JP2012145543A - Radiographic imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic imaging device that suppresses the effect of noise caused by electromagnetic waves from a power supply unit, and accurately detects irradiation of radiation.SOLUTION: A radiographic imaging device includes pixels for radiation detection 32A, for detecting radiation with which an imaging area 31 has been irradiated, arranged in various distribution in accordance with the degree of separation from a DC/DC converter 71, and detects irradiation of radiation based on the detection result by each of the pixels for radiation detection 32A.

Description

  The present invention relates to a radiographic image capturing apparatus, and more particularly to a radiographic image capturing apparatus that acquires a radiographic image indicated by radiation transmitted through a region to be imaged.

  In recent years, radiation detectors such as flat panel detectors (FPDs) that can arrange radiation sensitive layers on TFT (Thin Film Transistor) active matrix substrates and convert radiation directly into digital data have been put into practical use. A radiographic image capturing apparatus that captures a radiographic image represented by irradiated radiation has been put into practical use. The radiation detector used in this radiographic imaging apparatus has an indirect conversion system in which radiation is converted into light by a scintillator and then converted into electric charge in a semiconductor layer such as a photodiode, or the like. There is a direct conversion method in which a semiconductor layer such as amorphous selenium converts into electric charge, and there are various materials that can be used for the semiconductor layer in each method.

By the way, in a radiographic imaging apparatus, the technique which detects the start and completion | finish of irradiation of a radiation, the irradiation amount of a radiation, and controls the radiation source which irradiates a radiation is known, for example in patent document 1 on a board | substrate. A radiation detector is disclosed in which the pixels are formed in a matrix and some of the pixels are AEC pixels.

JP 2004-251892 A

  By the way, a portable radiation image capturing apparatus (hereinafter also referred to as “electronic cassette”) that captures a radiation image represented by irradiated radiation by using this radiation detector has been put into practical use.

  This electronic cassette is excellent in portability, and it is possible to take an image of the subject while it is placed on a stretcher or bed, and the position of the electronic cassette can be easily adjusted to adjust the imaging part. It is possible to cope flexibly when photographing a person. For this reason, it is more convenient for the electronic cassette to perform communication with an external device such as a control device (so-called console) by wireless communication than by wired communication using a cable.

  By the way, when the electronic cassette adopts a wireless communication system in which a cable is not connected to an external device, it is necessary to incorporate a battery and transform the power of the battery to supply power to each internal device. As a power supply unit that transforms the supplied power into different voltages, a switching power supply such as a DC / DC converter, a transformer using a coil, or the like is used. The switching power supply incorporates a switching element, and the output voltage is determined by the ratio of the input voltage and the time during which the switching element is turned on / off (duty ratio, duty cycle).

  However, the switching power supply generates an electromagnetic wave when the switching element is repeatedly turned on and off, and the transformer also generates an electromagnetic wave when an alternating current flows through the coil. And the noise generate | occur | produces in the detection part which detects a radiation by the influence of this generated electromagnetic waves.

  For this reason, when it is assumed that the radiation irradiation is detected from the change in the electrical signal generated in the detection unit, the radiation irradiation cannot be accurately detected if noise occurs in the detection unit.

  In addition, although the case where wireless communication was performed using an electronic cassette, which is a portable radiographic image capturing device, the same problem occurred when wireless communication was performed using a stationary radiographic image capturing device. To do.

  The present invention has been made in view of the above-described facts, and an object of the present invention is to provide a radiographic imaging apparatus capable of accurately detecting radiation irradiation while suppressing the influence of noise due to the influence of electromagnetic waves irradiated from a power supply unit. .

  In order to achieve the above object, the radiographic imaging device according to claim 1 generates charges when irradiated with radiation or light converted from radiation, and pixels that accumulate the generated charges are in the imaging region. A plurality of radiation detectors that output an electrical signal corresponding to the amount of electric charge accumulated in each pixel, a power supply unit that transforms supplied power into different voltages, and a distribution according to the degree of separation from the power supply unit And a detection unit that detects the radiation irradiated to the imaging region, and a detection unit that detects radiation irradiation based on a detection result by the detection unit.

  In the radiographic imaging apparatus according to claim 1, the radiation detector generates charges when irradiated with radiation or light converted from radiation, and a plurality of pixels for storing the generated charges are provided in the imaging region, An electrical signal corresponding to the amount of charge accumulated in the pixel is output. Moreover, the power supply part which transforms the supplied electric power into a different voltage is provided.

  And in this invention, the detection part which detects the radiation irradiated to the imaging | photography area | region is arrange | positioned by changing distribution according to the separation degree from a power supply part, and irradiation of radiation based on the detection result by a detection part by a detection means Is detected.

  Thus, according to the radiographic imaging device of claim 1, the detection unit that detects the radiation irradiated to the imaging region is arranged with a distribution changed according to the degree of separation from the power supply unit, and the detection unit By detecting the irradiation of radiation based on the detection result, it is possible to accurately detect the irradiation of radiation while suppressing the influence of noise due to the influence of electromagnetic waves irradiated from the power supply unit.

  In addition, as for invention of Claim 1, like the invention of Claim 2, the said detection part may be arrange | positioned so much as the area | region away from the said power supply part.

  Further, according to the first aspect of the present invention, as in the third aspect of the present invention, the detection unit is arranged in a region closer to the power supply unit, and the detection unit is located closer to the power supply unit. May detect radiation irradiation based on the result of adding or averaging the detection results of two or more detection units.

  Further, in the present invention, it is preferable that each region is divided approximately equally as in the invention described in claim 4.

  Further, in the invention described in claims 1 to 4, as in the invention described in claim 5, the pixel of the radiation detector may also serve as the detection unit.

  Further, according to the invention described in claims 1 to 4, as in the invention described in claim 6, the pixel is irradiated with radiation or light whose radiation has been converted while a bias voltage is applied. In this case, the sensor unit may generate a charge, and the detection unit may be a current detection unit that detects an amount of current flowing through a wiring that applies a bias voltage to the sensor unit.

  In addition, the invention described in claim 1 to claim 4 further includes an amplifier that amplifies an electrical signal output from each pixel of the radiation detector, as in the invention described in claim 7, May be a current detector that detects the amount of amplifier current supplied to the amplifier.

  Further, the invention according to claim 1 to claim 7 further includes a battery serving as a power source of the power supply unit, as in the invention according to claim 8, wherein the power supply unit and the battery are radiation detectors. It is preferable that they are arranged at positions facing each other with a gap therebetween.

  According to an eighth aspect of the invention, as in the ninth aspect of the invention, the detection unit corresponds to a portion where a power supply line for supplying power from the battery to the power supply unit is provided. It is preferable that the area is not arranged.

  According to the present invention, it is possible to obtain an effect that radiation irradiation can be accurately detected while suppressing an influence of noise due to an electromagnetic wave irradiated from a power supply unit.

It is a block diagram which shows the structure of the radiation information system which concerns on 1st Embodiment. It is a side view which shows an example of the arrangement | positioning state of each apparatus in the radiography room of the radiographic imaging system which concerns on 1st Embodiment. It is a cross-sectional schematic diagram which shows schematic structure of the 3 pixel part of the radiation detector which concerns on 1st Embodiment. It is the cross-sectional side view which showed schematically the structure of the signal output part of 1 pixel part of the radiation detector which concerns on 1st Embodiment. It is a top view which shows the structure of the radiation detector which concerns on 1st Embodiment. It is a perspective view which shows the structure of the electronic cassette concerning 1st Embodiment. It is a section side view showing the composition of the electronic cassette concerning a 1st embodiment. It is a block diagram which shows the principal part structure of the electric system of the radiographic imaging system which concerns on 1st Embodiment. It is a top view which shows an example of the arrangement | positioning state of the radiation detection pixel of the radiation detector which concerns on 1st Embodiment. It is a cross-sectional side view for demonstrating the 1st radiation image front surface reading system and back surface reading system. It is a top view which shows an example of the arrangement | positioning state of the radiation detection pixel of the radiation detector which concerns on 2nd Embodiment. It is a top view which shows the structure of the radiation detector which concerns on 3rd Embodiment. It is a perspective view which shows the structure of the electronic cassette concerning 3rd Embodiment. It is sectional drawing which showed typically the structure of the radiation detector and radiation detection part which concern on 3rd Embodiment. It is a block diagram which shows the principal part structure of the electric system of the electronic cassette concerning 3rd Embodiment. It is a top view which shows an example of the arrangement | positioning state of the sensor part of the radiation detection part which concerns on 3rd Embodiment. It is a top view which shows an example of the arrangement | positioning state of the sensor part of the radiation detection part which concerns on 3rd Embodiment. It is a block diagram which shows the principal part structure of the electric system of the electronic cassette concerning 4th Embodiment. It is a block diagram which shows the principal part structure of the electric system of the electronic cassette concerning 5th Embodiment. It is a top view which shows an example of a structure of the radiation detector which concerns on another form. It is a top view which shows an example of the arrangement | positioning state of the radiation detection pixel of the radiation detector which concerns on another form. It is a top view which shows an example of the arrangement | positioning state of the antenna which concerns on another form, and the amplifier in a 2nd signal processing part. It is a top view which shows an example of the arrangement | positioning state of the antenna which concerns on another form, and a 2nd signal processing part. It is a top view which shows an example of the arrangement | positioning state of the battery which concerns on another form, and a DC / DC converter.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. Here, a description will be given of an example in which the present invention is applied to a radiation information system that is a system for comprehensively managing information handled in a radiology department in a hospital.

  First, the configuration of a radiation information system (hereinafter referred to as “RIS” (Radiology Information System)) 100 according to the present embodiment will be described with reference to FIG.

  The RIS 100 is a system for managing information such as medical appointments and diagnosis records in the radiology department, and constitutes a part of a hospital information system (hereinafter referred to as “HIS” (Hospital Information System)).

  The RIS 100 includes a plurality of radiography requesting terminal devices (hereinafter referred to as “terminal devices”) 140, a RIS server 150, and a radiographic imaging system (hereinafter referred to as a radiographic imaging room (or operating room) in a hospital). , Which are referred to as “imaging systems”) 104, which are connected to a hospital network 102 composed of a wired or wireless LAN (Local Area Network) or the like. The RIS 100 constitutes a part of the HIS provided in the same hospital, and an HIS server (not shown) for managing the entire HIS is also connected to the in-hospital network 102.

  The terminal device 140 is used by doctors and radiographers to input and browse diagnostic information and facility reservations, and radiographic image capturing requests and imaging reservations are also performed via the terminal device 140. Each terminal device 140 includes a personal computer having a display device, and can communicate with the RIS server 150 via the hospital network 102.

  On the other hand, the RIS server 150 receives an imaging request from each terminal device 140 and manages a radiographic imaging schedule in the imaging system 104, and includes a database 150A.

  Database 150A includes patient (subject) attribute information (name, sex, date of birth, age, blood type, weight, patient ID (Identification), etc.), medical history, medical history, radiation images taken in the past, etc. Information regarding the patient, information regarding the electronic cassette 40 used in the imaging system 104, such as an identification number (ID information), model, size, sensitivity, start date of use, number of times of use, etc., and the electronic cassette 40 It includes the environment information which shows the environment which takes a radiographic image using, ie, the environment (for example, a radiography room, an operating room, etc.) which uses electronic cassette 40.

  The imaging system 104 captures a radiographic image by an operation of a doctor or a radiographer according to an instruction from the RIS server 150. The imaging system 104 includes a radiation generator 120 that irradiates a subject with radiation X (see also FIG. 6) that has been dosed according to the exposure conditions from a radiation source 121 (see also FIG. 2), and a subject. Electrons that incorporate a radiation detector 20 (see also FIG. 6) that absorbs radiation X that has passed through a region to be imaged by the person and generates charges, and generates image information indicating a radiation image based on the amount of charges generated. A cassette 40, a cradle 130 for charging a battery built in the electronic cassette 40, and a console 110 for controlling the electronic cassette 40 and the radiation generator 120 are provided.

  The console 110 acquires various types of information included in the database 150A from the RIS server 150 and stores them in an HDD 116 (see FIG. 8) described later, and uses the information as necessary to use the electronic cassette 40 and the radiation generator 120. Control.

  FIG. 2 shows an example of the arrangement state of each device in the radiation imaging room 180 of the imaging system 104 according to the present embodiment.

  As shown in the figure, the radiation imaging room 180 has a standing table 160 used when performing radiography in a standing position and a prone table 164 used when performing radiography in a lying position. The space in front of the standing stand 160 is set as a photographing position 170 of the subject when performing radiography in the standing position, and the space above the supine stand 164 is when performing radiography in the prone position. The imaging position 172 of the subject.

  The standing stand 160 is provided with a holding unit 162 that holds the electronic cassette 40, and the electronic cassette 40 is held by the holding unit 162 when a radiographic image is taken in the standing position. Similarly, the holding table 164 is provided with a holding unit 166 that holds the electronic cassette 40, and the electronic cassette 40 is held by the holding unit 166 when a radiographic image is taken in the lying position.

  Further, in the radiation imaging room 180, the radiation source 121 is placed around a horizontal axis (see FIG. 5) in order to enable radiation imaging in a standing position and radiation imaging in a lying position by radiation from a single radiation source 121. 2 is provided, and a support moving mechanism 124 is provided which can be rotated in the vertical direction (arrow b direction in FIG. 2) and can be moved in the horizontal direction (arrow c direction in FIG. 2). It has been. Here, the support moving mechanism 124 includes a drive source that rotates the radiation source 121 around a horizontal axis, a drive source that moves the radiation source 121 in the vertical direction, and a drive source that moves the radiation source 121 in the horizontal direction. Each is provided (not shown).

  On the other hand, the cradle 130 is formed with an accommodating portion 130 </ b> A capable of accommodating the electronic cassette 40.

  When the electronic cassette 40 is not in use, the built-in battery is charged in a state of being housed in the housing portion 130A of the cradle 130. When a radiographic image is taken, the electronic cassette 40 is taken out from the cradle 130 by a radiographer or the like, and the photographing posture is established. If it is in the upright position, it is held in the holding part 162 of the standing base 160, and if it is in the upright position, it is held in the holding part 166 of the standing base 164.

  Here, in the imaging system 104 according to the present embodiment, various types of information are transmitted and received between the radiation generation apparatus 120 and the console 110 and between the electronic cassette 40 and the console 110 by wireless communication.

  The electronic cassette 40 is not used only in a state where it is held by the holding part 162 of the standing base 160 or the holding part 166 of the prone base 164. When photographing, it can be used in a state where it is not held by the holding unit.

  Next, the configuration of the radiation detector 20 according to the present embodiment will be described. FIG. 3 is a schematic cross-sectional view schematically showing the configuration of the three pixel portions of the radiation detector 20 according to the present exemplary embodiment.

  As shown in the figure, in the radiation detector 20 according to the present embodiment, a signal output unit 14, a sensor unit 13, and a scintillator 8 are sequentially stacked on an insulating substrate 1. The pixels are configured by the sensor unit 13. A plurality of pixels are arranged on the substrate 1, and the signal output unit 14 and the sensor unit 13 in each pixel are configured to overlap each other.

  The scintillator 8 is formed on the sensor unit 13 via the transparent insulating film 7, and forms a phosphor that emits light by converting radiation incident from above (opposite side of the substrate 1) or from below into light. It is a thing. Providing such a scintillator 8 absorbs the radiation transmitted through the subject and emits light.

  The wavelength range of light emitted by the scintillator 8 is preferably a visible light range (wavelength 360 nm to 830 nm), and in order to enable monochrome imaging by the radiation detector 20, the wavelength range of green is included. Is more preferable.

  Specifically, the phosphor used in the scintillator 8 is preferably one containing cesium iodide (CsI) when imaging using X-rays as radiation, and has an emission spectrum of 420 nm to 700 nm upon X-ray irradiation. It is particularly preferable to use CsI (Tl) (cesium iodide with thallium added). Note that the emission peak wavelength of CsI (Tl) in the visible light region is 565 nm.

  The sensor unit 13 includes an upper electrode 6, a lower electrode 2, and a photoelectric conversion film 4 disposed between the upper and lower electrodes. The photoelectric conversion film 4 absorbs light emitted from the scintillator 8 and generates charges. It is composed of an organic photoelectric conversion material.

Since it is necessary for the upper electrode 6 to cause the light generated by the scintillator 8 to be incident on the photoelectric conversion film 4, it is preferable that the upper electrode 6 be made of a conductive material that is transparent at least with respect to the emission wavelength of the scintillator 8. It is preferable to use a transparent conductive oxide (TCO) having a high transmittance for visible light and a small resistance value. Although a metal thin film such as Au can be used as the upper electrode 6, TCO is preferable because it tends to increase the resistance value when it is desired to obtain a transmittance of 90% or more. For example, ITO, IZO, AZO, FTO, SnO ₂ , TiO ₂ , ZnO _{2 and the} like can be preferably used, and ITO is most preferable from the viewpoint of process simplicity, low resistance, and transparency. Note that the upper electrode 6 may have a single configuration common to all pixels, or may be divided for each pixel.

  The photoelectric conversion film 4 includes an organic photoelectric conversion material, absorbs light emitted from the scintillator 8, and generates a charge corresponding to the absorbed light. In this way, the photoelectric conversion film 4 containing an organic photoelectric conversion material has a sharp absorption spectrum in the visible range, and electromagnetic waves other than light emitted by the scintillator 8 are hardly absorbed by the photoelectric conversion film 4. The noise generated by the radiation such as being absorbed by the photoelectric conversion film 4 can be effectively suppressed.

  The organic photoelectric conversion material constituting the photoelectric conversion film 4 is preferably such that its absorption peak wavelength is closer to the emission peak wavelength of the scintillator 8 in order to absorb light emitted by the scintillator 8 most efficiently. Ideally, the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator 8, but if the difference between the two is small, the light emitted from the scintillator 8 can be sufficiently absorbed. . Specifically, the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength with respect to the radiation of the scintillator 8 is preferably within 10 nm, and more preferably within 5 nm.

  Examples of the organic photoelectric conversion material that can satisfy such conditions include quinacridone-based organic compounds and phthalocyanine-based organic compounds. For example, since the absorption peak wavelength in the visible region of quinacridone is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI (Tl) is used as the material of the scintillator 8, the difference in peak wavelength can be within 5 nm. Thus, the amount of charge generated in the photoelectric conversion film 4 can be substantially maximized.

  Next, the photoelectric conversion film 4 applicable to the radiation detector 20 according to the present embodiment will be specifically described.

  The electromagnetic wave absorption / photoelectric conversion site in the radiation detector 20 according to the present embodiment is configured by an organic layer including a pair of electrodes 2 and 6 and an organic photoelectric conversion film 4 sandwiched between the electrodes 2 and 6. be able to. More specifically, this organic layer is a part that absorbs electromagnetic waves, a photoelectric conversion part, an electron transport part, a hole transport part, an electron blocking part, a hole blocking part, a crystallization preventing part, an electrode, and an interlayer contact improvement. It can be formed by stacking or mixing parts.

  The organic layer preferably contains an organic p-type compound or an organic n-type compound.

  The organic p-type semiconductor (compound) is a donor organic semiconductor (compound) mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Accordingly, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound.

  An organic n-type semiconductor (compound) is an acceptor organic semiconductor (compound) mainly represented by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Accordingly, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound.

  The materials applicable as the organic p-type semiconductor and organic n-type semiconductor and the configuration of the photoelectric conversion film 4 are described in detail in Japanese Patent Application Laid-Open No. 2009-32854, and thus the description thereof is omitted. The photoelectric conversion film 4 may be formed by further containing fullerenes or carbon nanotubes.

  The thickness of the photoelectric conversion film 4 is preferably as large as possible in terms of absorbing light from the scintillator 8. However, when the thickness is more than a certain level, the photoelectric conversion film 4 is generated in the photoelectric conversion film 4 by a bias voltage applied from both ends of the photoelectric conversion film 4. Since electric field strength is reduced and charges cannot be collected, the thickness is preferably 30 nm to 300 nm, more preferably 50 nm to 250 nm, and particularly preferably 80 nm to 200 nm.

  In the radiation detector 20 shown in FIG. 3, the photoelectric conversion film 4 has a single configuration common to all pixels, but may be divided for each pixel.

  The lower electrode 2 is a thin film divided for each pixel. The lower electrode 2 can be made of a transparent or opaque conductive material, and aluminum, silver, or the like can be suitably used.

  The thickness of the lower electrode 2 can be, for example, 30 nm or more and 300 nm or less.

  In the sensor unit 13, by applying a predetermined bias voltage between the upper electrode 6 and the lower electrode 2, one of electric charges (holes, electrons) generated in the photoelectric conversion film 4 is moved to the upper electrode 6. The other can be moved to the lower electrode 2. In the radiation detector 20 of the present embodiment, a wiring is connected to the upper electrode 6, and a bias voltage is applied to the upper electrode 6 through this wiring. In addition, the polarity of the bias voltage is determined so that electrons generated in the photoelectric conversion film 4 move to the upper electrode 6 and holes move to the lower electrode 2, but this polarity is reversed. May be.

  The sensor unit 13 constituting each pixel only needs to include at least the lower electrode 2, the photoelectric conversion film 4, and the upper electrode 6. In order to suppress an increase in dark current, the electron blocking film 3 and the hole blocking film are used. 5 is preferably provided, and it is more preferable to provide both.

  The electron blocking film 3 can be provided between the lower electrode 2 and the photoelectric conversion film 4. When a bias voltage is applied between the lower electrode 2 and the upper electrode 6, electrons are transferred from the lower electrode 2 to the photoelectric conversion film 4. It is possible to suppress the dark current from increasing due to the injection of.

  An electron donating organic material can be used for the electron blocking film 3.

  The material actually used for the electron blocking film 3 may be selected according to the material of the adjacent electrode, the material of the adjacent photoelectric conversion film 4 and the like, and 1.3 eV or more from the work function (Wf) of the material of the adjacent electrode. Those having a large electron affinity (Ea) and an Ip equivalent to or smaller than the ionization potential (Ip) of the material of the adjacent photoelectric conversion film 4 are preferable. The material applicable as the electron donating organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, and thus the description thereof is omitted.

  The thickness of the electron blocking film 3 is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 13. It is 50 nm or more and 100 nm or less.

  The hole blocking film 5 can be provided between the photoelectric conversion film 4 and the upper electrode 6. When a bias voltage is applied between the lower electrode 2 and the upper electrode 6, the hole blocking film 5 is transferred from the upper electrode 6 to the photoelectric conversion film 4. It is possible to suppress the increase in dark current due to the injection of holes.

  An electron-accepting organic material can be used for the hole blocking film 5.

  The thickness of the hole blocking film 5 is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 13. Is from 50 nm to 100 nm.

  The material actually used for the hole blocking film 5 may be selected according to the material of the adjacent electrode, the material of the adjacent photoelectric conversion film 4 and the like, and 1.3 eV from the work function (Wf) of the material of the adjacent electrode. As described above, it is preferable that the ionization potential (Ip) is large and that the Ea is equal to or larger than the electron affinity (Ea) of the material of the adjacent photoelectric conversion film 4. Since the material applicable as the electron-accepting organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

  In addition, when a bias voltage is set so that holes move to the upper electrode 6 and electrons move to the lower electrode 2 among the charges generated in the photoelectric conversion film 4, the electron blocking film 3 and the hole blocking are set. The position of the film 5 may be reversed. Further, both the electron blocking film 3 and the hole blocking film 5 do not have to be provided. If either of them is provided, a certain amount of dark current suppressing effect is exerted on the surface of the substrate 1 below the lower electrode 2 of each pixel. An output unit 14 is formed. FIG. 4 schematically shows the configuration of the signal output unit 14.

  As shown in the figure, the signal output unit 14 according to the present embodiment corresponds to the lower electrode 2, and a capacitor 9 that accumulates the charges transferred to the lower electrode 2, and the electric charges accumulated in the capacitor 9 are electrically A field effect thin film transistor (Thin Film Transistor, hereinafter simply referred to as a thin film transistor) 10 that converts the signal into a signal and outputs the signal is formed. The region in which the capacitor 9 and the thin film transistor 10 are formed has a portion that overlaps the lower electrode 2 in a plan view. With this configuration, the signal output unit 14 and the sensor unit 13 in each pixel are thick. There will be overlap in the vertical direction. In order to minimize the plane area of the radiation detector 20 (pixel), it is desirable that the region where the capacitor 9 and the thin film transistor 10 are formed is completely covered by the lower electrode 2.

  The capacitor 9 is electrically connected to the corresponding lower electrode 2 through a wiring made of a conductive material penetrating an insulating film 11 provided between the substrate 1 and the lower electrode 2. Thereby, the electric charge collected by the lower electrode 2 can be moved to the capacitor 9.

  In the thin film transistor 10, a gate electrode 15, a gate insulating film 16, and an active layer (channel layer) 17 are stacked, and a source electrode 18 and a drain electrode 19 are formed on the active layer 17 at a predetermined interval. .

  The active layer 17 can be formed of, for example, amorphous silicon, amorphous oxide, organic semiconductor material, carbon nanotube, or the like. In addition, the material which comprises the active layer 17 is not limited to these.

The amorphous oxide constituting the active layer 17 is preferably an oxide containing at least one of In, Ga, and Zn (for example, In—O-based), and at least two of In, Ga, and Zn. An oxide containing In (eg, In—Zn—O, In—Ga—O, or Ga—Zn—O) is more preferable, and an oxide containing In, Ga, and Zn is particularly preferable. As the In—Ga—Zn—O-based amorphous oxide, an amorphous oxide whose composition in a crystalline state is represented by InGaO ₃ (ZnO) _m (m is a natural number less than 6) is preferable, and InGaZnO is particularly preferable. ₄ is more preferable.

  Examples of the organic semiconductor material that can form the active layer 17 include, but are not limited to, phthalocyanine compounds, pentacene, vanadyl phthalocyanine, and the like. In addition, about the structure of a phthalocyanine compound, since it is demonstrated in detail in Unexamined-Japanese-Patent No. 2009-212389, description is abbreviate | omitted.

  If the active layer 17 of the thin film transistor 10 is formed of an amorphous oxide, an organic semiconductor material, or a carbon nanotube, it will not absorb radiation such as X-rays, or even if it absorbs it, it will remain in a very small amount. Generation of noise in the portion 14 can be effectively suppressed.

  When the active layer 17 is formed of carbon nanotubes, the switching speed of the thin film transistor 10 can be increased, and the thin film transistor 10 having a low light absorption in the visible light region can be formed. In addition, when the active layer 17 is formed of carbon nanotubes, the performance of the thin film transistor 10 is remarkably deteriorated only by mixing a very small amount of metallic impurities into the active layer 17, so that extremely high purity carbon nanotubes can be obtained by centrifugation or the like. It is necessary to form by separating and extracting.

  Here, any of the amorphous oxides, organic semiconductor materials, carbon nanotubes constituting the active layer 17 of the thin film transistor 10 and organic photoelectric conversion materials constituting the photoelectric conversion film 4 can be formed at a low temperature. . Therefore, the substrate 1 is not limited to a substrate having high heat resistance such as a semiconductor substrate, a quartz substrate, and a glass substrate, and a flexible substrate such as plastic, aramid, or bionanofiber can also be used. Specifically, flexible materials such as polyesters such as polyethylene terephthalate, polybutylene phthalate, polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), etc. A conductive substrate can be used. If such a plastic flexible substrate is used, it is possible to reduce the weight, which is advantageous for carrying around, for example.

  In addition, the substrate 1 is provided with an insulating layer for ensuring insulation, a gas barrier layer for preventing permeation of moisture and oxygen, an undercoat layer for improving flatness or adhesion to electrodes, and the like. May be.

  On the other hand, since aramid can be applied at a high temperature process of 200 ° C. or more, the transparent electrode material can be cured at a high temperature to reduce its resistance, and it can be used for automatic mounting of a driver IC including a solder reflow process. Moreover, since aramid has a thermal expansion coefficient close to that of ITO (Indium Tin Oxide) or a glass substrate, there is little warping after manufacturing and it is difficult to crack. In addition, aramid can form a substrate thinner than a glass substrate or the like. The substrate may be formed by laminating an ultrathin glass substrate and aramid.

  The bionanofiber is a composite of a cellulose microfibril bundle (bacterial cellulose) produced by bacteria (Acetobacter Xylinum) and a transparent resin. The cellulose microfibril bundle has a width of 50 nm and a size of 1/10 of the visible light wavelength, and has high strength, high elasticity, and low thermal expansion. By impregnating and curing a transparent resin such as an acrylic resin or an epoxy resin in bacterial cellulose, a bio-nanofiber having a light transmittance of about 90% at a wavelength of 500 nm can be obtained while containing 60 to 70% of the fiber. Bionanofiber has a low coefficient of thermal expansion (3-7ppm) comparable to silicon crystals, and is as strong as steel (460MPa), highly elastic (30GPa), and flexible, compared to glass substrates, etc. The substrate 1 can be formed thinly.

  In the present embodiment, the TFT substrate 30 is formed on the substrate 1 by sequentially forming the signal output unit 14, the sensor unit 13, and the transparent insulating film 7, and the light-absorbing adhesive resin is formed on the TFT substrate 30. The radiation detector 20 is formed by pasting the scintillator 8 using, for example.

  As shown in FIG. 5, the TFT substrate 30 includes a pixel 32 including the sensor unit 13, the capacitor 9, and the thin film transistor 10 described above in a certain direction (row direction in FIG. 5) and crossing the certain direction. A plurality of two-dimensional shapes are provided in the direction (column direction in FIG. 5).

  Further, the radiation detector 20 extends in the predetermined direction (row direction), and extends in the intersecting direction (column direction) with a plurality of gate wirings 34 for turning on and off each thin film transistor 10. A plurality of data wirings 36 for reading out charges through the thin film transistor 10 in the on state are provided.

  The radiation detector 20 has a flat plate shape and a quadrilateral shape having four sides on the outer edge in a plan view, more specifically, a rectangular shape.

  Here, in the radiation detector 20 according to the present exemplary embodiment, a part of the pixels 32 is used to detect the irradiation state of the radiation, and a radiographic image is captured by the remaining pixels 32. Hereinafter, the pixels 32 for detecting the radiation irradiation state are referred to as radiation detection pixels 32A, and the remaining pixels 32 are referred to as radiation image acquisition pixels 32B.

  In the radiation detector 20 according to the present embodiment, the radiation image is captured by the radiation image acquisition pixel 32B excluding the radiation detection pixel 32A in the pixel 32. Therefore, the radiation image at the position where the radiation detection pixel 32A is disposed. Pixel information cannot be obtained. Therefore, in the present embodiment, the radiation detection pixels 32A are arranged so as to be dispersed, and the pixel information of the radiation image at the arrangement position of the radiation detection pixels 32A is used as the radiation positioned around the radiation detection pixels 32A. It generates by interpolating using the pixel information obtained by the image acquisition pixel 32B.

  As shown in FIG. 5, the radiation detector 20 according to the present embodiment is connected to a connection portion between the capacitor 9 and the thin film transistor 10 in the radiation detection pixel 32 </ b> A, and directly reads out the electric charge accumulated in the capacitor 9. For this purpose, a direct read wiring 38 is extended in the predetermined direction (row direction).

  In the radiation detector 20 according to the present exemplary embodiment, each radiation detection pixel 32A is arranged in a different pixel row in a certain direction, and directly to each pixel row in a certain direction in which the radiation detection pixel 32A is arranged. Read wiring 38 is provided. That is, one radiation detection pixel 32 </ b> A is connected to each direct readout wiring 38.

  Next, the configuration of the electronic cassette 40 according to the present embodiment will be described. FIG. 6 is a perspective view showing the configuration of the electronic cassette 40 according to the present exemplary embodiment.

  As shown in the figure, an electronic cassette 40 according to the present embodiment includes a housing 41 made of a material that transmits radiation, and has a waterproof and airtight structure. When the electronic cassette 40 is used in an operating room or the like, there is a risk that blood or other germs may adhere. Therefore, one electronic cassette 40 can be used repeatedly by sterilizing and cleaning the electronic cassette 40 as necessary with a waterproof and hermetic structure.

  A space A for accommodating various components is formed inside the housing 41, and the radiation X transmitted through the subject from the irradiation surface side of the housing 41 to which the radiation X is irradiated is formed in the space A. The radiation detector 20 for detecting the radiation X and the lead plate 43 for absorbing the back scattered radiation of the radiation X are arranged in this order.

  Here, in the electronic cassette 40 according to the present exemplary embodiment, a region corresponding to the arrangement position of the radiation detector 20 on one surface of the flat plate of the housing 41 is a quadrilateral detection region 41A capable of detecting radiation. Has been. The surface having the detection region 41A of the housing 41 is a top plate 41B in the electronic cassette 40. In the electronic cassette 40 according to the present embodiment, the radiation detector 20 is connected to the TFT substrate 30 on the top plate 41B side. The top plate 41B is affixed to the inner surface of the casing 41 (the surface on the opposite side of the surface on which the radiation of the top plate 41B is incident).

  On the other hand, as shown in FIG. 6, a cassette control unit 58 and a power supply unit 70 (both described later) are placed on one end side inside the housing 41 so as not to overlap the radiation detector 20 (outside the range of the detection region 41A). The case 42 which accommodates FIG. 8 is arrange | positioned.

  The casing 41 is made of, for example, carbon fiber (carbon fiber), aluminum, magnesium, bionanofiber (cellulose microfibril), or a composite material in order to reduce the weight of the entire electronic cassette 40.

  As the composite material, for example, a material including a reinforced fiber resin is used, and the reinforced fiber resin includes carbon, cellulose, and the like. Specifically, as the composite material, carbon fiber reinforced plastic (CFRP), a structure in which a foamed material is sandwiched with CFRP, or a material in which the surface of the foamed material is coated with CFRP is used. In the present embodiment, a structure in which a foam material is sandwiched with CFRP is used. Thereby, compared with the case where the housing | casing 41 is comprised with a carbon single-piece | unit, the intensity | strength (rigidity) of the housing | casing 41 can be improved.

  On the other hand, as shown in FIG. 7, a support body 44 is disposed on the inner surface of the back surface portion 41 </ b> C facing the top plate 41 </ b> B inside the housing 41, and radiation is provided between the support body 44 and the top plate 41 </ b> B. The detector 20 and the lead plate 43 are arranged in this order in the radiation X irradiation direction. The support body 44 is made of, for example, a foam material from the viewpoint of weight reduction and absorption of dimensional deviation, and supports the lead plate 43.

  As shown in the figure, an adhesive member 80 is provided on the inner surface of the top plate 41B to adhere the TFT substrate 30 of the radiation detector 20 in a peelable manner. As the adhesive member 80, for example, a double-sided tape is used. In this case, the double-sided tape is formed so that the adhesive force of one adhesive surface is stronger than the adhesive force of the other adhesive surface.

  Specifically, the weak adhesive surface (weakly adhesive surface) is set to 1.0 N / cm or less at 180 ° peel adhesive force. Then, the surface having a strong adhesive force (strong adhesion surface) is in contact with the top plate 41B, and the weak adhesion surface is in contact with the TFT substrate 30. Thereby, compared with the case where the radiation detector 20 is fixed to the top plate 41B with fixing members, such as a screw, the thickness of the electronic cassette 40 can be made thin. Even if the top plate 41B is deformed by an impact or load, the radiation detector 20 follows the deformation of the top plate 41B having high rigidity, so that only a large curvature (slow bend) is generated, and a local low curvature is generated. Therefore, the possibility that the radiation detector 20 is damaged is reduced. Furthermore, the radiation detector 20 contributes to the improvement of the rigidity of the top plate 41B.

  As described above, in the electronic cassette 40 according to the present exemplary embodiment, the radiation detector 20 is attached to the inside of the top plate 41B of the housing 41, so that the housing 41 is on the top plate 41B side and the back surface portion 41C side. When the radiation detector 20 is attached to the top plate 41B or the radiation detector 20 is peeled off from the top plate 41B, the housing 41 is placed on the top plate 41B side. And the back surface portion 41C side are separated into two.

  In the present embodiment, the radiation detector 20 may not be bonded to the top plate 41B in a clean room or the like. This is because when a foreign object such as a metal piece that absorbs radiation is mixed between the radiation detector 20 and the top plate 41B, the foreign object can be removed by peeling the radiation detector 20 from the top plate 41B.

  Next, with reference to FIG. 8, the configuration of the main part of the electrical system of imaging system 104 according to the present embodiment will be described.

  As shown in the figure, the radiation detector 20 incorporated in the electronic cassette 40 has a gate line driver 52 arranged on one side of two adjacent sides and a first signal processing unit 54 arranged on the other side. Yes. Each gate wiring 34 of the TFT substrate 30 is connected to the gate line driver 52, and each data wiring 36 of the TFT substrate 30 is connected to the first signal processing unit 54.

  The housing 41 includes an image memory 56, a cassette control unit 58, a wireless communication unit 60, and a bias power source 62.

  The radiation detector 20 is provided with a bias wiring 64 for supplying a bias voltage to the sensor unit 13 of each pixel 32. The bias power source 62 is connected to the bias wiring 64, and a predetermined bias voltage is applied to the sensor unit 13 of each pixel 32 via the bias wiring 64.

  Each thin film transistor 10 of the TFT substrate 30 is sequentially turned on in a row unit by a signal supplied from the gate line driver 52 via the gate wiring 34, and the electric charge read by the thin film transistor 10 in the on state is converted into an electric signal. The data wiring 36 is transmitted and input to the first signal processing unit 54. As a result, the charges are sequentially read out in units of rows, and a two-dimensional radiation image can be acquired.

  Although not shown, the first signal processing unit 54 includes a charge amplifier that amplifies and holds an input electrical signal and a correlated double sampling circuit for each data wiring 36, and each data wiring 36. The electric signal transmitted through the wiring 36 is amplified by a charge amplifier and then subjected to correlated double sampling by a correlated double sampling circuit. In addition, a multiplexer and an A / D (analog / digital) converter are connected in order to the output side of the correlated double sampling circuit, and the electrical signal that has been correlated double sampled by each correlated double sampling circuit is sent to the multiplexer. The data are sequentially input (serially) and converted into digital image data by an A / D converter.

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

  The image memory 56 is connected to the cassette control unit 58. The cassette control unit 58 includes a microcomputer, and includes a CPU (Central Processing Unit) 58A, a memory 58B including a ROM (Read Only Memory) and a RAM (Random Access Memory), a nonvolatile storage unit 58C including a flash memory and the like. And controls the entire operation of the electronic cassette 40.

  Further, a wireless communication unit 60 is connected to the cassette control unit 58, and an antenna 66 is connected to the wireless communication unit 60. The wireless communication unit 60 corresponds to a wireless local area network (LAN) standard represented by IEEE (Institute of Electrical and Electronics Engineers) 802.11a / b / g and performs wireless communication via an antenna 66. And controls transmission of various types of information to and from an external device by wireless communication. As shown in FIG. 9, the antenna 66 is provided on one side of the radiation detector 20.

  The cassette control unit 58 can wirelessly communicate with an external device such as the console 110 that performs control related to radiographic image capturing via the wireless communication unit 60, and can transmit and receive various types of information to and from the console 110 and the like. It is possible.

  In the electronic cassette 40, a second signal processing unit 55 is disposed on the opposite side of the gate line driver 52 across the TFT substrate 30, and each direct readout wiring 38 of the TFT substrate 30 is connected to the second signal processing unit. 55.

  The second signal processing unit 55 includes an amplifier and an A / D converter provided for each direct readout wiring 38 and is connected to the cassette control unit 58. Under the control of the cassette control unit 58, the second signal processing unit 55 samples each direct readout wiring 38 at a predetermined cycle to convert an electrical signal transmitted through each direct readout wiring 38 into digital data, The digital data is output to the cassette control unit 58 sequentially.

  Also, the electronic cassette 40 has various circuits built therein, a battery 70 serving as a power source for each element, and power supplied from the battery 70 is transformed into various circuits and voltages according to each element to convert the various circuits and each element. A DC / DC converter 71 that supplies electric power is provided. In the present embodiment, a DC / DC converter 71 is used as a power supply unit that transforms power supplied from the viewpoint of power efficiency into different voltages. The various circuits and elements described above (gate line driver 52, first signal processing unit 54, second signal processing unit 55, image memory 56, wireless communication unit 60, microcomputer functioning as cassette control unit 58, etc.) It operates with the electric power supplied from the DC converter 71. In FIG. 8, wirings connecting the DC / DC converter 71 with various circuits and elements are omitted.

  On the other hand, the console 110 is configured as a server computer, and includes a display 111 that displays an operation menu, a captured radiographic image, and the like, and a plurality of keys, and inputs various information and operation instructions. An operation panel 112.

  The console 110 according to the present embodiment includes a CPU 113 that controls the operation of the entire apparatus, a ROM 114 that stores various programs including a control program in advance, a RAM 115 that temporarily stores various data, and various data. An HDD (Hard Disk Drive) 116 that stores and holds, a display driver 117 that controls display of various types of information on the display 111, and an operation input detection unit 118 that detects an operation state of the operation panel 112 are provided. . In addition, the console 110 transmits and receives various types of information such as an exposure condition, which will be described later, to and from the radiation generation apparatus 120 through wireless communication, and transmits and receives various types of information such as image data to and from the electronic cassette 40. A wireless communication unit 119 is provided.

  The CPU 113, ROM 114, RAM 115, HDD 116, display driver 117, operation input detection unit 118, and wireless communication unit 119 are connected to each other via the system bus BUS. Therefore, the CPU 113 can access the ROM 114, RAM 115, and HDD 116, controls display of various information on the display 111 via the display driver 117, and the radiation generator 120 via the wireless communication unit 119 and Control of transmission and reception of various types of information with the electronic cassette 40 can be performed. Further, the CPU 113 can grasp the operation state of the user with respect to the operation panel 112 via the operation input detection unit 118.

  On the other hand, the radiation generator 120 includes a radio communication unit 123 that transmits and receives various types of information such as an exposure condition between the radiation source 121 and the console 110, and a line that controls the radiation source 121 based on the received exposure condition. A source control unit 122.

  The radiation source control unit 122 is also configured to include a microcomputer, and stores the received exposure conditions and the like. The exposure conditions received from the console 110 include information such as tube voltage and tube current. The radiation source control unit 122 causes the radiation source 121 to emit radiation X based on the received exposure conditions.

  Next, the operation of the imaging system 104 according to the present embodiment will be described.

  When the radiographer performs radiographic image capture, the radiographing target region, the posture at the time of radiographing, and the electronic cassette 40 are placed on the console 110 via the operation panel 112. Shooting conditions such as holding state information indicating whether shooting is performed in a state in which the holding unit 166 is held or shooting is performed in a state where the electronic cassette 40 is not held in the holding unit, and tube voltage, tube current, and irradiation period are input. Enter the exposure conditions. When the imaging condition and the exposure condition are input, the console 110 transmits the input imaging condition and the exposure condition to the electronic cassette 40 via the wireless communication unit 119, and the exposure condition is transmitted via the wireless communication unit 119. To the radiation generator 120.

  When receiving the exposure condition from the console 110, the radiation source control unit 122 of the radiation generator 120 stores the received exposure condition and prepares for exposure under the exposure condition.

  When the cassette control unit 58 of the electronic cassette 40 receives the imaging conditions and the exposure conditions from the console 110, the cassette control unit 58 stores the received imaging conditions and the exposure conditions in the storage unit 58C.

  The photographer holds the electronic cassette 40 on the holding unit 162 of the standing table 160 or the holding unit 166 of the standing table 164 and holds the radiation source 121 when the posture at the time of imaging is standing or lying. After positioning at the corresponding position, the subject is positioned at a predetermined imaging position. On the other hand, when taking a radiographic image in a state where the imaging target part does not hold the electronic cassette 40 such as an arm part or a leg part in the holding part, the photographer covers the imaging target part in a state where the imaging target part can be photographed. The examiner, the electronic cassette 40, and the radiation source 121 are positioned.

  Then, when the photographing preparation is completed, the photographer performs a photographing instruction operation for instructing photographing on the operation panel 112 of the console 110.

  In the console 110, when an imaging instruction operation is performed on the operation panel 112, instruction information for instructing the start of exposure is transmitted to the radiation generator 120 and the electronic cassette 40 via the wireless communication unit 119.

  In response to this, the radiation source 121 emits the radiation X for the irradiation period at a tube voltage and a tube current corresponding to the exposure conditions received by the radiation generator 120 from the console 110. The radiation X emitted from the radiation source 121 reaches the electronic cassette 40 after passing through the subject. Thereby, an electric charge is generated in each pixel 32 of the radiation detector 20.

  By the way, in the radiation detector 20, even when X-rays are not irradiated, charges are generated in the sensor unit 13 by dark current or the like, and the charges are accumulated in the capacitors 9 of each pixel 32.

  Therefore, in the electronic cassette 40 according to the present exemplary embodiment, the reset operation for taking out and removing the charge accumulated in the capacitor 9 of each pixel 32 of the radiation detector 20 is repeatedly performed.

  In the electronic cassette 40 according to the present exemplary embodiment, the second signal processing unit 55 performs sampling of the electric signal that has flowed out from the radiation detection pixel 32A to each readout wiring 38 and converts it into digital data, and the cassette control unit 58 includes Radiation irradiation is detected based on the converted digital data, and the reset operation is stopped at the timing when the radiation irradiation is detected, and the radiographic image capturing operation is started. That is, the electronic cassette 40 detects the irradiation of radiation and starts an imaging operation. Thereby, in the imaging system 104 according to the present embodiment, the operation of irradiating the radiation from the radiation generator 120 by transmitting / receiving information regarding the start of radiation irradiation between the console 110 or the radiation generator 120 and the electronic cassette 40. A radiographic image can be taken without synchronizing the imaging operation with the electronic cassette 40.

  By the way, the electronic cassette 40 flows out from the radiation detection pixels 32 </ b> A directly to the respective readout wirings 38 due to the influence of electromagnetic waves emitted from the DC / DC converter 71, and noise is detected in the electric signal detected by the second signal processing unit 55. appear. This noise is more likely to occur as the intensity of electromagnetic waves increases. In general, the strength changes according to the distance from the DC / DC converter 71, and the strength decreases as the distance from the DC / DC converter 71 increases.

  Therefore, in the first embodiment, as shown in FIG. 9, the imaging region 31 in which the pixels 32 of the radiation detector 20 are provided in a two-dimensional manner is divided into two areas according to the degree of separation from the DC / DC converter 71. The region 33 (33A, 33B) is divided, and in each region 33, the distribution of the radiation detection pixels 32A is changed. Specifically, more radiation detection pixels 32 </ b> A are arranged in the region 33 </ b> B farther from the DC / DC converter 71 than in the region 33 </ b> A near the DC / DC converter 71.

  As a result, the number of radiation detection pixels 32A decreases in the region 33A close to the DC / DC converter 71 where a lot of noise is likely to occur, so that the influence of noise can be suppressed and detection of radiation irradiation can be accurately detected.

  Further, as shown in FIG. 7, the electronic cassette 40 according to the present exemplary embodiment is built in such that the radiation detector 20 is irradiated with the radiation X from the TFT substrate 30 side.

  Here, as shown in FIG. 10, the radiation detector 20 is irradiated with radiation from the side on which the scintillator 8 is formed, and reads a radiation image by the TFT substrate 30 provided on the back side of the incident surface of the radiation. In the case of a so-called back surface reading method, light is emitted more strongly on the upper surface side of the scintillator 8 (opposite side of the TFT substrate 30), radiation is irradiated from the TFT substrate 30 side, and the surface side of the incident surface of the radiation In the case of a so-called surface reading method in which a radiation image is read by the TFT substrate 30 provided on the TFT substrate 30, the radiation transmitted through the TFT substrate 30 enters the scintillator 8 and the TFT substrate 30 side of the scintillator 8 emits light more strongly. Electric charges are generated in each sensor unit 13 provided on the TFT substrate 30 by light generated by the scintillator 8. For this reason, since the radiation detector 20 is closer to the light emission position of the scintillator 8 with respect to the TFT substrate 30 when the front surface reading method is used than when the rear surface reading method is used, the resolution of the radiation image obtained by imaging is higher. high.

  In the radiation detector 20, the photoelectric conversion film 4 is made of an organic photoelectric conversion material, and the photoelectric conversion film 4 hardly absorbs radiation. For this reason, the radiation detector 20 according to the present embodiment suppresses a decrease in sensitivity to radiation because the amount of radiation absorbed by the photoelectric conversion film 4 is small even when radiation is transmitted through the TFT substrate 30 by the surface reading method. Can do. In the surface reading method, radiation passes through the TFT substrate 30 and reaches the scintillator 8. Thus, when the photoelectric conversion film 4 of the TFT substrate 30 is made of an organic photoelectric conversion material, the radiation in the photoelectric conversion film 4 is obtained. Therefore, it is suitable for the surface reading method.

  In addition, both the amorphous oxide constituting the active layer 17 of the thin film transistor 10 and the organic photoelectric conversion material constituting the photoelectric conversion film 4 can be formed at a low temperature. For this reason, the board | substrate 1 can be formed with a plastic resin, aramid, and bio-nanofiber with little radiation absorption. Since the substrate 1 formed in this way has a small amount of radiation absorption, even when the radiation passes through the TFT substrate 30 by the surface reading method, it is possible to suppress a decrease in sensitivity to radiation.

  Further, according to the present embodiment, as shown in FIG. 7, the radiation detector 20 is attached to the top plate 41B in the housing 41 so that the TFT substrate 30 is on the top plate 41B side. When 1 is formed of a highly rigid plastic resin, aramid, or bio-nanofiber, the radiation detector 20 itself has high rigidity, so that the top plate 41B of the housing 41 can be formed thin. Further, when the substrate 1 is formed of a highly rigid plastic resin, aramid, or bionanofiber, the radiation detector 20 itself has flexibility, so that even when an impact is applied to the detection region 41A, the radiation detector 20 is damaged. It ’s hard.

  As described above in detail, in the present embodiment, the imaging region 31 in which the pixels 32 of the radiation detector 20 are provided in a two-dimensional manner is divided into two regions 33A and 33A according to the degree of separation from the DC / DC converter 71. 33B, since more radiation detection pixels 32A are arranged in the region 33B farther from the DC / DC converter 71 than in the region 33A close to the DC / DC converter 71, the electromagnetic wave emitted from the DC / DC converter 71 It is possible to accurately detect radiation irradiation while suppressing the influence of noise due to the influence.

  Further, in the present embodiment, by forming the radiation detection pixel 32A as the radiation detection unit in the radiation detector 20, it is not necessary to provide a means for detecting radiation separately from the radiation detector 20, and thus the manufacturing cost is reduced. Can be reduced.

  In the present embodiment, since the direct readout wiring 38 for reading out the charges accumulated from the plurality of radiation detection pixels 32A is provided, the radiation irradiation state is detected regardless of the radiographic image capturing operation. As a result, a radiographic image can be taken at a higher speed.

[Second Embodiment]
Next, a second embodiment will be described.

  Since the configurations of the RIS 100, the imaging system 104, and the electronic cassette 40 according to the second embodiment are the same as those in the first embodiment (see FIGS. 1 to 8), description thereof is omitted here.

  As described above, the electronic cassette 40 flows from the radiation detection pixels 32 </ b> A to the respective direct readout wirings 38 due to the influence of the electromagnetic waves irradiated from the DC / DC converter 71 and is detected by the second signal processing unit 55. Noise is generated. Since this noise is random noise, the noise is reduced by averaging.

  Therefore, the radiation detector 20 according to the second embodiment divides the imaging region 31 into two regions 33A and 33B according to the degree of separation from the DC / DC converter 71, as shown in FIG. More radiation detection pixels are arranged in the region 33A closer to the DC / DC converter 71 than in the region 33B far from the DC / DC converter 71.

  The second signal processing unit 55 samples the electrical signal that has flowed from the radiation detection pixels 32 </ b> A to the respective direct readout wirings 38, converts it into digital data, and outputs the digital data to the cassette control unit 58. The cassette control unit 58 detects the start of radiation irradiation based on the converted digital data. For the region 33A close to the DC / DC converter 71, the detection results of two or more radiation detection pixels 32A are averaged. Radiation detection is performed. In this way, by averaging the detection results of two or more radiation detection pixels 32A, the influence of noise can be suppressed and detection of radiation irradiation can be accurately detected.

  As described above in detail, in the present embodiment, the imaging region 31 in which the pixels 32 of the radiation detector 20 are provided in a two-dimensional manner is divided into two regions 33A and 33A according to the degree of separation from the DC / DC converter 71. 33B, and more radiation detection pixels 32A are arranged than the region 33A closer to the DC / DC converter 71 than the region 33B far from the DC / DC converter 71, and the region 33A closer to the DC / DC converter 71 is two or more. Since the radiation detection is performed by averaging the detection results of the radiation detection pixels 32A, it is possible to accurately detect the radiation irradiation while suppressing the influence of noise caused by the electromagnetic wave irradiated from the DC / DC converter 71.

  In the second embodiment, the case where the detection of radiation is performed by averaging the detection results of two or more radiation detection pixels 32A in the region 33A close to the DC / DC converter 71 has been described. It is not limited. For example, when the detection result of the radiation detection pixel 32A is compared with a threshold value for detection of radiation irradiation, and the radiation irradiation start is detected when the detection result is equal to or higher than the threshold value for detection of radiation irradiation, For the region 33A close to the DC converter 71, the detection results of two or more radiation detection pixels 32A may be added together, and the radiation irradiation detection threshold may be multiplied by the total number of pixels for comparison.

[Third Embodiment]
Next, a third embodiment will be described.

  Since the configurations of the RIS 100 and the imaging system 104 according to the third embodiment are the same as those of the first embodiment (see FIGS. 1 to 4 and FIGS. 6 to 8), description thereof is omitted here. To do.

  FIG. 12 is a plan view showing the configuration of the radiation detector 20 according to the third exemplary embodiment.

  In the radiation detector 20 according to the present embodiment, the direct readout wiring 38 is not provided, and all the pixels 32 are radiation image acquisition pixels.

  FIG. 13 shows an internal configuration of the electronic cassette 40 according to the present exemplary embodiment.

  In the electronic cassette 40, an imaging unit 21 configured by laminating a later-described radiation detection unit 200 and a radiation detector 20 is disposed inside a housing 41.

  The radiation detector 200 is attached to the surface of the radiation detector 20 on the TFT substrate 30 side.

  In the electronic cassette 40 according to the present embodiment, the radiation detection unit 200 detects radiation irradiation, and when the radiation irradiation is detected, the radiation detector 20 captures a radiation image.

  FIG. 14 is a cross-sectional view schematically showing the configuration of the radiation detector 20 and the radiation detection unit 200 according to this embodiment.

  In the radiation detection unit 200, a wiring layer 204 and an insulating layer 206 in which wiring 210 (FIG. 15) described later is patterned are formed on a resinous support substrate 202 that is transparent to radiation. A plurality of sensor portions 208 are formed, and a scintillator 210 made of GOS or the like is formed on the sensor portion 208. The sensor unit 208 includes an upper electrode 208A, a lower electrode 208B, and a photoelectric conversion film 208C disposed between the upper and lower electrodes. The photoelectric conversion film 208 </ b> C generates a charge when the light converted by the scintillator 210 is incident thereon. The sensor unit 208 is preferably a photoelectric conversion film containing the above-described organic photoelectric conversion material, rather than a PIN-type or MIS-type photodiode using amorphous silicon as the photoelectric conversion film 208C. This is because it is better to use a photoelectric conversion film containing an organic photoelectric conversion material in terms of reduction in manufacturing cost and flexibility in comparison with the case of using a PIN type photodiode or a MIS type photodiode. Because it is advantageous. The sensor unit 208 of the radiation detection unit 200 does not need to be formed as finely as the sensor unit 13 provided in each pixel 32 of the radiation detector 20, and is larger than the sensor unit 13. It may be formed with a size of one hundred pixels.

  FIG. 15 is a block diagram showing the main configuration of the electrical system of the electronic cassette 40. In addition, the same code | symbol is attached | subjected to the part same as the said 1st Embodiment (FIG. 8), and description is abbreviate | omitted.

  As described above, the radiation detection unit 200 includes a large number of sensor units 208. The radiation detection unit 200 is provided with a plurality of wirings 210 individually connected to the sensor units 208, and the wirings 210 are connected to the second signal processing unit 55.

  The second signal processing unit 55 includes an amplifier and an A / D converter provided for each wiring 210 and is connected to the cassette control unit 58. Under the control of the cassette control unit 58, the second signal processing unit 55 samples each direct readout wiring 38 at a predetermined cycle to convert an electrical signal transmitted through each direct readout wiring 38 into digital data, The digital data is output to the cassette control unit 58 sequentially.

  As described above, even when the sensor unit 208 detects radiation irradiation, the sensor unit 208 flows out to the wirings 210 due to the influence of the electromagnetic wave irradiated from the DC / DC converter 71, and the second signal processing is performed. Noise is generated in the electrical signal detected by the unit 55.

  Therefore, as in the first and second embodiments, the radiation detector 20 includes two regions 220 in which the sensor unit 208 is provided in a two-dimensional manner according to the degree of separation from the DC / DC converter 71. 221 (221A, 221B), and the distribution of the sensor unit 208 may be changed in each region 221.

  For example, as shown in FIG. 16, more sensor units 208 may be arranged in a region 221 </ b> B farther from the DC / DC converter 71 than in a region 221 </ b> A near the DC / DC converter 71.

  As a result, the number of sensor units 208 is reduced in the region 221A close to the DC / DC converter 71 where a lot of noise is likely to occur, so that the influence of noise can be suppressed and detection of radiation irradiation can be accurately detected.

  In addition, as shown in FIG. 17, more sensor units 208 may be arranged in a region 221 </ b> A closer to the DC / DC converter 71 than in a region 221 </ b> B far from the DC / DC converter 71. In this case, as in the second embodiment, the cassette control unit 58 detects the radiation by averaging the detection results of the two or more sensor units 208 for the region 221A close to the DC / DC converter 71. To do. Thus, by averaging the detection results of two or more sensor units 208, the influence of noise can be suppressed and detection of radiation irradiation can be accurately detected.

[Fourth Embodiment]
Next, a fourth embodiment will be described.

  Since the configurations of the RIS 100 and the imaging system 104 according to the fourth embodiment are the same as those of the first embodiment (see FIGS. 1 to 8), description thereof is omitted here.

  FIG. 18 shows a main configuration of the electrical system of the electronic cassette 40 according to the fourth exemplary embodiment. In addition, the same code | symbol is attached | subjected to the part same as the said 1st-3rd embodiment (FIG. 8, FIG. 15), and description is abbreviate | omitted.

  Here, in the sensor unit 13, a bias voltage is applied between the upper electrode 6 and the lower electrode 2 via the bias wiring 64, but the amount of current flowing through the bias wiring 64 changes when irradiated with radiation.

  Therefore, in the electronic cassette 40 according to the present exemplary embodiment, a current detection unit 72 that detects the amount of current flowing through the bias wiring 64 is provided.

  The current detection unit 72 includes an amplifier circuit such as an amplifier that amplifies a change in the current amount in order to detect the current amount with high accuracy, detects the amount of current flowing through the bias wiring 64, and outputs it to the cassette control unit 58. . The cassette control unit 58 detects the start of radiation irradiation based on the change in the amount of current detected by the current detection unit 72.

  Therefore, as in the third embodiment, the radiation detector 20 according to the present embodiment is not provided with the direct readout wiring 38, and all the pixels 32 are used as radiation image acquisition pixels. The electronic cassette 40 is not provided with the second signal processing unit 55.

  By the way, noise is generated in an amplification circuit such as an amplifier built in the current detection unit 72 due to the influence of electromagnetic waves emitted from the DC / DC converter 71. This noise is more likely to occur as the intensity of electromagnetic waves increases.

  Therefore, in the present embodiment, the current detection unit 72 is disposed so as to be separated from the DC / DC converter 71.

  As described above, in the present embodiment, when the radiation irradiation is detected from the change in the amount of current flowing through the bias wiring 64, the current detection unit 72 that detects the amount of current flowing through the bias wiring 64 is replaced with the DC / DC converter 71. By arranging so as to be away from the antenna, it is possible to accurately detect radiation irradiation while suppressing the influence of noise due to the influence of the electromagnetic wave irradiated from the DC / DC converter 71.

[Fifth Embodiment]
Next, a fifth embodiment will be described.

  Since the configurations of the RIS 100 and the imaging system 104 according to the fifth embodiment are the same as those of the first embodiment (see FIGS. 1 to 8), description thereof is omitted here.

  FIG. 19 shows a main configuration of an electric system of an electronic cassette 40 according to the fifth exemplary embodiment. In addition, the same code | symbol is attached | subjected to the part same as the said 1st-3rd embodiment (FIG. 8, FIG. 15), and description is abbreviate | omitted.

  As shown in the figure, the first signal processing unit 54 of the electronic cassette 40 according to the present embodiment amplifies the input electrical signal for each data wiring 36 and for each data wiring 36. A charge amplifier 54A for holding and a correlated double sampling circuit (denoted as “CDS” in FIG. 19) 54B are provided. On the output side of the correlated double sampling circuit 54B, a multiplexer 54C and an A / D converter 54D are sequentially provided. It is connected. Each charge amplifier 54A is supplied with an amplifier current from an amplifier power supply 76 via a wiring 78.

  The first signal processing unit 54 amplifies and holds the electric signal input to each data wiring 36 by the charge amplifier 54A, performs correlated double sampling by the correlated double sampling circuit 54B, and then performs A / D by the multiplexer 54C. The signals are sequentially input to the converter 54D, and converted into digital image data by the A / D converter 54D.

  Here, in the radiation detector 20, charges are accumulated in each pixel 32 when irradiated with radiation, and due to this influence, a change occurs in the current flowing through the data wiring 36, and the charge built in the first signal processing unit 54. The amplifier current to the amplifier 54A also changes.

  Therefore, in the electronic cassette 40 according to the present exemplary embodiment, a current detection unit 79 that detects an amplifier current flowing through the wiring 78 is provided. The current detection unit 79 includes an amplifier circuit such as an amplifier that amplifies a change in the amount of current in order to accurately detect the amplifier current, detects the amount of amplifier current flowing through the wiring 78, and outputs the detected amount to the cassette control unit 58. . The cassette controller 58 detects the start of radiation irradiation based on the change in the amount of current detected by the current detector 79.

  Therefore, the radiation detector 20 according to the present embodiment is not provided with the direct readout wiring 38 as in the fourth embodiment, and all the pixels 32 are used as radiation image acquisition pixels. The electronic cassette 40 is not provided with the second signal processing unit 55.

  By the way, noise is generated in an amplification circuit such as an amplifier built in the current detection unit 79 due to the influence of electromagnetic waves emitted from the DC / DC converter 71. This noise is more likely to occur as the intensity of electromagnetic waves increases.

  Therefore, in the present embodiment, the DC / DC converter 71 is disposed away from the current detection unit 79.

  As described above, in the present embodiment, when the irradiation of radiation is detected from the change in the amplifier current to the charge amplifier 54A incorporated in the first signal processing unit 54, the current detection unit 79 that detects the amplifier current is provided. By disposing the DC / DC converter 71 away from the DC / DC converter 71, it is possible to accurately detect the irradiation of radiation while suppressing the influence of noise caused by the electromagnetic wave irradiated from the DC / DC converter 71.

  As mentioned above, although this invention was demonstrated using the 1st-5th embodiment, the technical scope of this invention is not limited to the range as described in each said embodiment. Various modifications or improvements can be added to the above-described embodiments without departing from the gist of the invention, and embodiments to which the modifications or improvements are added are also included in the technical scope of the present invention.

  The above embodiments do not limit the invention according to the claims (claims), and all the combinations of features described in the embodiments are essential for the solution means of the invention. Is not limited. The embodiments described above include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.

  In the first and second embodiments described above, as an example, as illustrated in FIG. 20A, a case where a part of the radiation image acquisition pixel 32B is applied as the radiation detection pixel 32A has been described. The present invention is not limited to this. For example, as shown in FIG. 20B, for example, the radiation detection pixels 32A may be provided in the gaps between the radiation image acquisition pixels 32B. In this case, since the area of the radiation image acquisition pixel 32B corresponding to the position where the radiation detection pixel 32A is provided is reduced, the sensitivity of the pixel is reduced, but the pixel is also used for detection of the radiation image. Therefore, the quality of the radiographic image can be improved.

  In the first and second embodiments, the case where the imaging region 31 of the radiation detector 20 is divided into two regions 33 according to the degree of separation from the DC / DC converter 71 will be described. In the above embodiment, the case where the region 220 of the radiation detection unit 200 is divided into the two regions 221 according to the degree of separation from the DC / DC converter 71 has been described, but may be divided into three or more regions. Moreover, although the case where the imaging region 31 and the region 220 are divided into regions by linear dividing lines has been described, they may be divided by curved dividing lines. Furthermore, although the case where one DC / DC converter 71 is provided has been described, a plurality of DC / DC converters 71 may be provided. Further, in order to suppress a specific change in detection within the imaging region 31 and the region 220, the imaging region 31 and the region 220 are preferably divided into the region 33 and the region 221 approximately equally.

  In FIG. 21, the imaging region 31 is separated into three regions 33A, 33B, and 31C by a linear dividing line so as to be separated from the DC / DC converter 71 by a curvilinear dividing line with substantially the same electromagnetic wave intensity. An example is shown in which the radiation detection pixels 32A are arranged so that the distribution increases as the area increases. When a plurality of DC / DC converters 71 are provided, the distribution of the radiation detection pixels 32 </ b> A may be changed in accordance with the intensity distribution of the electromagnetic wave intensity from each DC / DC converter 71.

  In the first embodiment, the case has been described in which the distribution is changed such that the region farther from the DC / DC converter 71 has more radiation image acquisition pixels 32B, but the present invention is limited to this. It is not a thing. As shown in FIG. 22, the second signal processing unit 55 is provided with a plurality of amplifiers 55A such as amplifiers that amplify an electric signal flowing directly through the readout wiring 38. The amplifier 55A includes a DC / DC converter 71. Noise is generated due to the influence of electromagnetic waves irradiated from. Therefore, the amplifier 55 </ b> A may be arranged by changing the distribution according to the degree of separation from the DC / DC converter 71. FIG. 22 shows a configuration in which the amplifier 55A is arranged so that the distribution increases in a region far from the DC / DC converter 71. In addition, the amplifier 55A is arranged so that the distribution is larger in the region closer to the DC / DC converter 71, and in the region closer to the DC / DC converter 71, digital data obtained by digitally converting the signals amplified by the amplifiers 55A is averaged. It is good also as what detects a radiation.

  The second signal processing unit 55, the current detection unit 72, the current detection unit 79, and the DC / DC converter 71 are preferably arranged apart from each other. In FIG. 23, when the DC / DC converter 71 is provided in a corner portion on the opposite side to the side where the second signal processing unit 55 of the casing 41 is disposed, the inside of the casing 41 is separated by a diagonal line. The form which has arrange | positioned the DC / DC converter 71 and the 2nd signal processing part 55 in a separate area | region is shown. As shown in FIG. 23 and FIG. 19, the influence of the electromagnetic wave irradiated from the DC / DC converter 71 by separating the second signal processing unit 55, the current detection unit 72, the current detection unit 79 and the DC / DC converter 71. Therefore, it is possible to suppress the noise generated by.

  In the second embodiment, the case where the detection of radiation is performed by averaging digital data of two or more radiation detection pixels 32A in the region 33A close to the DC / DC converter 71 has been described. It is not limited. For example, in the region 33A close to the DC / DC converter 71, the radiation detector 20 is formed such that a plurality of radiation detection pixels 32A are connected to the direct readout wiring 38 or a plurality of direct readout wirings 38 are connected in parallel. Then, the electrical signals of the plurality of radiation detection pixels 32A are directly added in analog form on the readout wiring 38, and the summed electrical signals are digitally converted and divided by the total number of radiation detection pixels 32A. May be averaged. Further, in the region 33A close to the DC / DC converter 71, the radiation detection threshold value may be multiplied by the number of the radiation detection pixels 32A and compared with the summed digital data of the electrical signal. Good.

  In each of the above-described embodiments, the case where the DC / DC converter 71 is used as a power supply unit that transforms supplied power to a different voltage has been described. However, the present invention is not limited to this. For example, you may use the transformer which used the coil as a power supply part.

  Further, not only the power supply unit such as the DC / DC converter 71 but also the battery 70 is heavy. For this reason, in the electronic cassette 40, in order to have a weight balance, as shown in FIG. 24, the power supply unit such as the battery 70 and the DC / DC converter 71 may be disposed at a position facing the radiation detector 20. preferable. At this time, the power supply line connecting the battery 70 and the DC / DC converter 71 generates electromagnetic waves when the switching element of the DC / DC converter 71 is repeatedly turned on and off. For this reason, it is preferable not to arrange a detection unit such as the radiation detection pixel 32A or the sensor unit 208 in a region corresponding to a portion where a power supply line connecting the battery 70 and the DC / DC converter 71 is disposed.

  Further, in each of the above embodiments, in order to avoid complications, no particular mention was made regarding discharging the charge accumulated in the radiation detection pixels 32A, but at the timing when the start of radiation irradiation is detected, It is also possible to detect the end of radiation irradiation after discharging the charge accumulated by the detection pixel 32A. Thereby, the saturation of the said radiation dose at the time of detecting completion | finish of irradiation of a radiation can be prevented.

  Further, in each of the above embodiments, the case where the sensor unit 13 is configured to include an organic photoelectric conversion material that generates charges by receiving light generated by the scintillator 8 has been described. It is good also as a form which applies what was constituted without including an organic photoelectric conversion material as sensor part 13 without being limited to.

  In the third embodiment, the radiation detection unit 200 has been described with respect to the case where each sensor unit 208 detects light from the scintillator 210. However, the present invention is not limited to this. For example, the radiation detection unit 200 may detect light from the scintillator 8 without forming the scintillator 210. The radiation detection unit 200 may be disposed on the scintillator 8 side of the radiation detection unit 200.

  Further, in each of the above embodiments, the case where the radiation detector 20 is of the indirect conversion type has been described, but the radiation detector 20 may be of the direct conversion type.

  Further, in each of the above-described embodiments, the case has been described in which the case 42 that accommodates the cassette control unit 58 and the power supply unit 70 and the radiation detector 20 are arranged so as not to overlap each other inside the casing 41 of the electronic cassette 40. However, the present invention is not limited to this. For example, the radiation detector 20 and the cassette control unit 58 or the power supply unit 70 may be arranged so as to overlap each other.

  In each of the above embodiments, the case where wireless communication is performed between the electronic cassette 40 and the console 110 and between the radiation generator 120 and the console 110 has been described, but the present invention is not limited thereto. For example, at least one of these may be configured to perform wired communication.

  In each of the above embodiments, the case where X-rays are applied as radiation has been described. However, the present invention is not limited to this, and other radiation such as γ-rays may be applied.

  In addition, the configuration of the RIS 100, the configuration of the radiation imaging room, the configuration of the electronic cassette 40, and the configuration of the imaging system 104 described in the above embodiments are merely examples, and are unnecessary portions within the scope of the present invention. Needless to say, can be deleted, a new part can be added, or the connection state can be changed.

20 radiation detector 31 imaging region 32 pixel 32A each radiation detection pixel (detection unit)
33 area 40 electronic cassette 55 second signal processing unit 58 cassette control unit (detection means)
71 DC / DC converter (power supply)
72 Current detector (detector)
79 Current detector (detector)
208 Sensor unit

Claims (9)

Charges are generated by irradiation with radiation or light converted to radiation, and a plurality of pixels for storing the generated charges are provided in an imaging region, and an electric signal corresponding to the amount of charge stored in each pixel is output. A radiation detector;
A power supply that transforms the supplied power to a different voltage; and
A detection unit that detects radiation applied to the imaging region, and is arranged with a different distribution according to the degree of separation from the power supply unit.
Detection means for detecting radiation irradiation based on the detection result by the detection unit;
A radiographic imaging apparatus comprising: The radiographic image capturing apparatus according to claim 1, wherein the number of the detection units is arranged in a region farther from the power supply unit. The detection unit is arranged in a smaller area away from the power supply unit,
The radiographic imaging apparatus according to claim 1, wherein the detection unit detects radiation irradiation based on a result obtained by adding or averaging the detection results of two or more detection units for an area close to the power supply unit. The radiographic image capturing apparatus according to claim 1, wherein each region is divided substantially equally. The radiographic image capturing apparatus according to claim 1, wherein the detection unit also serves as a pixel of the radiation detector. The pixel includes a sensor unit that generates electric charges when irradiated with radiation or light converted from radiation in a state where a bias voltage is applied,
The radiographic imaging device according to any one of claims 1 to 4, wherein the detection unit is a current detection unit that detects an amount of current flowing in a wiring that applies a bias voltage to the sensor unit. An amplifier that amplifies an electrical signal output from each pixel of the radiation detector;
The radiographic imaging apparatus according to claim 1, wherein the detection unit is a current detection unit that detects an amount of an amplifier current supplied to the amplifier. The battery further serves as a power source of the power supply unit,
The radiographic imaging apparatus according to any one of claims 1 to 5, wherein the power supply unit and the battery are arranged at positions facing each other with a radiation detector interposed therebetween. The radiographic imaging apparatus according to claim 8, wherein the detection unit is not arranged in a region corresponding to a portion where a power supply line that supplies power from the battery to the power supply unit is arranged.

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