JP4383899B2 - Radiation imaging apparatus and radiation imaging system - Google Patents

Description

  The present invention relates to a radiation imaging apparatus and a radiation imaging system suitable for medical image diagnostic apparatuses, nondestructive inspection apparatuses, analyzers using radiation, and the like. In this specification, in addition to α rays, β rays, γ rays and the like, electromagnetic waves such as visible rays and X rays are included in the radiation.

  As a method of obtaining a radiographic image of a subject by irradiating the subject with radiation and detecting the intensity distribution of the radiation that has passed through the subject, pixels consisting of minute photoelectric conversion devices, switching elements, etc. are in a grid pattern. A technique for acquiring a digital image using a photoelectric conversion device arranged in the above has been developed. In these radiation imaging apparatuses, the acquired image data can be displayed immediately.

  In a conventional radiation imaging apparatus, when the amount of radiation reaching the radiation imaging apparatus becomes a low region, the influence of quantum noise due to a decrease in the amount of arrival information and system noise of the apparatus increases, and the S / N ratio of the image deteriorates. To do. For this reason, an X-ray automatic exposure control (AEC) circuit called a phototimer is used for the purpose of obtaining the minimum amount of radiation that can be reached in order to ensure the necessary minimum quality of the acquired image. ing. As shown in FIGS. 8A and 8B, the AEC radiation detection region 5 of the radiation detection element used in the AEC circuit is, for example, two to three so that it can be used for both chest imaging and abdominal imaging. It is said that.

  At this time, in the case of a flat panel detector (FPD) using a solid-state light detecting element as an imaging element of the radiation imaging apparatus, as disclosed in Patent Document 1 (US Pat. No. 5,585,638), the FPD A radiation detection element separate from the FPD is disposed on the front surface to operate the AEC circuit.

  However, when a separate AEC control sensor is provided and the amount of incident radiation is adjusted (AEC control), the placement of this sensor becomes a problem. That is, in order to dispose the AEC control sensor on the front surface of the FPD so as not to hinder the image pickup by the image pickup sensor, the attenuation of radiation by the AEC control sensor needs to be extremely small. For this reason, the cost rise of the whole apparatus is caused. In addition, since there is no sensor with no attenuation at all, a reduction in image quality of the captured image is unavoidable.

US Pat. No. 5,585,638

  The present invention has been made in view of such problems, and provides a radiation imaging apparatus and a radiation imaging system that can automatically adjust the amount of incident radiation while suppressing attenuation of radiation before detection. For the purpose.

  As a result of intensive studies to solve the above problems, the present inventor has come up with various aspects of the invention described below.

  The inventors of the present application made it possible to arrange the radiation detecting element for AEC inside the FPD because of the demand for miniaturization and simplification of the apparatus, the demand for cost reduction, and the improvement of the manufacturing technology. However, in this case, it is desirable to dispose the AEC radiation detection elements so as not to hinder the operation of the image capturing radiation detection pixels. Specifically, it is desired to optimize the configuration of a portion from which signals are read out from an insulating substrate constituting the FPD via a printed wiring board such as a tape carrier package (TCP). Here, the hindrance to the operation of the radiation detection pixel for imaging is because the wiring pattern of the radiation detection pixel for imaging in the vicinity of the AEC radiation detection pixel is different from other portions as a result of the arrangement of the AEC radiation detection pixel in the FPD. In other words, the wiring capacity increases, noise increases, and the image quality deteriorates due to a significant decrease in the aperture ratio of the radiation detection pixels for imaging.

The radiation imaging apparatus according to the present invention includes a plurality of pixel areas arranged in row and column directions on a base plate, a plurality of printed circuit board connected to the plurality of pixel regions, from the plurality of pixel areas A reading unit that reads an electrical signal through the plurality of printed wiring boards; and an exposure control unit that controls exposure of the plurality of pixel regions. The plurality of pixel regions include a plurality of second pixels for imaging. One pixel region and a plurality of second pixel regions for imaging and acquiring an output value for exposure control, wherein the first pixel region includes a plurality of first pixels for imaging Each of the plurality of first pixels includes a first semiconductor conversion element that converts radiation into an electric signal; and a switch element that outputs an electric signal converted by the first semiconductor conversion element; And the second pixel area A plurality of second pixels for imaging, and a plurality of third pixels for acquiring an output value for exposure control arranged in a group between the plurality of second pixels. Each of the plurality of second pixels has a second semiconductor conversion element that converts radiation into an electric signal and a switch element that outputs the electric signal converted by the second semiconductor conversion element. Each of the plurality of third pixels includes a third semiconductor conversion element that converts radiation into an electrical signal, and each of the plurality of printed wiring boards includes a plurality of first prints each provided with a spare wiring. A wiring board and a plurality of second printed wiring boards; the preliminary wiring of the first printed wiring does not connect the third pixel and the exposure control unit; The wiring connects the third pixel and the exposure control unit. Characterized in that it continue.

In the present invention, AEC control can be performed based on the radiation dose detected via the third semiconductor conversion element. At this time, the third semiconductor conversion element because it is disposed in a second pixel region identical to the second semiconductor conversion element, there is no attenuation of the radiation by the third semiconductor conversion element. Further, since the third semiconductor conversion element is provided in a part of the pixel region and is arranged in a printed wiring board unit, the third semiconductor conversion element hinders the operation of the first and second semiconductor conversion elements. do not become.

According to the present invention, since the third semiconductor conversion element is arranged in the pixel region, the attenuation of radiation by the third semiconductor element can be suppressed, and the third semiconductor conversion element is the first semiconductor conversion element. And it does not hinder the operation of the second semiconductor conversion element.

  Hereinafter, a radiation imaging apparatus according to a preferred embodiment of the present invention will be specifically described with reference to the accompanying drawings.

(First embodiment)
First, a preferred first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing a layout of a radiation imaging apparatus according to a preferred first embodiment of the present invention.

  In the present embodiment, imaging radiation detection pixels for m columns and n rows are arranged in a matrix on the insulating substrate 1. One imaging radiation detection pixel is provided with a conversion unit for converting radiation into an electrical signal. This conversion unit is composed of a MIS photoelectric conversion element (first semiconductor conversion element) and a thin film transistor (TFT) (switch element) for reading. The m rows of radiation detection pixels for imaging are divided into, for example, nine groups, and each group is connected to one of the readout TCPs a1 to a9. Further, the n rows of imaging radiation detection pixels are divided into, for example, eight groups, and each group is connected to one of the driving TCPs d1 to d8. The read TCPs a1 to a9 and the drive TCPs d1 to d9 are configured by mounting a semiconductor chip on a tape on which wiring is formed by TAB (Tape Automated Bonding). The read TCPs a 1 to a 9 are connected to the read device 2, and the drive TCPs d 1 to d 8 are connected to the gate drive device 3.

  As described above, when m rows of imaging radiation detection pixels are divided into nine groups and n rows of imaging radiation detection pixels are divided into eight groups, m is determined in accordance with these divisions. The imaging radiation detection pixels in the row n column are divided into 72 pixel regions 4, and the imaging radiation detection pixels belonging to one pixel region 4 are connected to the same readout TCP and drive TCP.

  Further, in the present embodiment, a plurality of AEC radiation detection pixels are arranged in three of the 72 pixel regions 4 described above, and the read TCPs a3, a5, and a7 serve as specific printed wiring boards. ing. The AEC radiation detection pixel is provided with a TFT type sensor (second semiconductor conversion element). In the specification of the present application, the pixel area 4 provided with such AEC radiation detection pixels is referred to as an AEC radiation detection area 5.

  Next, the configuration of the AEC radiation detection region 5 will be described. FIG. 2 is an equivalent circuit diagram showing a circuit configuration of the AEC radiation detection region 5 in the radiation imaging apparatus according to the first embodiment, and FIG. 3 is a schematic diagram showing a layout of the AEC radiation detection region 5. .

  In one AEC radiation detection region 5, for example, 4 rows and 4 columns (16) of imaging radiation detection pixels are arranged. The imaging radiation detection pixels in the a-th row and the b-th column from the top in FIGS. 2 and 3 are provided with photoelectric conversion elements Mba and thin-film transistors Tba (a, b = 1, 2, 3, 4). . Further, between the third column imaging radiation detection pixels and the fourth column imaging radiation detection pixels, one column and four rows (four) AEC radiation detection pixels are arranged in a column. ing. A TFT type sensor MA3a is provided in the AEC radiation detection pixel in the a-th row from the top in FIGS.

  Further, the four MIS type photoelectric conversion elements arranged in the b-th column are connected to a common bias line Vsb, and a constant bias is applied from the reading device 2. The gate electrodes of the four readout TFTs arranged in the a-th row are connected to a common gate line Vga, and the gate driving device 3 controls the gate ON / OFF. Furthermore, the source electrodes or drain electrodes of the four readout TFTs arranged in the b-th column are connected to the common signal line Sigb. The signal lines Sig1 to Sig4 are connected to the reading device 2.

  Next, the connection relationship between the readout TCP and drive TCP and the electrodes in the pixel will be described. FIG. 4 is a schematic diagram showing a connection relationship between the read TCPa and the AEC radiation detection region 5. 2 and 3 show an AEC radiation detection area in which four rows of imaging radiation detection pixels are arranged and only one row of AEC radiation detection pixels is arranged. In FIG. 1 shows an AEC radiation detection region in which k rows of radiation detection pixels are arranged and a plurality of rows of AEC radiation detection pixels are arranged.

  As shown in FIG. 4, an amplifier semiconductor chip (Amp IC) 6 is mounted on the read TCPa. The semiconductor chip 6 amplifies the signal input lines Sigc1 to Sigck to which the output signals from the signal lines Siga1 to Sigak of the imaging radiation detection pixels are input, and the signals input from these signal input lines to amplify the readout device 2. Is connected to the signal output line. The readout TCPa is connected to the bias lines Vsa1 to Vsak of the imaging radiation detection pixels and connected to the readout device 2, and the TFT type sensor of the AEC radiation detection pixels constituting each column. A spare line G, a spare line S, and a spare line D, which are connected to the reading device 2 by connecting the gate line GL, the source line SL, and the drain line DL, are provided. The read-out TCPa is further provided with a spare wiring GND. The signal line Siga1 and the like correspond to the signal line Sig1 and the like in FIGS. 2 and 3, and the bias line Vas1 and the like correspond to the bias line Vs1 and the like in FIGS.

  Further, a semiconductor chip (driver IC) (not shown) is mounted on the driving TCP, and a gate pulse output line for applying a gate driving pulse to the gate line of the imaging radiation detection pixel is connected to the semiconductor chip. Has been.

  In the AEC radiation detection region 5, the bias lines Vsa1 to Vsak are shared among all the columns of the imaging radiation detection pixels, and are connected to the bias connection wiring Vsc of the read TCPa. The signal lines Siga1 to Sigak are connected to the signal input lines Sigc1 to Sigck of the read TCPa, respectively. In addition, regarding the TFT type sensor of the AEC radiation detection pixel, the source line SL, the drain line DL, and the gate line GL are shared among all the columns in the AEC radiation detection region 5, and the read TCPa The spare wiring S, the spare wiring D, and the spare wiring G are connected.

  Further, the reading device 2 includes a reading circuit 7 that reads a signal output from the semiconductor chip 6, a DC power supply 8 that supplies a constant voltage VG to the spare wiring G, a DC power supply 9 that supplies a constant voltage VD to the spare wiring D, An amplifier 10, a gain switching circuit 11, and an AD conversion circuit 12 to which the spare wiring S is connected are provided. Although not shown here, the wirings connected to the DC power supply 8, the DC power supply 9, and the amplifier 10 are made common in the reading device 2 so as to be connected to each spare wiring of all the read TCPs. Has been placed. Further, as shown in FIG. 4, the read circuit 7 is provided with a sample-and-hold capacitor CL <b> 1 for a signal input to the semiconductor chip 6 from the signal input line Sigc <b> 1 and amplified by the semiconductor chip 6. For this signal, a switch Sr1 is provided between the sample hold capacitor CL1 and the output of the readout circuit 7. Similarly, although not shown in the figure, for the signal input lines Sigc2, Sigc3, Sigc4,..., Sigck, sample hold capacitors CL2, CL3, CL4,. ..Srk is provided. Further, a shift register SR that sequentially generates pulses for switching on / off of the switches Sr1, Sr2, Sr3, Sr4,..., Srk is provided.

  Next, the operation of the radiation imaging apparatus according to the first embodiment configured as described above will be described with reference to FIGS.

  When X-rays are exposed to a subject such as a human body on the radiation imaging apparatus configured as described above, the X-rays pass through the subject while being attenuated by the subject, and the phosphor layer (Not shown) is converted into visible light. Then, the visible light is incident on the MIS photoelectric conversion element M11 and the like, and is converted into electric charges. This electric charge is transferred to the signal line Sig1 or the like via the readout TFT T11 or the like according to the gate drive pulse applied by the gate drive device 3, and is output to the outside via the readout device 2. Thereafter, the charges generated in the MIS photoelectric conversion element M11 and the like and not transferred are removed from the common bias line Vs1 and the like.

  On the other hand, for the TFT type sensors MA31 to MA34, for example, a constant bias for depleting the TFT semiconductor layer is applied between the gate and drain electrodes from the DC power supplies 8 and 9 via the spare wirings G and D. Keep it. Thus, by applying a constant bias, a charge corresponding to incident light is always output. Therefore, the output value can be amplified by the amplifier (AMP) 10 and added to detect the total X-ray dose by the readout device. Then, X-ray exposure is controlled based on the total X-ray dose.

  Here, FIG. 11 shows a conceptual diagram of a TFT type sensor that is a radiation detection pixel for AEC and an AEC circuit, FIG. 12 shows a drive timing chart in this embodiment, and FIG. 2, FIG. 4, FIG. The drive timing will be described with reference to FIG.

  First, by inputting an X-ray START signal to the ON / OFF circuit 1101, X-rays are exposed from the X-ray source 1102. This X-ray is attenuated by the subject (not shown), passes through the subject, and can be detected by the phosphor layer 1103 by the MIS type photoelectric conversion element (photoelectric conversion element Mab in FIG. 2) and the TFT type sensor MA. Wavelength conversion to a simple light (visible light). The wavelength-converted light is incident on the MIS type photoelectric conversion element and the TFT type sensor MA, and charges are generated in each element.

  The electric charge generated in the TFT type sensor MA is integrated as a voltage value Vaec by the integration circuit 1105 through the spare wiring S. When the voltage value Vaec reaches a set value (for example, 2 V) of the comparison circuit 1106, the X-ray OFF signal S1 is input from the comparison circuit 1106 to the ON / OFF circuit 1101. As a result, X-rays are blocked (see FIG. 12).

  In the above description and FIG. 11, an example in which the analog integration circuit 1105 is used has been described. However, the output of the TFT type sensor MA is A / D converted as shown in FIG. Compare with the set value.

  Next, the charge generated in the MIS photoelectric conversion element is read out. Referring to FIG. 2, the read operation is performed in the order of photoelectric conversion elements M11 to M41 in the first row, then photoelectric conversion elements M12 to M42 in the second row, and then photoelectric conversion elements M13 to M43 in the third row. Is called. First, in order to read out the photoelectric conversion elements M11 to M41 in the first row, a gate pulse is applied to the gate wiring Vg1 of the switch elements (TFTs) T11 to T41 (see FIG. 12). Thereby, the switch elements T11 to T41 are turned on, and the charges accumulated in the photoelectric conversion elements M11 to M41 are transferred to the signal lines Sig1 to Sig4. Read capacitances (not shown) are added to the signal lines Sig1 to Sig4, and the charges accumulated in the photoelectric conversion elements M11 to M41 are transferred to the read capacitances via the TFTs. For example, the readout capacitance added to the signal line Sig1 is the total (four pieces) of the interelectrode capacitance (Cgs) between the gates / sources of the TFTs of the switch elements T11 to T14 connected to the signal line Sig1. is there. The charges transferred to the signal lines Sig1 to Sig4 are input to the semiconductor chip (Amp IC) 6 through the signal input lines Sigc1 to Sigc4, and are amplified by the semiconductor chip (Amp IC) 6. Next, the data are transferred to and held by the sample hold capacitors CL1 to CL4 in the readout circuit 7, respectively. Next, by applying pulses in the order of the switches Sr1, Sr2, Sr3, and Sr4 in the read circuit 7 from the shift register SR in the read circuit 7 (see FIG. 12), the sample hold capacitors CL1 to CL4 hold the pulses. The received signals are output to the outside of the readout circuit 7 in the order of the sample and hold capacitors CL1, CL2, CL3, and CL4. As a result, as shown in FIG. 12, photoelectric conversion signals for one row of the photoelectric conversion elements M11 to M41 are sequentially output from the readout circuit 7 as Vout. The read operation of the photoelectric conversion elements M12 to M42 in the second row is performed in the same manner as the photoelectric conversion elements M13 to M43 in the third row and the subsequent read operations.

  According to the first embodiment as described above, since the TFT type sensor for AEC is provided on the insulating substrate 1 separately from the MIS type photoelectric conversion element, X-rays are incident on the MIS type photoelectric conversion element. In the meantime, X-rays are not attenuated by the AEC radiation detection pixels. Therefore, good image quality can be obtained.

  In addition, if it is in the radiation detection area 5 for AEC, a TFT type sensor can be selectively arrange | positioned in a required place. In the radiation detection pixel for imaging adjacent to the radiation detection pixel for AEC, the aperture ratio of the MIS type photoelectric conversion element decreases, but this decrease in area can be easily compensated by image correction after reading. It is.

  In addition, some of the pixel areas 4 formed by aggregating pixels connected to the same TCP are set as the AEC radiation detection areas 5, and the AEC radiation detection pixels are arranged in the AEC radiation detection areas 5. Has been. For this reason, it is possible to easily pull out the wiring (gate line GL, source line SL, and drain line DL) connected to the AEC radiation detection pixel to the readout TCP.

  Each read TCP is provided with spare wirings G, S, and D at both end portions thereof, and each spare wiring G, S, and D is connected to a predetermined circuit (DC power supplies 8 and 9 and amplifier 10 in the reading device 2). ), The AEC radiation detection pixels can be connected to a predetermined circuit. Therefore, the radiation imaging apparatus can be manufactured at a low cost.

  The read TCP according to the preferred embodiment of the present invention includes a plurality of spare wirings, and when connected to a necessary AEC area, the read TCP is connected to a predetermined circuit via the above-described spare wirings. There is a feature in doing. That is, the read TCP may or may not use spare wiring.

  In addition, all spare wirings that are not used can be directly connected to the ground, thereby maintaining a more stable state against external noise and static electricity.

  In other words, by using TCP with spare wiring, it is necessary to not only drive the AEC sensor and read the output, but also achieve environmental stability at the same time, and prepare multiple types of TCP. It is possible to eliminate high quality and low price.

  In the first embodiment, the AEC radiation detection pixel wiring is connected to the readout TCP. However, as shown in FIG. 9, the AEC radiation detection pixel wiring is connected to the drive TCP. Also good. In this case, for example, the layout of each pixel is the same as in FIG. 3, and the wiring layout is such that the source line SL and drain line DL of the AEC radiation detection pixel are gated via contact holes CNT1 and CNT2, respectively. Each is connected to a wiring arranged in the wiring layer (the same wiring layer as the gate wiring GL). Further, the DC power supplies 8 and 9 and the amplifier 10 are provided in the gate driving device.

  In addition, the bias line on the insulating substrate 1 may be shared not only in the AEC radiation detection region but also in all the pixel regions 4, for example.

  Further, FIG. 2 and FIG. 3 show an example in which one AEC radiation detection region is provided with 4 rows and 4 columns (16 pixels), but the number is limited to this. is not. In addition, for example, a total of 2000 × 2000 pixels may be provided on the insulating substrate 1.

  Here, although the MIS type photoelectric conversion element is shown as the first semiconductor conversion element in the present embodiment, a PIN type photoelectric conversion element may be used. In addition, regarding the structure of the imaging radiation detection pixel, even if the first semiconductor conversion element and the switch element are configured in the same layer, the first semiconductor conversion element is formed on the layer where the switch element is formed. The formed laminated type may be used. Still further, the first semiconductor conversion element is a conversion element using a direct conversion film such as amorphous selenium (a-Se) or polycrystalline CdS, which directly converts radiation into an electrical signal, without using a scintillator. A radiation imaging apparatus that directly converts radiation into an electrical signal may be used.

(Second Embodiment)
Next, a preferred second embodiment of the present invention will be described. FIG. 5 is a schematic diagram showing a layout of a radiation imaging apparatus according to the preferred second embodiment of the present invention.

  Also in the present embodiment, as in the first embodiment, imaging radiation detection pixels of m columns and n rows are arranged in a matrix on the insulating substrate 1. The m rows of imaging radiation detection pixels are divided into, for example, nine groups. Further, the n rows of imaging radiation detection pixels are divided into, for example, eight groups, and each group is connected to one of the driving TCPs d1 to d8. Among the m rows of imaging radiation detection pixels divided into nine groups, one connected to any one of the driving TCPs d1 to d4 is connected to any one of the reading TCPs a1 to a9, and the driving TCP d5. Those connected to any of d8 to d8 are connected to any of the read TCPs b1 to b9.

  Then, according to these divisions, the imaging radiation detection pixels of m rows and n columns are divided into 72 pixel regions 4, and the imaging radiation detection pixels belonging to one pixel region 4 are the same readout TCP. And connected to the driving TCP. The read TCPs a1 to a9 are connected to the read device 2, the read TCPs b1 to b9 are connected to the read device 2b, and the drive TCPs d1 to d8 are connected to the gate drive device 3. The read TCPs b1 to b9 are configured in the same manner as the read TCPa1 to a9, and the read device 2b is configured in the same manner as the read device 2. Preferably, the read TCPs a1 to a9 and the read TCPs b1 to b9 can be arranged in the same number on two opposite sides of the insulating substrate 1 so as to sandwich a conversion unit that converts radiation into an electrical signal.

  In the present embodiment, a plurality of AEC radiation detection pixels are arranged in six of the 72 pixel regions 4, and the read TCPs a3, a5, a7, b3, b5, and b7 are specified prints. It is a wiring board.

  In the second embodiment configured as described above, readout from the radiation detection pixels for imaging for two rows can be simultaneously performed. Therefore, compared with the first embodiment, reading of data from the imaging radiation detection pixel can be completed in half the time.

  In addition, for example, n rows of imaging radiation detection pixels are vertically divided into n / 2 rows by a boundary line parallel to two opposite sides of the insulating substrate 1, and the AEC radiation is based on the boundary line. The detection areas 5 may be arranged line-symmetrically.

  Further, as shown in FIG. 6, m rows of imaging radiation detection pixels are divided into, for example, 8 groups, and n rows of imaging radiation detection pixels are divided into, for example, 9 groups, and gate driving is performed. In addition to the device 3, a gate driving device 3e may be provided. At this time, m rows of imaging radiation detection pixels may be divided into left and right m / 2 columns, and the AEC radiation detection regions 5 may be arranged in line symmetry with reference to these boundaries.

  In this case, the driving TCP d9 is added to the driving TCPs d1 to d8 on the gate driving device 3 side, and the driving TCPs e1 to e9 are provided on the gate driving device 3e side. The drive TCPd9 and e1 to e9 are configured in the same manner as the drive TCPd1 to d8, and the gate drive device 3e is configured in the same manner as the gate drive device 3. The driving TCPs d3, d5, d7, e3, e5, and e7 are specific printed wiring boards.

  By the way, when the planar shape of the FPD is a rectangle like the conventional silver salt film, for example, a rectangle of a half-cut film size, the longitudinal direction of the FPD is set to be vertical or horizontal according to the physique of the subject (subject) to be photographed. Shooting is performed in either direction. However, when the FPD is rotated and used in this way, the conventional AEC radiation detection region incorporated in the FPD is sufficient in the conventional two to three locations as shown in FIGS. 8A and 8B. I can't say that. That is, as shown in FIG. 8A, when the longitudinal direction of the FPD is set vertically, optimization is performed so that two to three AEC radiation detection regions 5 are arranged at the position of the lung field portion 21. However, as shown in FIG. 8 (b), when the FPD longitudinal direction is set horizontally, a region that is not arranged at the position of the lung field portion 21 in the AEC radiation detection region 5 is generated. The optimal placement is not made.

  On the other hand, in the preferred embodiment of the present invention, as shown in FIG. 5 or FIG. 6, when the AEC radiation detection regions 5 are provided at six locations of the FPD, FIGS. As shown in (2), the AEC radiation detection region 5 is arranged at an optimum position regardless of whether it is placed vertically or horizontally. That is, as shown in FIG. 7 (a), even if the FPD 22 is placed vertically or as shown in FIG. 7 (b), the AEC radiation detection region 5 with respect to the lung field portion 21 is placed. Arrangement is appropriate.

  In this way, by providing spare wiring at both end portions of each TCP and making it possible to arrange the radiation detection area for AEC in units of TCP, the arrangement can be easily made at a required place. Regardless, the AEC radiation detection region 5 can be arranged at an optimal position, and the radiation imaging apparatus can be manufactured at low cost.

  Here, although the MIS type photoelectric conversion element is shown as the first semiconductor conversion element in the present embodiment, a PIN type photoelectric conversion element may be used. In addition, regarding the structure of the imaging radiation detection pixel, even if the first semiconductor conversion element and the switch element are configured in the same layer, the first semiconductor conversion element is formed on the layer where the switch element is formed. A laminated type formed may be used. Still further, the first semiconductor conversion element is a conversion element that directly converts radiation into an electric signal, for example, using a direct conversion film such as amorphous selenium (a-Se) or polycrystalline CdS, without using a scintillator. A radiation imaging apparatus that directly converts radiation into an electrical signal may be used.

(Application examples)
The radiation imaging system using the radiation imaging apparatus according to the preferred embodiment of the present invention will be described below. FIG. 10 is a schematic diagram showing an application example of the radiation imaging apparatus according to the preferred embodiment of the present invention to a radiation imaging system.

  X-rays 6060 generated by the X-ray tube 6050 pass through the chest 6062 of the patient or subject 6061 and enter a radiation detection apparatus (radiation imaging apparatus) 6040 as shown in FIG. The incident X-ray includes information inside the body of the patient 6061. The scintillator (phosphor) emits light in response to the incidence of X-rays, and this is photoelectrically converted by the photoelectric conversion element of the sensor panel to obtain electrical information. The radiation detection device (radiation imaging device) 6040 outputs this information to the image processor 6070 as an electrical signal. An image processor 6070 serving as an image processing unit converts an electrical signal output from the radiation detection apparatus (radiation imaging apparatus) 6040 into a digital signal, and then performs image processing on the digital signal to display a display unit serving as a display unit in the control room. Output to 6080. The user can observe the image displayed on the display 6080 and obtain information on the inside of the patient 6061 body.

  In addition, the image processor 6070 transfers the electrical signal output from the radiation detection apparatus (radiation imaging apparatus) 6040 to a remote place via a transmission processing unit such as a telephone line 6090, and displays it in another place such as a doctor room. It can also be displayed on means (display) 6081. It is also possible to store an electrical signal output from the radiation detection apparatus (radiation imaging apparatus) 6040 in a recording means such as an optical disk and make a diagnosis by a remote doctor using this recording means. Moreover, it can also record on the film 6110 by the film processor 6100 used as a recording means.

  Here, in this application example, the radiation imaging apparatus is a conversion element that directly converts radiation into an electrical signal, for example, a direct conversion film such as amorphous selenium (a-Se) or polycrystalline CdS, and a scintillator is used. You may use the radiation imaging device which converts a radiation directly into an electric signal without using it.

It is a schematic diagram which shows the layout of the radiation detection apparatus which concerns on suitable 1st Embodiment of this invention. It is an equivalent circuit diagram which shows the circuit structure of the radiation detection area for AEC in the radiation imaging device which concerns on 1st Embodiment. It is a schematic diagram which shows the layout of the radiation detection area | region 5 for AEC. It is a schematic diagram which shows the connection relation of read-out TCPa and the radiation detection area 5 for AEC. It is a schematic diagram which shows the layout of the radiation detection apparatus which concerns on suitable 2nd Embodiment of this invention. It is a schematic diagram which shows the layout of the radiation detection apparatus which concerns on the modification of suitable 2nd Embodiment of this invention. It is a schematic diagram which shows the positional relationship of the radiation detection area for AEC and a lung field part. It is a schematic diagram which shows the positional relationship of the radiation detection area for AEC and the lung field part in the conventional radiation imaging device. It is a schematic diagram which shows the modification of 1st Embodiment. It is a schematic diagram which shows the example of application to the radiation imaging system of the radiation imaging device which concerns on suitable embodiment of this invention. It is a schematic diagram which shows the TFT type sensor and AEC circuit which concern on suitable embodiment of this invention. It is a figure which shows the drive timing chart in FIG.

Explanation of symbols

1: Insulating substrate 2, 2b: Reading device 3, 3e: Gate drive device 4: Pixel region 5: Radiation detection region for AEC 6040: Radiation detection device (radiation imaging device)
6050: X-ray tube 6060: X-ray 6061: Subject (patient)
6062: Chest 6070: Image processor 6080, 6081: Display 6090: Telephone line 6100: Film processor 6110: Film a, a1 to a9, b1 to b9: Read TCP
d1-d9, e1-e9: TCP for driving

Claims (8)

A plurality of pixel areas arranged in row and column directions on a base plate,
A plurality of printed wiring boards connected to the plurality of pixel regions ;
A readout unit that reads out an electrical signal from the plurality of pixel regions via the plurality of printed wiring boards;
An exposure control unit that controls exposure of the plurality of pixel regions ,
The plurality of pixel areas include a plurality of first pixel areas for imaging, and a plurality of second pixel areas for imaging and obtaining an output value for exposure control,
The first pixel region has a plurality of first pixels for imaging, and each of the plurality of first pixels converts a first semiconductor conversion element that converts radiation into an electrical signal, and the first A switch element that outputs an electrical signal converted by the semiconductor conversion element of
The second pixel region includes a plurality of second pixels for capturing an image and a plurality of second pixels for acquiring an output value for exposure control arranged in a group between the plurality of second pixels. 3, and each of the plurality of second pixels outputs a second semiconductor conversion element that converts radiation into an electric signal, and an electric signal converted by the second semiconductor conversion element A plurality of third pixels each having a third semiconductor conversion element that converts radiation into an electrical signal;
The plurality of printed wiring boards have a plurality of first printed wiring boards and a plurality of second printed wiring boards each having a spare wiring, and the spare wiring of the first printed wiring is the third wiring. A radiation imaging apparatus , wherein a pixel and the exposure control unit are not connected, and a spare wiring of the second printed wiring connects the third pixel and the exposure control unit . The second semiconductor conversion element includes a semiconductor conversion element having a first area and a semiconductor conversion element having a second area smaller than the first area,
The radiation imaging apparatus according to claim 1, wherein the semiconductor conversion element having the second area is disposed adjacent to the third semiconductor conversion element. Said first printed circuit board has a first semiconductor chip which transfers an electrical signal from the first pixel to the readout unit,
The second printed wiring board includes a second semiconductor chip that transfers an electrical signal from the second pixel to the readout unit,
The third semiconductor conversion element, a radiation imaging apparatus according to claim 1 or 2, characterized in that it is not connected to the second semiconductor chip. The first semiconductor conversion element and the second semiconductor conversion element each include a MIS photoelectric conversion element,
The third semiconductor conversion element includes a TFT type sensor,
Each of the plurality of printed wiring boards controls the exposure of the gate and drain auxiliary wirings for applying a bias voltage between the gate and drain of the TFT type sensor and the electrical signal output from the source of the TFT type sensor. 4. The radiation imaging apparatus according to claim 1, further comprising: a source spare wiring for transmitting to the unit AEC circuit. 5. The radiation imaging apparatus according to claim 4, wherein the source spare wiring is connected to a ground potential. The radiation imaging apparatus according to claim 4, wherein the plurality of spare wirings are arranged at both end portions of the printed wiring board. A radiation source for generating the radiation;
The radiation imaging apparatus according to any one of claims 1 to 6, wherein the radiation incident from the radiation source is converted into an electrical signal.
Image processing means for image processing the electrical signal output from the radiation imaging apparatus;
Display means for displaying an electrical signal image-processed by the image processing means;
A radiation imaging system comprising: The transmission processing means for transmitting the electrical signal output from the image processing means, the image processing means outputs the electrical signal to the display means via the transmission processing means. 8. The radiation imaging system according to 7 .

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