JPWO2013057941A1 - 2D image detector - Google Patents

Abstract

The imaging control unit operates the bias applying unit and the switch driving unit to accumulate charges in the capacitors of the plurality of detection elements, and reads out the charge information of all the capacitors as abnormal pixel information. A capacitor whose pixel information is equal to or greater than a predetermined value is determined to be an abnormal pixel, and the switch of the capacitor is operated by the switch driving unit to be in a non-conductive state. Therefore, since the abnormal pixel is electrically disconnected, the charge information of other normal detection elements connected to the same data line can be correctly extracted. As a result, excessive charges are accumulated during X-ray imaging, and no adverse effects are exerted on other normal detection elements of the same data line at the time of reading, and a high-quality image with no missing image can be obtained.

Description

  The present invention relates to a two-dimensional image detector for detecting an image by radiation such as X-rays, electromagnetic waves such as visible light and infrared rays.

  Conventionally, as this type of device, there is one including a semiconductor layer and an active matrix substrate that reads out electric charges generated in the semiconductor layer (see, for example, Patent Document 1). The semiconductor layer converts electromagnetic wave information into charge information. The active matrix substrate includes a plurality of charge storage capacitors for storing charge information generated in the semiconductor layer, a read switch for reading the charge information of each charge storage information via the data line, the semiconductor layer, and each charge storage capacitor And a switch for switching between a conductive state and a non-conductive state.

  In the case of performing the slot scan method in which irradiation and reading of radiation are alternately performed, the above apparatus sets a switch in a conductive state at the time of irradiation and sets a switch in a non-conductive state at the time of reading without irradiation. As a result, it is possible to suppress degradation in image quality due to scattered rays from the subject.

JP 2010-51689 A

However, the conventional example having such a configuration has the following problems.
That is, the conventional device is line-driven in which a data line for reading out each charge accumulation information is common to each pixel. Therefore, in any of the pixels connected to the same data line, if the charge storage capacity stores excessive charge, the charge of other pixels connected to the same data line is caused by the charge overflowing from the capacity. May be adversely affected. As a cause of excessive charge, there is a leakage current due to crystal defects in the semiconductor layer. When adversely affected, there is a problem that even if the pixel is normal, the pixel value sticks to the upper limit value, and normal pixel information cannot be obtained from pixels on the same data line.

  The present invention has been made in view of such circumstances, and by electrically disconnecting abnormal pixels, it is possible to correctly extract charge information from other pixels even if abnormal pixels exist on the same data line. An object of the present invention is to provide a two-dimensional image detector capable of

In order to achieve such an object, the present invention has the following configuration.
That is, the present invention provides a semiconductor layer for converting electromagnetic wave information into charge information, a plurality of charge storage capacitors for storing charge information converted by the semiconductor layer, and a charge of each charge storage capacitor through a data line. In a two-dimensional image detector comprising an active matrix substrate having a readout switch for reading out information, the two-dimensional image detector is arranged between the semiconductor layer and each of the charge storage capacitors, and switches between a conduction state and a non-conduction state for each pixel. A switch for switching to any one of the plurality of charge storage capacitors, and a switch driving means for switching any one of the switches to a conductive state or a non-conductive state. And operating the charge storage means and the switch driving means to store charges in the plurality of charge storage capacitors, Information is acquired as abnormal pixel information, and regarding the charge storage capacitor whose charge information is greater than or equal to a predetermined value among the abnormal pixel information, it is determined as an abnormal pixel and the switch driving means is operated to make the switch non-conductive. And a control means.

  [Operation / Effect] According to the present invention, the control means operates the charge accumulation means and the switch drive means to accumulate charges in a plurality of charge accumulation capacitors, and the charge information of all the charge accumulation capacitors is abnormal pixel information. Read as. If the charge storage capacity is greater than or equal to a predetermined value, it is determined that the pixel is an abnormal pixel, and the switch of the charge storage capacity is turned off by operating the switch driving means. Accordingly, since the abnormal pixel is electrically disconnected, the charge information of other normal pixels connected to the same data line can be correctly extracted.

  In the present invention, it is preferable that the charge accumulating unit applies a bias voltage, which is lower than a bias voltage used when photographing by irradiating electromagnetic waves, to the semiconductor layer.

  If there is a defect in the semiconductor layer, it is possible to store charges in the charge storage capacitor with a bias voltage lower than that without applying a bias voltage during photographing. Therefore, power consumption can be suppressed. For example, during normal photographing, a bias voltage higher than 0.1 and about 0.3 V / μm is applied, but abnormal pixels can be determined even at a lower voltage of 0.1 V / μm.

  In the present invention, it is preferable that the charge accumulating unit applies a bias voltage for photographing to the semiconductor layer and emits an electromagnetic wave.

  An abnormal pixel is determined in a normal shooting state in which an electromagnetic wave is applied by applying a bias voltage for shooting. Thereby, it is possible to determine an abnormal pixel even when the leakage current of the semiconductor layer increases only when the electromagnetic wave is irradiated during normal photographing.

  In the present invention, the control means stores all the charges by setting all the switches of the plurality of charge storage capacitors to a conductive state, reads out the charge information of the plurality of charge storage capacitors, and as a result, detects abnormal pixels. It is preferable that the charge storage capacitor switch corresponding to the center of the region including the non-conductive state is made non-conductive to store the charge, read the charge information, and repeat this to acquire the abnormal pixel information.

  Depending on the defect of the semiconductor layer, if abnormal pixel information is acquired with all the charge storage capacitor switches turned on, other normal pixels of the same data line may be erroneously determined as abnormal pixels due to the influence of the abnormal pixels. Can occur. Therefore, all the switches of the plurality of charge storage capacitors are turned on to store the charges and read the charge information. As a result, the charge storage capacitor switch corresponding to the center of the region that has become an abnormal pixel is set in a non-conductive state, and the charge is stored again to read the charge information. By setting the switch to the non-conductive state, the charge information of normal pixels on the same data line can be read correctly, so that abnormal pixels and normal pixels can be determined appropriately. By detecting such an abnormal pixel such as chasing, the abnormal pixel information can be made accurate in a relatively short time.

  Also, in the present invention, the control means causes only one charge storage capacitor switch of the plurality of charge storage capacitors to be in a conductive state and other charge storage capacitor switches to be in a non-conductive state to store charges. , Reading out the charge information of the one charge storage capacitor, and sequentially reading out the charge information of all the charge storage capacitors by setting the switches one by one for the remaining charge storage capacitors to obtain the abnormal pixel information. preferable.

  Depending on the defect of the semiconductor layer, if abnormal pixel information is acquired with all the charge storage capacitor switches turned on, other normal pixels of the same data line may be erroneously determined as abnormal pixels due to the influence of the abnormal pixels. Can occur. Therefore, among the plurality of charge storage capacitors, only one charge storage capacitor switch is turned on and the other charge storage capacitor switches are turned off to store charges, and the charge information of one charge storage capacitor is stored. Read, sequentially, the charge information of all the charge storage capacitors is read by turning on the switches one by one for the remaining charge storage capacitors. By detecting abnormal pixels one by one in this way, abnormal pixel information can be obtained accurately, although detection takes time.

  Also, in the present invention, the control means turns on only one charge storage capacitor switch in each data line among the plurality of charge storage capacitors and makes another charge storage in the same data line. Charges are stored by setting the capacitance switch to the non-conductive state, the charge information of one charge storage capacitor is read out in the data line, and the switches are sequentially turned on one by one for the remaining charge storage capacitors in the data line. It is preferable to read out the charge information of all the charge storage capacitors and acquire the abnormal pixel information.

  Depending on the defect of the semiconductor layer, if abnormal pixel information is acquired with all the charge storage capacitor switches turned on, other normal pixels of the same data line may be erroneously determined as abnormal pixels due to the influence of the abnormal pixels. Can occur. Therefore, only one charge storage capacitor switch in each data line is turned on, and other charge storage capacitor switches in the same data line are turned off to store charges. The charge information of one charge storage capacitor is read out, and the charge information of all the charge storage capacitors is read out by sequentially turning on the switches one by one for the remaining charge storage capacitors in the data line. By detecting each abnormal pixel in the data line in this way, it is possible to accurately acquire abnormal pixel information while reducing the time required for detection.

  According to the present invention, the storage unit stores the abnormal pixel information. The control unit stores the acquired abnormal pixel information in the storage unit, and based on the abnormal pixel information stored in the storage unit, the storage unit stores the abnormal pixel information. It is preferable to operate the switch driving means.

  By storing the abnormal pixel information in the storage means, the control means can appropriately operate the switch drive means by referring to the storage means.

  Moreover, in this invention, it is preferable that the said control means acquires the said abnormal pixel information regularly.

  By acquiring abnormal pixel information periodically, even if the characteristics of the semiconductor layer change with time, the switch can be appropriately operated based on the latest abnormal pixel information.

  According to the two-dimensional image detector of the present invention, the control means operates the charge storage means and the switch drive means to store charges in the plurality of charge storage capacitors, and abnormally stores the charge information of all the charge storage capacitors. Read out as pixel information. If the charge storage capacity is greater than or equal to a predetermined value, it is determined that the pixel is an abnormal pixel, and the switch of the charge storage capacity is turned off by operating the switch driving means. Accordingly, since the abnormal pixel is electrically disconnected, the charge information of other normal pixels connected to the same data line can be correctly extracted.

It is a block diagram which shows schematic structure of the X-ray imaging apparatus provided with the two-dimensional image detector which concerns on an Example. It is a figure which shows the connection relation of an active matrix substrate and an external circuit. It is the longitudinal cross-sectional view which showed the two-dimensional image detector typically. It is a block diagram which shows the principal part of an imaging | photography control part. It is the flowchart which showed the procedure which acquires abnormal pixel information.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a schematic configuration of an X-ray imaging apparatus including a two-dimensional image detector according to an embodiment.

  The top plate 1 is made of a member that transmits X-rays, and a subject M to be examined is placed thereon. An X-ray tube 3 is disposed above the top plate 1. A flat panel detector 5 is disposed on the opposite side of the X-ray tube 3 across the top plate 1.

  The flat panel detector 5 corresponds to the “two-dimensional image detector” in the present invention.

  The imaging control unit 7 controls an irradiation control unit 9 that controls X-ray irradiation from the X-ray tube 3. The irradiation control unit 9 is controlled by a command signal output from the imaging control unit 7 in response to an instruction from the keyboard 11 or mouse 13 operated by the photographer. Information such as the X-ray irradiation intensity and irradiation time of the X-ray tube 3 is instructed from the keyboard 11 and the mouse 13.

  Signals corresponding to transmitted X-rays detected by the flat panel detector 5 (signals including charge information described later) are collected by the signal collecting unit 15. The collected signal is processed in the data processing unit 17 and an X-ray image is displayed on the monitor 19. The flat panel detector 5 is connected to a bias applying unit 21 for applying a bias voltage to an electrode layer 33 described later. The bias application unit 21 is controlled by the imaging control unit 7.

  The bias applying unit 21 and the X-ray tube 3 correspond to the “charge storage unit” in the present invention.

  Here, the flat panel detector 5 will be described in detail with reference to FIGS. 2 is a diagram showing the connection relationship between the active matrix substrate and the external circuit, and FIG. 3 is a longitudinal sectional view schematically showing the two-dimensional image detector.

  The active matrix substrate 23 has detection elements DU arranged in a two-dimensional matrix, and is patterned on an insulating substrate 25 such as glass. The active matrix substrate 23 includes a carrier collection electrode 27, a capacitor Ca corresponding to “charge storage capacity”, and a thin film transistor Tr. The carrier collection electrode 27 collects charge information converted by the semiconductor layer 29. The capacitor Ca stores the charge information collected by the carrier collection electrode 27. The thin film transistor Tr corresponding to the “read switch” in the present invention is a switching element that is turned on and off by an external signal and reads the charge information stored in the capacitor Ca.

  A switch 31 is provided between the semiconductor layer 29 and the carrier collecting electrode 27 and the capacitor Ca. One detection element DU corresponding to a “pixel” in the present invention includes a carrier collection electrode 27, a capacitor Ca, a switch 31, a thin film transistor Tr, and a semiconductor layer 29 and an electrode layer 33 in regions corresponding to these. Has been. A bias voltage Va is applied to the electrode layer 33 by the bias applying unit 21. The two-dimensional matrix of the active matrix substrate 23 is composed of, for example, 1536 × 1536 detection elements DU, but is simplified to 3 × 3 for easy understanding of the description. The switch 31 is preferably a normally closed type. As will be described later, the switch 31 is turned off for a detection element DU having an abnormality, but the number of detection elements DU is generally smaller than that of a normal detection element DU. Therefore, the drive power for turning off can be reduced by using the normally closed switch 31.

  Note that the semiconductor layer 29 described above has, for example, high resistance to darkness, good photoconductive properties with respect to X-ray irradiation, and amorphous selenium (amorphous selenium (a-Se) capable of forming a large area by vapor deposition. )). Further, the semiconductor layer 29 is formed with a thickness of 300 to 1200 μm by, for example, a vacuum deposition method.

  As the semiconductor layer 29, a material having a crystal structure such as CdZnTe and generating more charges can be used. When CdZnTe is used for the semiconductor layer 29, it is preferably formed by a sublimation method. In the X-ray imaging apparatus, in order to irradiate energy of several tens to several hundreds keV, it is preferable to form a film containing Zn having a thickness of 100 to 600 μm containing several to several tens mol% by the proximity sublimation method.

  The active matrix substrate 23 includes gate lines G1 to G3 and data lines D1 to D3. The gate lines G1 to G3 are electrically connected to the gate of the thin film transistor Tr for each row of the detection elements DU. The data lines D1 to D3 are electrically connected to the reading side of the thin film transistor Tr for each column of the detection elements DU. Further, the active matrix substrate 23 includes switch lines SL1 to SL3 for each detection element DU. The switch lines SL1 to SL3 are for individually switching between the conduction state and the non-conduction state of the switch 31 of all the detection elements DU. In FIG. 2, switch lines SL1 to SL3 are drawn for each row for the purpose of illustration, but the switches 31 of each detection element DU can be individually switched between a conductive state and a non-conductive state. In the following description, the gate lines G1 to G3, the data lines D1 to D3, and the switch lines SL1 to SL3 are referred to as the gate line G, the data line D, and the switch line SL unless particularly distinguished.

  The gate lines G <b> 1 to G <b> 3 are connected to the gate driving unit 35. The data lines D1 to D3 are connected to the data reading unit 37. The data reading unit 37 includes a charge / voltage conversion amplifier, a multiplexer, and an A / D converter. The switch lines SL1 to SL3 are connected to the switch drive unit 39.

  The gate driver 35 applies a voltage to the gate lines G <b> 1 to G <b> 3 to turn on the thin film transistor Tr and output the charge information stored in the capacitor Ca from the data line D to the data reading unit 37. The data reading unit 37 converts the received charge information into a voltage signal, converts the plurality of voltage signals into one voltage signal, converts the voltage signal into a digital signal, and outputs the digital signal. All the charge information converted in this way is collected by the signal collecting unit 15. The switch drive unit 39 switches the switch 31 of any detection element DU between the conductive state and the non-conductive state according to an instruction from an abnormal pixel determination unit 43 described later.

  The switch drive unit 39 corresponds to “switch drive means” in the present invention.

  The imaging control unit 7 described above will be described with reference to FIG. FIG. 4 is a block diagram illustrating a main part of the imaging control unit.

  The imaging control unit 7 controls the irradiation control unit 9 and the bias application unit 21 as described above, and also performs the following control.

  The imaging control unit 7 includes an abnormal pixel information memory 41 and an abnormal pixel determination unit 43. The abnormal pixel memory 41 stores abnormal pixel information obtained by the abnormal pixel information acquisition process under the control of the imaging control unit 7. The abnormal pixel determination unit 43 accesses the abnormal pixel information memory 41, compares the charge information of each detection element DU in the abnormal pixel information with a predetermined value, and determines which detection element DU is abnormal. Determine if there is. Then, the abnormal pixel determination unit 43 sets the switch 31 of the detection element DU that has been determined to be abnormal by operating the switch driving unit 39 to a non-conductive state.

  The photographing control unit 7 described above corresponds to the “control unit” in the present invention.

  Next, an operation for acquiring abnormal pixel information in the above-described apparatus will be described with reference to FIG. FIG. 5 is a flowchart showing a procedure for acquiring abnormal pixel information. The acquisition of abnormal pixel information is a process performed before the subject M is imaged by the X-ray imaging apparatus. Preferably, taking into account the change over time in the semiconductor layer 29 of the flat panel detector 5, it is more preferably performed at every photographing, at the start-up of the apparatus, or periodically. Accordingly, the switch 31 can be appropriately operated regardless of a change in the semiconductor layer 29 with time, and a captured image free from artifacts due to abnormal pixels can be obtained over a long period of time.

Step S1
The imaging control unit 7 applies a bias voltage Va to the flat panel detector 5. The bias voltage Va at this time may be lower than the bias voltage Va at the time of imaging by X-ray irradiation because there is no need to accelerate the charge generated in the semiconductor layer 29. For example, since the bias voltage Va of about 0.3 V / μm is applied during normal X-ray imaging, a lower bias voltage Va (for example, 0.1 V / μm) may be applied. Thereby, power consumption can be suppressed.

Step S2
Abnormal pixel information is acquired. In a state where the bias voltage Va is applied, the imaging control unit 7 collects the charge information of each detection element DU from the flat panel detector 5. Specifically, the gate lines G <b> 1 to G <b> 3 are sequentially turned on, and charge information is collected from all the detection elements DU via the data reading unit 37. The charge information obtained from all the detection elements DU is stored in the abnormal pixel information memory 41 as abnormal pixel information.

Step S3
An abnormal pixel is determined based on the abnormal pixel information. The abnormal pixel determination unit 43 refers to the abnormal pixel information in the abnormal pixel information memory 41 to determine which detection element DU is abnormal. Specifically, for example, when the value exceeds 10% with reference to the maximum output value (maximum charge information) at the detection element DU during X-ray imaging, the detection element DU is abnormal. Judge. It is possible for the normal detection element DU to generate 10% of charge information with respect to the maximum output value even though the bias voltage Va is low and X-ray irradiation is not performed. Because there is no. Since the bias voltage Va is low and the charge information is small, the probability that an abnormal detection element DU adversely affects other detection elements DU of the same data line D is sufficiently low. Therefore, in this case, the probability that another detection element DU is erroneously determined to be abnormal due to an adverse effect of the abnormal detection element DU is sufficiently low. However, depending on a defect or the like of the detection element DU, there may be a situation in which it is erroneously determined that another detection element DU on the same data line D is abnormal in acquiring abnormal pixel information. A technique for avoiding this will be described later in a modification.

Step S4
The abnormal pixel switch 31 is turned off. The abnormal pixel determination unit 43 operates the switch drive unit 39 of the flat panel detector 5 based on the determination result. Specifically, the switches 31 of all the detection elements DU that are determined to be abnormal pixels are set to be in a non-conductive state. Thereby, the detection element DU which is an abnormal pixel is electrically separated.

  After acquiring abnormal pixel information as described above and separating abnormal pixels, the imaging control unit 7 performs X-ray imaging by irradiating the subject M with X-rays.

  According to the present embodiment, the imaging control unit 7 operates the bias applying unit 21 and the switch driving unit 39 to accumulate charges in the capacitors Ca of the plurality of detection elements DU, and stores the charge information of all the capacitors Ca as abnormal pixels. Read as information. If the pixel information of the capacitor Ca is greater than or equal to a predetermined value, it is determined that the pixel is an abnormal pixel, and the switch 31 of the capacitor Ca is operated to operate in a non-conductive state. Therefore, since the abnormal pixel is electrically disconnected, the charge information of other normal detection elements DU connected to the same data line D can be correctly extracted. As a result, it is possible to obtain a high-quality image without accumulating excessive charges during X-ray imaging and without adversely affecting other normal detection elements DU of the same data line D during reading.

  Next, a modified example of obtaining the abnormal pixel information described above will be described.

  When there is an abnormality in a plurality of detection elements DU in the same data line D of abnormal pixel information, a very large amount of charge information is accumulated in the capacitor Ca of the detection element DU having an abnormality. This may be a result of adversely affecting the charge information of other normal detection elements DU. When the bias voltage Va is low and the X-ray irradiation is not performed as in the above-described embodiment, the charge information is small, so that such an adverse effect is unlikely to occur. However, when the bias voltage Va is increased or X-ray irradiation is performed simultaneously, the above situation can occur. In such a state, even if the switch 31 is operated based on the abnormal pixel information, the surrounding normal detection elements DU are also turned off in addition to the abnormal detection elements DU. In order to avoid such misjudgment, the following is preferable.

(Modification 1)
All the switches 31 of all the detection elements DU are turned on to accumulate charges, and the charge information of the plurality of detection elements DU is read. As a result, only the switch 31 of the detection element DU corresponding to the center of the region including the detection element DU that is abnormal in the abnormal pixel information is set in a non-conductive state, charge information is accumulated again, and pixel information is read out. If only the detection element DU is abnormal, the surrounding detection element DU may become normal if abnormal pixel information is reacquired in this state. Abnormal pixel information is acquired by repeating this process an appropriate number of times and attempting to drive it.

  In this way, it is possible to acquire abnormal pixel information that can appropriately determine a detection element DU having an abnormality and a normal detection element DU. Therefore, the abnormal pixel information can be made accurate in a relatively short time.

(Modification 2)
Of all the detection elements DU, only the switch 31 of one detection element DU is turned on, and the switches 31 of other detection elements DU are turned off to accumulate charges, and the charge information of that one detection element DU is stored. read out. Then, the switch 31 is turned on one by one for the remaining detection elements DU, and the charge information of all the detection elements DU is read out. Thereby, abnormal pixel information is acquired.

  By detecting the charge information of the detection element DU one by one in this way, abnormal pixel information can be accurately acquired although it takes time to detect.

(Modification 3)
Among all the detection elements DU, only the switch 31 of one detection element DU in each data line D is made conductive, and the switch 31 of the other detection element DU is made non-conductive in the same data line D. And the charge information of one detection element DU in the data line D is read out. Then, the switch 31 is sequentially turned on one by one for the remaining detection elements DU in the data line D, and the charge information of all the detection elements DU is read to acquire abnormal pixel information.

  In this way, by detecting the charge information of each detection element DU in the data line D, it is possible to accurately acquire abnormal pixel information while reducing the time required for detection.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In the above-described embodiment, only the bias voltage Va lower than that during X-ray imaging is applied when acquiring abnormal pixel information. However, the bias voltage Va at the time of X-ray imaging may be applied, and X-rays may be irradiated from the X-ray tube 3 to acquire abnormal pixel information. Thereby, for example, a detection element DU having a defect in which a leakage current increases only at the time of X-ray irradiation can be detected as an abnormal pixel.

  (2) In the above-described embodiment, the abnormal pixel information memory 41 is provided, and abnormal pixel information is stored therein. However, the abnormal pixel information memory 41 is not necessarily provided. In that case, while reading abnormal pixel information from the data reading unit 37, it is determined whether or not the abnormal pixel determination unit 43 is abnormal in order, and the switch driving unit 39 is operated to switch the switch corresponding to the abnormal pixel. 21 may be fixed off.

  As described above, the present invention is suitable for a two-dimensional image detector that detects an image.

M ... Subject 1 ... Top plate 3 ... X-ray tube 5 ... Flat panel detector 7 ... Imaging control unit 9 ... Irradiation control unit 21 ... Bias application unit 23 ... Active matrix substrate DU ... Detection element 25 ... Insulating substrate 27 ... Carrier Collection electrode Ca ... Capacitor Tr ... Thin film transistor 29 ... Semiconductor layer 31 ... Switch 33 ... Electrode layer Va ... Bias voltage G1-G3 ... Gate line D1-D3 ... Data line SL1-SL3 ... Switch line 35 ... Gate drive part 37 ... Data read-out Unit 39 ... Switch drive unit 41 ... Abnormal pixel memory 43 ... Abnormal pixel determination unit

Claims (8)

A semiconductor layer for converting electromagnetic wave information into charge information, a plurality of charge storage capacitors for storing charge information converted by the semiconductor layer, and reading for reading out charge information of each charge storage capacitor via a data line In a two-dimensional image detector comprising an active matrix substrate with a switch,
A switch that is disposed between the semiconductor layer and each of the charge storage capacitors, and switches between a conductive state and a non-conductive state for each pixel;
Charge storage means for storing charge in the plurality of charge storage capacitors;
Of the switches, switch driving means for switching any switch between a conductive state and a non-conductive state;
The charge storage means and the switch driving means are operated to store charges in the plurality of charge storage capacitors, and charge information of all the charge storage capacitors is acquired as abnormal pixel information. For a charge storage capacity greater than or equal to a predetermined value, a control means that determines that the pixel is an abnormal pixel and operates the switch driving means to place the switch in a non-conductive state;
A two-dimensional image detector. The two-dimensional image detector according to claim 1,
The two-dimensional image detector, wherein the charge accumulating means applies a bias voltage to the semiconductor layer that is lower than a bias voltage when photographing by irradiating electromagnetic waves. The two-dimensional image detector according to claim 1,
The two-dimensional image detector, wherein the charge accumulating unit applies a bias voltage for photographing to the semiconductor layer and emits an electromagnetic wave. The two-dimensional image detector according to any one of claims 1 to 3,
The control means sets all the switches of the plurality of charge storage capacitors in a conductive state to store charges, reads the charge information of the plurality of charge storage capacitors, and as a result, corresponds to the center of a region including abnormal pixels A two-dimensional image detector characterized in that a charge storage capacitor switch is set in a non-conducting state to accumulate charges and read out charge information, and repeat this to acquire the abnormal pixel information. The two-dimensional image detector according to any one of claims 1 to 3,
The control means stores only one charge storage capacitor among the plurality of charge storage capacitors in a conductive state and stores other charge storage capacitor switches in a non-conductive state to store the one charge storage. A two-dimensional image characterized by reading out the charge information of the capacitors and sequentially reading out the charge information of all the charge storage capacitors with the switches one by one for the remaining charge storage capacitors to obtain the abnormal pixel information. Detector. The two-dimensional image detector according to any one of claims 1 to 3,
The control means turns on only one charge storage capacitor switch in each data line among the plurality of charge storage capacitors, and turns off the other charge storage capacitor switch in the same data line. The charge is stored as a state, the charge information of one charge storage capacitor is read out in the data line, and the switches are sequentially turned on one by one for the remaining charge storage capacitors in the data line. A two-dimensional image detector, wherein charge information is read to obtain the abnormal pixel information. The two-dimensional image detector according to any one of claims 1 to 6,
Storage means for storing the abnormal pixel information;
The control means stores the acquired abnormal pixel information in the storage means, and operates the switch driving means based on the abnormal pixel information stored in the storage means. The two-dimensional image detector according to any one of claims 1 to 7,
The two-dimensional image detector, wherein the control means periodically acquires the abnormal pixel information.

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