplifier 201, and the reference voltage source 202 can be connected to the non-inverting input terminal of the differential amplifier 201. A feedback capacitor 203 and a short-circuit switch 204 can be connected in parallel between the inverting input terminal and the output terminal of the differential amplifier 201. The output terminal of the differential amplifier 201 can be connected to the storage capacitor 206 via the write switch 205.

  Description will be made with reference to FIGS. 1 and 2 again. One electrode (for example, the upper electrode) of the first photoelectric conversion unit 2 of the plurality of pixels 1 and one electrode (for example, the upper electrode) of the second photoelectric conversion unit 5 of the plurality of irradiation detection units S have a common bias. Can be connected to line 11. A bias voltage is supplied to the bias line 11 by a bias power supply 32.

  The first control lines 6 driven by the control unit 31 are connected to the first switches 3 of the plurality of pixels 1 and supplied with the first control signals Vg (Vg1 to Vg6...). Here, one first control line 6 is commonly connected to the first switches 3 of the pixels 1 constituting one row. A second control line 8 driven by the control unit 31 is connected to the second switches 4 of the plurality of irradiation detection units S, and a second control signal Vd (Vd1, Vd2,...) Is supplied. Here, the second switch 4 of one irradiation detection unit S may be connected to one second control line 8, or the second switch 4 of two or more irradiation detection units S may be connected. Good. The first control signal Vg and the second control signal Vd can be driven to the on voltage Von or the off voltage Voff by the control unit 31. The on voltage Von is a voltage that turns on the first switch 3 and the second switch 4, and the off voltage Voff is a voltage that turns off the first switch 3 and the second switch 4.

  Here, for the following explanation, the row direction and the column direction are defined. The row direction is a direction in which the pixels 1 connected to one control line 6 for controlling the pixels 1 are arranged. The column direction is a direction in which the pixels 1 connected to one first readout signal line 7 are arranged.

  The imaging region IR has a plurality of region of interest candidates (ROI) R1 to R4. Of the region of interest candidates, a region that can be considered in exposure control is a region of interest. Each region of interest candidate includes at least one irradiation detection unit S. In the example shown in FIG. 1, each irradiation detection unit S of the region of interest candidates R1 and R2 is connected to one second readout signal line 9, and each irradiation detection unit S of the region of interest candidates R3 and R4 is 1 Two second read signal lines 9 are connected. The second switch 4 of each irradiation detection unit S of the region of interest candidates R1 and R3 is connected to one second control line 8, and the second switch of each irradiation detection unit S of the region of interest candidates R2 and R4. 4 is connected to one second control line 8. With such a configuration, random access or XY addressing to the irradiation detection unit S of each region of interest candidate is possible, and a signal can be read from the irradiation detection unit S of each region of interest candidate. Here, the second control line 8 and / or the second readout signal line 9 may be provided independently for each region of interest.

  As illustrated in FIG. 2, the second photoelectric conversion unit 5 has a maximum dimension Sxmax in a direction along a plurality of rows of the imaging region IR, that is, in the row direction (first direction) (X direction in FIG. 2). It is larger than the arrangement pitch Px in the row direction X of the pixels 1 constituting one row among the plurality of pixels 1. Further, the second photoelectric conversion unit 5 has a maximum dimension Symax in the direction along the plurality of columns of the imaging region IR, that is, the column direction (second direction) (Y direction in FIG. 2) of the plurality of pixels 1. It is larger than the arrangement pitch Py in the second direction Y of the pixels 1 constituting one column. 1 and 2, the dotted line indicating the pixel 1 can be equivalent to the region occupied by the first photoelectric conversion unit 2.

  According to such a configuration, for example, even when a grid is arranged and the arrangement pitch of the grid is substantially the same as the arrangement pitch Px, Py of the pixel 1, the second photoelectric conversion unit 5 of the irradiation detection unit S. Have areas where radiation is not blocked by the grid. Thereby, the influence of a grid can be reduced. In the example shown in FIGS. 1 and 2, the second photoelectric conversion unit 5 has dimensions of three pixels in the row direction X and pixels in the column direction Y, but this is merely an example.

  Such a configuration is advantageous for reducing the number of second photoelectric conversion units 5, for example, for reducing the number of pixels 1. This is effective for reducing the influence of gate injection. The second switch 4 can be configured by a transistor such as a TFT. When a voltage is applied to the gate of the transistor constituting the second switch 4 in order to turn on the second switch 4 in order to connect the second photoelectric conversion unit 5 of the irradiation detection unit S to the readout signal line 9, A charge corresponding to the product of the capacitance is transferred to the second readout signal line 9. This is called gate injection. For this reason, charges flow into the second readout circuit 22. When the second switches 4 of the plurality of irradiation detection units S connected to the second readout signal line 9 are simultaneously turned on, the influence due to gate injection becomes significant. Therefore, in the case where a plurality of irradiation detection units S are arranged in the region of interest candidate and signals are read simultaneously from them, it is necessary to consider the influence of gate injection. In the first embodiment, one irradiation detection unit S is provided for a plurality of pixels 1 (9 pixels 1 in FIGS. 1 and 2), and traverses an area where the plurality of pixels 1 are arranged. In this manner, the second photoelectric conversion unit 5 of the irradiation detection unit S is arranged. Therefore, the number of the second photoelectric conversion units 5 that are simultaneously connected to one second readout signal line 9 via the second switch 4 is one, thereby reducing the influence of gate injection. In addition, by reducing the number of irradiation detection units S connected to one second control line 8, the time required for driving the second control line 8 (the time required for voltage transition) can be shortened. As a result, the readout cycle of the signal from the irradiation detector S can be shortened. Thereby, the time resolution of reading the signal from the irradiation detection unit S can be improved.

  The operation of the radiation imaging apparatus RD will be described with reference to FIG. The operation period of the radiation imaging apparatus RD may include a first period T1, a second period T2, and a third period T3. The first period T1 is a period of waiting for the start of radiation irradiation. The second period T2 is a period during which radiation is irradiated. The third period T3 is a period for reading signals from the plurality of pixels 1.

  The first period T1 starts when the power of the radiation imaging apparatus RD is turned on. A radiation source (not shown) starts irradiation by operating an exposure switch. In the first period T1, the pixels of each row are driven by sequentially driving the first control signals Vg1 to Vgm (Vg1 means the first row and Vgm means the last row) supplied through the first control line 6 to the ON voltage Von. A first operation of resetting the output electrode of one first photoelectric conversion unit 2 to the potential of the first readout signal line 7 can be performed. The reset of the first photoelectric conversion unit 2 in the first period T1 can be performed in order to prevent the charge due to the dark current from being accumulated in the first photoelectric conversion unit 2 for a long time.

  Further, in the first period T1, the second control signal Vd supplied through the second control lines Vd1 to Vd3... Is sequentially driven to the ON voltage Von, whereby the second readout signal lines 9 from the plurality of irradiation detection units S are driven. A second operation of reading a signal by the second readout circuit 22 can be performed via the. In the example shown in FIG. 4, the first operation and the second operation are alternately performed, but these may be performed in parallel. The signal processing unit 25 can detect the start of radiation irradiation based on the signal read by the second reading circuit 22. That is, the signal processing unit 25 can detect the start of radiation irradiation based on the output of all or part of the plurality of irradiation detection units S arranged in the imaging region IR. When the start of radiation irradiation is detected, the period shifts from the period T1 to the period T2.

  Alternatively, the second operation may be replaced with an operation of resetting the output electrodes of the second photoelectric conversion units 5 of the plurality of irradiation detection units S. The reset of the second photoelectric conversion unit 5 in the first period T1 can be performed in order to prevent the charge due to the dark current from being accumulated in the second photoelectric conversion unit 5 for a long time. The reset of the plurality of second photoelectric conversion units 5 is performed by sequentially driving the second control signals Vd1 to Vd3... Supplied through the second control line 8 to the ON voltage Von, for example. The operation of resetting the output electrode 5 to the potential of the second output signal line 9 may be performed.

  In the first period T1, when the second photoelectric conversion unit 5 of the irradiation detection unit S is reset, the start of radiation irradiation cannot be detected by signal reading from the second photoelectric conversion unit 5. In this case, for example, the signal processing unit 25 detects the start of radiation irradiation by receiving a notification informing the start of radiation irradiation in response to the operation of the exposure switch, and performs the operation in the first period T1. The operation may be terminated and the operation may be shifted to the second period.

  In the second period T2, the first control signals Vg1 to Vgm driven through the first control line 6 are continuously driven to the off voltage Voff, and charges are accumulated in the first photoelectric conversion unit 2 in all the pixels 1. Continue to be. In the second period T2, the signal processing unit 25 stops radiation irradiation based on the signal read out by the second readout circuit 22 from the irradiation detection unit S arranged in one or more candidate regions of interest in the imaging region IR. Determine the timing. When the signal processing unit 25 determines the timing for stopping the radiation irradiation, the signal processing unit 25 transmits a command for stopping the radiation irradiation to the radiation source in accordance with the determination. This command may be transmitted directly from the signal processing unit 25 to the radiation source or may be transmitted via another device.

  It can be said that the second period T2 is a period during which the radiation dose is monitored. In the second period T2, the second control signals Vd1 to Vd3... Supplied via the second control line 8 are intermittently maintained at the on voltage Von. As a result, the signal of the second photoelectric conversion unit 5 of the irradiation detection unit S in which the second switch 4 is turned on is read out by the second readout circuit 22 via the second readout signal line 9. The signal processing unit 25 integrates signals read by the second readout circuit 22 from the irradiation detection unit S arranged in each region of interest in the imaging region IR, and determines a timing at which radiation irradiation should be stopped based on the integrated value. Yes. That is, the signal processing unit 25 can determine the timing at which radiation irradiation should be stopped based on the output of all or part of the plurality of irradiation detection units S arranged in the imaging region IR.

  In the third period T3, the first control signals Vg1 to Vgm supplied via the first control line 6 are sequentially driven to the ON voltage Von, whereby the first readout signal is output from the first photoelectric conversion unit 2 of the pixels 1 in each row. Reading is performed by the first reading circuit 21 via the line 7. As a result, a radiographic image composed of signals from a plurality of pixels 1 is obtained.

  5 is a schematic plan view of one pixel 1, FIG. 6A is a schematic cross-sectional view taken along the line AA ′ in FIG. 5, and FIG. It is typical sectional drawing of a BB 'line. The pixel 1 includes a first photoelectric conversion unit 2 and a first switch element 3. The first switch 3 is composed of a TFT, and the first control line 6 is connected to the gate of the first switch 3. One of the two main electrodes (source, drain) 105 of the first switch 3 is connected to the first readout signal line 7, and the other is a lower electrode (output electrode) of the first photoelectric conversion unit 2 via a contact plug. 108 is connected. The upper electrode 112 of the first photoelectric conversion unit 2 is connected to the bias line 11 via a contact plug.

  In this example, the first switch 3 includes a control electrode (gate) 101, a first insulating layer 102, a first semiconductor layer 103, a first impurity semiconductor layer 104, two main electrodes (source and drain) 105, and a second insulation. It has a layer 106. The first switch 3 is covered with a first interlayer insulating layer 107. The first photoelectric conversion unit 2 is disposed on the first interlayer insulating layer 107. The first photoelectric conversion unit 2 is configured as a PIN photoelectric conversion element. The first photoelectric conversion unit 2 includes a second impurity semiconductor layer 109, a second semiconductor layer 110, a third impurity semiconductor layer 111, an upper electrode 112, and a third insulating layer 113 in this order on the lower electrode. The first photoelectric conversion unit 2 is covered with a second interlayer insulating layer 114. The bias line 11 is disposed on the second interlayer insulating layer 114, and the second interlayer insulating layer 114 and the bias line 11 are covered with the fourth insulating layer 116.

  FIG. 7 is a schematic plan view showing a plurality of pixels 1 and an irradiation detection unit S arranged between them. FIG. 8 is a schematic sectional view taken along line C-C ′ of FIG. 7. As described above, each irradiation detection unit S includes one second photoelectric conversion unit 5 and one or a plurality of second switches 4, and the second photoelectric conversion unit 5 is a gap between the plurality of first photoelectric conversion units 2. Is arranged. The second switch 4 is also disposed in the gap between the plurality of first photoelectric conversion units 2. In the second photoelectric conversion unit 5, the maximum dimension Sxmax in the row direction (first direction) (X direction in FIG. 7) of the imaging region IR has a row direction X of the pixels 1 constituting one row among the plurality of pixels 1. It is larger than the arrangement pitch Px. Further, the second photoelectric conversion unit 5 has a maximum dimension Symax in the column direction (second direction) (Y direction in FIG. 7) of the imaging region IR of the pixels 1 constituting one column among the plurality of pixels 1. It is larger than the arrangement pitch Py in the two directions Y.

  The second photoelectric conversion unit 5 extends in the fourth direction (Y direction in FIG. 7) that intersects the third direction with one or more first portions 51 extending in the third direction (X direction in FIG. 7). One or more second portions 52 may be included. Each of the plurality of first photoelectric conversion units 2 may have a side parallel to the third direction and a side parallel to the fourth direction. In the example shown in FIG. 7, the third direction is parallel to the row direction (first direction), and the fourth direction is parallel to the column direction (second direction).

  The second photoelectric conversion unit 5 includes a portion disposed between a first row which is one of a plurality of rows in the array of pixels 1 and a second row adjacent to the first row, A portion disposed between two rows and a third row that is adjacent to the second row and is different from the first row may be included. The second photoelectric conversion unit 5 includes a portion disposed between a first column that is one of a plurality of columns in the arrangement of the pixels 1 and a second column adjacent to the first column; A portion disposed between the second row and a third row that is adjacent to the second row and is different from the first row may be included. Alternatively, the second photoelectric conversion unit 5 may include a # shape part.

  The imaging region IR may include a first group of pixels 1 in which the irradiation detection unit S is arranged in the gap and a second group of pixels 1 in which the irradiation detection unit is not arranged in the gap. In this case, the first photoelectric conversion unit 2 of the first group of pixels 1 may have a smaller area than the first photoelectric conversion unit 2 of the second group of pixels 1 or may have the same area. Good. In the former case, the signal processing unit 25 can perform correction according to the difference in area. In the latter case, another detection unit may be arranged in the gap between the pixels 1 of the second group. For example, the other detection unit can be used to detect the start of radiation irradiation, and the irradiation detection unit S can be used to determine the timing for stopping the radiation irradiation.

  In this example, the second switch 4 is composed of a TFT, and the second control line 8 is connected to the control electrode (gate) 101 of the second switch 4. One of the two main electrodes (source, drain) 105 of the second switch 4 is connected to the second readout signal line 9, and the other is a lower electrode (output electrode) of the second photoelectric conversion unit 5 via a contact plug. 108 is connected. The upper electrode 112 of the second photoelectric conversion unit 5 is connected to the bias line 11 via a contact plug.

  In this example, the second switch 4 includes a control electrode (gate) 101, a first insulating layer 102, a first semiconductor layer 103, a first impurity semiconductor layer 104, two main electrodes (source and drain) 105, a second insulation. It has a layer 106. The first switch 3 is covered with a first interlayer insulating layer 107. The first photoelectric conversion unit 2 is disposed on the first interlayer insulating layer 107. The first photoelectric conversion unit 2 is configured as a PIN photoelectric conversion element. The second photoelectric conversion unit 5 includes a second impurity semiconductor layer 109, a second semiconductor layer 110, a third impurity semiconductor layer 111, an upper electrode 112, and a third insulating layer 113 in this order on the lower electrode. The second photoelectric conversion unit 5 is covered with a second interlayer insulating layer 114. The bias line 11 is disposed on the second interlayer insulating layer 114, and the second interlayer insulating layer 114 and the bias line 11 are covered with the fourth insulating layer 116.

  Here, in the first switch 3 and the second switch 4, the control electrode (gate) 101, the first insulating layer 102, the first semiconductor layer 103, the first impurity semiconductor layer 104, the two main electrodes 105, and the second insulating layer 106 may be arranged in the same layer. In the first photoelectric conversion unit 2 and the second photoelectric conversion unit 5, the lower electrode 108, the second impurity semiconductor layer 109, the second semiconductor layer 110, the third impurity semiconductor layer 111, the upper electrode 112, and the third insulating layer 113. Can be arranged in the same layer.

  FIG. 9 shows an arrangement example of the plurality of irradiation detection units S. In FIG. 9, the pixel 1 is not shown. In the example shown in FIG. 9, the plurality of irradiation detection units S are arranged to form a plurality of rows and a plurality of columns. However, the rows and columns formed by the plurality of pixels 1 do not match the rows and columns formed by the plurality of irradiation detection units S.

  FIG. 10 is a plan view schematically showing the configuration of the pixel 1 and the irradiation detection unit S in the radiation imaging apparatus RD of the second embodiment of the present invention. The second embodiment may have the same configuration as that of the first embodiment except for the matters mentioned below. In the second embodiment, the odd-numbered pixels 1 and the even-numbered pixels 1 are arranged so as to be shifted from each other in the row direction by 1/2 pitch (1/2 of the arrangement pitch in the row direction of each row). Such an arrangement can also be understood as a honeycomb structure.

  The second photoelectric conversion unit 5 may include one or more first portions 53 extending in the third direction and one or more second portions 54 extending in the fourth direction intersecting the third direction. The second photoelectric conversion unit 5 may include one or a plurality of third portions 55 extending in a fifth direction intersecting the third direction and the fourth direction. Each of the plurality of first photoelectric conversion units 2 may have a side parallel to the third direction, a side parallel to the fourth direction, and a side parallel to the fifth direction. In the example shown in FIG. 10, the third direction is parallel to the row direction (first direction) and the column direction (second direction), and the fourth direction is a direction intersecting the row direction and the column direction. The fifth direction is a direction intersecting the row direction and the column direction. However, this is only an example, the third direction is a direction intersecting the row direction (first direction) and the column direction (second direction), and / or the fourth direction is a direction intersecting the row direction and the column direction. And / or the fifth direction may be a direction intersecting the row direction and the column direction. The second photoelectric conversion unit 5 of the second embodiment has an extended portion in the direction intersecting the row direction and the column direction, which is advantageous for reducing the influence of the grid.

  Also in the second embodiment, in the second photoelectric conversion unit 5, the maximum dimension Sxmax in the row direction (first direction) (X direction in FIG. 10) of the imaging region IR forms one row of the plurality of pixels 1. It is larger than the arrangement pitch Px in the row direction X of the pixel 1 to be processed. Further, the second photoelectric conversion unit 5 has a maximum dimension Symax in the column direction (second direction) (Y direction in FIG. 10) of the imaging region IR of the pixels 1 constituting one column among the plurality of pixels 1. It is larger than the arrangement pitch Py in the two directions Y.

  FIG. 11 is a plan view schematically showing the configuration of the pixel 1 and the irradiation detection unit S in the radiation imaging apparatus RD of the third embodiment of the present invention. The third embodiment can have the same configuration as that of the first or second embodiment except for the matters mentioned below. Also in the third embodiment, the odd-numbered pixels 1 and the even-numbered pixels 1 are arranged so as to be shifted from each other by 1/2 pitch in the row direction (1/2 of the arrangement pitch in the row direction of each row).

  The second photoelectric conversion unit 5 can include one or more first portions 56 extending in the third direction and one or more second portions 57 extending in the fourth direction intersecting the third direction. Each of the plurality of first photoelectric conversion units 2 may have a side parallel to the third direction and a side parallel to the fourth direction. In the example shown in FIG. 11, the third direction is a direction intersecting the row direction (first direction) and the column direction (second direction), and the fourth direction is a direction intersecting the row direction and the column direction. It is. However, this is only an example, the third direction is a direction intersecting the row direction (first direction) and the column direction (second direction), and / or the fourth direction is a direction intersecting the row direction and the column direction. It can be. The second photoelectric conversion unit 5 of the third embodiment also has a portion extending in the direction intersecting the row direction and the column direction, which is advantageous for reducing the influence of the grid.

  Also in the third embodiment, in the second photoelectric conversion unit 5, the maximum dimension Sxmax in the row direction (first direction) (X direction in FIG. 11) of the imaging region IR constitutes one row among the plurality of pixels 1. It is larger than the arrangement pitch Px in the row direction X of the pixel 1 to be processed. In addition, the second photoelectric conversion unit 5 has a maximum dimension Symax in the column direction (second direction) (Y direction in FIG. 11) of the imaging region IR of the pixels 1 constituting one column among the plurality of pixels 1. It is larger than the arrangement pitch Py in the two directions Y.

  FIG. 12 shows the configuration of a radiation imaging system according to an embodiment of the present invention. X-ray 6060 which is radiation generated by the X-ray tube 6050 which is a radiation source passes through the chest 6062 of the patient or subject 6061 and enters the conversion element included in the detection device 6040. This incident X-ray includes information inside the body of the patient 6061. Corresponding to the incidence of X-rays, the conversion unit 3 converts the radiation into electric charges to obtain electrical information. This information is converted into digital data, image-processed by an image processor 6070 as a signal processing means, and can be observed on a display 6080 as a display means in a control room.

  Further, this information can be transferred to a remote place by transmission processing means such as a telephone line 6090, and can be displayed on a display 6081 serving as a display means such as a doctor room in another place or stored in a recording means such as an optical disk. It is also possible for a doctor to make a diagnosis. Moreover, it can also record on the film 6110 used as a recording medium by the film processor 6100 used as a recording means.

Claims (16)

A plurality of pixels for detecting radiation have an imaging region arranged to form a plurality of rows and a plurality of columns, and each of the plurality of pixels includes a first photoelectric conversion unit,
A plurality of irradiation detection units for detecting radiation irradiation to the imaging region;
Each of the plurality of irradiation detection units includes a second photoelectric conversion unit, and the second photoelectric conversion unit is disposed in a gap between the plurality of first photoelectric conversion units, and is in a first direction along the plurality of rows. The maximum dimension in the second direction along the plurality of columns is larger than the arrangement pitch in the first direction of pixels constituting one row of the plurality of pixels. Larger than the arrangement pitch of the pixels constituting one column in the second direction,
A radiation imaging apparatus. The second photoelectric conversion unit includes one or more first portions extending in a third direction and one or more second portions extending in a fourth direction intersecting the third direction.
The radiation imaging apparatus according to claim 1. The first photoelectric conversion unit has a side parallel to the third direction and a side parallel to the fourth direction.
The radiation imaging apparatus according to claim 2. The third direction is parallel to the first direction, and the fourth direction is parallel to the second direction.
The radiation imaging apparatus according to claim 3. The third direction is a direction intersecting the first direction and the second direction, and / or the fourth direction is a direction intersecting the first direction and the second direction;
The radiation imaging apparatus according to claim 3. The second photoelectric conversion unit includes one or more first portions extending in a third direction, one or more second portions extending in a fourth direction intersecting the third direction, the third direction, and A third portion extending in a fifth direction intersecting the fourth direction,
The radiation imaging apparatus according to claim 1. The third direction is a direction intersecting the first direction and the second direction, and / or the fourth direction is a direction intersecting the first direction and the second direction, and / or The radiation imaging apparatus according to claim 6, wherein the fifth direction is a direction that intersects the first direction and the second direction. The second photoelectric conversion unit includes a portion disposed between a first row that is one of the plurality of rows and a second row adjacent to the first row, the second row, A portion disposed between a third row adjacent to the second row and different from the first row, and a first column and the first column that are one of the plurality of columns And a portion arranged between the second row adjacent to the second row and a third row adjacent to the second row and different from the first row Including,
The radiation imaging apparatus according to claim 1, wherein: The second photoelectric conversion unit includes a # shape part,
The radiation imaging apparatus according to claim 1, wherein: The second photoelectric conversion unit includes a lower electrode, an upper electrode, and a semiconductor layer disposed between the lower electrode and the upper electrode.
The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a radiation imaging apparatus. The first photoelectric conversion unit includes a lower electrode, an upper electrode, and a semiconductor layer disposed between the lower electrode and the upper electrode,
The lower electrode of the first photoelectric conversion unit and the lower electrode of the second photoelectric conversion unit are arranged in the same layer, and the upper electrode of the first photoelectric conversion unit and the upper part of the second photoelectric conversion unit The electrode is disposed in the same layer, and the semiconductor layer of the first photoelectric conversion unit and the semiconductor layer of the second photoelectric conversion unit are disposed in the same layer,
The radiation imaging apparatus according to claim 10. A read circuit for reading signals from the plurality of irradiation detection units;
Each of the plurality of irradiation detection units further includes a switch that connects the second photoelectric conversion unit to the readout circuit.
The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a radiation imaging apparatus. The number of the plurality of irradiation detection units is less than the number of the plurality of pixels.
The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a radiation imaging apparatus. Based on the output of all or part of the plurality of irradiation detection units, the start of radiation irradiation is detected,
The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a radiation imaging apparatus. Based on the output of all or part of the plurality of irradiation detection units, the timing to stop radiation irradiation is determined,
The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a radiation imaging apparatus. A radiation imaging apparatus according to any one of claims 1 to 15,
A control unit for controlling the radiation imaging apparatus;
A radiation imaging system comprising:

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