WO2011118286A1 - Radiograph imaging device, radiograph imaging system, defective pixel map generation method, and defective pixel map generation system - Google Patents

Radiograph imaging device, radiograph imaging system, defective pixel map generation method, and defective pixel map generation system Download PDF

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Publication number
WO2011118286A1
WO2011118286A1 PCT/JP2011/053189 JP2011053189W WO2011118286A1 WO 2011118286 A1 WO2011118286 A1 WO 2011118286A1 JP 2011053189 W JP2011053189 W JP 2011053189W WO 2011118286 A1 WO2011118286 A1 WO 2011118286A1
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Prior art keywords
radiation detection
image data
detection element
radiation
output abnormality
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PCT/JP2011/053189
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French (fr)
Japanese (ja)
Inventor
剛 齋藤
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コニカミノルタエムジー株式会社
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Priority to JP2012506882A priority Critical patent/JP5761176B2/en
Publication of WO2011118286A1 publication Critical patent/WO2011118286A1/en

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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03BAPPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B42/00Obtaining records using waves other than optical waves; Visualisation of such records by using optical means
    • G03B42/02Obtaining records using waves other than optical waves; Visualisation of such records by using optical means using X-rays
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/42Arrangements for detecting radiation specially adapted for radiation diagnosis
    • A61B6/4208Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector
    • A61B6/4233Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector using matrix detectors
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/30Cameras or camera modules comprising electronic image sensors; Control thereof for generating image signals from X-rays
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/60Noise processing, e.g. detecting, correcting, reducing or removing noise
    • H04N25/68Noise processing, e.g. detecting, correcting, reducing or removing noise applied to defects
    • H04N25/69SSIS comprising testing or correcting structures for circuits other than pixel cells

Definitions

  • the present invention relates to a radiographic image capturing apparatus, a radiographic image capturing system, a defective pixel map creating method for a radiographic image capturing apparatus, and a defective pixel map creating system for a radiographic image capturing apparatus capable of detecting a radiation detecting element exhibiting an abnormal detection value.
  • a radiographic image capturing apparatus a radiographic image capturing system, a defective pixel map creating method for a radiographic image capturing apparatus, and a defective pixel map creating system for a radiographic image capturing apparatus capable of detecting a radiation detecting element exhibiting an abnormal detection value.
  • a radiation image forming apparatus in which radiation detection elements called flat panel detectors (FPD) are two-dimensionally arranged is known.
  • FPD flat panel detectors
  • radiation energy is directly converted into charges using a photoconductive substance such as a-Se (amorphous selenium) as a radiation detection element, and the charges are arranged two-dimensionally.
  • a direct readout method that reads out electrical signals pixel by pixel using a signal readout switch element such as a TFT (Thin Film Transistor), or radiation energy is converted into light by a scintillator, etc., and this light is arranged two-dimensionally.
  • TFT Thintillator
  • radiation detection that outputs abnormal image data constantly or with a certain probability due to impurities mixed into the radiation detection element when forming the radiation detection element on the sensor panel.
  • An element may occur.
  • a radiographic image forming apparatus having a means for registering in (Patent Document 1) has been proposed.
  • the radiation detection element that outputs an output outside the range of m ⁇ 5 ⁇ is determined to be a defective radiation detection element.
  • the preliminary defect radiation detection element must be registered in the defect element map after it can be identified as a complete defect radiation detection element through repeated use.
  • even radiation detection elements that are not necessary are subject to interpolation processing, which may lead to a reduction in imaging accuracy.
  • an object of the present invention is to provide a radiographic image capturing apparatus, a radiographic image capturing system, a defective pixel map creating method, and a defective pixel map creating system that can more accurately identify a radiation detection element that is regarded as a defect. It is.
  • a radiographic imaging apparatus is divided by a plurality of scanning lines and a plurality of signal lines arranged so as to cross each other, and the plurality of scanning lines and a plurality of signal lines.
  • a plurality of radiation detection elements arranged two-dimensionally in each region, and a charge is read from the radiation detection element through the signal line, and the charge is converted into an electrical signal for each radiation detection element.
  • a readout circuit that outputs as data, and the readout circuit outputs actual image data as the data based on the charges accumulated by the respective radiation detection elements at a predetermined accumulation time at the time of imaging irradiated with radiation, and The readout circuit is based on charges accumulated in the same accumulation time as each of the radiation detection elements during the non-irradiation of the radiation.
  • a radiographic imaging apparatus comprising: control means for controlling to output dark image data for correcting the real image data; and communication means for transmitting / receiving data to / from an external device, wherein the control means Control is performed so that the readout circuit outputs dark image data for determining the output abnormality of the radiation detection element based on the charge accumulated in each radiation detection element during the non-irradiation with a longer accumulation time than during the imaging. It is characterized by doing.
  • the radiographic imaging system which is another side surface of this invention is a radiation provided with the radiographic imaging apparatus of Claim 1, and a console provided with the communication means which receives data between the said radiographic imaging apparatus.
  • the console has output abnormality determination means for determining an output abnormality of each radiation detection element from dark image data for determining the output abnormality, and any radiation detection element has an output abnormality.
  • a defect element map for storing the position of the radiation detection element to be output abnormal, and a registration means for registering the position of the radiation detection element determined to be output abnormal by the output abnormality determination means in the defect element map. It is characterized by.
  • a defective pixel map creating method for a radiographic image capturing apparatus, wherein a plurality of scanning lines and a plurality of signal lines arranged to intersect each other, and the plurality of scanning lines and a plurality of signals are arranged.
  • a detection unit including a plurality of radiation detection elements arranged in a two-dimensional manner in each region partitioned by lines, and reads out charges from the radiation detection elements through the signal lines, and electrically charges the charges for each of the radiation detection elements.
  • a radiographic imaging apparatus including a readout circuit that converts the signal into a signal and outputs the data, a defective pixel map that stores which radiation detection element has an output abnormality or the position of the radiation detection element to be output abnormal is created.
  • a method for creating a defective pixel map wherein charges are accumulated in each of the plurality of radiation detection elements and charges are read by the readout circuit. And after the aging step, each radiation detection element accumulates charges in a longer accumulation time than when photographing in a non-irradiated state, and determines an output abnormality of the radiation detection element from the accumulated charges.
  • a dark image data acquisition step for acquiring dark image data for the determination; a determination step for determining an output abnormality of each radiation detection element based on dark image data for an output abnormality determination of the radiation detection element;
  • a defective pixel map creation system for a radiographic imaging apparatus includes a plurality of scanning lines and a plurality of signal lines arranged to intersect each other, and the plurality of scanning lines and a plurality of signals.
  • a detection unit including a plurality of radiation detection elements arranged in a two-dimensional manner in each region partitioned by lines, and reads out charges from the radiation detection elements through the signal lines, and electrically charges the charges for each of the radiation detection elements.
  • a defective pixel map that stores which radiation detection element has an output abnormality or a position of the radiation detection element that causes an output abnormality is created.
  • a defective pixel map creation system for creating a defective pixel map
  • charge accumulation and reading of each of the plurality of radiation detection elements are performed.
  • An aging control unit that repeatedly reads out charges by the extraction circuit, and each of the radiation detection elements that has repeatedly performed charge accumulation and charge read-out has a longer accumulation time than that during imaging in a non-radiation state.
  • a dark image data acquisition control unit for acquiring dark image data for determining output abnormality of the radiation detection element from the stored charge, and based on dark image data for determining output abnormality of the radiation detection element And a defect that creates the defective pixel map in which the radiation detection element that causes the output abnormality is registered based on the determination unit that determines the output abnormality of the radiation detection element and the determination of the output abnormality of the radiation detection element. And a pixel map creating unit.
  • the radiographic image capturing apparatus and the radiographic image capturing system according to the present invention are configured such that the control unit of the radiographic image capturing apparatus has a longer accumulation time for each radiation detection element when no radiation is applied (so-called dark charge acquisition time) than when imaging. Control is performed so as to acquire dark image data for determining an output abnormality of the radiation detection element from the readout circuit based on the electric charge accumulated in step.
  • the charge accumulation time of each radiation detection element at the time of dark image data acquisition is made longer, the value of the distribution of the dark image data of the normal radiation detection element is concentrated and the dark image by the radiation detection element of abnormal output The difference from the data can be widened according to the accumulation time.
  • an abnormal value becomes obvious, it becomes easy to discriminate between a normal value and an abnormal value, and the threshold value can also easily take an appropriate value.
  • the threshold value can also easily take an appropriate value.
  • a radiation detection element that outputs dark image data close to a normal value while causing an abnormality can be separated and distinguished from a normal radiation detection element. For example, a radiation detection element that was originally normal can be identified. Even if it is gradually becoming abnormal, it can be determined as abnormal at an early stage, and it is possible to reduce the frequency of maintenance for monitoring the radiation detecting element with abnormal output.
  • the determination accuracy improvement by the dark image data for the output abnormality determination obtained based on the charge accumulated in the accumulation time longer than that at the time of the imaging is improved. It is possible to obtain the effect.
  • the defective pixel map creation method and the defective pixel map creation system of the radiographic imaging apparatus since the aging is performed on the radiation detection element and the readout circuit, a weak output abnormality occurs. It is possible to advance an abnormal state for a radiation detection element that is likely to cause an output abnormality later, such that it is not determined, and to detect it as an abnormal output in subsequent determination.
  • radiation detectors that become abnormal after the repeated use can be found at an early stage, and radiation detectors that output abnormalities can be registered in the defective pixel map, so the use of the radiographic imaging device is started.
  • the number of radiation detecting elements that will cause an abnormality later is reduced, and the maintenance burden can be reduced.
  • FIG. 2 is a cross-sectional view taken along line AA in FIG. It is a top view which shows the structure of the board
  • FIG. 5 is a cross-sectional view taken along line BB in FIG. 4. It is a side view explaining the board
  • FIG. 6 is a diagram showing a correspondence relationship between dark image data and the frequency when dark image data is acquired with the same charge accumulation time of each radiation detection element as in normal imaging.
  • FIG. 6 is a diagram showing a correspondence relationship between dark image data and the frequency when dark image data is acquired with the charge accumulation time of each radiation detection element set longer than that in normal imaging.
  • It is a flowchart shown about the processing content of the image display control of a console.
  • It is a conceptual diagram which shows the content of the interpolation of the image data based on the output of the radiation detection element of an output abnormality.
  • It is a block diagram which shows the structure of the other example of a radiographic imaging apparatus. It is a figure which shows the whole structure of a defective pixel map production system.
  • the radiographic imaging device is a so-called indirect radiographic imaging device that includes a scintillator or the like and converts the irradiated radiation into electromagnetic waves of other wavelengths such as visible light to obtain an electrical signal.
  • the present invention can also be applied to a direct radiographic imaging apparatus.
  • the radiographic image capturing apparatus is portable will be described, the present invention is also applicable to a radiographic image capturing apparatus formed integrally with a support base or the like.
  • FIG. 1 is an external perspective view of the radiographic image capturing apparatus according to the present embodiment
  • FIG. 2 is a cross-sectional view taken along the line AA in FIG.
  • the radiographic image capturing apparatus 1 according to the present embodiment is configured by housing a scintillator 3, a substrate 4, and the like inside a housing 2.
  • the housing 2 is formed of a material such as a carbon plate or plastic that transmits at least the radiation incident surface R. 1 and 2 show a case where the housing 2 is a so-called lunch box type formed by the frame plate 2A and the back plate 2B, but the shape of the housing 2 is not limited to this. . It is also possible to use a so-called monocoque type in which the housing 2 is integrally formed in a rectangular tube shape.
  • the side surface of the housing 2 is opened and closed for replacement of a power switch 36, an indicator 37 composed of LEDs and the like, and a battery 41 (not shown) (see FIG. 7 described later).
  • a possible lid member 38 and the like are arranged.
  • an antenna device that is a communication unit for wirelessly transferring image data G (described later) to an external device such as a console 58 (described later) illustrated in FIG. 39 is embedded. It is also possible to transfer the image data G to an external device in a wired manner. In that case, for example, as a communication means, a connection terminal or the like for connection by inserting a cable or the like is used as radiation. It is provided on the side surface of the image capturing apparatus 1 or the like.
  • a base 31 is disposed inside the housing 2 via a thin lead plate or the like (not shown) on the lower side of the substrate 4.
  • the disposed PCB substrate 33, the buffer member 34, and the like are attached.
  • a glass substrate 35 for protecting the substrate 4 and the radiation incident surface R of the scintillator 3 is disposed.
  • the scintillator 3 is affixed to a detection part P (described later) of the substrate 4.
  • the scintillator 3 is, for example, a phosphor whose main component is converted into an electromagnetic wave having a wavelength of 300 to 800 nm, that is, an electromagnetic wave centered on visible light when it receives radiation, and that is output.
  • the substrate 4 is formed of a glass substrate. As shown in FIG. 3, a plurality of scanning lines 5 and a plurality of signal lines are provided on a surface 4 a of the substrate 4 facing the scintillator 3. 6 are arranged so as to cross each other. In each small region r defined by the plurality of scanning lines 5 and the plurality of signal lines 6 on the surface 4 a of the substrate 4, radiation detection elements 7 are respectively provided.
  • the region is a detection unit P.
  • a photodiode is used as the radiation detection element 7, but other than this, for example, a phototransistor or the like can also be used.
  • Each radiation detection element 7 is connected to the source electrode 8s of the TFT 8 serving as a switching element, as shown in the enlarged views of FIGS.
  • the drain electrode 8 d of the TFT 8 is connected to the signal line 6.
  • the TFT 8 is turned on when an ON voltage is applied to the connected scanning line 5 and applied to the gate electrode 8g by a scanning driving means 15 (see FIG. 7), which will be described later, and the radiation detection element 7 is turned on.
  • the electric charge generated and accumulated therein is discharged to the signal line 6.
  • the TFT 8 is turned off when an OFF voltage is applied to the connected scanning line 5 and an OFF voltage is applied to the gate electrode 8g, and the emission of charges from the radiation detection element 7 to the signal line 6 is stopped.
  • the charges generated in the radiation detection element 7 are held and accumulated in the radiation detection element 7.
  • FIG. 5 is a sectional view taken along line BB in FIG.
  • a gate electrode 8g of a TFT 8 made of Al, Cr, or the like is formed on the surface 4a of the substrate 4 so as to be integrally laminated with the scanning line 5, and the gate electrode 8g and the surface 4a.
  • the radiation detecting element 7 is disposed above the gate electrode 8g on the gate insulating layer 81 made of silicon nitride (SiNx) or the like laminated thereon via a semiconductor layer 82 made of hydrogenated amorphous silicon (a-Si) or the like.
  • the source electrode 8 s connected to the first electrode 74 and the drain electrode 8 d formed integrally with the signal line 6 are laminated.
  • the source electrode 8s and the drain electrode 8d are divided by a first passivation layer 83 made of silicon nitride (SiNx) or the like, and the first passivation layer 83 covers both the electrodes 8s and 8d from above.
  • ohmic contact layers 84a and 84b formed in an n-type by doping hydrogenated amorphous silicon with a group VI element are stacked between the semiconductor layer 82 and the source electrode 8s and the drain electrode 8d, respectively.
  • the TFT 8 is formed as described above.
  • an auxiliary electrode 72 is formed by laminating Al, Cr, or the like on the insulating layer 71 formed integrally with the gate insulating layer 81 on the surface 4 a of the substrate 4.
  • a first electrode 74 made of Al, Cr, Mo or the like is laminated on the auxiliary electrode 72 with an insulating layer 73 formed integrally with the first passivation layer 83 interposed therebetween.
  • the first electrode 74 is connected to the source electrode 8 s of the TFT 8 through the hole H formed in the first passivation layer 83.
  • a p layer 77 formed by doping a group III element into silicon and forming a p-type layer is formed by laminating sequentially from below.
  • the electromagnetic wave When radiation enters from the radiation incident surface R of the housing 2 of the radiographic imaging apparatus 1 and is converted into an electromagnetic wave such as visible light by the scintillator 3, and the converted electromagnetic wave is irradiated from above in the figure, the electromagnetic wave is detected by radiation.
  • the electron hole pair is generated in the i layer 76 by reaching the i layer 76 of the element 7. In this way, the radiation detection element 7 converts the electromagnetic waves irradiated from the scintillator 3 into electric charges.
  • a second electrode 78 made of a transparent electrode such as ITO is laminated and formed so that the irradiated electromagnetic wave reaches the i layer 76 and the like.
  • the radiation detection element 7 is formed as described above. The order of stacking the p layer 77, the i layer 76, and the n layer 75 may be reversed. Further, in the present embodiment, a case where a so-called pin-type radiation detection element formed by sequentially stacking the p layer 77, the i layer 76, and the n layer 75 as described above is used as the radiation detection element 7. However, it is not limited to this.
  • a bias line 9 for applying a bias voltage to the radiation detection element 7 is connected to the upper surface of the second electrode 78 of the radiation detection element 7 via the second electrode 78.
  • the second electrode 78 and the bias line 9 of the radiation detection element 7, the first electrode 74 extended to the TFT 8 side, the first passivation layer 83 of the TFT 8, that is, the upper surfaces of the radiation detection element 7 and the TFT 8 are The upper side is covered with a second passivation layer 79 made of silicon nitride (SiNx) or the like.
  • one bias line 9 is connected to a plurality of radiation detection elements 7 arranged in rows, and each bias line 9 is connected to a signal line 6. Are arranged in parallel with each other. Further, each bias line 9 is bound to the connection 10 at a position outside the detection portion P of the substrate 4.
  • each scanning line 5, each signal line 6, and connection 10 of the bias line 9 are input / output terminals (also referred to as pads) provided near the edge of the substrate 4. 11 is connected.
  • each input / output terminal 11 has a COF (Chip On ⁇ Film) 12 in which a chip such as an IC 12 a is incorporated, an anisotropic conductive adhesive film (Anisotropic Conductive Film) or an anisotropic conductive paste (Anisotropic paste). It is connected via an anisotropic conductive adhesive material 13 such as Conductive Paste).
  • the COF 12 is routed to the back surface 4b side of the substrate 4 and connected to the PCB substrate 33 described above on the back surface 4b side.
  • substrate 4 part of the radiographic imaging apparatus 1 is formed.
  • illustration of the electronic component 32 and the like is omitted.
  • FIG. 7 is a block diagram illustrating an equivalent circuit of the radiographic imaging apparatus 1 according to the present embodiment
  • FIG. 8 is a block diagram illustrating an equivalent circuit for one pixel constituting the detection unit P.
  • each radiation detection element 7 of the detection unit P of the substrate 4 has the bias line 9 connected to the second electrode 78, and each bias line 9 is bound to the connection 10 to the bias power supply 14. It is connected.
  • the bias power supply 14 applies a bias voltage to the second electrode 78 of each radiation detection element 7 via the connection 10 and each bias line 9.
  • the bias power source 14 is connected to a control unit 22 described later, and the control unit 22 controls a bias voltage applied to each radiation detection element 7 from the bias power source 14.
  • the current detection means 43 for detecting the amount of current flowing through the connection 10 is provided in the connection 10 of the bias line 9.
  • the current detection means 43 can detect the start and end of radiation irradiation by detecting the increase or decrease of the current flowing through the connection 10. In the present invention, the current detection means 43 is not necessarily provided.
  • the bias line 9 is connected via the second electrode 78 to the p-layer 77 side (see FIG. 5) of the radiation detection element 7.
  • the bias power supply 14 supplies a voltage equal to or lower than a voltage applied to the second electrode 78 of the radiation detection element 7 via the bias line 9 as a bias voltage on the first electrode 74 side of the radiation detection element 7 (that is, a so-called reverse bias voltage). Is applied.
  • the first electrode 74 of each radiation detection element 7 is connected to the source electrode 8s of the TFT 8 (indicated as S in FIGS. 7 and 8), and the gate electrode 8g of each TFT 8 (FIGS. 7 and 8). Are respectively connected to the lines L1 to Lx of the scanning line 5 extending from a gate driver 15b of the scanning driving means 15 described later. Further, the drain electrode 8 d (denoted as D in FIGS. 7 and 8) of each TFT 8 is connected to each signal line 6.
  • the scanning drive unit 15 includes a power supply circuit 15a that supplies an ON voltage and an OFF voltage to the gate driver 15b, and a voltage applied to each of the lines L1 to Lx of the scanning line 5 between the ON voltage and the OFF voltage.
  • a gate driver 15b that switches between an ON voltage application state and an OFF voltage application state of each TFT 8 is provided.
  • Each signal line 6 is connected to each readout circuit 17 formed in the readout IC 16. Note that the readout IC 16 is provided with one readout circuit 17 for each signal line 6.
  • the readout circuit 17 includes an amplification circuit 18, a correlated double sampling circuit 19, an analog multiplexer 21, and an A / D converter 20. 7 and 8, the correlated double sampling circuit 19 is represented as CDS. In FIG. 8, the analog multiplexer 21 is omitted.
  • the amplifier circuit 18 is configured by a charge amplifier circuit, and is configured by connecting a capacitor 18b and a charge reset switch 18c in parallel to the operational amplifier 18a and the operational amplifier 18a, respectively.
  • a power supply unit 18 d for supplying power to the amplifier circuit 18 is connected to the amplifier circuit 18.
  • the signal line 6 is connected to the inverting input terminal on the input side of the operational amplifier 18a of the amplifier circuit 18, and the reference potential V0 is applied to the non-inverting input terminal on the input side of the amplifier circuit 18. Yes.
  • the reference potential V0 is set to an appropriate value, and in this embodiment, for example, 0 [V] is applied.
  • the charge reset switch 18c of the amplifier circuit 18 is connected to the control means 22 to be described later, and ON / OFF is controlled by the control means 22.
  • ON / OFF is controlled by the control means 22.
  • the amplification circuit 18 outputs a voltage value according to the amount of charge output from each radiation detection element 7 and converts the charge voltage.
  • the charge reset switch 18c When the charge reset switch 18c is turned on, the input side and the output side of the amplifier circuit 18 are short-circuited, and the charge accumulated in the capacitor 18b is discharged to reset the amplifier circuit 18. ing.
  • the amplifier circuit 18 may be configured to output a current in accordance with the charge output from the radiation detection element 7.
  • the “reading process of data from the radiation detecting element 7” includes reading process of the actual image data J as data based on the accumulated charge amount of the radiation detecting element 7 at the time of radiation irradiation, and radiation at the time of non-irradiating radiation There are dark image data B, BH1, BH2, etc. as data based on the accumulated charge amount (dark charge) of the detection element 7. These are collectively referred to as “data reading process from the radiation detection element 7”. And Further, in the case of “data D”, the real image data J and the dark image data B, BH1, and BH2 are collectively shown, and in the case of “image data G”, the real image data J is the dark image data. Data corrected based on data B is shown.
  • each radiation detection element 7 During the process of reading data from each radiation detection element 7, the charge is read from each radiation detection element 7, and the voltage value output by charge-voltage conversion by the amplifier circuit 18 is sampled by the correlated double sampling circuit 19. And output as data D downstream.
  • the data D of each radiation detection element 7 output from the correlated double sampling circuit 19 is transmitted to the analog multiplexer 21 (see FIG. 7), and is sequentially transmitted from the analog multiplexer 21 to the A / D converter 20.
  • the A / D converter 20 sequentially converts the data into digital value data D, outputs it to the storage means 40, and sequentially stores it.
  • the lines L1 to Lx of the scanning line 5 to which the ON voltage is applied are sequentially switched while the radiations as described above are performed.
  • a process for reading data from the detection element 7 is performed.
  • control means 22 Here, the structure of the control means 22 in this embodiment is demonstrated, referring FIG.7 and FIG.8.
  • the control unit 22 is connected to the nonvolatile storage unit 40 and the antenna device 39 described above.
  • the control means 22 is connected to a battery 41 for supplying power to each member such as the detection section P, the scanning drive means 15, the readout circuit 17, the storage means 40, and the bias power supply 14.
  • the battery 41 is provided with a connection terminal 42 for charging the battery 41 by supplying power to the battery 41 from a charging device (not shown) such as a cradle.
  • control means 22 controls the bias power supply 14 to set a bias voltage to be applied to each radiation detection element 7 from the bias power supply 14, or the charge reset switch 18 c of the amplification circuit 18 of the readout circuit 17.
  • Various processes such as ON / OFF control and transmission of a pulse signal to the correlated double sampling circuit 19 to control ON / OFF of the sample hold function are executed.
  • control means 22 performs scanning from the scanning driving means 15 to the scanning driving means 15 at the time of reset processing of each radiation detecting element 7 or reading of data D from each radiation detecting element 7 after radiographic imaging.
  • a pulse signal for switching the voltage applied to the gate electrode 8g of each TFT 8 between the ON voltage and the OFF voltage via the line 5 is transmitted.
  • control unit 22 is a computer configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and each functional unit of the radiation image capturing apparatus 1.
  • the operation etc. are controlled.
  • the ROM stores, for example, an imaging control program for performing operation control of each component of the radiographic imaging device 1 at the time of imaging, a dark image data acquisition control program for determining an output abnormality of each radiation detection element 7, and the like. Yes.
  • Various programs, information, and the like are not limited to being stored in the ROM, and a separate program memory or the like may be provided and stored therein.
  • FIG. 9 is an explanatory diagram showing each process during photographing.
  • the radiation image capturing apparatus 1 is installed at a radiation irradiation position of the radiation generating apparatus 52 (see FIG. 11) in the radiation image capturing system 50 at the time of capturing.
  • control means 22 applies an ON voltage to the lines L1 to Lx of the scanning line 5 simultaneously or sequentially and turns on each charge reset switch 18c so as to be stored in each radiation detection element 7.
  • the charge is reset (FIG. 9: K1).
  • the radiation generator 52 starts irradiation of radiation in synchronization with the radiographic imaging device 1 under the control of the console 58 (see FIG. 11), and the control means 22 scans each scanning line 5 through each scanning line 5.
  • An OFF voltage is simultaneously applied to the TFTs 8 connected to the line 5, and the charge of the photographed image is accumulated for each radiation detection element 7 according to the radiation dose (FIG. 9: K2).
  • the charge accumulation time of the photographed image is individually set to an appropriate value according to imaging conditions such as an imaging region such as the chest and abdomen of the patient's body as a subject and a radiation dose.
  • a setting input unit may be provided in the control unit 22 so that an arbitrary time can be set.
  • a table in which a suitable accumulation time is determined according to individual imaging conditions such as an imaging region and a radiation dose is stored in the ROM 23b.
  • a storage time may be automatically selected from a table in response to an input of imaging conditions from the setting input means.
  • an ON voltage is sequentially applied to each scanning line 5 so that each radiation detection element 7 connected to each scanning line 5 is connected to each amplification circuit 18 for each scanning line 5.
  • the charge is discharged, the voltage based on the amount of accumulated charge is A / D converted, and is sequentially stored in the storage means 40 as the actual image data J of each radiation detecting element 7 (FIG. 9: K3).
  • the OFF voltage is simultaneously applied to all the scanning lines 5 to start accumulation, while the ON voltage is sequentially applied to the scanning lines 5 to read out and complete the accumulation. Different for each line.
  • each radiation detection element 7 Reset is performed (FIG. 9: K4).
  • charge accumulation processing of a dark image by each radiation detection element 7 is executed. That is, in this dark image charge accumulation process, the radiation generator 52 is not irradiated with radiation under the control of the console 58, and each radiation detection element 7 is darkened in the same accumulation time as in the above imaging for each scanning line. Image charge accumulation (dark charge accumulation) is performed (FIG. 9: K5).
  • the voltage value corresponding to the amount of charge accumulated in each capacitor 18b is A / D converted and read as dark image data B of each radiation detection element 7 (FIG. 9: K6).
  • the average value of the dark image data for each radiation detection element 7 obtained by averaging the dark image data B of each radiation detection element 7 obtained each time by repeating the steps K4 to K6 a plurality of times is obtained as a formal darkness. It may be adopted as the image data B.
  • the actual image data J acquired by the above processing for each radiation detection element 7 and the dark image data B acquired accompanying the capturing are set as an external device.
  • the console 58 the data value is corrected by taking the difference of the dark image data B with respect to the actual image data J for each radiation detection element 7, and the image data of each radiation detection element 7 is acquired.
  • each radiation detection element 7 has an offset amount due to dark charges accumulated in each radiation detection element 7 in the accumulation time from the reset process to the readout process at the time of imaging.
  • This dark charge is generated by thermal excitation or the like of each radiation detection element 7 itself, and the offset due to the dark charge has a different value for each radiation detection element 7.
  • the actual image data J of each radiation detection element 7 includes a charge (dark charge) derived from thermal excitation caused by heat of each radiation detection element 7 itself, etc. ) Are included in a superimposed manner.
  • the radiographic imaging apparatus 1 detects dark charges generated by thermal excitation or the like of each element itself as dark image data B for each radiation detection element 7 in a state in which radiation is not irradiated, and together with the actual image data J This is transmitted to the console 58, and the offset of the dark charge superposition can be removed from the photographed image data J on the console 58 side.
  • the acquisition processing (K4 to K6) of the dark image data B at the time of photographing is performed for detection of dark charges derived from thermal excitation or the like due to heat of each radiation detection element 7 itself. It is desirable that the temperature state of the detection element 7 is close to that at the time of acquisition of the actual image data, and therefore, the acquisition processing of the actual image data J and the acquisition processing of the dark image data B are continuous so as not to be separated in time. It is desirable to do it automatically. On the contrary, if the processing is continuous, the dark image data B acquisition processing may be performed first. In addition, as described above, when dark image data is acquired a plurality of times and the average value is set to the formal dark image data B, the dark image is obtained before and after the acquisition process of the actual image data J. Data B may be acquired and averaged.
  • FIG. 10A and FIG. 10B are explanatory diagrams showing respective steps at the time of obtaining dark image data for output abnormality determination.
  • the acquisition of dark image data for output abnormality determination is performed by performing dark image charge accumulation processing at a first accumulation time and a second accumulation time, each having a different length, to obtain dark image data BH1 and BH2. Is called.
  • the acquisition of dark image data for determining the output abnormality is not performed accompanying radiographic image capturing, and is not particularly limited as to when it is executed.
  • the control means 22 may be provided with an operation input means for executing dark image data acquisition processing for output abnormality determination, and may be arbitrarily executed by an operation, or may be executed periodically and automatically. You may comprise.
  • the acquisition of the dark image data BH1 for the output abnormality determination based on the first accumulation time and the acquisition of the dark image data BH2 for the output abnormality determination based on the second accumulation time are performed continuously, and the time It is designed not to be executed after each other.
  • the radiographic image capturing apparatus 1 is configured to acquire two types of dark image data for determining the output abnormality of each radiation detection element 7 with different accumulation times.
  • the dark image data for determining the output abnormality may be acquired.
  • the control unit 22 first or sequentially applies to the lines L1 to Lx of the scanning line 5 in advance.
  • an ON voltage is applied to each charge reset switch 18c and each charge reset switch 18c is turned on to reset the charge accumulated in each radiation detection element 7 (FIG. 10A: K11).
  • the control means 22 applies an OFF voltage to the TFTs 8 connected to the respective scanning lines 5 through all the scanning lines 5 at the same time.
  • the dark image charge is accumulated for (FIG. 10A: K12).
  • the first accumulation time at this time is set to be longer than at least the above-described accumulation time at the time of photographing.
  • the first accumulation time may be set several times to several tens of times or longer, but the dark charge is not saturated. It is desirable to limit the range.
  • the accumulation time at the time of shooting is set to 500 [ms], and the first accumulation time is set to 10 [s].
  • the accumulation start is simultaneous for all the scanning lines, whereas the accumulation end is different for each scanning line. Strictly speaking, the accumulation time differs for each scanning line, but the explanation is complicated. Therefore, the accumulation time here indicates, for example, the accumulation time of the scanning line where accumulation ends first as a representative value.
  • Image data BH1 is detected and read out by sequentially storing it in the storage means 40 (FIG. 10A: K13).
  • the steps K11 to K13 are also repeatedly executed a plurality of times, and each radiation obtained by averaging the dark image data BH1 of each radiation detecting element 7 obtained each time is obtained.
  • An average value of dark image data for each detection element 7 may be adopted as the formal dark image data BH1.
  • the steps K21 to K23 of the dark image data BH2 acquisition process for determining the output abnormality in the second accumulation time are set longer than the first accumulation time, as shown in FIG. 10B.
  • the detailed description is omitted because it is exactly the same except for the point.
  • the second accumulation time is set to 20 [s], for example, twice the first accumulation time.
  • the processes of K21 to K23 are repeatedly executed a plurality of times, and each radiation detection element 7 obtained by averaging the dark image data BH2 of each radiation detection element 7 obtained each time.
  • the average value of the dark image data may be adopted as the formal dark image data BH2.
  • dark image data BH1 for output abnormality determination based on the first accumulation time and dark image data BH2 for output abnormality determination based on the second accumulation time are set as an external device.
  • To the console 58. Processing on the console 58 side in the dark image data BH1 and BH2 for the output abnormality determination will be described later.
  • the acquisition processing of the dark image data BH1 for output abnormality determination based on the first accumulation time and the dark image data BH2 for output abnormality determination based on the second accumulation time is continuously performed without taking time. Although it is desirable to be performed, any of these acquisition processes may be performed first.
  • the radiographic image capturing system 50 is a system that assumes radiographic image capturing performed in, for example, a hospital or a clinic, and can be employed as a system that captures a medical diagnostic image as a radiographic image, but is not necessarily limited thereto. Not.
  • FIG. 11 is a diagram showing an overall configuration of the radiation image capturing system 50 in the present embodiment.
  • the radiographic imaging system 50 includes, for example, an imaging room R ⁇ b> 1 that performs imaging of a subject that is a part of a patient by irradiating radiation (an imaging target part of the patient), and an operator such as a radiographer Are arranged in the anterior chamber R2 for performing various operations such as control of radiation applied to the subject, and outside thereof.
  • a bucky device 51 that can be loaded with the radiographic imaging device 1 described above, a radiation generating device 52 that includes an X-ray tube (not shown) that generates radiation to irradiate a subject, the radiographic imaging device 1 and a console.
  • a base station 54 equipped with a wireless antenna 53 is provided as a communication means for relaying these communications when wirelessly communicating with 58.
  • FIG. 11 shows a case where the portable radiographic imaging device 1 is used by being loaded into the cassette holding portion 51a of the standing-up imaging bucky device 51A or the standing-up imaging bucky device 51B.
  • the radiographic imaging device 1 may be formed integrally with the bucky device 51, a support base, or the like. Further, as shown in FIG. 11, the radiographic image capturing apparatus 1 and the base station 54 can be connected by a cable so that data can be transmitted by wired communication via the cable.
  • the cradle 55 that reads the cassette ID from the radiographic image capturing apparatus 1 and notifies the console 58 via the base station 54 when the radiographic image capturing apparatus 1 is inserted into the radiographing room R1.
  • the cradle 55 may be configured to charge the radiographic image capturing apparatus 1 or the like.
  • the front chamber R2 is provided with an operation console 57 for controlling radiation irradiation, which includes switch means 56 for instructing the radiation generator 52 to start radiation irradiation and the like.
  • the configuration of the radiographic image capturing apparatus 1 is as described above.
  • the radiographic image capturing apparatus 1 may be used by being loaded into the bucky device 51 as described above, but it is not loaded into the bucky device 51. It can also be used in a single state.
  • the radiation image capturing apparatus 1 is arranged in a single state, for example, on the upper surface side of a bed provided in the imaging room R1 or a bucky apparatus 51B for supine photography as shown in FIG. (See FIG. 1)
  • the patient's hand which is the subject, can be placed on the top, or the patient's waist, legs, etc. lying on the bed can be inserted between the bed and the bed. It has become.
  • radiation image capturing is performed by irradiating the radiation image capturing apparatus 1 with radiation from a portable radiation generating device 52B or the like via a subject.
  • the console 58 that controls the entire radiographic imaging system 50 is provided outside the imaging room R1 and the front room R2.
  • the console 58 is configured to be provided in the front room R2. Is also possible.
  • the console 58 is constituted by a computer or the like in which a CPU, a ROM, a RAM, an input / output interface and the like (not shown) are connected to a bus.
  • a predetermined program is stored in the ROM, and the console 58 reads out the necessary program, expands it in the work area of the RAM, executes various processes according to the program, and controls the entire radiographic imaging system 50 as described above. Is supposed to do.
  • the console 58 is connected to the above-described base station 54, console 57, storage means 59 composed of a hard disk or the like, and a cradle 55 or the like is connected via the base station 54.
  • the radiation generating device 52 and the like are connected via this.
  • the console 58 is provided with a display screen 58a such as a CRT (Cathode Ray Tube) or LCD (Liquid Crystal Display), and other input means such as a keyboard and a mouse are connected thereto.
  • CTR Cathode Ray Tube
  • LCD Liquid Crystal Display
  • the console 58 When the console 58 is notified of the cassette ID of the radiographic imaging apparatus 1 from the cradle 55 via the base station 54, the console 58 saves it in the storage means 59, and the radiographic imaging apparatus 1 existing in the imaging room R1.
  • the storage unit 59 stores the real image data J received from the radiographic image capturing apparatus 1, the dark image data B associated therewith, the dark image data BH1 for determining output abnormality based on the first accumulation time, the second
  • a defective element map showing the arrangement of the radiation detection element 7 that performs abnormal output of the radiation image capturing apparatus 1 in the detection unit P Is remembered.
  • the radiation detecting element 7 is formed by integrating millions, tens of millions or more of the elements in the detection part P, and some of them show abnormal output from the beginning of manufacture. It is.
  • the abnormal output of the radiation detection element 7 is one that does not output any charge despite the radiation irradiation, one that outputs only a constant regardless of changes in the radiation dose, and is output every time a fixed dose of radiation is incident. Are different and do not show the law.
  • the object of abnormality determination is a radiation detection element 7 that performs only a constant output regardless of a change in radiation dose (in some cases, random output)
  • the radiation detection element 7 that performs the detection can also be detected), and the radiation detection element 7 that is newly determined to be abnormal in output by the abnormality determination is sequentially added.
  • the defect element map may be one in which only position information (position coordinates) in the detection unit P of the radiation detection element 7 that is regarded as an output abnormality is recorded, or normal or abnormal for all the radiation detection elements 7 of the detection unit P. May be recorded.
  • the console 58 reads the two dark image data BH1 and BH2 from the storage means 59 (step S11), and calculates the difference data ⁇ BH by subtracting them (step S12). That is, for each radiation detection element 7, the dark image data BH1 is subtracted from the dark image data BH2, and difference data ⁇ BH for each radiation detection element 7 is calculated.
  • FIG. 13 is a conceptual diagram showing the difference calculation process.
  • the pixel position on the horizontal axis indicates, for example, the arrangement direction of the radiation detection elements 7 along the scanning line 5, and the vertical axis indicates dark image data or a difference value thereof. Since each radiation detection element 7 in the detection unit P has a value corresponding to the amount of charge accumulated in a non-radiation state, the influence of variation due to a difference in incident dose is suppressed. In addition, since the temperature difference between the radiation detecting elements 7 is small and almost constant unless the state is special, it is considered that the influence of the temperature difference is small.
  • one of the factors that cause variation in dark image data for each pixel position in the normal radiation detection element 7 is a difference in characteristics when reading is performed by a plurality of readout circuits 17 individually provided in the scanning line direction. Conceivable. Although it is possible to directly determine a threshold value for determining an output abnormality for the dark image data BH1 or BH2 and determine an output abnormality, the determination is made in consideration of the influence of the variation for each readout circuit 17 described above. It is difficult to avoid a certain decrease in accuracy. However, by taking the difference between the dark image data BH1 and BH2 as in step S12, the variation for each readout circuit 17 is canceled, and the value of the output abnormality appears remarkably without being buried in the variation. The threshold value can be brought closer to the normal value, and the radiation abnormality detecting element 7 having the output abnormality can be accurately determined.
  • the console 58 calculates the standard deviation of each difference data ⁇ BH.
  • the upper limit threshold value of the difference data ⁇ BH for output abnormality determination is set to ⁇ + 5 ⁇
  • the lower limit threshold value is set to ⁇ 5 ⁇ .
  • each of the dark image data BH1 and BH2 serving as the base data of the difference data ⁇ BH has accumulated charges in each radiation detection element 7 with an accumulation time longer than the accumulation time during normal imaging. The effect of this will be described with reference to FIGS. 14A and 14B.
  • FIG. 14A is a diagram showing the correspondence between dark image data and the frequency (number of elements) when dark image charge accumulation is performed with the charge accumulation time of each radiation detection element 7 being the same as in normal imaging.
  • FIG. 14B shows the correspondence between dark image data and the frequency (number of elements) when dark image charge accumulation is performed with the charge accumulation time of each radiation detection element 7 set longer than that during normal imaging.
  • FIG. In the case where the charge accumulation time of each radiation detection element 7 is the same as in normal imaging, for example, when the value d1 deviates significantly from the value where the dark image data of the radiation detection element 7 that is abnormal in output is concentrated in the distribution. In this case, it is possible to determine the radiation detection element 7 that causes an output abnormality by setting a value (for example, the value indicated by a dotted line) that is far from the value where the distribution is concentrated with a margin.
  • a value for example, the value indicated by a dotted line
  • the radiation detection element 7 that is becoming abnormal in output if it is determined until the value d2 close to the value where the distribution is concentrated and the determination of the output abnormality is performed with high accuracy, the radiation detection element that performs normal output It becomes difficult to set a threshold value that enables discrimination from 7. That is, it is necessary to set a value close to the value where the distribution is concentrated as a threshold value, and there is a high possibility that it is determined that the output is abnormal up to the normal radiation detection element 7, and a certain decrease in determination accuracy is inevitable.
  • a value d3 in FIG. 14B indicates an output as a result of extending the accumulation time for the radiation detection element 7 that has output the value d2.
  • step S12 which is a step for obtaining the difference between dark image data BH1 and BH2, is omitted.
  • a threshold value for determination is calculated by obtaining a standard deviation for the dark image data BH1 (or BH2) of each radiation detection element 7, and further, a dark image of each radiation detection element 7 is calculated based on the threshold value.
  • the determination for the data BH1 (or BH2) is performed.
  • the radiation detection element 7 is registered in the defect element map in the storage unit 59 (step S15).
  • the console 58 stores the positional information of the radiation detection element 7 determined as abnormal in output or A process of adding an address or the like to the map is executed.
  • the defect element map is, for example, information indicating whether the radiation detection elements 7 are normal or abnormal as described above
  • the recording is performed for the radiation detection elements 7 determined to be abnormal in output. Execute the process of rewriting it to indicate something abnormal.
  • the console 58 functions as “output abnormality determination means” and “registration means” by executing the output abnormality determination program.
  • the processing contents of the image display control performed by the CPU of the console 58 according to the image display control program will be described based on the flowchart of FIG.
  • the console 58 reads out the real image data J in each radiation detection element 7 and the dark image data B for correcting the real image data acquired accompanying it from the storage means 59 (step S21).
  • the image data excluding the offset component of the dark charge by difference is calculated (step S22). Note that correction (calibration) of sensitivity characteristics of each radiation detection element 7 may be further performed on the image data of each radiation detection element according to a known method.
  • the console 58 refers to the defect element map in the storage device 59 and identifies the radiation detection element 7 having an abnormal output. Then, when the radiation detection element 7 having an abnormal output is specified, interpolation processing is performed from the image data of the surrounding radiation detection elements 7 (step S23). An example of the interpolation processing method is shown in FIG.
  • Image data G (m, n) (m is the position coordinate in the direction of the scanning line 5, and n is the position coordinate in the direction of the signal line 6)
  • An average of (m, n + 1), G (m + 1, n-1), G (m + 1, n), and G (m + 1, n + 1) is calculated and replaced with the value of G (m, n).
  • the console 58 displays an image on the display screen 58a (step S24).
  • the control unit 22 is not irradiated with radiation (so-called dark charge acquisition).
  • Control to acquire dark image data BH1 and BH2 for determining an output abnormality of the radiation detection element 7 from the readout circuit 17 based on the charge accumulated for each radiation detection element 7 with a longer accumulation time than at the time of imaging. Is going.
  • the charge accumulation time of each radiation detection element 7 during the charge accumulation of the dark image is made longer, the value where the distribution of the dark image data of the normal radiation detection element 7 is concentrated and the radiation detection of the abnormal output is performed.
  • the difference from the dark image data by the element 7 can be widened according to the accumulation time. As a result, it is easy to distinguish between normal values and abnormal values, and the threshold value is also likely to take an appropriate value. As a result, it is possible to reduce the possibility that the normal radiation detection element 7 is determined to be abnormal in output, and to improve the determination accuracy. Further, the radiation detection element 7 that outputs dark image data close to a normal value while causing an abnormality can be identified separately from the normal radiation detection element 7. For example, the radiation detection that was originally normal is detected. Even when the element 7 is gradually becoming abnormal, it can be determined to be abnormal at an early stage by determination, and the frequency of maintenance for monitoring the radiation detecting element 7 with abnormal output can also be reduced.
  • the control means 22 of the radiographic imaging device 1 obtains dark image data BH1 and BH2 for determining a plurality of (two in this embodiment) output abnormality for each radiation detection element 7 by changing the accumulation time, This is transmitted to the console 58 as an external device. Therefore, on the console 58 side, the difference data ⁇ BH can be obtained for each radiation detection element 7 for the two dark image data BH1 and BH2. In this case, as described above, the difference data ⁇ BH can cancel the influence of the variation in the output characteristics in the plurality of readout circuits 17, and thus radiation that is abnormal in output in the difference data ⁇ BH in which the variation is reduced. It becomes easy to identify the difference data ⁇ BH based on the output of the detection element 7 as being prominent, and it is possible to further improve the determination accuracy of the radiation detection element 7 with an abnormal output.
  • the dark image data BH1 and BH2 of each radiation detection element 7 a plurality of data is acquired by accumulating a plurality of times, and the average value thereof is also used as the formal dark image data BH1 and BH2. It is good, but when averaging is done in such a way, noise components such as horizontal noise can be removed, and furthermore, it is possible to accurately detect the radiation detection element 7 that causes output abnormality. It is said.
  • radiographic imaging device 1 In the radiographic imaging device 1 described above, when processing for obtaining dark image data BH1 and BH2 for output abnormality determination of the radiation detection element is performed, all of these dark image data BH1 and BH2 are transmitted to the console 58 side.
  • the determination of the radiation detection element 7 that is abnormal in output from the dark image data BH1 and BH2 and the registration of the defect element map are all referred to the console 58.
  • the radiographic imaging device stores and holds the defect element map.
  • a configuration may be adopted in which the radiation detection element 7 determined to be abnormal in output is determined from the dark image data BH1 and BH2 and is registered in the defect element map.
  • FIG. 17 is a block diagram showing a configuration of such a radiographic image capturing apparatus 100.
  • the radiographic imaging device 100 has all the same configurations as those of the radiographic imaging device 1 described above. Therefore, in the description of the radiographic image capturing apparatus 100, the same components as those of the radiographic image capturing apparatus 1 are denoted by the same reference numerals and description thereof is omitted.
  • the detection unit P, the gate driver 15b, and the power supply circuit 15a are not shown.
  • the radiographic image capturing apparatus 100 includes a control unit 122, and the control unit 122 includes a CPU 123, a RAM 124, and a ROM 125, similar to the control unit 22 described above. Further, the control unit 122 includes a program memory 126, and the photographing control program 127 for executing the process of FIG. 9 and dark image data for executing the process of FIGS. 10A and 10B. The acquisition control program 128 is stored.
  • the program memory 126 stores an output abnormality determination program 129 that has been processed by the CPU of the console 58 described above.
  • the output abnormality determination program 129 is a program for executing the same processing as the processing of FIG. 12 executed by the CPU of the console 59.
  • the output abnormality is detected for the detection unit P possessed by the device.
  • the radiation detecting element 7 can be specified.
  • this makes it possible to register the radiation detection element 7 whose output is abnormal with respect to the defective element map M. That is, the control means 22 that executes the output abnormality determination program 129 functions as “output abnormality determination means” and “registration means”.
  • the storage unit 140 provided in the control unit 122 includes an output abnormality in addition to the actual image data J, the dark image data B, and the dark image data BH1 and BH2 for determining the output abnormality for each radiation detection element 7.
  • the configuration is such that difference data ⁇ BH and defect element map M obtained in the course of execution of the determination program 129 are stored.
  • the radiographic image capturing apparatus 100 executes the same processing as steps S21 to S23 in FIG. 15, and the image data G subjected to the interpolation processing is transmitted to the console 58 through the antenna device 39. Therefore, the storage unit 140 is configured to store image data G for one screen that has been completed up to the interpolation processing.
  • the radiographic image capturing apparatus 100 obtains the image data G, the processing burden on the console 58 side can be reduced.
  • the radiation image capturing apparatus 100 has a defect element map M and can manage information on the radiation detection elements 7 that cause output abnormalities by self-processing, individual radiation image capturing on the console 58 side is possible. It is also possible to eliminate the management of the device 100.
  • the defect element map M may be managed by both the radiation image capturing apparatus 100 side and the console 58 side. In this case, the radiographic imaging apparatus 100 may be configured to transmit the data of the defective element map M to the console 58 every time the registered content of the defective element map M is updated.
  • the correction is performed by subtracting the dark image data B from the actual captured image data J for each radiation detection element 7. Calculating the completed image data and transmitting the corrected image data to the console 58 instead of the actual image data J and the dark image data B, or the difference between the dark image data BH1 and BH2 for each radiation detection element 7 It is possible to calculate the data ⁇ BH and transmit the difference data ⁇ BH to the console 58 instead of the dark image data BH1 and BH2, or to perform both. With these configurations, the amount of data transmitted from the radiographic apparatus to the console 58 can be reduced, and the transfer time can be shortened.
  • the defective pixel map creation system 200 is a system that creates a defective pixel map by determining a defective pixel by performing an inspection involving radiation irradiation, for example, at the time of a shipping inspection performed before the radiation image capturing apparatus 1 is shipped.
  • FIG. 18 is a diagram showing the overall configuration of the defective pixel map creation system 200.
  • the defective pixel map creation system 200 creates a defective pixel map for the substrate 4 at the previous stage stored in the housing 2 of the radiation imaging apparatus 1. That is, the substrate 4 is in a state where all the configurations (the entire internal configuration of the housing 2 in FIG. 2) directly provided on both surfaces of the substrate 4 such as the detection unit P and the scintillator 3 are already mounted or formed.
  • the COF 12, the substrate 33, the scanning drive unit 15, the readout IC 16, the control unit 22, the storage unit 40, the antenna device 39, and the like are all mounted, and a radiographic image can be captured when power is supplied.
  • detection function unit 4A an electric double layer capacitor such as a lithium ion capacitor and a secondary battery such as a lithium ion battery are usually mounted on the substrate 4 as a battery 41. These are in an aging step (described later) in creating a defective pixel map. In order to avoid influences such as destruction and deterioration due to heating, the battery 41 is removed in advance or a defective pixel map is created at a stage before mounting.
  • the defective pixel map creation system 200 mainly includes a thermostatic chamber 210 as a heating unit that stores the detection function unit 4A and a defective pixel map creation device 220.
  • the thermostatic chamber 210 can accommodate the detection function unit 4A inside, has high sealing property and heat insulation, and blocks electromagnetic waves including visible light and radiation from the outside to make the inside a dark room. It is possible to do.
  • the thermostatic chamber 210 includes a heater 211 that raises the temperature inside, a temperature sensor 212 that detects the temperature inside, and a power supply circuit 213 that supplies necessary power to each part of the housed detection function unit 4A.
  • a communication unit 214 that performs wireless communication through the antenna device 39 of the housed detection function unit 4A.
  • the heater 211 and the temperature sensor 212 are connected to the controller 215, and the controller can input the setting of the internal temperature of the thermostat 210.
  • the controller performs heating control of the heater 211 based on the temperature detected by the temperature sensor 212, and performs control to maintain the constant temperature bath 210 at a set temperature.
  • the detection function unit 4A is accommodated in the thermostatic chamber 210 without the battery 41 mounted.
  • the power supply circuit 213 supplies power to the detection function unit 4A so that the detection function unit 4A housed in the thermostat 210 can execute radiographic image capturing.
  • the power supply circuit 213 is disposed outside the thermostatic chamber 210 and supplies power to the detection function unit 4A through a power supply connector 213A in the bath through wiring.
  • the power supply connector 213A is the same type as the connector that connects the battery 41 to the substrate 4, and the power supply connector 213A can be connected instead of the battery 41 being removed, and thus the detection function unit 4A can be connected. Power is supplied to each part.
  • the communication unit 214 is a wireless device in which an antenna is arranged inside the thermostat 210, and enables wireless transmission and reception with the detection function unit 4A through the antenna device 39 on the detection function unit 4A side.
  • the communication unit 214 is connected to the defective pixel map creation device 220 via a communication cable, and transmits a control command to the detection function unit 4A from the control unit 221 of the defective pixel map creation device 220 described later, or a detection function.
  • the dark image data acquired by the unit 4A can be received and transmitted to the defective pixel map creating apparatus 220.
  • the defective pixel map creation device 220 controls the detection function unit 4A heated in the thermostat 210 to acquire dark image data BH3 and BH4 for aging processing and output abnormality determination of each radiation detection element 7. The processing is executed in order, the radiation detection element 7 with abnormal output is identified from the acquired dark image data BH3 and BH4, and the defective pixel map M is created for the radiation detection element 7 with abnormal output.
  • the defective pixel map creating apparatus 220 includes a control unit 221 and various data storage units 230, and the control unit 221 includes a CPU 222, a RAM 223, and a ROM 224.
  • the control means 221 includes a program memory 225, and an aging control program 227 for causing the detection function unit 4A to execute an aging process described later, and a dark image for determining an output abnormality of each radiation detection element 7.
  • a dark image data acquisition control program 228 for causing the detection function unit 4A to execute a data acquisition process for acquiring the data BH3 and BH4, and specifying the radiation detection element 7 having an abnormal output from the acquired dark image data BH3 and BH4
  • An output abnormality determination program 229 for creating a defective pixel map M for the radiation abnormality detecting element 7 with an abnormality in output is stored.
  • control unit 221 executes the aging control program 227 to start heating the heater 211 to a set temperature (for example, 60 degrees Celsius) in the thermostatic chamber 210, and through the communication unit 214, the detection function unit A control command for executing the aging process is transmitted to the control means 22 of 4A (step S31: aging step).
  • a set temperature for example, 60 degrees Celsius
  • the detection function unit A control command for executing the aging process is transmitted to the control means 22 of 4A (step S31: aging step).
  • the aging process is a process of repeatedly executing the reset of accumulated charges, the accumulation of charges, and the charge reading operation (charge releasing operation) within a predetermined duration.
  • the detection function unit 4A resets the accumulated charge of each radiation detection element 7 by applying an ON voltage to the lines L1 to Lx of the scanning line 5 and switching each charge reset switch 18c to the ON state. Then, charge accumulation by each radiation detection element 7 is performed by turning off each charge reset switch 18 c and application of an OFF voltage to each TFT 8, and readout of charge accumulated in each radiation detection element 7 by application of an ON voltage to each TFT 8. (Discharge of electric charge) is repeatedly executed a plurality of times.
  • the control unit 221 functions as an “aging control unit” by causing the detection function unit 4A to repeatedly execute the reset, charge accumulation, and charge readout.
  • the reset, storage, and readout operations are executed in a shorter cycle than the operation at the time of normal imaging of an actual radiation image.
  • the cycle is repeatedly executed for a predetermined time.
  • the repetition time is about 10 to 20 hours, for example.
  • the charge accumulation of each radiation detection element 7 is performed in the thermostatic chamber 210 in a non-irradiated state, dark charges are accumulated, but the charge of each radiation detection element 7 in the aging process is accumulated. Accumulation is not limited to dark charges, and may be performed in a radiation irradiation state, for example.
  • the read operation of the accumulated charges of each radiation detection element 7 is not intended to acquire data but is intended to perform the discharge operation of charges, so A / D conversion and storage of the converted data are performed. Is not done.
  • step S32 dark image data acquisition step.
  • the acquisition control of the dark image data BH3 and BH4 is almost the same operation control as the acquisition of the dark image data BH1 and BH2 shown in FIGS. 10A and 10B.
  • the control means 22 of the detection function unit 4A resets the charge of each radiation detection element 7, accumulates the charge of the dark image in the third accumulation time in the non-irradiated state, and each radiation detection element 7 Read processing is executed for.
  • the third accumulation time is set so that the accumulation time at the time of shooting is longer than the accumulation time at the time of shooting.
  • the third accumulation time is set to 10 [s], which is the same as the first accumulation time in FIG. 10A.
  • the control means 22 of the detection function unit 4A resets the charge of each radiation detection element 7, accumulates the charge of the dark image in the fourth accumulation time in the non-irradiated state, and each radiation detection element 7 Is read out, and dark image data BH4 for output abnormality determination based on the fourth accumulation time of each radiation detection element 7 is acquired and transmitted to the control means 221 of the defective pixel map creation device 220.
  • the fourth accumulation time is set to a length different from the third accumulation time and longer than the accumulation time at the time of shooting. Specifically, the fourth accumulation time is set to 20 [s], which is the same as the second accumulation time in FIG. 10B.
  • the control unit 221 stores the dark image data BH4 in the storage unit 230.
  • the control means 221 functions as a “dark image data acquisition control unit” by executing control for acquiring dark image data BH3 and BH4 for output abnormality determination from the detection function unit 4A.
  • the control unit 221 reads out the two dark image data BH3 and BH4 from the storage unit 230, and calculates the difference data ⁇ BH2 by subtracting them (step S33). : Difference step). That is, the dark image data BH3 is subtracted from the dark image data BH4, and difference data ⁇ BH2 including the difference value of the output value for each radiation detection element 7 is calculated.
  • the control unit 221 functions as a “difference calculation unit” by calculating a difference between the dark image data BH3 and BH4.
  • the control unit 221 determines the output abnormality from the average value ⁇ and the standard deviation ⁇ of each difference data ⁇ BH2.
  • the upper limit threshold ⁇ + 5 ⁇ and the lower limit threshold ⁇ 5 ⁇ of the difference data ⁇ BH2 are calculated (step S34).
  • the coefficient of ⁇ is not limited to “5”, and setting means may be provided to allow arbitrary setting input.
  • the threshold value itself may be set arbitrarily.
  • the control means 221 sequentially determines the output abnormality for the difference data ⁇ BH2 of each radiation detection element 7 (step S35: determination step).
  • FIG. 20A is a diagram showing a correspondence relationship between the output value of each radiation detection element 7 and its frequency (number of elements) when the detection function unit 4A is not subjected to the aging process
  • FIG. 20B is an aging diagram for the detection function unit 4A. It is a diagram which shows the correspondence of the output value of each radiation detection element 7 at the time of processing, and its frequency (element number).
  • the control means 221 functions as a “determination unit” by determining the output abnormality of each radiation detection element 7 from the difference data of the dark image data BH3 and BH4.
  • the control unit 221 executes the output abnormality determination program 229 to register the radiation detection element 7 in the defect element map M in the storage unit 230 for the radiation detection element 7 determined to be output abnormality.
  • Step S36 defective pixel map creation step.
  • the defect element map may be a record of the position information of the radiation detection elements 7 that are abnormal in output, and whether all the radiation detection elements 7 are normal or abnormal (which radiation detection element 7 is abnormal). The information shown may be recorded.
  • the control means 221 functions as a “defective pixel map creation unit” by registering a defective pixel map.
  • the abnormality of the output value of each radiation detection element 7 is determined after the aging process is performed on the detection function unit 4A. It becomes possible to detect early by actively proceeding with an abnormal state of the radiation detecting element 7 which will cause an abnormal output later, which is not considered to be. And since the generation
  • the thermostat 210 which accommodates the detection function part 4A is provided and the aging process with respect to the detection function part 4A can be performed in a high temperature state, the aging can be efficiently advanced with a small number of process repetitions. It is possible to improve the detection accuracy of the abnormality of the detection element 7.
  • the temperature setting of the detection function unit 4A by the thermostatic chamber 210 is not limited to the above-described example as long as it is higher than the normal temperature that is the normal use environment temperature.
  • the set temperature may be set equal to the continuous use temperature in the housing 2 that is reached by the heat generation of each component of the detection function unit 4A when the radiographic imaging device 1 is used a plurality of times.
  • It may be used in the field of radiographic imaging (especially in the medical field).

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Abstract

The present disclosure is intended to determine radiation sensing elements with output anomalies with a high degree of precision. A radiograph imaging device (1) comprises a plurality of radiation sensing elements (7) that are arranged in a two-dimensional array by a plurality of scan lines and signal lines; a read-out circuit (17) that outputs either actual image data (J) or dark image data (B) on a per radiation sensing element basis; a communications means (39) for communicating the data to an external device (58); and a control means for controlling such that the read-out circuit outputs dark image data (BH1, BH2) for the output anomaly determination of the radiation sensing elements, on the basis of the charge that each radiation sensing element accumulates when radiation is not projected in an accumulation time that is longer than when imaging.

Description

放射線画像撮影装置、放射線画像撮影システム、欠陥画素マップ作成方法及び欠陥画素マップ作成システムRadiation image capturing apparatus, radiation image capturing system, defective pixel map creating method, and defective pixel map creating system
 本発明は、異常な検出値を示す放射線検出素子の検出を可能とする放射線画像撮影装置、放射線画像撮影システム、放射線画像撮影装置の欠陥画素マップ作成方法及び放射線画像撮影装置の欠陥画素マップ作成システムに関する。 The present invention relates to a radiographic image capturing apparatus, a radiographic image capturing system, a defective pixel map creating method for a radiographic image capturing apparatus, and a defective pixel map creating system for a radiographic image capturing apparatus capable of detecting a radiation detecting element exhibiting an abnormal detection value. About.
 従来、医療用の放射線画像を取得する手段として、いわゆるフラットパネルディテクタ(Flat Panel Detector:FPD)と呼ばれる放射線検出素子を2次元的に配置した放射線画像形成装置が知られている。このような放射線画像形成装置には、放射線検出素子として、a-Se(アモルファスセレン)のような光導電物質を用いて放射線エネルギーを直接電荷に変換し、この電荷を2次元的に配置されたTFT(Thin Film Transistor:薄膜トランジスタ)等の信号読出し用のスイッチ素子によって画素単位に電気信号として読み出す直接方式のものや、放射線エネルギーをシンチレータ等で光に変換し、この光を2次元的に配置されたフォトダイオード等の光電変換素子で電荷に変換してTFT等によって電気信号として読み出す間接方式のもの等があることが知られている。 Conventionally, as a means for acquiring a medical radiation image, a radiation image forming apparatus in which radiation detection elements called flat panel detectors (FPD) are two-dimensionally arranged is known. In such a radiation image forming apparatus, radiation energy is directly converted into charges using a photoconductive substance such as a-Se (amorphous selenium) as a radiation detection element, and the charges are arranged two-dimensionally. A direct readout method that reads out electrical signals pixel by pixel using a signal readout switch element such as a TFT (Thin Film Transistor), or radiation energy is converted into light by a scintillator, etc., and this light is arranged two-dimensionally. It is known that there is an indirect type that is converted into electric charge by a photoelectric conversion element such as a photodiode and read out as an electric signal by a TFT or the like.
 FPD型の放射線画像形成装置では、センサパネル上に放射線検出素子を形成する際に放射線検出素子中に不純物が混入する等により、恒常的に或いは一定の確率で異常な画像データを出力する放射線検出素子が生じる場合がある。 In an FPD type radiation image forming apparatus, radiation detection that outputs abnormal image data constantly or with a certain probability due to impurities mixed into the radiation detection element when forming the radiation detection element on the sensor panel. An element may occur.
 このような欠陥のある放射線検出素子が存在すると、その部分に画像の欠損が生じ、高精細な画像を得ることができない。
 そこで、従来、欠陥のある放射線検出素子を有するセンサパネルを用いて撮影が行われた場合には、当該欠陥のある放射線検出素子の近傍の正常放射線検出素子の検出値を用いて単純平均補間を行ったり、重み付け平均補間を行う等の手法により欠陥のある放射線検出素子の検出値を補間する補間処理が行われてきた。
If such a defective radiation detection element exists, an image defect occurs in that portion, and a high-definition image cannot be obtained.
Therefore, conventionally, when imaging is performed using a sensor panel having a defective radiation detection element, simple average interpolation is performed using detection values of normal radiation detection elements in the vicinity of the defective radiation detection element. Interpolation processing for interpolating detection values of defective radiation detection elements has been performed by techniques such as performing weighted average interpolation.
 そして、欠陥のある放射線検出素子の補正を行うためには、欠陥のある放射線検出素子の位置を特定する必要があり、一貫しない出力信号を出力する放射線検出素子を欠陥のある放射線検出素子としてマップに登録する手段を有する放射線画像形成装置が提案されている(例えば、特許文献1参照)。
 この放射線画像撮影装置では、センサパネルにおける一定の処理領域(例えば128×128画素)内の各放射線検出素子の暗電流に基づく出力(放射線の非照射時における出力)の平均値mと標準偏差σとを求め、m±5σの範囲外となる出力を行う放射線検出素子について欠陥のある放射線検出素子と判断していた。
In order to correct a defective radiation detection element, the position of the defective radiation detection element needs to be specified, and the radiation detection element that outputs an inconsistent output signal is mapped as a defective radiation detection element. A radiographic image forming apparatus having a means for registering in (Patent Document 1) has been proposed.
In this radiographic imaging apparatus, an average value m and a standard deviation σ of outputs (outputs when radiation is not irradiated) based on dark current of each radiation detection element in a certain processing region (for example, 128 × 128 pixels) in the sensor panel. The radiation detection element that outputs an output outside the range of m ± 5σ is determined to be a defective radiation detection element.
特開2005-6169号公報Japanese Patent Laid-Open No. 2005-6169
 しかしながら、上述の手法により欠陥のある放射線検出素子の識別を行う場合、通常とかけ離れた異常な出力を行っている明らかな欠陥放射線検出素子については容易に識別することが可能であるが、判別のための閾値に近い値で出力を行うような異常な状態に移行しつつある予備的な欠陥放射線検出素子については、識別を行うことが難しかった。このような予備的な欠陥放射線検出素子は、放射線検出素子の成膜形成時に不純物が混入したことを原因とする場合が多い。不純物が混入すると、放射線検出素子の電極間でリークパスを発生させ、繰り返される使用に応じて徐々にリーク量が増加して、いずれは欠陥放射線検出素子となる過程をたどる可能性が高い。このため、予備的な欠陥放射線検出素子は、繰り返される使用を経て完全な欠陥放射線検出素子となって識別可能となってから欠陥素子マップに登録しなければならないことから、定期的なメンテナンスによる監視を余儀なくされるという問題を生じていた。
 また、上記予備的な欠陥放射線検出素子を早期段階で識別するために、正常と見なす範囲をより狭くすることも考えられるが、その場合、正常な放射線検出素子までもが欠陥放射線検出素子と誤認される場合を生じ、本来必要のない放射線検出素子までもが補間処理の対象となり、撮像精度の低下を招くおそれがあった。
However, when identifying a radiation detection element having a defect by the above-described method, it is possible to easily identify an apparent defect radiation detection element that is performing an abnormal output far from normal, Therefore, it has been difficult to identify a preliminary defective radiation detection element that is shifting to an abnormal state in which output is performed at a value close to the threshold value. Such preliminary defective radiation detection elements are often caused by impurities being mixed during the formation of the radiation detection elements. When impurities are mixed, a leak path is generated between the electrodes of the radiation detection element, and the amount of leakage gradually increases with repeated use, and there is a high possibility that the process will eventually become a defective radiation detection element. For this reason, the preliminary defect radiation detection element must be registered in the defect element map after it can be identified as a complete defect radiation detection element through repeated use. The problem of being forced to have occurred.
In addition, in order to identify the preliminary defective radiation detection element at an early stage, it may be possible to narrow the range regarded as normal, but in that case, even the normal radiation detection element is misidentified as a defective radiation detection element. In some cases, even radiation detection elements that are not necessary are subject to interpolation processing, which may lead to a reduction in imaging accuracy.
 そこで、本発明は欠陥とされる放射線検出素子をより的確に識別可能とする放射線画像撮影装置、放射線画像撮影システム、欠陥画素マップ作成方法及び欠陥画素マップ作成システムを提供することを目的とするものである。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a radiographic image capturing apparatus, a radiographic image capturing system, a defective pixel map creating method, and a defective pixel map creating system that can more accurately identify a radiation detection element that is regarded as a defect. It is.
 前記の問題を解決するために、本発明の放射線画像撮影装置は、互いに交差するように配設された複数の走査線および複数の信号線と、前記複数の走査線および複数の信号線により区画された各領域に二次元状に配列された複数の放射線検出素子とを備える検出部と、前記放射線検出素子から前記信号線を通じて電荷を読み出し、前記放射線検出素子ごとに前記電荷を電気信号に変換してデータとして出力する読み出し回路と、放射線が照射される撮影時に前記各放射線検出素子が所定の蓄積時間で蓄積した電荷に基づいて前記読み出し回路が前記データとして実写画像データを出力すると共に、当該撮影に付随して、前記放射線の非照射時に前記各放射線検出素子が前記撮影時と同じ蓄積時間で蓄積した電荷に基づいて前記読み出し回路が前記実写画像データを補正するための暗画像データを出力するよう制御する制御手段と、外部装置との間でデータを送受信する通信手段と、と備える放射線画像撮影装置であって、前記制御手段は、放射線の非照射時に前記各放射線検出素子が前記撮影時よりも長い蓄積時間で蓄積した電荷に基づいて、前記読み出し回路が放射線検出素子の出力異常判定のための暗画像データを出力するよう制御することを特徴とする。 In order to solve the above problem, a radiographic imaging apparatus according to the present invention is divided by a plurality of scanning lines and a plurality of signal lines arranged so as to cross each other, and the plurality of scanning lines and a plurality of signal lines. A plurality of radiation detection elements arranged two-dimensionally in each region, and a charge is read from the radiation detection element through the signal line, and the charge is converted into an electrical signal for each radiation detection element. And a readout circuit that outputs as data, and the readout circuit outputs actual image data as the data based on the charges accumulated by the respective radiation detection elements at a predetermined accumulation time at the time of imaging irradiated with radiation, and The readout circuit is based on charges accumulated in the same accumulation time as each of the radiation detection elements during the non-irradiation of the radiation. A radiographic imaging apparatus comprising: control means for controlling to output dark image data for correcting the real image data; and communication means for transmitting / receiving data to / from an external device, wherein the control means Control is performed so that the readout circuit outputs dark image data for determining the output abnormality of the radiation detection element based on the charge accumulated in each radiation detection element during the non-irradiation with a longer accumulation time than during the imaging. It is characterized by doing.
 また、本発明の別の側面である放射線画像撮影システムは、請求項1記載の放射線画像撮影装置と、前記放射線画像撮影装置との間でデータを受信する通信手段を備えるコンソールと、を備える放射線画像撮影システムであって、前記コンソールは、前記出力異常判定のための暗画像データから、前記各放射線検出素子の出力異常を判定する出力異常判定手段と、いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥素子マップと、前記出力異常判定手段により出力異常と判定された放射線検出素子の位置を前記欠陥素子マップに登録する登録手段とを有することを特徴とする。 Moreover, the radiographic imaging system which is another side surface of this invention is a radiation provided with the radiographic imaging apparatus of Claim 1, and a console provided with the communication means which receives data between the said radiographic imaging apparatus. In the imaging system, the console has output abnormality determination means for determining an output abnormality of each radiation detection element from dark image data for determining the output abnormality, and any radiation detection element has an output abnormality. Or a defect element map for storing the position of the radiation detection element to be output abnormal, and a registration means for registering the position of the radiation detection element determined to be output abnormal by the output abnormality determination means in the defect element map. It is characterized by.
 また、本発明の別の側面である放射線画像撮影装置の欠陥画素マップ作成方法では、互いに交差するように配設された複数の走査線および複数の信号線と前記複数の走査線および複数の信号線により区画された各領域に二次元状に配列された複数の放射線検出素子とを備える検出部と、前記放射線検出素子から前記信号線を通じて電荷を読み出し、前記放射線検出素子ごとに前記電荷を電気信号に変換してデータとして出力する読み出し回路とを備える放射線画像撮影装置について、いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥画素マップを作成する欠陥画素マップ作成方法であって、前記複数の放射線検出素子の各々に対する電荷の蓄積と前記読み出し回路による電荷の読み出しとを繰り返し行うエイジングステップと、前記エイジングステップの後に、前記各放射線検出素子が、放射線の非照射状態で撮影時よりも長い蓄積時間で電荷を蓄積し、蓄積した電荷から放射線検出素子の出力異常判定のための暗画像データを取得する暗画像データ取得ステップと、前記放射線検出素子の出力異常判定のための暗画像データに基づいて、前記各放射線検出素子の出力異常を判定する判定ステップと、前記各放射線検出素子の出力異常の判定に基づいて、当該出力異常となる放射線検出素子を登録した前記欠陥画素マップを作成する欠陥画素マップ作成ステップと、を備えることを特徴とする。 According to another aspect of the present invention, there is provided a defective pixel map creating method for a radiographic image capturing apparatus, wherein a plurality of scanning lines and a plurality of signal lines arranged to intersect each other, and the plurality of scanning lines and a plurality of signals are arranged. A detection unit including a plurality of radiation detection elements arranged in a two-dimensional manner in each region partitioned by lines, and reads out charges from the radiation detection elements through the signal lines, and electrically charges the charges for each of the radiation detection elements. For a radiographic imaging apparatus including a readout circuit that converts the signal into a signal and outputs the data, a defective pixel map that stores which radiation detection element has an output abnormality or the position of the radiation detection element to be output abnormal is created. A method for creating a defective pixel map, wherein charges are accumulated in each of the plurality of radiation detection elements and charges are read by the readout circuit. And after the aging step, each radiation detection element accumulates charges in a longer accumulation time than when photographing in a non-irradiated state, and determines an output abnormality of the radiation detection element from the accumulated charges. A dark image data acquisition step for acquiring dark image data for the determination; a determination step for determining an output abnormality of each radiation detection element based on dark image data for an output abnormality determination of the radiation detection element; And a defective pixel map creating step of creating the defective pixel map in which the radiation detecting element having the output abnormality is registered based on the determination of the output abnormality of each radiation detecting element.
 また、本発明の別の側面である放射線画像撮影装置の欠陥画素マップ作成システムは、互いに交差するように配設された複数の走査線および複数の信号線と前記複数の走査線および複数の信号線により区画された各領域に二次元状に配列された複数の放射線検出素子とを備える検出部と、前記放射線検出素子から前記信号線を通じて電荷を読み出し、前記放射線検出素子ごとに前記電荷を電気信号に変換してデータとして出力する読み出し回路とを備える放射線画像撮影装置について、いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥画素マップを作成する欠陥画素マップを作成する欠陥画素マップ作成システムにおいて、前記複数の放射線検出素子の各々に対する電荷の蓄積と前記読み出し回路による電荷の読み出しとを繰り返し行うエイジング制御部と、前記電荷の蓄積と前記電荷の読み出しとが繰り返し行われた前記各放射線検出素子が、放射線の非照射状態で撮影時よりも長い蓄積時間で電荷を蓄積し、蓄積した電荷から放射線検出素子の出力異常判定のための暗画像データを取得する暗画像データ取得制御部と、前記放射線検出素子の出力異常判定のための暗画像データに基づいて、前記各放射線検出素子の出力異常を判定する判定部と、前記各放射線検出素子の出力異常の判定に基づいて、当該出力異常となる放射線検出素子を登録した前記欠陥画素マップを作成する欠陥画素マップ作成部と、を備えることを特徴とする。 In addition, a defective pixel map creation system for a radiographic imaging apparatus according to another aspect of the present invention includes a plurality of scanning lines and a plurality of signal lines arranged to intersect each other, and the plurality of scanning lines and a plurality of signals. A detection unit including a plurality of radiation detection elements arranged in a two-dimensional manner in each region partitioned by lines, and reads out charges from the radiation detection elements through the signal lines, and electrically charges the charges for each of the radiation detection elements. For a radiographic imaging apparatus including a readout circuit that converts the signal into a signal and outputs the data, a defective pixel map that stores which radiation detection element has an output abnormality or a position of the radiation detection element that causes an output abnormality is created. In a defective pixel map creation system for creating a defective pixel map, charge accumulation and reading of each of the plurality of radiation detection elements are performed. An aging control unit that repeatedly reads out charges by the extraction circuit, and each of the radiation detection elements that has repeatedly performed charge accumulation and charge read-out has a longer accumulation time than that during imaging in a non-radiation state. And a dark image data acquisition control unit for acquiring dark image data for determining output abnormality of the radiation detection element from the stored charge, and based on dark image data for determining output abnormality of the radiation detection element And a defect that creates the defective pixel map in which the radiation detection element that causes the output abnormality is registered based on the determination unit that determines the output abnormality of the radiation detection element and the determination of the output abnormality of the radiation detection element. And a pixel map creating unit.
 本発明にかかる放射線画像撮影装置および放射線画像撮影システムは、放射線画像撮影装置の制御手段が放射線の非照射時(いわゆる暗電荷の取得時)に各放射線検出素子について、撮影時よりも長い蓄積時間で蓄積した電荷に基づいて読み出し回路から放射線検出素子の出力異常判定のための暗画像データを取得するよう制御を行っている。
 このように、暗画像データ取得の際の各放射線検出素子の電荷の蓄積時間をより長くすると、正常な放射線検出素子の暗画像データの分布が集中する値と出力異常の放射線検出素子による暗画像データとの差をその蓄積時間に応じて広げることが可能となる。
 これにより、異常な値が顕在化し、正常な値と異常な値との判別が容易となり、閾値も適正な値をとりやすくなる。その結果、正常な放射線検出素子まで出力異常と判定される可能性が低減され、判定精度の向上を図ることが可能となる。
 さらに、異常を生じつつも正常な値に近い暗画像データを出力する放射線検出素子についても正常な放射線検出素子から分離して識別することが可能となり、例えば、もともと正常であった放射線検出素子が徐々に異常となりつつある場合でも早期にこれを異常と判定することができ、出力異常の放射線検出素子を監視するためのメンテナンスの頻度を低減することも可能となる。
The radiographic image capturing apparatus and the radiographic image capturing system according to the present invention are configured such that the control unit of the radiographic image capturing apparatus has a longer accumulation time for each radiation detection element when no radiation is applied (so-called dark charge acquisition time) than when imaging. Control is performed so as to acquire dark image data for determining an output abnormality of the radiation detection element from the readout circuit based on the electric charge accumulated in step.
As described above, when the charge accumulation time of each radiation detection element at the time of dark image data acquisition is made longer, the value of the distribution of the dark image data of the normal radiation detection element is concentrated and the dark image by the radiation detection element of abnormal output The difference from the data can be widened according to the accumulation time.
Thereby, an abnormal value becomes obvious, it becomes easy to discriminate between a normal value and an abnormal value, and the threshold value can also easily take an appropriate value. As a result, it is possible to reduce the possibility that it is determined that the output is abnormal up to a normal radiation detection element, and it is possible to improve the determination accuracy.
Furthermore, a radiation detection element that outputs dark image data close to a normal value while causing an abnormality can be separated and distinguished from a normal radiation detection element. For example, a radiation detection element that was originally normal can be identified. Even if it is gradually becoming abnormal, it can be determined as abnormal at an early stage, and it is possible to reduce the frequency of maintenance for monitoring the radiation detecting element with abnormal output.
 また、放射線画像撮影装置の欠陥画素マップ作成方法及び欠陥画素マップ作成システムでも、上記撮影時よりも長い蓄積時間で蓄積した電荷に基づいて取得した出力異常判定のための暗画像データによる判定精度向上の効果を得ることが可能である。そして、当該効果に加えて、放射線画像撮影装置の欠陥画素マップ作成方法及び欠陥画素マップ作成システムでは、放射線検出素子及び読み出し回路にエイジングを行うことから、微弱な出力異常を生じているが、異常とする判定はされないような、後発的に出力異常を発生する可能性の高い放射線検出素子に対して、異常状態を進行させ、その後の判定において異常出力として発見することが可能となる。つまり、繰り返される使用によって後発的に異常となる放射線検出素子を早期の段階で発見し、当該出力異常となる放射線検出素子を欠陥画素マップに登録することができるため、放射線画像撮影装置の使用開始後に異常を発生する放射線検出素子が低減され、メンテナンスの負担の軽減を図ることが可能となる。 Further, even in the defective pixel map creation method and the defective pixel map creation system of the radiographic image capturing apparatus, the determination accuracy improvement by the dark image data for the output abnormality determination obtained based on the charge accumulated in the accumulation time longer than that at the time of the imaging is improved. It is possible to obtain the effect. In addition to the effect, in the defective pixel map creation method and the defective pixel map creation system of the radiographic imaging apparatus, since the aging is performed on the radiation detection element and the readout circuit, a weak output abnormality occurs. It is possible to advance an abnormal state for a radiation detection element that is likely to cause an output abnormality later, such that it is not determined, and to detect it as an abnormal output in subsequent determination. In other words, radiation detectors that become abnormal after the repeated use can be found at an early stage, and radiation detectors that output abnormalities can be registered in the defective pixel map, so the use of the radiographic imaging device is started. The number of radiation detecting elements that will cause an abnormality later is reduced, and the maintenance burden can be reduced.
本実施形態における放射線画像撮影装置を示す外観斜視図である。It is an external appearance perspective view which shows the radiographic imaging apparatus in this embodiment. 図1におけるA-A線に沿う断面図である。FIG. 2 is a cross-sectional view taken along line AA in FIG. 放射線画像撮影装置の基板の構成を示す平面図である。It is a top view which shows the structure of the board | substrate of a radiographic imaging apparatus. 図3の基板上の小領域に形成された放射線検出素子とTFT等の構成を示す拡大図である。It is an enlarged view which shows the structure of the radiation detection element, TFT, etc. which were formed in the small area | region on the board | substrate of FIG. 図4におけるB-B線に沿う断面図である。FIG. 5 is a cross-sectional view taken along line BB in FIG. 4. COFやPCB基板等が取り付けられた基板を説明する側面図である。It is a side view explaining the board | substrate with which COF, a PCB board | substrate, etc. were attached. 放射線画像撮影装置の等価回路を表すブロック図である。It is a block diagram showing the equivalent circuit of a radiographic imaging apparatus. 検出部を構成する1画素分についての等価回路を表すブロック図である。It is a block diagram showing the equivalent circuit about 1 pixel which comprises a detection part. 撮影動作制御の各工程を示す説明図である。It is explanatory drawing which shows each process of imaging | photography operation control. 出力異常判定のための暗画像データ取得時の各工程を示す説明図であり、第一の蓄積時間に基づく暗画像データの取得工程を示す。It is explanatory drawing which shows each process at the time of dark image data acquisition for output abnormality determination, and shows the acquisition process of the dark image data based on 1st accumulation | storage time. 出力異常判定のための暗画像データ取得時の各工程を示す説明図であり、第二の蓄積時間に基づく暗画像データの取得工程を示す。It is explanatory drawing which shows each process at the time of dark image data acquisition for output abnormality determination, and shows the acquisition process of the dark image data based on 2nd accumulation time. 本実施形態における放射線画像撮影システムの全体構成を示す図である。It is a figure which shows the whole structure of the radiographic imaging system in this embodiment. 出力異常判定の処理を示すフローチャートである。It is a flowchart which shows the process of output abnormality determination. 暗画像データ同士の差分算出処理を示す概念図である。It is a conceptual diagram which shows the difference calculation process between dark image data. 各放射線検出素子の電荷の蓄積時間を通常の撮影時と同じくして暗画像データの取得を行った場合の暗画像データとその頻度の対応関係を示す線図である。FIG. 6 is a diagram showing a correspondence relationship between dark image data and the frequency when dark image data is acquired with the same charge accumulation time of each radiation detection element as in normal imaging. 各放射線検出素子の電荷の蓄積時間を通常の撮影時よりも長く設定して暗画像データの取得を行った場合の暗画像データとその頻度の対応関係を示す線図である。FIG. 6 is a diagram showing a correspondence relationship between dark image data and the frequency when dark image data is acquired with the charge accumulation time of each radiation detection element set longer than that in normal imaging. コンソールの画像表示制御の処理内容について示すフローチャートである。It is a flowchart shown about the processing content of the image display control of a console. 出力異常の放射線検出素子の出力に基づく画像データの補間の内容を示す概念図である。It is a conceptual diagram which shows the content of the interpolation of the image data based on the output of the radiation detection element of an output abnormality. 放射線画像撮影装置の他の例の構成を示すブロック図である。It is a block diagram which shows the structure of the other example of a radiographic imaging apparatus. 欠陥画素マップ作成システムの全体構成を示す図である。It is a figure which shows the whole structure of a defective pixel map production system. 欠陥画素マップ作成方法のフローチャートである。It is a flowchart of a defective pixel map creation method. 検出機能部にエイジング処理を行っていない場合の各放射線検出素子の出力値とその頻度(素子数)の対応関係を示す線図である。It is a diagram which shows the correspondence of the output value of each radiation detection element when not performing the aging process to a detection function part, and its frequency (number of elements). 検出機能部にエイジング処理を行った場合の各放射線検出素子の出力値とその頻度(素子数)の対応関係を示す線図である。It is a diagram which shows the correspondence of the output value of each radiation detection element at the time of performing an aging process to a detection function part, and its frequency (number of elements).
 以下、本発明に係る放射線画像撮影装置及び放射線画像撮影システムの実施の形態について、図面を参照して説明する。 Hereinafter, embodiments of a radiographic imaging apparatus and a radiographic imaging system according to the present invention will be described with reference to the drawings.
[放射線画像撮影装置]
 まず、図1から図10Bまでを参照しつつ、本実施形態における放射線画像撮影装置の構成について説明する。なお、以下では、放射線画像撮影装置が、シンチレータ等を備え、照射された放射線を可視光等の他の波長の電磁波に変換して電気信号を得るいわゆる間接型の放射線画像撮影装置である場合について説明するが、本発明は、直接型の放射線画像撮影装置に対しても適用することが可能である。また、放射線画像撮影装置が可搬型である場合について説明するが、支持台等と一体的に形成された放射線画像撮影装置に対しても適用される。
[Radiation imaging equipment]
First, the configuration of the radiographic image capturing apparatus according to the present embodiment will be described with reference to FIGS. 1 to 10B. In the following description, the radiographic imaging device is a so-called indirect radiographic imaging device that includes a scintillator or the like and converts the irradiated radiation into electromagnetic waves of other wavelengths such as visible light to obtain an electrical signal. As will be described, the present invention can also be applied to a direct radiographic imaging apparatus. Although the case where the radiographic image capturing apparatus is portable will be described, the present invention is also applicable to a radiographic image capturing apparatus formed integrally with a support base or the like.
 図1は、本実施形態における放射線画像撮影装置の外観斜視図であり、図2は、図1のA-A線に沿う断面図である。本実施形態に係る放射線画像撮影装置1は、図1、図2に示すように、筐体2の内部にシンチレータ3や基板4等が収納されて構成されている。 FIG. 1 is an external perspective view of the radiographic image capturing apparatus according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. As shown in FIGS. 1 and 2, the radiographic image capturing apparatus 1 according to the present embodiment is configured by housing a scintillator 3, a substrate 4, and the like inside a housing 2.
 筐体2は、少なくとも放射線入射面Rが放射線を透過するカーボン板やプラスチック等の材料で形成されている。なお、図1や図2では、筐体2がフレーム板2Aとバック板2Bとで形成された、いわゆる弁当箱型である場合が示されているが、筐体2の形状はこれに限定されない。筐体2を一体的に角筒状に形成した、いわゆるモノコック型とすることも可能である。 The housing 2 is formed of a material such as a carbon plate or plastic that transmits at least the radiation incident surface R. 1 and 2 show a case where the housing 2 is a so-called lunch box type formed by the frame plate 2A and the back plate 2B, but the shape of the housing 2 is not limited to this. . It is also possible to use a so-called monocoque type in which the housing 2 is integrally formed in a rectangular tube shape.
 また、図1に示すように、筐体2の側面部分には、電源スイッチ36や、LED等で構成されたインジケータ37、図示しないバッテリ41(後述する図7参照)の交換等のために開閉可能とされた蓋部材38等が配置されている。また、本実施形態では、蓋部材38の側面部には、画像データG(後述)を、後述するコンソール58(図11参照)等の外部装置に無線で転送するための通信手段であるアンテナ装置39が埋め込まれている。なお、画像データGを外部装置に有線方式で転送するように構成することも可能であり、その場合は、例えば、通信手段として、ケーブル等を差し込むなどして接続するための接続端子等が放射線画像撮影装置1の側面部等に設けられる。 As shown in FIG. 1, the side surface of the housing 2 is opened and closed for replacement of a power switch 36, an indicator 37 composed of LEDs and the like, and a battery 41 (not shown) (see FIG. 7 described later). A possible lid member 38 and the like are arranged. Further, in the present embodiment, an antenna device that is a communication unit for wirelessly transferring image data G (described later) to an external device such as a console 58 (described later) illustrated in FIG. 39 is embedded. It is also possible to transfer the image data G to an external device in a wired manner. In that case, for example, as a communication means, a connection terminal or the like for connection by inserting a cable or the like is used as radiation. It is provided on the side surface of the image capturing apparatus 1 or the like.
 また、図2に示すように、筐体2の内部には、基板4の下方側に図示しない鉛の薄板等を介して基台31が配置され、基台31には、電子部品32等が配設されたPCB基板33や緩衝部材34等が取り付けられている。なお、本実施形態では、基板4やシンチレータ3の放射線入射面Rには、それらを保護するためのガラス基板35が配設されている。 As shown in FIG. 2, a base 31 is disposed inside the housing 2 via a thin lead plate or the like (not shown) on the lower side of the substrate 4. The disposed PCB substrate 33, the buffer member 34, and the like are attached. In the present embodiment, a glass substrate 35 for protecting the substrate 4 and the radiation incident surface R of the scintillator 3 is disposed.
 シンチレータ3は、基板4の後述する検出部Pに貼り合わされるようになっている。シンチレータ3は、例えば、蛍光体を主成分とし、放射線の入射を受けると300~800nmの波長の電磁波、すなわち可視光を中心とした電磁波に変換して出力するものが用いられる。 The scintillator 3 is affixed to a detection part P (described later) of the substrate 4. The scintillator 3 is, for example, a phosphor whose main component is converted into an electromagnetic wave having a wavelength of 300 to 800 nm, that is, an electromagnetic wave centered on visible light when it receives radiation, and that is output.
 基板4は、本実施形態では、ガラス基板で構成されており、図3に示すように、基板4のシンチレータ3に対向する側の面4a上には、複数の走査線5と複数の信号線6とが互いに交差するように配設されている。基板4の面4a上の複数の走査線5と複数の信号線6により区画された各小領域rには、放射線検出素子7がそれぞれ設けられている。 In the present embodiment, the substrate 4 is formed of a glass substrate. As shown in FIG. 3, a plurality of scanning lines 5 and a plurality of signal lines are provided on a surface 4 a of the substrate 4 facing the scintillator 3. 6 are arranged so as to cross each other. In each small region r defined by the plurality of scanning lines 5 and the plurality of signal lines 6 on the surface 4 a of the substrate 4, radiation detection elements 7 are respectively provided.
 このように、走査線5と信号線6で区画された各小領域rに二次元状に配列された複数の放射線検出素子7が設けられた領域r全体、すなわち図3に一点鎖線で示される領域が検出部Pとされている。 Thus, the entire region r in which a plurality of radiation detection elements 7 arranged in a two-dimensional manner are provided in each small region r partitioned by the scanning line 5 and the signal line 6, that is, shown by a one-dot chain line in FIG. The region is a detection unit P.
 本実施形態では、放射線検出素子7としてフォトダイオードが用いられているが、この他にも例えばフォトトランジスタ等を用いることも可能である。各放射線検出素子7は、図3や図4の拡大図に示すように、スイッチ素子であるTFT8のソース電極8sに接続されている。また、TFT8のドレイン電極8dは信号線6に接続されている。 In the present embodiment, a photodiode is used as the radiation detection element 7, but other than this, for example, a phototransistor or the like can also be used. Each radiation detection element 7 is connected to the source electrode 8s of the TFT 8 serving as a switching element, as shown in the enlarged views of FIGS. The drain electrode 8 d of the TFT 8 is connected to the signal line 6.
 そして、TFT8は、後述する走査駆動手段15(図7参照)により、接続された走査線5にON電圧が印加され、ゲート電極8gにON電圧が印加されるとON状態となり、放射線検出素子7内で発生し蓄積されている電荷を信号線6に放出させるようになっている。また、TFT8は、接続された走査線5にOFF電圧が印加され、ゲート電極8gにOFF電圧が印加されるとOFF状態となり、放射線検出素子7から信号線6への電荷の放出を停止して、放射線検出素子7内で発生した電荷を放射線検出素子7内に保持して蓄積させるようになっている。 Then, the TFT 8 is turned on when an ON voltage is applied to the connected scanning line 5 and applied to the gate electrode 8g by a scanning driving means 15 (see FIG. 7), which will be described later, and the radiation detection element 7 is turned on. The electric charge generated and accumulated therein is discharged to the signal line 6. In addition, the TFT 8 is turned off when an OFF voltage is applied to the connected scanning line 5 and an OFF voltage is applied to the gate electrode 8g, and the emission of charges from the radiation detection element 7 to the signal line 6 is stopped. The charges generated in the radiation detection element 7 are held and accumulated in the radiation detection element 7.
 ここで、本実施形態における放射線検出素子7やTFT8の構造について、図5に示す断面図を用いて簡単に説明する。図5は、図4におけるB-B線に沿う断面図である。 Here, the structure of the radiation detection element 7 and the TFT 8 in this embodiment will be briefly described with reference to a cross-sectional view shown in FIG. FIG. 5 is a sectional view taken along line BB in FIG.
 図5に示すように、基板4の面4a上には、AlやCr等からなるTFT8のゲート電極8gが走査線5と一体的に積層されて形成されており、ゲート電極8g上および面4a上に積層された窒化シリコン(SiNx)等からなるゲート絶縁層81上のゲート電極8gの上方部分に、水素化アモルファスシリコン(a-Si)等からなる半導体層82を介して、放射線検出素子7の第1電極74と接続されたソース電極8sと、信号線6と一体的に形成されるドレイン電極8dとが積層されて形成されている。 As shown in FIG. 5, a gate electrode 8g of a TFT 8 made of Al, Cr, or the like is formed on the surface 4a of the substrate 4 so as to be integrally laminated with the scanning line 5, and the gate electrode 8g and the surface 4a. The radiation detecting element 7 is disposed above the gate electrode 8g on the gate insulating layer 81 made of silicon nitride (SiNx) or the like laminated thereon via a semiconductor layer 82 made of hydrogenated amorphous silicon (a-Si) or the like. The source electrode 8 s connected to the first electrode 74 and the drain electrode 8 d formed integrally with the signal line 6 are laminated.
 ソース電極8sとドレイン電極8dとは、窒化シリコン(SiNx)等からなる第1パッシベーション層83によって分割されており、さらに第1パッシベーション層83は両電極8s、8dを上側から被覆している。また、半導体層82とソース電極8sやドレイン電極8dとの間には、水素化アモルファスシリコンにVI族元素をドープしてn型に形成されたオーミックコンタクト層84a、84bがそれぞれ積層されている。以上のようにしてTFT8が形成されている。 The source electrode 8s and the drain electrode 8d are divided by a first passivation layer 83 made of silicon nitride (SiNx) or the like, and the first passivation layer 83 covers both the electrodes 8s and 8d from above. In addition, ohmic contact layers 84a and 84b formed in an n-type by doping hydrogenated amorphous silicon with a group VI element are stacked between the semiconductor layer 82 and the source electrode 8s and the drain electrode 8d, respectively. The TFT 8 is formed as described above.
 また、放射線検出素子7の部分では、基板4の面4a上に前記ゲート絶縁層81と一体的に形成される絶縁層71の上にAlやCr等が積層されて補助電極72が形成されており、補助電極72上に前記第1パッシベーション層83と一体的に形成される絶縁層73を挟んでAlやCr、Mo等からなる第1電極74が積層されている。第1電極74は、第1パッシベーション層83に形成されたホールHを介してTFT8のソース電極8sに接続されている。 In the radiation detecting element 7, an auxiliary electrode 72 is formed by laminating Al, Cr, or the like on the insulating layer 71 formed integrally with the gate insulating layer 81 on the surface 4 a of the substrate 4. A first electrode 74 made of Al, Cr, Mo or the like is laminated on the auxiliary electrode 72 with an insulating layer 73 formed integrally with the first passivation layer 83 interposed therebetween. The first electrode 74 is connected to the source electrode 8 s of the TFT 8 through the hole H formed in the first passivation layer 83.
 第1電極74の上には、水素化アモルファスシリコンにVI族元素をドープしてn型に形成されたn層75、水素化アモルファスシリコンで形成された変換層であるi層76、水素化アモルファスシリコンにIII族元素をドープしてp型に形成されたp層77が下方から順に積層されて形成されている。 On the first electrode 74, an n layer 75 formed in an n-type by doping a hydrogenated amorphous silicon with a group VI element, an i layer 76 which is a conversion layer formed of hydrogenated amorphous silicon, and a hydrogenated amorphous A p layer 77 formed by doping a group III element into silicon and forming a p-type layer is formed by laminating sequentially from below.
 放射線画像撮影装置1の筐体2の放射線入射面Rから放射線が入射し、シンチレータ3で可視光等の電磁波に変換され、変換された電磁波が図中上方から照射されると、電磁波は放射線検出素子7のi層76に到達して、i層76内で電子正孔対が発生する。放射線検出素子7は、このようにして、シンチレータ3から照射された電磁波を電荷に変換するようになっている。 When radiation enters from the radiation incident surface R of the housing 2 of the radiographic imaging apparatus 1 and is converted into an electromagnetic wave such as visible light by the scintillator 3, and the converted electromagnetic wave is irradiated from above in the figure, the electromagnetic wave is detected by radiation. The electron hole pair is generated in the i layer 76 by reaching the i layer 76 of the element 7. In this way, the radiation detection element 7 converts the electromagnetic waves irradiated from the scintillator 3 into electric charges.
 また、p層77の上には、ITO等の透明電極とされた第2電極78が積層されて形成されており、照射された電磁波がi層76等に到達するように構成されている。本実施形態では、以上のようにして放射線検出素子7が形成されている。なお、p層77、i層76、n層75の積層の順番は上下逆であってもよい。また、本実施形態では、放射線検出素子7として、上記のようにp層77、i層76、n層75の順に積層されて形成されたいわゆるpin型の放射線検出素子を用いる場合が説明されているが、これに限定されない。 Further, on the p layer 77, a second electrode 78 made of a transparent electrode such as ITO is laminated and formed so that the irradiated electromagnetic wave reaches the i layer 76 and the like. In the present embodiment, the radiation detection element 7 is formed as described above. The order of stacking the p layer 77, the i layer 76, and the n layer 75 may be reversed. Further, in the present embodiment, a case where a so-called pin-type radiation detection element formed by sequentially stacking the p layer 77, the i layer 76, and the n layer 75 as described above is used as the radiation detection element 7. However, it is not limited to this.
 放射線検出素子7の第2電極78の上面には、第2電極78を介して放射線検出素子7にバイアス電圧を印加するバイアス線9が接続されている。なお、放射線検出素子7の第2電極78やバイアス線9、TFT8側に延出された第1電極74、TFT8の第1パッシベーション層83等、すなわち放射線検出素子7とTFT8の上面部分は、その上方側から窒化シリコン(SiNx)等からなる第2パッシベーション層79で被覆されている。 A bias line 9 for applying a bias voltage to the radiation detection element 7 is connected to the upper surface of the second electrode 78 of the radiation detection element 7 via the second electrode 78. The second electrode 78 and the bias line 9 of the radiation detection element 7, the first electrode 74 extended to the TFT 8 side, the first passivation layer 83 of the TFT 8, that is, the upper surfaces of the radiation detection element 7 and the TFT 8 are The upper side is covered with a second passivation layer 79 made of silicon nitride (SiNx) or the like.
 図3や図4に示すように、本実施形態では、それぞれ列状に配置された複数の放射線検出素子7に1本のバイアス線9が接続されており、各バイアス線9はそれぞれ信号線6に平行に配設されている。また、各バイアス線9は、基板4の検出部Pの外側の位置で結線10に結束されている。 As shown in FIGS. 3 and 4, in this embodiment, one bias line 9 is connected to a plurality of radiation detection elements 7 arranged in rows, and each bias line 9 is connected to a signal line 6. Are arranged in parallel with each other. Further, each bias line 9 is bound to the connection 10 at a position outside the detection portion P of the substrate 4.
 本実施形態では、図3に示すように、各走査線5や各信号線6、バイアス線9の結線10は、それぞれ基板4の端縁部付近に設けられた入出力端子(パッドともいう)11に接続されている。各入出力端子11には、図6に示すように、IC12a等のチップが組み込まれたCOF(Chip On Film)12が異方性導電接着フィルム(Anisotropic Conductive Film)や異方性導電ペースト(Anisotropic Conductive Paste)等の異方性導電性接着材料13を介して接続されている。 In this embodiment, as shown in FIG. 3, each scanning line 5, each signal line 6, and connection 10 of the bias line 9 are input / output terminals (also referred to as pads) provided near the edge of the substrate 4. 11 is connected. As shown in FIG. 6, each input / output terminal 11 has a COF (Chip On 等 Film) 12 in which a chip such as an IC 12 a is incorporated, an anisotropic conductive adhesive film (Anisotropic Conductive Film) or an anisotropic conductive paste (Anisotropic paste). It is connected via an anisotropic conductive adhesive material 13 such as Conductive Paste).
 また、COF12は、基板4の裏面4b側に引き回され、裏面4b側で前述したPCB基板33に接続されるようになっている。このようにして、放射線画像撮影装置1の基板4部分が形成されている。なお、図6では、電子部品32等の図示が省略されている。 Further, the COF 12 is routed to the back surface 4b side of the substrate 4 and connected to the PCB substrate 33 described above on the back surface 4b side. Thus, the board | substrate 4 part of the radiographic imaging apparatus 1 is formed. In FIG. 6, illustration of the electronic component 32 and the like is omitted.
 ここで、放射線画像撮影装置1の回路構成について説明する。
 図7は本実施形態に係る放射線画像撮影装置1の等価回路を表すブロック図であり、図8は検出部Pを構成する1画素分についての等価回路を表すブロック図である。
Here, the circuit configuration of the radiation image capturing apparatus 1 will be described.
FIG. 7 is a block diagram illustrating an equivalent circuit of the radiographic imaging apparatus 1 according to the present embodiment, and FIG. 8 is a block diagram illustrating an equivalent circuit for one pixel constituting the detection unit P.
 前述したように、基板4の検出部Pの各放射線検出素子7は、その第2電極78にそれぞれバイアス線9が接続されており、各バイアス線9は結線10に結束されてバイアス電源14に接続されている。バイアス電源14は、結線10および各バイアス線9を介して各放射線検出素子7の第2電極78にそれぞれバイアス電圧を印加するようになっている。また、バイアス電源14は、後述する制御手段22に接続されており、制御手段22は、バイアス電源14から各放射線検出素子7に印加するバイアス電圧を制御するようになっている。 As described above, each radiation detection element 7 of the detection unit P of the substrate 4 has the bias line 9 connected to the second electrode 78, and each bias line 9 is bound to the connection 10 to the bias power supply 14. It is connected. The bias power supply 14 applies a bias voltage to the second electrode 78 of each radiation detection element 7 via the connection 10 and each bias line 9. The bias power source 14 is connected to a control unit 22 described later, and the control unit 22 controls a bias voltage applied to each radiation detection element 7 from the bias power source 14.
 本実施形態では、バイアス線9の結線10に、結線10(バイアス線9)を流れる電流の電流量を検出する電流検出手段43が設けられている。そして、前述したように、放射線画像撮影装置1に放射線が照射されると各放射線検出素子7のi層76(図5参照)内で電子正孔対が発生し、それがバイアス線9や結線10に流れ出して結線10等に電流が流れるが、電流検出手段43は、その結線10を流れる電流の増減を検出して放射線の照射の開始や終了を検出できるようになっている。なお、本発明においては、電流検出手段43は必ずしも設けられなくてもよい。 In this embodiment, the current detection means 43 for detecting the amount of current flowing through the connection 10 (bias line 9) is provided in the connection 10 of the bias line 9. As described above, when the radiation imaging apparatus 1 is irradiated with radiation, electron-hole pairs are generated in the i layer 76 (see FIG. 5) of each radiation detection element 7, and this is the bias line 9 or the connection. The current detection means 43 can detect the start and end of radiation irradiation by detecting the increase or decrease of the current flowing through the connection 10. In the present invention, the current detection means 43 is not necessarily provided.
 図7や図8に示すように、本実施形態では、放射線検出素子7のp層77側(図5参照)に第2電極78を介してバイアス線9が接続されていることからも分かるように、バイアス電源14からは、放射線検出素子7の第2電極78にバイアス線9を介してバイアス電圧として放射線検出素子7の第1電極74側にかかる電圧以下の電圧(すなわちいわゆる逆バイアス電圧)が印加されるようになっている。 As shown in FIGS. 7 and 8, in this embodiment, it can be seen that the bias line 9 is connected via the second electrode 78 to the p-layer 77 side (see FIG. 5) of the radiation detection element 7. In addition, the bias power supply 14 supplies a voltage equal to or lower than a voltage applied to the second electrode 78 of the radiation detection element 7 via the bias line 9 as a bias voltage on the first electrode 74 side of the radiation detection element 7 (that is, a so-called reverse bias voltage). Is applied.
 各放射線検出素子7の第1電極74はTFT8のソース電極8s(図7、図8中ではSと表記されている。)に接続されており、各TFT8のゲート電極8g(図7、図8中ではGと表記されている。)は、後述する走査駆動手段15のゲートドライバ15bから延びる走査線5の各ラインL1~Lxにそれぞれ接続されている。また、各TFT8のドレイン電極8d(図7、図8中ではDと表記されている。)は各信号線6にそれぞれ接続されている。 The first electrode 74 of each radiation detection element 7 is connected to the source electrode 8s of the TFT 8 (indicated as S in FIGS. 7 and 8), and the gate electrode 8g of each TFT 8 (FIGS. 7 and 8). Are respectively connected to the lines L1 to Lx of the scanning line 5 extending from a gate driver 15b of the scanning driving means 15 described later. Further, the drain electrode 8 d (denoted as D in FIGS. 7 and 8) of each TFT 8 is connected to each signal line 6.
 走査駆動手段15は、本実施形態では、ゲートドライバ15bにON電圧とOFF電圧を供給する電源回路15aと、走査線5の各ラインL1~Lxに印加する電圧をON電圧とOFF電圧の間で切り替えて各TFT8のON電圧印加状態とOFF電圧印加状態とを切り替えるゲートドライバ15bとを備えている。 In this embodiment, the scanning drive unit 15 includes a power supply circuit 15a that supplies an ON voltage and an OFF voltage to the gate driver 15b, and a voltage applied to each of the lines L1 to Lx of the scanning line 5 between the ON voltage and the OFF voltage. A gate driver 15b that switches between an ON voltage application state and an OFF voltage application state of each TFT 8 is provided.
 各信号線6は、読み出しIC16内に形成された各読み出し回路17にそれぞれ接続されている。なお、読み出しIC16には1本の信号線6に1個ずつ読み出し回路17が設けられている。 Each signal line 6 is connected to each readout circuit 17 formed in the readout IC 16. Note that the readout IC 16 is provided with one readout circuit 17 for each signal line 6.
 読み出し回路17は、増幅回路18と、相関二重サンプリング(Correlated Double Sampling)回路19と、アナログマルチプレクサ21と、A/D変換器20とで構成されている。なお、図7や図8中では、相関二重サンプリング回路19はCDSと表記されている。また、図8中では、アナログマルチプレクサ21は省略されている。 The readout circuit 17 includes an amplification circuit 18, a correlated double sampling circuit 19, an analog multiplexer 21, and an A / D converter 20. 7 and 8, the correlated double sampling circuit 19 is represented as CDS. In FIG. 8, the analog multiplexer 21 is omitted.
 本実施形態では、増幅回路18はチャージアンプ回路で構成されており、オペアンプ18aと、オペアンプ18aにそれぞれ並列にコンデンサ18bおよび電荷リセット用スイッチ18cが接続されて構成されている。また、増幅回路18には、増幅回路18に電力を供給するための電源供給部18dが接続されている。 In the present embodiment, the amplifier circuit 18 is configured by a charge amplifier circuit, and is configured by connecting a capacitor 18b and a charge reset switch 18c in parallel to the operational amplifier 18a and the operational amplifier 18a, respectively. In addition, a power supply unit 18 d for supplying power to the amplifier circuit 18 is connected to the amplifier circuit 18.
 また、増幅回路18のオペアンプ18aの入力側の反転入力端子には信号線6が接続されており、増幅回路18の入力側の非反転入力端子には基準電位V0が印加されるようになっている。なお、基準電位V0は適宜の値に設定され、本実施形態では、例えば0[V]が印加されるようになっている。 The signal line 6 is connected to the inverting input terminal on the input side of the operational amplifier 18a of the amplifier circuit 18, and the reference potential V0 is applied to the non-inverting input terminal on the input side of the amplifier circuit 18. Yes. The reference potential V0 is set to an appropriate value, and in this embodiment, for example, 0 [V] is applied.
 また、増幅回路18の電荷リセット用スイッチ18cは、後述する制御手段22に接続されており、制御手段22によりON/OFFが制御されるようになっている。各放射線検出素子7からのデータの読み出し処理時に、電荷リセット用スイッチ18cがOFFの状態で放射線検出素子7のTFT8にON電圧が印加されると(すなわち、TFT8のゲート電極8gに走査線5を介して信号読み出し用のON電圧が印加されると)、当該放射線検出素子7から放出された電荷がコンデンサ18bに流入して蓄積され、蓄積された電荷量に応じた電圧値がオペアンプ18aの出力側から出力されるようになっている。 Further, the charge reset switch 18c of the amplifier circuit 18 is connected to the control means 22 to be described later, and ON / OFF is controlled by the control means 22. When data is read from each radiation detection element 7, if an ON voltage is applied to the TFT 8 of the radiation detection element 7 with the charge reset switch 18 c being OFF (that is, the scanning line 5 is applied to the gate electrode 8 g of the TFT 8). When an ON voltage for signal readout is applied via the signal), the electric charge released from the radiation detection element 7 flows into the capacitor 18b and is accumulated, and a voltage value corresponding to the accumulated electric charge is output from the operational amplifier 18a. Output from the side.
 増幅回路18は、このようにして、各放射線検出素子7から出力された電荷量に応じて電圧値を出力して電荷電圧変換するようになっている。また、電荷リセット用スイッチ18cがON状態とされると、増幅回路18の入力側と出力側とが短絡されてコンデンサ18bに蓄積された電荷が放電されて増幅回路18がリセットされるようになっている。なお、増幅回路18を、放射線検出素子7から出力された電荷に応じて電流を出力するように構成することも可能である。 In this way, the amplification circuit 18 outputs a voltage value according to the amount of charge output from each radiation detection element 7 and converts the charge voltage. When the charge reset switch 18c is turned on, the input side and the output side of the amplifier circuit 18 are short-circuited, and the charge accumulated in the capacitor 18b is discharged to reset the amplifier circuit 18. ing. Note that the amplifier circuit 18 may be configured to output a current in accordance with the charge output from the radiation detection element 7.
 なお、「放射線検出素子7からのデータの読み出し処理」については、放射線照射時における放射線検出素子7の蓄積電荷量に基づくデータとしての実写画像データJの読み出し処理と、放射線の非照射時における放射線検出素子7の蓄積電荷量(暗電荷)に基づくデータとしての暗画像データB、BH1、BH2等があるが、これらを総称して「放射線検出素子7からのデータの読み出し処理」と記載することとする。
 また、「データD」という場合には、実画像データJと暗画像データB、BH1、BH2とを総称して示すものとし、「画像データG」という場合には、実画像データJが暗画像データBに基づいて補正されたデータを示すものとする。
Note that the “reading process of data from the radiation detecting element 7” includes reading process of the actual image data J as data based on the accumulated charge amount of the radiation detecting element 7 at the time of radiation irradiation, and radiation at the time of non-irradiating radiation There are dark image data B, BH1, BH2, etc. as data based on the accumulated charge amount (dark charge) of the detection element 7. These are collectively referred to as “data reading process from the radiation detection element 7”. And
Further, in the case of “data D”, the real image data J and the dark image data B, BH1, and BH2 are collectively shown, and in the case of “image data G”, the real image data J is the dark image data. Data corrected based on data B is shown.
 各放射線検出素子7からのデータの読み出し処理時に、各放射線検出素子7から電荷が読み出され、増幅回路18で電荷電圧変換されて出力された電圧値は、相関二重サンプリング回路19でサンプリング処理されてデータDとして下流側に出力される。そして、相関二重サンプリング回路19から出力された各放射線検出素子7のデータDは、アナログマルチプレクサ21(図7参照)に送信され、アナログマルチプレクサ21から順次A/D変換器20に送信される。そして、A/D変換器20で順次デジタル値のデータDに変換されて記憶手段40に出力されて順次保存されるようになっている。 During the process of reading data from each radiation detection element 7, the charge is read from each radiation detection element 7, and the voltage value output by charge-voltage conversion by the amplifier circuit 18 is sampled by the correlated double sampling circuit 19. And output as data D downstream. The data D of each radiation detection element 7 output from the correlated double sampling circuit 19 is transmitted to the analog multiplexer 21 (see FIG. 7), and is sequentially transmitted from the analog multiplexer 21 to the A / D converter 20. The A / D converter 20 sequentially converts the data into digital value data D, outputs it to the storage means 40, and sequentially stores it.
 なお、本実施形態では、各放射線検出素子7からのデータの読み出し処理の際には、ON電圧が印加される走査線5の各ラインL1~Lxが順次切り替えられながら、上記のような各放射線検出素子7からのデータの読み出し処理が行われるようになっている。 In the present embodiment, in the process of reading data from each radiation detection element 7, the lines L1 to Lx of the scanning line 5 to which the ON voltage is applied are sequentially switched while the radiations as described above are performed. A process for reading data from the detection element 7 is performed.
[制御手段]
 ここで、本実施形態における制御手段22の構成について、図7及び図8を参照しつつ説明する。
 本実施形態では、制御手段22には、不揮発性の記憶手段40、前述したアンテナ装置39が接続されている。
 また、制御手段22には、検出部Pや走査駆動手段15、読み出し回路17、記憶手段40、バイアス電源14等の各部材に電力を供給するためのバッテリ41が接続されている。また、バッテリ41には、クレードル等の図示しない充電装置からバッテリ41に電力を供給してバッテリ41を充電する際の接続端子42が取り付けられている。
[Control means]
Here, the structure of the control means 22 in this embodiment is demonstrated, referring FIG.7 and FIG.8.
In the present embodiment, the control unit 22 is connected to the nonvolatile storage unit 40 and the antenna device 39 described above.
The control means 22 is connected to a battery 41 for supplying power to each member such as the detection section P, the scanning drive means 15, the readout circuit 17, the storage means 40, and the bias power supply 14. The battery 41 is provided with a connection terminal 42 for charging the battery 41 by supplying power to the battery 41 from a charging device (not shown) such as a cradle.
 前述したように、制御手段22は、バイアス電源14を制御してバイアス電源14から各放射線検出素子7に印加するバイアス電圧を設定したり、読み出し回路17の増幅回路18の電荷リセット用スイッチ18cのON/OFFを制御したり、相関二重サンプリング回路19にパルス信号を送信して、そのサンプルホールド機能のON/OFFを制御する等の各種の処理を実行するようになっている。 As described above, the control means 22 controls the bias power supply 14 to set a bias voltage to be applied to each radiation detection element 7 from the bias power supply 14, or the charge reset switch 18 c of the amplification circuit 18 of the readout circuit 17. Various processes such as ON / OFF control and transmission of a pulse signal to the correlated double sampling circuit 19 to control ON / OFF of the sample hold function are executed.
 また、制御手段22は、各放射線検出素子7のリセット処理時や放射線画像撮影後の各放射線検出素子7からのデータDの読み出し時に、走査駆動手段15に対して、走査駆動手段15から各走査線5を介して各TFT8のゲート電極8gに印加する電圧をON電圧とOFF電圧との間で切り替えさせるためのパルス信号を送信するようになっている。 Further, the control means 22 performs scanning from the scanning driving means 15 to the scanning driving means 15 at the time of reset processing of each radiation detecting element 7 or reading of data D from each radiation detecting element 7 after radiographic imaging. A pulse signal for switching the voltage applied to the gate electrode 8g of each TFT 8 between the ON voltage and the OFF voltage via the line 5 is transmitted.
 制御手段22は、具体的には、図示しないCPU(Central Processing Unit)、ROM(Read Only Memory)、RAM(Random Access Memory)等により構成されるコンピュータであり、放射線画像撮影装置1の各機能部の動作等を制御するようになっている。
 ROMには、例えば撮影時の放射線画像撮影装置1の各構成の動作制御を行うための撮影制御プログラム、各放射線検出素子7の出力異常判定のための暗画像データ取得制御プログラム等が記憶されている。
 なお、各種プログラムや情報等はROMに格納されている場合に限定されず、別途プログラムメモリ等を設けて、これに格納してもよい。
Specifically, the control unit 22 is a computer configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and each functional unit of the radiation image capturing apparatus 1. The operation etc. are controlled.
The ROM stores, for example, an imaging control program for performing operation control of each component of the radiographic imaging device 1 at the time of imaging, a dark image data acquisition control program for determining an output abnormality of each radiation detection element 7, and the like. Yes.
Various programs, information, and the like are not limited to being stored in the ROM, and a separate program memory or the like may be provided and stored therein.
[制御手段:撮影動作制御]
 ここで、撮影制御プログラムに基づいて制御手段22が行う撮影動作制御について説明する。図9は撮影時の各工程を示す説明図である。
 放射線画像撮影装置1は、撮影時には、放射線画像撮影システム50内において、放射線発生装置52(図11参照)の放射線照射位置に設置される。
[Control means: shooting operation control]
Here, the photographing operation control performed by the control unit 22 based on the photographing control program will be described. FIG. 9 is an explanatory diagram showing each process during photographing.
The radiation image capturing apparatus 1 is installed at a radiation irradiation position of the radiation generating apparatus 52 (see FIG. 11) in the radiation image capturing system 50 at the time of capturing.
 まず、制御手段22は、予め、走査線5のラインL1~Lxに同時又は順次にON電圧を印加すると共に各々の電荷リセット用スイッチ18cをON状態とし、各放射線検出素子7に蓄積されていた電荷のリセットを行う(図9:K1)。 First, the control means 22 applies an ON voltage to the lines L1 to Lx of the scanning line 5 simultaneously or sequentially and turns on each charge reset switch 18c so as to be stored in each radiation detection element 7. The charge is reset (FIG. 9: K1).
 そして、放射線発生装置52がコンソール58(図11参照)の制御の下で放射線画像撮影装置1と同期して放射線の照射を開始し、制御手段22は、全ての走査線5を通じて、それぞれの走査線5に接続されたTFT8に対して同時にOFF電圧を印加し、各放射線検出素子7について放射線の線量に応じて実写画像の電荷の蓄積を行う(図9:K2)。
 実写画像の電荷の蓄積時間は、被写体である患者の身体の胸部や腹部等の撮影部位や放射線の線量等の撮影条件に応じて個々に適切な値に設定される。
 例えば、制御手段22に設定入力手段を併設し、任意の時間設定を可能としても良いし、撮影部位や放射線の線量等の個々の撮影条件に応じて好適な蓄積時間を定めたテーブルをROM23bに用意し、設定入力手段からの撮影条件の入力を受けて蓄積時間をテーブルから自動的に選択するよう構成しても良い。
Then, the radiation generator 52 starts irradiation of radiation in synchronization with the radiographic imaging device 1 under the control of the console 58 (see FIG. 11), and the control means 22 scans each scanning line 5 through each scanning line 5. An OFF voltage is simultaneously applied to the TFTs 8 connected to the line 5, and the charge of the photographed image is accumulated for each radiation detection element 7 according to the radiation dose (FIG. 9: K2).
The charge accumulation time of the photographed image is individually set to an appropriate value according to imaging conditions such as an imaging region such as the chest and abdomen of the patient's body as a subject and a radiation dose.
For example, a setting input unit may be provided in the control unit 22 so that an arbitrary time can be set. A table in which a suitable accumulation time is determined according to individual imaging conditions such as an imaging region and a radiation dose is stored in the ROM 23b. A storage time may be automatically selected from a table in response to an input of imaging conditions from the setting input means.
 そして、上記蓄積時間の経過を待って、各走査線5に順次にON電圧を印加することにより、各走査線5に接続された各放射線検出素子7は走査線5ごとに各増幅回路18に電荷を放出し、蓄積電荷量に基づく電圧がA/D変換され、各放射線検出素子7の実写画像データJとして記憶手段40に順次保存させることで読み出し処理が行われる(図9:K3)。
 なお、前述したように、全ての走査線5について同時にOFF電圧を印加して蓄積を開始する一方、走査線5に順次ON電圧を印加して読み出しを行い蓄積を終了するので、蓄積時間は走査線ごとに異なる。
Then, after the accumulation time has elapsed, an ON voltage is sequentially applied to each scanning line 5 so that each radiation detection element 7 connected to each scanning line 5 is connected to each amplification circuit 18 for each scanning line 5. The charge is discharged, the voltage based on the amount of accumulated charge is A / D converted, and is sequentially stored in the storage means 40 as the actual image data J of each radiation detecting element 7 (FIG. 9: K3).
As described above, the OFF voltage is simultaneously applied to all the scanning lines 5 to start accumulation, while the ON voltage is sequentially applied to the scanning lines 5 to read out and complete the accumulation. Different for each line.
 そして、各放射線検出素子7の実写画像データJが取得されると、制御手段22は、再び、走査線5のラインL1~Lxに同時又は順次にON電圧を印加して各放射線検出素子7のリセットを行う(図9:K4)。
 次に、各放射線検出素子7による暗画像の電荷蓄積処理を実行する。即ち、この暗画像の電荷蓄積処理は、コンソール58の制御の下で放射線発生装置52が放射線の非照射状態とされ、走査線ごとに上記撮影時と同じ蓄積時間で各放射線検出素子7について暗画像の電荷蓄積(暗電荷の蓄積)を行う(図9:K5)。その後、各コンデンサ18bに蓄積された電荷量に応じた電圧値をA/D変換し、各放射線検出素子7の暗画像データBとして読み出しが行われる(図9:K6)。
 なお、K4~K6の工程を繰り返し複数回実行し、毎回得られる各放射線検出素子7の暗画像データBを平均化して得られる各放射線検出素子7ごとの暗画像データの平均値を正式な暗画像データBとして採用することとしても良い。
Then, when the actual image data J of each radiation detection element 7 is acquired, the control means 22 applies the ON voltage to the lines L1 to Lx of the scanning line 5 simultaneously or sequentially again, so that each radiation detection element 7 Reset is performed (FIG. 9: K4).
Next, charge accumulation processing of a dark image by each radiation detection element 7 is executed. That is, in this dark image charge accumulation process, the radiation generator 52 is not irradiated with radiation under the control of the console 58, and each radiation detection element 7 is darkened in the same accumulation time as in the above imaging for each scanning line. Image charge accumulation (dark charge accumulation) is performed (FIG. 9: K5). Thereafter, the voltage value corresponding to the amount of charge accumulated in each capacitor 18b is A / D converted and read as dark image data B of each radiation detection element 7 (FIG. 9: K6).
Note that the average value of the dark image data for each radiation detection element 7 obtained by averaging the dark image data B of each radiation detection element 7 obtained each time by repeating the steps K4 to K6 a plurality of times is obtained as a formal darkness. It may be adopted as the image data B.
 この放射線画像撮影装置1では、放射線画像の撮影時に、各放射線検出素子7について上記処理により取得された実写画像データJと当該撮影に付随して取得された暗画像データBとがセットで外部装置であるコンソール58に送信される。
 コンソール58では、各放射線検出素子7ごとに、実写画像データJに対して暗画像データBの差分を採ることでデータ値の補正を行い、各放射線検出素子7の画像データを取得する。
In this radiographic image capturing apparatus 1, when capturing a radiographic image, the actual image data J acquired by the above processing for each radiation detection element 7 and the dark image data B acquired accompanying the capturing are set as an external device. To the console 58.
In the console 58, the data value is corrected by taking the difference of the dark image data B with respect to the actual image data J for each radiation detection element 7, and the image data of each radiation detection element 7 is acquired.
 即ち、各放射線検出素子7は、その撮影時におけるリセット処理から読み出し処理までの間の蓄積時間において、各放射線検出素子7内に蓄積される暗電荷によるオフセット分がある。この暗電荷は、各放射線検出素子7自体の熱による熱励起等により発生するものであり、暗電荷によるオフセット分は各放射線検出素子7ごとに異なる値となっている。
 そして、各放射線検出素子7の実写画像データJは、放射線の照射に由来する電荷(すなわち本来検出すべき電荷)に、各放射線検出素子7自体の熱による熱励起等に由来する電荷(暗電荷)が重畳して含まれた状態で検出が行われている。
 従って、放射線画像撮影装置1は、放射線を照射しない状態で各放射線検出素子7について、各素子自体の熱による熱励起等により発生する暗電荷を暗画像データBとして検出し、実写画像データJと共にコンソール58に送信して、コンソール58側で実写画像データJから暗電荷の重畳分のオフセットを除去することを可能としている。
That is, each radiation detection element 7 has an offset amount due to dark charges accumulated in each radiation detection element 7 in the accumulation time from the reset process to the readout process at the time of imaging. This dark charge is generated by thermal excitation or the like of each radiation detection element 7 itself, and the offset due to the dark charge has a different value for each radiation detection element 7.
Then, the actual image data J of each radiation detection element 7 includes a charge (dark charge) derived from thermal excitation caused by heat of each radiation detection element 7 itself, etc. ) Are included in a superimposed manner.
Therefore, the radiographic imaging apparatus 1 detects dark charges generated by thermal excitation or the like of each element itself as dark image data B for each radiation detection element 7 in a state in which radiation is not irradiated, and together with the actual image data J This is transmitted to the console 58, and the offset of the dark charge superposition can be removed from the photographed image data J on the console 58 side.
 なお、上記撮影時の暗画像データBの取得処理(K4~K6)については各放射線検出素子7自体の熱による熱励起等に由来する暗電荷の検出のために行うものであるため、各放射線検出素子7の温度状態が実写画像データの取得時と近い状態にあることが望ましく、そのために、実写画像データJの取得処理と暗画像データBの取得処理とは時間的に隔たりがないよう連続的に行うことが望ましい。逆に処理が連続するのであれば、暗画像データBの取得処理を先に行っても良い。
 また、前述したように、複数回暗画像データを取得して、その平均値を正式な暗画像データBとするような場合には、実写画像データJの取得処理を挟んでその前後で暗画像データBを取得し、それらを平均化しても良い。
Note that the acquisition processing (K4 to K6) of the dark image data B at the time of photographing is performed for detection of dark charges derived from thermal excitation or the like due to heat of each radiation detection element 7 itself. It is desirable that the temperature state of the detection element 7 is close to that at the time of acquisition of the actual image data, and therefore, the acquisition processing of the actual image data J and the acquisition processing of the dark image data B are continuous so as not to be separated in time. It is desirable to do it automatically. On the contrary, if the processing is continuous, the dark image data B acquisition processing may be performed first.
In addition, as described above, when dark image data is acquired a plurality of times and the average value is set to the formal dark image data B, the dark image is obtained before and after the acquisition process of the actual image data J. Data B may be acquired and averaged.
[制御手段:出力異常判定のための暗画像データ取得制御]
 次に、各放射線検出素子7の出力異常判定のための暗画像データを取得するための暗画像データ取得制御プログラムに基づいて制御手段22が行う処理について説明する。図10A及び図10Bは出力異常判定のための暗画像データ取得時の各工程を示す説明図である。
 出力異常判定のための暗画像データの取得は、それぞれ長さが異なる第一の蓄積時間と第二の蓄積時間とで暗画像の電荷蓄積処理を行って暗画像データBH1、BH2の取得が行われる。
[Control means: dark image data acquisition control for output abnormality determination]
Next, processing performed by the control unit 22 based on a dark image data acquisition control program for acquiring dark image data for determining output abnormality of each radiation detection element 7 will be described. FIG. 10A and FIG. 10B are explanatory diagrams showing respective steps at the time of obtaining dark image data for output abnormality determination.
The acquisition of dark image data for output abnormality determination is performed by performing dark image charge accumulation processing at a first accumulation time and a second accumulation time, each having a different length, to obtain dark image data BH1 and BH2. Is called.
 なお、これらの出力異常判定のための暗画像データの取得は、放射線画像の撮影に付随して行われるものではないので、いつ実行するかについて特に制約を受けるものではない。例えば、制御手段22に出力異常判定のための暗画像データの取得処理を実行させるための操作入力手段を併設し、操作により任意に実行する構成としても良いし、定期的且つ自動的に実行されるよう構成しても良い。但し、第一の蓄積時間に基づく出力異常判定のための暗画像データBH1の取得と第二の蓄積時間に基づく出力異常判定のための暗画像データBH2の取得とは連続して行われ、時間を隔てて実行されることがないようになっている。
 また、この放射線画像撮影装置1では、各放射線検出素子7の出力異常判定のための暗画像データについては蓄積時間を異ならせて二種類取得するよう構成されているが、蓄積時間が異なるより多くの出力異常判定のための暗画像データを取得するようにしても良い。
It should be noted that the acquisition of dark image data for determining the output abnormality is not performed accompanying radiographic image capturing, and is not particularly limited as to when it is executed. For example, the control means 22 may be provided with an operation input means for executing dark image data acquisition processing for output abnormality determination, and may be arbitrarily executed by an operation, or may be executed periodically and automatically. You may comprise. However, the acquisition of the dark image data BH1 for the output abnormality determination based on the first accumulation time and the acquisition of the dark image data BH2 for the output abnormality determination based on the second accumulation time are performed continuously, and the time It is designed not to be executed after each other.
The radiographic image capturing apparatus 1 is configured to acquire two types of dark image data for determining the output abnormality of each radiation detection element 7 with different accumulation times. The dark image data for determining the output abnormality may be acquired.
 図10Aに示す第一の蓄積時間での出力異常判定のための暗画像データBH1の取得処理の際には、まず、制御手段22は、予め、走査線5のラインL1~Lxに同時又は順次にON電圧を印加すると共に各々の電荷リセット用スイッチ18cをON状態とし、各放射線検出素子7に蓄積されていた電荷のリセットを行う(図10A:K11)。 In the process of acquiring the dark image data BH1 for the output abnormality determination in the first accumulation time shown in FIG. 10A, first, the control unit 22 first or sequentially applies to the lines L1 to Lx of the scanning line 5 in advance. In addition, an ON voltage is applied to each charge reset switch 18c and each charge reset switch 18c is turned on to reset the charge accumulated in each radiation detection element 7 (FIG. 10A: K11).
 そして、放射線の照射が行われない状況下で、制御手段22は、全ての走査線5を通じて、それぞれの走査線5に接続されたTFT8に対して同時にOFF電圧を印加し、各放射線検出素子7について暗画像の電荷の蓄積を行う(図10A:K12)。
 このときの第一の蓄積時間は、少なくとも前述した撮影時の蓄積時間よりも長く設定されており、例えば、数倍から数十倍、或いはより長く設定しても良いが、暗電荷が飽和しない範囲を限度とすることが望ましい。例えば、前述の撮影時の蓄積時間は500[ms]、第一の蓄積時間は10[s]に設定される。
 なお、前述したように、蓄積開始は全ての走査線で同時であるのに対し、蓄積終了は走査線ごとに異なるので、厳密には蓄積時間は走査線ごとに異なるが、説明が複雑になるので、ここでの蓄積時間は、例えば最初に蓄積が終了する走査線の蓄積時間を代表値として示す。
Then, under the situation where no radiation is irradiated, the control means 22 applies an OFF voltage to the TFTs 8 connected to the respective scanning lines 5 through all the scanning lines 5 at the same time. The dark image charge is accumulated for (FIG. 10A: K12).
The first accumulation time at this time is set to be longer than at least the above-described accumulation time at the time of photographing. For example, the first accumulation time may be set several times to several tens of times or longer, but the dark charge is not saturated. It is desirable to limit the range. For example, the accumulation time at the time of shooting is set to 500 [ms], and the first accumulation time is set to 10 [s].
As described above, the accumulation start is simultaneous for all the scanning lines, whereas the accumulation end is different for each scanning line. Strictly speaking, the accumulation time differs for each scanning line, but the explanation is complicated. Therefore, the accumulation time here indicates, for example, the accumulation time of the scanning line where accumulation ends first as a representative value.
 そして、各走査線5ごとに上記第一の蓄積時間の経過を待って、順番にON電圧を印加することにより、各放射線検出素子7の第一の蓄積時間に基づく出力異常判定のための暗画像データBH1が検出され、記憶手段40に順次保存させることで読み出し処理が行われる(図10A:K13)。 Then, after the elapse of the first accumulation time for each scanning line 5, the ON voltage is applied in order, whereby darkness for output abnormality determination based on the first accumulation time of each radiation detection element 7 is obtained. Image data BH1 is detected and read out by sequentially storing it in the storage means 40 (FIG. 10A: K13).
 なお、撮影動作制御のK4~K6の工程の場合と同様に、K11~K13の工程も繰り返し複数回実行し、毎回得られる各放射線検出素子7の暗画像データBH1を平均化して得られる各放射線検出素子7ごとの暗画像データの平均値を正式な暗画像データBH1として採用することとしても良い。 Similarly to the steps K4 to K6 of the imaging operation control, the steps K11 to K13 are also repeatedly executed a plurality of times, and each radiation obtained by averaging the dark image data BH1 of each radiation detecting element 7 obtained each time is obtained. An average value of dark image data for each detection element 7 may be adopted as the formal dark image data BH1.
 第二の蓄積時間での出力異常判定のための暗画像データBH2の取得処理の各工程K21~K23は、図10Bに示すように、第二の蓄積時間が第一の蓄積時間よりも長く設定されている点を除いて全く同じであることから詳細な説明は省略する。
 第二の蓄積時間は、少なくとも前述した第一の蓄積時間に一致しないことが要求される。ここでは、第二の蓄積時間は、例えば、第一の蓄積時間の二倍の20[s]に設定される。
 なお、K11~K13の工程の場合と同様に、K21~K23の工程も繰り返し複数回実行し、毎回得られる各放射線検出素子7の暗画像データBH2を平均化して得られる各放射線検出素子7ごとの暗画像データの平均値を正式な暗画像データBH2として採用することとしても良い。
As shown in FIG. 10B, the steps K21 to K23 of the dark image data BH2 acquisition process for determining the output abnormality in the second accumulation time are set longer than the first accumulation time, as shown in FIG. 10B. The detailed description is omitted because it is exactly the same except for the point.
It is required that the second accumulation time does not coincide with at least the first accumulation time described above. Here, the second accumulation time is set to 20 [s], for example, twice the first accumulation time.
Similarly to the processes of K11 to K13, the processes of K21 to K23 are repeatedly executed a plurality of times, and each radiation detection element 7 obtained by averaging the dark image data BH2 of each radiation detection element 7 obtained each time. The average value of the dark image data may be adopted as the formal dark image data BH2.
 この放射線画像撮影装置1では、上記第一の蓄積時間に基づく出力異常判定のための暗画像データBH1と第二の蓄積時間に基づく出力異常判定のための暗画像データBH2とがセットで外部装置であるコンソール58に送信される。
 これら出力異常判定のための暗画像データBH1,BH2におけるコンソール58側での処理については後述する。
 なお、第一の蓄積時間に基づく出力異常判定のための暗画像データBH1と第二の蓄積時間に基づく出力異常判定のための暗画像データBH2のそれぞれの取得処理は時間をおかずに連続して行われることが望ましいが、これらの取得処理の順番についてはいずれを先に行っても良い。
In this radiographic imaging device 1, dark image data BH1 for output abnormality determination based on the first accumulation time and dark image data BH2 for output abnormality determination based on the second accumulation time are set as an external device. To the console 58.
Processing on the console 58 side in the dark image data BH1 and BH2 for the output abnormality determination will be described later.
The acquisition processing of the dark image data BH1 for output abnormality determination based on the first accumulation time and the dark image data BH2 for output abnormality determination based on the second accumulation time is continuously performed without taking time. Although it is desirable to be performed, any of these acquisition processes may be performed first.
[放射線画像撮影システム]
 次に、本実施形態における放射線画像撮影システム50の構成について説明する。放射線画像撮影システム50は、例えば、病院や医院内で行われる放射線画像撮影を想定したシステムであり、放射線画像として医療用の診断画像を撮影するシステムとして採用することができるが、必ずしもこれに限定されない。
[Radiation imaging system]
Next, the configuration of the radiographic image capturing system 50 in the present embodiment will be described. The radiographic image capturing system 50 is a system that assumes radiographic image capturing performed in, for example, a hospital or a clinic, and can be employed as a system that captures a medical diagnostic image as a radiographic image, but is not necessarily limited thereto. Not.
 図11は、本実施形態における放射線画像撮影システム50の全体構成を示す図である。放射線画像撮影システム50は、図11に示すように、例えば、放射線を照射して患者の一部である被写体(患者の撮影対象部位)の撮影を行う撮影室R1と、放射線技師等の操作者が被写体に照射する放射線の制御等の種々の操作を行う前室R2、及びそれらの外部に配置される。 FIG. 11 is a diagram showing an overall configuration of the radiation image capturing system 50 in the present embodiment. As shown in FIG. 11, the radiographic imaging system 50 includes, for example, an imaging room R <b> 1 that performs imaging of a subject that is a part of a patient by irradiating radiation (an imaging target part of the patient), and an operator such as a radiographer Are arranged in the anterior chamber R2 for performing various operations such as control of radiation applied to the subject, and outside thereof.
 撮影室R1には、前述した放射線画像撮影装置1を装填可能なブッキー装置51や、被写体に照射する放射線を発生させる図示しないX線管球を備える放射線発生装置52、放射線画像撮影装置1とコンソール58とが無線通信する際にこれらの通信を中継する通信手段としての無線アンテナ53を備えた基地局54等が設けられている。 In the radiographing room R1, a bucky device 51 that can be loaded with the radiographic imaging device 1 described above, a radiation generating device 52 that includes an X-ray tube (not shown) that generates radiation to irradiate a subject, the radiographic imaging device 1 and a console. A base station 54 equipped with a wireless antenna 53 is provided as a communication means for relaying these communications when wirelessly communicating with 58.
 なお、図11では、可搬型の放射線画像撮影装置1を立位撮影用のブッキー装置51Aや臥位撮影用のブッキー装置51Bのカセッテ保持部51aに装填して用いる場合が示されているが、放射線画像撮影装置1はブッキー装置51や支持台等と一体的に形成されたものであってもよい。また、図11に示したように、放射線画像撮影装置1と基地局54とをケーブルで接続し、ケーブルを介して有線通信でデータを送信することができるように構成することも可能である。 FIG. 11 shows a case where the portable radiographic imaging device 1 is used by being loaded into the cassette holding portion 51a of the standing-up imaging bucky device 51A or the standing-up imaging bucky device 51B. The radiographic imaging device 1 may be formed integrally with the bucky device 51, a support base, or the like. Further, as shown in FIG. 11, the radiographic image capturing apparatus 1 and the base station 54 can be connected by a cable so that data can be transmitted by wired communication via the cable.
 本実施形態では、撮影室R1には、放射線画像撮影装置1が持ち込まれた際に挿入されると放射線画像撮影装置1からカセッテIDを読み取って基地局54を介してコンソール58に通知するクレードル55が備えられている。クレードル55で放射線画像撮影装置1の充電等を行うように構成することも可能である。 In the present embodiment, the cradle 55 that reads the cassette ID from the radiographic image capturing apparatus 1 and notifies the console 58 via the base station 54 when the radiographic image capturing apparatus 1 is inserted into the radiographing room R1. Is provided. The cradle 55 may be configured to charge the radiographic image capturing apparatus 1 or the like.
 また、前室R2には、放射線発生装置52に対して放射線の照射開始等を指示するためのスイッチ手段56等を備えた放射線の照射を制御する操作卓57等が設けられている。 The front chamber R2 is provided with an operation console 57 for controlling radiation irradiation, which includes switch means 56 for instructing the radiation generator 52 to start radiation irradiation and the like.
 放射線画像撮影装置1の構成については前述したとおりであり、放射線画像撮影装置1は、上記のようにブッキー装置51に装填されて用いられる場合もあるが、ブッキー装置51には装填されず、いわば単独の状態で用いることもできるようになっている。 The configuration of the radiographic image capturing apparatus 1 is as described above. The radiographic image capturing apparatus 1 may be used by being loaded into the bucky device 51 as described above, but it is not loaded into the bucky device 51. It can also be used in a single state.
 すなわち、放射線画像撮影装置1を単独の状態で例えば撮影室R1内に設けられたベッドや図11に示すように臥位撮影用のブッキー装置51B等の上面側に配置してその放射線入射面R(図1参照)上に被写体である患者の手等を載置したり、或いは、例えばベッドの上に横臥した患者の腰や足等とベッドとの間に差し込んだりして用いることもできるようになっている。この場合、例えばポータブルの放射線発生装置52B等から、被写体を介して放射線画像撮影装置1に放射線を照射して放射線画像撮影が行われる。 That is, the radiation image capturing apparatus 1 is arranged in a single state, for example, on the upper surface side of a bed provided in the imaging room R1 or a bucky apparatus 51B for supine photography as shown in FIG. (See FIG. 1) The patient's hand, which is the subject, can be placed on the top, or the patient's waist, legs, etc. lying on the bed can be inserted between the bed and the bed. It has become. In this case, for example, radiation image capturing is performed by irradiating the radiation image capturing apparatus 1 with radiation from a portable radiation generating device 52B or the like via a subject.
 本実施形態では、放射線画像撮影システム50全体の制御を行うコンソール58が、撮影室R1や前室R2の外側に設けられているが、例えば、コンソール58を前室R2に設けるように構成することも可能である。 In this embodiment, the console 58 that controls the entire radiographic imaging system 50 is provided outside the imaging room R1 and the front room R2. For example, the console 58 is configured to be provided in the front room R2. Is also possible.
 コンソール58は、図示しないCPUやROM、RAM、入出力インターフェース等がバスに接続されたコンピュータ等で構成されている。ROMには所定のプログラムが格納されており、コンソール58は、必要なプログラムを読み出してRAMの作業領域に展開してプログラムに従って各種処理を実行し、前述したように放射線画像撮影システム50全体の制御を行うようになっている。 The console 58 is constituted by a computer or the like in which a CPU, a ROM, a RAM, an input / output interface and the like (not shown) are connected to a bus. A predetermined program is stored in the ROM, and the console 58 reads out the necessary program, expands it in the work area of the RAM, executes various processes according to the program, and controls the entire radiographic imaging system 50 as described above. Is supposed to do.
 コンソール58には、前述した基地局54や操作卓57、ハードディスク等で構成された記憶手段59等が接続されており、また、基地局54を介してクレードル55等が接続され、操作卓57を介して放射線発生装置52等が接続されている。また、コンソール58には、CRT(Cathode Ray Tube)やLCD(Liquid Crystal Display)等からなる表示画面58aが設けられており、その他、キーボードやマウス等の図示しない入力手段が接続されている。 The console 58 is connected to the above-described base station 54, console 57, storage means 59 composed of a hard disk or the like, and a cradle 55 or the like is connected via the base station 54. The radiation generating device 52 and the like are connected via this. The console 58 is provided with a display screen 58a such as a CRT (Cathode Ray Tube) or LCD (Liquid Crystal Display), and other input means such as a keyboard and a mouse are connected thereto.
 コンソール58は、基地局54を介してクレードル55から放射線画像撮影装置1のカセッテIDが通知されてくると、それを記憶手段59に保存して、撮影室R1内に存在する放射線画像撮影装置1を管理するようになっている。
 また、記憶手段59には、放射線画像撮影装置1から受信した実写画像データJ、これに付随する暗画像データB、第一の蓄積時間に基づく出力異常判定のための暗画像データBH1、第二の蓄積時間に基づく出力異常判定のための暗画像データBH2等の各種のデータに加えて、放射線画像撮影装置1の異常出力を行う放射線検出素子7の検出部P内の配置を示す欠陥素子マップが記憶されている。これらの各種データ及び欠陥素子マップは、登録されているカセッテIDごとに個々に管理されており、前述したカセッテIDの通知により対応するデータ又はマップが読み出されるようになっている。
When the console 58 is notified of the cassette ID of the radiographic imaging apparatus 1 from the cradle 55 via the base station 54, the console 58 saves it in the storage means 59, and the radiographic imaging apparatus 1 existing in the imaging room R1. To manage.
In addition, the storage unit 59 stores the real image data J received from the radiographic image capturing apparatus 1, the dark image data B associated therewith, the dark image data BH1 for determining output abnormality based on the first accumulation time, the second In addition to various data such as dark image data BH2 for output abnormality determination based on the accumulation time, a defective element map showing the arrangement of the radiation detection element 7 that performs abnormal output of the radiation image capturing apparatus 1 in the detection unit P Is remembered. These various data and defective element maps are individually managed for each registered cassette ID, and the corresponding data or map is read by the notification of the cassette ID described above.
 放射線検出素子7は、検出部Pにおいて、数百万、数千万或いはそれ以上の数量のものが集積されて形成されており、それらの中には製造当初から出力が異常を示すものが含まれている。放射線検出素子7の出力異常としては、放射線の照射にもかかわらず全く電荷を出力しないもの、放射線の線量変化にかかわらず一定の出力しか行わないもの、一定線量の放射線の入射に対して毎回出力が異なり法則性を示さないもの等が挙げられる。
 上記出力異常判定のための暗画像データBH1,BH2で異常判定の対象となるのは、もっぱら放射線の線量変化にかかわらず一定の出力しか行わない放射線検出素子7であり(場合によってはランダムな出力を行う放射線検出素子7も検出可能)、異常判定により新たに出力異常と判定された放射線検出素子7について順次追記されるようになっている。
 欠陥素子マップは、出力異常とされる放射線検出素子7の検出部Pにおける位置情報(位置座標)のみが記録されているものでも良いし、検出部Pの全ての放射線検出素子7について正常又は異常を示すデータが記録されているもので良い。
The radiation detecting element 7 is formed by integrating millions, tens of millions or more of the elements in the detection part P, and some of them show abnormal output from the beginning of manufacture. It is. The abnormal output of the radiation detection element 7 is one that does not output any charge despite the radiation irradiation, one that outputs only a constant regardless of changes in the radiation dose, and is output every time a fixed dose of radiation is incident. Are different and do not show the law.
In the dark image data BH1 and BH2 for output abnormality determination, the object of abnormality determination is a radiation detection element 7 that performs only a constant output regardless of a change in radiation dose (in some cases, random output) The radiation detection element 7 that performs the detection can also be detected), and the radiation detection element 7 that is newly determined to be abnormal in output by the abnormality determination is sequentially added.
The defect element map may be one in which only position information (position coordinates) in the detection unit P of the radiation detection element 7 that is regarded as an output abnormality is recorded, or normal or abnormal for all the radiation detection elements 7 of the detection unit P. May be recorded.
[放射線検出素子の出力異常判定処理]
 コンソール58のCPUが放射線検出素子7の出力異常判定プログラムに従って行う出力異常判定の処理内容について図12のフローチャートに基づいて説明する。
 まず前提として、放射線画像撮影装置1において、放射線の非照射状態で各々の蓄積時間で出力異常判定のための暗画像データBH1,BH2が取得され、コンソール58はこれら暗画像データBH1,BH2を放射線画像撮影装置1から受信して記憶手段59に格納しているものとする。
[Radiation detection element output abnormality determination processing]
The processing contents of the output abnormality determination performed by the CPU of the console 58 according to the output abnormality determination program of the radiation detection element 7 will be described based on the flowchart of FIG.
First, as a premise, in the radiographic imaging device 1, dark image data BH1 and BH2 for output abnormality determination are acquired in each accumulation time in a non-irradiated state, and the console 58 uses these dark image data BH1 and BH2 as radiation. It is assumed that it is received from the image capturing device 1 and stored in the storage means 59.
 コンソール58は、記憶手段59から二つの暗画像データBH1,BH2の読み出しを行い(ステップS11)、それらを差分して差分データΔBHを算出する(ステップS12)。
 即ち、各放射線検出素子7ごとに、暗画像データBH2から暗画像データBH1が減算され、各放射線検出素子7ごとの差分データΔBHが算出される。
The console 58 reads the two dark image data BH1 and BH2 from the storage means 59 (step S11), and calculates the difference data ΔBH by subtracting them (step S12).
That is, for each radiation detection element 7, the dark image data BH1 is subtracted from the dark image data BH2, and difference data ΔBH for each radiation detection element 7 is calculated.
 図13は上記差分算出処理を示す概念図である。図中で横軸の画素位置とは例えば走査線5に沿った放射線検出素子7の並び方向を示し、縦軸は暗画像データ又はその差分値を示す。
 検出部Pにおける各放射線検出素子7は、いずれも放射線非照射の状態で蓄積される電荷量に応じた値であることから、入射線量の違いによるばらつきの影響は抑制される。また、特別な状態ではない限り各放射線検出素子7の温度差は少なく一定に近い状態であることから温度差による影響も少ないと考えられる。従って、正常な放射線検出素子7について画素位置ごとに暗画像データのばらつきが発生する要因の一つとしては走査線方向について個別に設けられた複数の読み出し回路17の読み取りの際の特性の違いが考えられる。
 暗画像データBH1又はBH2に対して出力異常を判定するための閾値を直接設定し、出力異常の判定を行うことは可能であるが、上述の読み出し回路17ごとのばらつきの影響を考慮すると、判定の精度のある程度の低下は避けることが難しい。しかしながら、ステップS12のように各暗画像データBH1,BH2の差分をとることで読み出し回路17ごとのばらつきがキャンセルされ、出力異常の値がばらつきの中に埋もれることなく、顕著に現れるので、判定の閾値をより正常値に近付けることができるようになり、出力異常の放射線検出素子7を精度良く判定することが可能である。
FIG. 13 is a conceptual diagram showing the difference calculation process. In the figure, the pixel position on the horizontal axis indicates, for example, the arrangement direction of the radiation detection elements 7 along the scanning line 5, and the vertical axis indicates dark image data or a difference value thereof.
Since each radiation detection element 7 in the detection unit P has a value corresponding to the amount of charge accumulated in a non-radiation state, the influence of variation due to a difference in incident dose is suppressed. In addition, since the temperature difference between the radiation detecting elements 7 is small and almost constant unless the state is special, it is considered that the influence of the temperature difference is small. Therefore, one of the factors that cause variation in dark image data for each pixel position in the normal radiation detection element 7 is a difference in characteristics when reading is performed by a plurality of readout circuits 17 individually provided in the scanning line direction. Conceivable.
Although it is possible to directly determine a threshold value for determining an output abnormality for the dark image data BH1 or BH2 and determine an output abnormality, the determination is made in consideration of the influence of the variation for each readout circuit 17 described above. It is difficult to avoid a certain decrease in accuracy. However, by taking the difference between the dark image data BH1 and BH2 as in step S12, the variation for each readout circuit 17 is canceled, and the value of the output abnormality appears remarkably without being buried in the variation. The threshold value can be brought closer to the normal value, and the radiation abnormality detecting element 7 having the output abnormality can be accurately determined.
 コンソール58は、各放射線検出素子7の差分データΔBHが求まると、これら各差分データΔBHの標準偏差を算出する。そして、差分データΔBHの平均値をμ、標準偏差をσとした場合に、出力異常の判定のための差分データΔBHの上限の閾値をμ+5σ、下限の閾値をμ-5σとする設定を行う(ステップS13)。これにより、各放射線検出素子7の差分データΔBHの中で特異な値を識別することができる。
 なお、σの係数は「5」に限らず、設定手段を設けて任意に設定入力可能としても良い。また、閾値そのものを任意に設定可能としても良い。
When the difference data ΔBH of each radiation detection element 7 is obtained, the console 58 calculates the standard deviation of each difference data ΔBH. When the average value of the difference data ΔBH is μ and the standard deviation is σ, the upper limit threshold value of the difference data ΔBH for output abnormality determination is set to μ + 5σ, and the lower limit threshold value is set to μ−5σ. Step S13). Thereby, a peculiar value can be identified in the difference data ΔBH of each radiation detection element 7.
Note that the coefficient of σ is not limited to “5”, and a setting unit may be provided to allow arbitrary setting input. Further, the threshold value itself may be set arbitrarily.
 コンソール58は、上記の閾値が設定されると、各放射線検出素子7の差分データΔBHについて順番に出力異常の判定を行う(ステップS14)。
 ここで、差分データΔBHの基データとなる各暗画像データBH1,BH2がいずれも、各放射線検出素子7に対して通常の撮影時の蓄積時間よりも長い蓄積時間で電荷の蓄積を行ったことによる効果について図14A及び図14Bに基づいて説明する。
 図14Aは各放射線検出素子7の電荷の蓄積時間を通常の撮影時と同じくして暗画像の電荷蓄積を行った場合の暗画像データとその頻度(素子数)の対応関係を示す線図であり、図14Bは各放射線検出素子7の電荷の蓄積時間を通常の撮影時よりも長く設定して暗画像の電荷蓄積を行った場合の暗画像データとその頻度(素子数)の対応関係を示す線図である。
 各放射線検出素子7の電荷の蓄積時間を通常の撮影時と同じとした場合、例えば、出力異常である放射線検出素子7の暗画像データが分布の集中する値から大きく外れた値d1を採る場合には、分布の集中する値から余裕を持って離れた値を閾値(例えば図示点線の値)とすることで出力異常となる放射線検出素子7を判別することが可能である。しかしながら、出力異常となりつつある放射線検出素子7の場合等、分布の集中する値に近い値d2をとる場合まで判別して出力異常の判定を精度良く行おうとすると、正常な出力を行う放射線検出素子7との判別を可能とする閾値の設定が難しくなる。つまり、分布の集中する値に近い値を閾値として設定する必要があり、正常な放射線検出素子7まで出力異常と判定される可能性が高くなり、判定精度のある程度の低下は免れない。
 しかしながら、暗画像の電荷蓄積の際の各放射線検出素子7の電荷の蓄積時間をより長くすると、分布の集中する値と出力異常の放射線検出素子7による暗画像データとの差も蓄積時間に応じて広げることができる。図14Bの値d3は前述の値d2を出力した放射線検出素子7について蓄積時間の延長を行った結果の出力を示している。このように、蓄積時間の延長を図ると、正常な値と異常な値との判別が容易となり、閾値も適正な値をとりやすくなる。その結果、正常な放射線検出素子7まで出力異常と判定される可能性が低減され、判定精度の向上を図ることが可能となる。
When the above threshold is set, the console 58 sequentially determines the output abnormality for the difference data ΔBH of each radiation detection element 7 (step S14).
Here, each of the dark image data BH1 and BH2 serving as the base data of the difference data ΔBH has accumulated charges in each radiation detection element 7 with an accumulation time longer than the accumulation time during normal imaging. The effect of this will be described with reference to FIGS. 14A and 14B.
FIG. 14A is a diagram showing the correspondence between dark image data and the frequency (number of elements) when dark image charge accumulation is performed with the charge accumulation time of each radiation detection element 7 being the same as in normal imaging. FIG. 14B shows the correspondence between dark image data and the frequency (number of elements) when dark image charge accumulation is performed with the charge accumulation time of each radiation detection element 7 set longer than that during normal imaging. FIG.
In the case where the charge accumulation time of each radiation detection element 7 is the same as in normal imaging, for example, when the value d1 deviates significantly from the value where the dark image data of the radiation detection element 7 that is abnormal in output is concentrated in the distribution. In this case, it is possible to determine the radiation detection element 7 that causes an output abnormality by setting a value (for example, the value indicated by a dotted line) that is far from the value where the distribution is concentrated with a margin. However, in the case of the radiation detection element 7 that is becoming abnormal in output, if it is determined until the value d2 close to the value where the distribution is concentrated and the determination of the output abnormality is performed with high accuracy, the radiation detection element that performs normal output It becomes difficult to set a threshold value that enables discrimination from 7. That is, it is necessary to set a value close to the value where the distribution is concentrated as a threshold value, and there is a high possibility that it is determined that the output is abnormal up to the normal radiation detection element 7, and a certain decrease in determination accuracy is inevitable.
However, if the charge accumulation time of each radiation detection element 7 during charge accumulation of the dark image is made longer, the difference between the value where the distribution is concentrated and the dark image data by the radiation detection element 7 with abnormal output also depends on the accumulation time. Can be spread. A value d3 in FIG. 14B indicates an output as a result of extending the accumulation time for the radiation detection element 7 that has output the value d2. As described above, when the accumulation time is extended, it is easy to distinguish between a normal value and an abnormal value, and it is easy to take an appropriate threshold value. As a result, it is possible to reduce the possibility that the normal radiation detection element 7 is determined to be abnormal in output, and to improve the determination accuracy.
 なお、上記図14A及び図14Bの例では、蓄積時間を長くすることにより異常出力の検出精度を高めるという効果について暗画像データそのものから判定する場合について例示したが、二つの暗画像データBH1,BH2の差分値である差分データΔBHから各放射線検出素子7の出力異常を判定する場合についても同様のことがいえる。
 なお、上述のように、暗画像の電荷蓄積の際の各放射線検出素子7の電荷の蓄積時間の延長のみでも出力異常の判定精度を向上させることが可能であるため、差分データを用いることなく、蓄積時間が通常よりも延長された暗画像データからの出力異常の判定のみで十分な精度が得られる場合には、暗画像データBH1とBH2の差分を求める工程であるステップS12は省略することが可能である。従って、その場合には、各放射線検出素子7の暗画像データBH1(又はBH2)について標準偏差を求めて判定の閾値が算出され、さらには、当該閾値に基づいて各放射線検出素子7の暗画像データBH1(又はBH2)に対する判定が行われることとなる。
In the example of FIGS. 14A and 14B described above, the case of determining from the dark image data itself the effect of increasing the detection accuracy of the abnormal output by increasing the accumulation time, but the two dark image data BH1, BH2 The same applies to the case where the output abnormality of each radiation detection element 7 is determined from the difference data ΔBH which is the difference value of.
As described above, the output abnormality determination accuracy can be improved only by extending the charge accumulation time of each radiation detection element 7 during the charge accumulation of the dark image, so that the difference data is not used. If sufficient accuracy can be obtained only by determining output abnormality from dark image data whose storage time is longer than usual, step S12, which is a step for obtaining the difference between dark image data BH1 and BH2, is omitted. Is possible. Therefore, in that case, a threshold value for determination is calculated by obtaining a standard deviation for the dark image data BH1 (or BH2) of each radiation detection element 7, and further, a dark image of each radiation detection element 7 is calculated based on the threshold value. The determination for the data BH1 (or BH2) is performed.
 コンソール58は、上記判定において出力異常とした場合には、記憶手段59内の欠陥素子マップに対してその放射線検出素子7の登録を行う(ステップS15)。欠陥素子マップが例えば、前述したように出力異常である放射線検出素子7の位置情報のみを記録したものである場合には、コンソール58は、出力異常と判定された放射線検出素子7の位置情報又はアドレス等をマップに追記する処理を実行する。
 また、欠陥素子マップが例えば、前述したように全ての放射線検出素子7について正常か異常かを示す情報を記録したものである場合には、出力異常と判定された放射線検出素子7についてその記録を異常を示すものに書き換える処理を実行する。
 このようにコンソール58は、出力異常判定プログラムを実行することにより「出力異常判定手段」及び「登録手段」として機能することとなる。
When the console 58 determines that the output is abnormal in the above determination, the radiation detection element 7 is registered in the defect element map in the storage unit 59 (step S15). For example, when the defective element map is a record of only the position information of the radiation detection element 7 that is abnormal in output as described above, the console 58 stores the positional information of the radiation detection element 7 determined as abnormal in output or A process of adding an address or the like to the map is executed.
In addition, when the defect element map is, for example, information indicating whether the radiation detection elements 7 are normal or abnormal as described above, the recording is performed for the radiation detection elements 7 determined to be abnormal in output. Execute the process of rewriting it to indicate something abnormal.
As described above, the console 58 functions as “output abnormality determination means” and “registration means” by executing the output abnormality determination program.
[画像表示制御]
 コンソール58のCPUが画像表示制御プログラムに従って行う画像表示制御の処理内容について図15のフローチャートに基づいて説明する。
 コンソール58は、記憶手段59から各放射線検出素子7における実写画像データJ及びこれに付随して取得された実写画像データを補正するための暗画像データBの読み出しを行い(ステップS21)、それらを差分して暗電荷のオフセット成分を除いた画像データを算出する(ステップS22)。
 なお、各放射線検出素子の画像データに対して、さらに、各放射線検出素子7の感度特性の補正(キャリブレーション)を周知の手法に従って実行しても良い。
[Image display control]
The processing contents of the image display control performed by the CPU of the console 58 according to the image display control program will be described based on the flowchart of FIG.
The console 58 reads out the real image data J in each radiation detection element 7 and the dark image data B for correcting the real image data acquired accompanying it from the storage means 59 (step S21). The image data excluding the offset component of the dark charge by difference is calculated (step S22).
Note that correction (calibration) of sensitivity characteristics of each radiation detection element 7 may be further performed on the image data of each radiation detection element according to a known method.
 次に、コンソール58は、記憶装置59内の欠陥素子マップを参照し、出力異常の放射線検出素子7を特定する。そして、出力異常の放射線検出素子7を特定すると、その周囲の放射線検出素子7の画像データから補間処理を行う(ステップS23)。補間処理の方法の一例を図16に示す。図示のように、出力異常の放射線検出素子7の画像データをG(m,n)とすると(mは走査線5の方向の位置座標、nは信号線6の方向の位置座標とする)、その周囲八つの放射線検出素子7の画像データG(m-1,n-1)、G(m-1,n)、G(m-1,n+1)、G(m,n-1)、G(m,n+1)、G(m+1,n-1)、G(m+1,n)、G(m+1,n+1)の平均を算出し、G(m,n)の値に置換する処理を行う。なお、走査線5の方向に隣接する二つの画像データG(m,n-1)、G(m,n+1)の平均値や信号線6の方向に隣接する二つの画像データG(m-1,n)、G(m+1,n)の平均値で置換したり、その他の周知の方法により置換しても良い。 Next, the console 58 refers to the defect element map in the storage device 59 and identifies the radiation detection element 7 having an abnormal output. Then, when the radiation detection element 7 having an abnormal output is specified, interpolation processing is performed from the image data of the surrounding radiation detection elements 7 (step S23). An example of the interpolation processing method is shown in FIG. As shown in the figure, if the image data of the radiation detection element 7 with abnormal output is G (m, n) (m is the position coordinate in the direction of the scanning line 5, and n is the position coordinate in the direction of the signal line 6), Image data G (m−1, n−1), G (m−1, n), G (m−1, n + 1), G (m, n−1), G of the surrounding eight radiation detection elements 7 An average of (m, n + 1), G (m + 1, n-1), G (m + 1, n), and G (m + 1, n + 1) is calculated and replaced with the value of G (m, n). Note that the average value of the two image data G (m, n−1) and G (m, n + 1) adjacent in the direction of the scanning line 5 and the two image data G (m−1) adjacent in the direction of the signal line 6. , N), G (m + 1, n), or other known methods.
 そして、補正処理と補間処理が行われた画像データに基づいてコンソール58は、表示画面58aに画像表示を実行する(ステップS24)。 Then, based on the image data subjected to the correction process and the interpolation process, the console 58 displays an image on the display screen 58a (step S24).
[発明の実施形態の効果]
 以上のように、本実施形態で示した放射線画像撮影装置1及びこれを構成の一部として含んでいる放射線画像撮影システム50では、その制御手段22が放射線の非照射時(いわゆる暗電荷の取得時)に各放射線検出素子7について撮影時よりも長い蓄積時間で蓄積した電荷に基づいて読み出し回路17から放射線検出素子7の出力異常判定のための暗画像データBH1,BH2を取得するよう制御を行っている。
 前述したように、暗画像の電荷蓄積の際の各放射線検出素子7の電荷の蓄積時間をより長くすると、正常な放射線検出素子7の暗画像データの分布が集中する値と出力異常の放射線検出素子7による暗画像データとの差をその蓄積時間に応じて広げることが可能となる。
 これにより、正常な値と異常な値との判別が容易となり、閾値も適正な値をとりやすくなる。その結果、正常な放射線検出素子7まで出力異常と判定される可能性が低減され、判定精度の向上を図ることが可能となる。
 さらに、異常を生じつつも正常な値に近い暗画像データを出力する放射線検出素子7についても正常な放射線検出素子7から分離して識別することが可能となり、例えば、もともと正常であった放射線検出素子7が徐々に異常となりつつある場合でも早期にこれを判定により異常と判定することができ、出力異常の放射線検出素子7を監視するためのメンテナンスの頻度を低減することも可能となる。
[Effect of the embodiment of the invention]
As described above, in the radiographic image capturing apparatus 1 shown in the present embodiment and the radiographic image capturing system 50 including this as a part of the configuration, the control unit 22 is not irradiated with radiation (so-called dark charge acquisition). Control) to acquire dark image data BH1 and BH2 for determining an output abnormality of the radiation detection element 7 from the readout circuit 17 based on the charge accumulated for each radiation detection element 7 with a longer accumulation time than at the time of imaging. Is going.
As described above, if the charge accumulation time of each radiation detection element 7 during the charge accumulation of the dark image is made longer, the value where the distribution of the dark image data of the normal radiation detection element 7 is concentrated and the radiation detection of the abnormal output is performed. The difference from the dark image data by the element 7 can be widened according to the accumulation time.
As a result, it is easy to distinguish between normal values and abnormal values, and the threshold value is also likely to take an appropriate value. As a result, it is possible to reduce the possibility that the normal radiation detection element 7 is determined to be abnormal in output, and to improve the determination accuracy.
Further, the radiation detection element 7 that outputs dark image data close to a normal value while causing an abnormality can be identified separately from the normal radiation detection element 7. For example, the radiation detection that was originally normal is detected. Even when the element 7 is gradually becoming abnormal, it can be determined to be abnormal at an early stage by determination, and the frequency of maintenance for monitoring the radiation detecting element 7 with abnormal output can also be reduced.
 さらに、放射線画像撮影装置1の制御手段22は、各放射線検出素子7について、蓄積時間を変えて複数(この実施形態では二つ)の出力異常判定のための暗画像データBH1,BH2を求め、これを外部装置としてのコンソール58に送信している。
 このため、コンソール58側では、二つの暗画像データBH1,BH2について各放射線検出素子7ごとに差分データΔBHを求めることが可能となる。
 かかる場合、前述したように、差分データΔBHは、複数ある読み出し回路17における出力特性のばらつきの影響をキャンセルすることができ、これによりばらつきの低減された差分データΔBHの中で出力異常である放射線検出素子7の出力に基づく差分データΔBHを顕著なものとして識別することが容易となり、出力異常の放射線検出素子7の判定精度をさらに向上させることが可能となる。
Furthermore, the control means 22 of the radiographic imaging device 1 obtains dark image data BH1 and BH2 for determining a plurality of (two in this embodiment) output abnormality for each radiation detection element 7 by changing the accumulation time, This is transmitted to the console 58 as an external device.
Therefore, on the console 58 side, the difference data ΔBH can be obtained for each radiation detection element 7 for the two dark image data BH1 and BH2.
In this case, as described above, the difference data ΔBH can cancel the influence of the variation in the output characteristics in the plurality of readout circuits 17, and thus radiation that is abnormal in output in the difference data ΔBH in which the variation is reduced. It becomes easy to identify the difference data ΔBH based on the output of the detection element 7 as being prominent, and it is possible to further improve the determination accuracy of the radiation detection element 7 with an abnormal output.
 また、前述したように、各放射線検出素子7の暗画像データBH1,BH2については、それぞれ複数回の蓄積により複数のデータを取得し、それらの平均値を正式な暗画像データBH1,BH2としても良いが、そのように平均化を図った場合には、いずれも横引きノイズ等のノイズ成分を除去することができ、さらに、出力異常となる放射線検出素子7の検出を精度良く行うことを可能としている。 Further, as described above, for the dark image data BH1 and BH2 of each radiation detection element 7, a plurality of data is acquired by accumulating a plurality of times, and the average value thereof is also used as the formal dark image data BH1 and BH2. It is good, but when averaging is done in such a way, noise components such as horizontal noise can be removed, and furthermore, it is possible to accurately detect the radiation detection element 7 that causes output abnormality. It is said.
[放射線画像撮影装置の他の例]
 上述した放射線画像撮影装置1では、放射線検出素子の出力異常判定のための暗画像データBH1,BH2を取得する処理を行うと、これらの暗画像データBH1,BH2を全てコンソール58側に送信し、暗画像データBH1,BH2から出力異常とされる放射線検出素子7の判定及び欠陥素子マップの登録は全てコンソール58にゆだねる構成となっていたが、放射線画像撮影装置が欠陥素子マップを記憶保持し、暗画像データBH1,BH2から出力異常とされる放射線検出素子7の判定を行い、欠陥素子マップへの登録までを行う構成としても良い。
 図17は、そのような放射線画像撮影装置100の構成を示すブロック図である。放射線画像撮影装置100は、前述の放射線画像撮影装置1と同様の構成を全て備えている。従って、かかる放射線画像撮影装置100の説明において、放射線画像撮影装置1と同じ構成について同じ符号を付して説明は省略するものとする。また、図17では、検出部P、ゲートドライバ15b及び電源回路15aの図示は省略している。
[Other examples of radiographic imaging equipment]
In the radiographic imaging device 1 described above, when processing for obtaining dark image data BH1 and BH2 for output abnormality determination of the radiation detection element is performed, all of these dark image data BH1 and BH2 are transmitted to the console 58 side. The determination of the radiation detection element 7 that is abnormal in output from the dark image data BH1 and BH2 and the registration of the defect element map are all referred to the console 58. However, the radiographic imaging device stores and holds the defect element map. A configuration may be adopted in which the radiation detection element 7 determined to be abnormal in output is determined from the dark image data BH1 and BH2 and is registered in the defect element map.
FIG. 17 is a block diagram showing a configuration of such a radiographic image capturing apparatus 100. The radiographic imaging device 100 has all the same configurations as those of the radiographic imaging device 1 described above. Therefore, in the description of the radiographic image capturing apparatus 100, the same components as those of the radiographic image capturing apparatus 1 are denoted by the same reference numerals and description thereof is omitted. In FIG. 17, the detection unit P, the gate driver 15b, and the power supply circuit 15a are not shown.
 放射線画像撮影装置100は制御手段122を備え、かかる制御手段122は前述の制御手段22と同様に、CPU123,RAM124,ROM125を備えている。
 また、この制御手段122は、プログラムメモリ126を具備しており、前述の図9の工程を実行するための撮影制御プログラム127と前述の図10A及び図10Bの工程を実行するための暗画像データ取得制御プログラム128とを記憶している。
The radiographic image capturing apparatus 100 includes a control unit 122, and the control unit 122 includes a CPU 123, a RAM 124, and a ROM 125, similar to the control unit 22 described above.
Further, the control unit 122 includes a program memory 126, and the photographing control program 127 for executing the process of FIG. 9 and dark image data for executing the process of FIGS. 10A and 10B. The acquisition control program 128 is stored.
 さらに、放射線画像撮影装置100の重要な特徴として、上記プログラムメモリ126に、前述したコンソール58のCPUが処理を行っていた出力異常判定プログラム129を記憶している。
 出力異常判定プログラム129はコンソール59のCPUが実行する図12の処理と同じ処理を実行するためのプログラムであり、これにより、放射線画像撮影装置100では、当該装置が保有する検出部Pについて出力異常の放射線検出素子7を特定することが可能となっている。また、これにより、欠陥素子マップMに対して出力異常とされる放射線検出素子7について登録を行うことが可能となっている。
 つまり、出力異常判定プログラム129を実行する制御手段22は、「出力異常判定手段」及び「登録手段」として機能することとなる。
 従って、制御手段122に併設された記憶手段140には、各放射線検出素子7についての実写画像データJ、暗画像データB、出力異常判定のための暗画像データBH1,BH2に加えて、出力異常判定プログラム129の実行の過程で求められる差分データΔBH、欠陥素子マップMを記憶する構成となっている。
Furthermore, as an important feature of the radiation image capturing apparatus 100, the program memory 126 stores an output abnormality determination program 129 that has been processed by the CPU of the console 58 described above.
The output abnormality determination program 129 is a program for executing the same processing as the processing of FIG. 12 executed by the CPU of the console 59. With this, in the radiographic imaging device 100, the output abnormality is detected for the detection unit P possessed by the device. The radiation detecting element 7 can be specified. In addition, this makes it possible to register the radiation detection element 7 whose output is abnormal with respect to the defective element map M.
That is, the control means 22 that executes the output abnormality determination program 129 functions as “output abnormality determination means” and “registration means”.
Therefore, the storage unit 140 provided in the control unit 122 includes an output abnormality in addition to the actual image data J, the dark image data B, and the dark image data BH1 and BH2 for determining the output abnormality for each radiation detection element 7. The configuration is such that difference data ΔBH and defect element map M obtained in the course of execution of the determination program 129 are stored.
 なお、この放射線画像撮影装置100は、図15のステップS21~S23までと同じ処理を実行し、補間処理を行った画像データGがアンテナ装置39を通じてコンソール58に送信されるようになっている。
 従って、記憶手段140には、補間処理まで完了した一画面分の画像データGが記憶される構成となっている。
The radiographic image capturing apparatus 100 executes the same processing as steps S21 to S23 in FIG. 15, and the image data G subjected to the interpolation processing is transmitted to the console 58 through the antenna device 39.
Therefore, the storage unit 140 is configured to store image data G for one screen that has been completed up to the interpolation processing.
 このように、放射線画像撮影装置100で画像データGまで求めてしまうので、コンソール58側の処理負担を軽減することが可能となる。
 また、この放射線画像撮影装置100では、欠陥素子マップMを保有して、自己処理により出力異常となる放射線検出素子7の情報を管理することができるので、コンソール58側での個々の放射線画像撮影装置100についての管理を不要とすることも可能である。
 また、放射線画像撮影装置100側でもコンソール58側でも欠陥素子マップMを双方で管理する構成としても良い。その場合には、この放射線画像撮影装置100において、欠陥素子マップMの登録内容が更新されるたびに、コンソール58に欠陥素子マップMのデータを送信するように構成しても良い。
Thus, since the radiographic image capturing apparatus 100 obtains the image data G, the processing burden on the console 58 side can be reduced.
In addition, since the radiation image capturing apparatus 100 has a defect element map M and can manage information on the radiation detection elements 7 that cause output abnormalities by self-processing, individual radiation image capturing on the console 58 side is possible. It is also possible to eliminate the management of the device 100.
Further, the defect element map M may be managed by both the radiation image capturing apparatus 100 side and the console 58 side. In this case, the radiographic imaging apparatus 100 may be configured to transmit the data of the defective element map M to the console 58 every time the registered content of the defective element map M is updated.
 また、上記放射線画像撮影装置100以外の放射線画像撮影装置の他の例としては、前述した放射線画像撮影装置1において、各放射線検出素子7について実写画像データJから暗画像データBを差分して補正済みの画像データを算出し、実写画像データJと暗画像データBに替えて補正済みの画像データをコンソール58に送信するもの、或いは、各放射線検出素子7について暗画像データBH1とBH2との差分データΔBHを算出し、暗画像データBH1とBH2に替えて差分データΔBHをコンソール58に送信するもの、或いはこれら両方を実施するものが考えられる。これらの構成とすることで放射線画像撮影装置からコンソール58側へのデータ送信量を低減することができ、転送時間を短縮することが可能となる。 Further, as another example of the radiographic imaging apparatus other than the radiographic imaging apparatus 100, in the radiographic imaging apparatus 1 described above, the correction is performed by subtracting the dark image data B from the actual captured image data J for each radiation detection element 7. Calculating the completed image data and transmitting the corrected image data to the console 58 instead of the actual image data J and the dark image data B, or the difference between the dark image data BH1 and BH2 for each radiation detection element 7 It is possible to calculate the data ΔBH and transmit the difference data ΔBH to the console 58 instead of the dark image data BH1 and BH2, or to perform both. With these configurations, the amount of data transmitted from the radiographic apparatus to the console 58 can be reduced, and the transfer time can be shortened.
[欠陥画素マップ作成システム]
 次に、本実施形態に係る欠陥画素マップ作成システム200の構成について説明する。
 欠陥画素マップ作成システム200は、例えば、放射線画像撮影装置1の出荷前に行う出荷検査時に、放射線照射を伴う検査を実施することで欠陥画素を判定して欠陥画素マップを作成するシステムである。
[Defective pixel map creation system]
Next, the configuration of the defective pixel map creation system 200 according to the present embodiment will be described.
The defective pixel map creation system 200 is a system that creates a defective pixel map by determining a defective pixel by performing an inspection involving radiation irradiation, for example, at the time of a shipping inspection performed before the radiation image capturing apparatus 1 is shipped.
 図18は、欠陥画素マップ作成システム200の全体構成を示す図である。
 欠陥画素マップ作成システム200は、図示のように、放射線撮影装置1における筐体2に格納する前段階の基板4を対象として、欠陥画素マップの作成を行うものである。
 即ち、当該基板4は、検出部P、シンチレータ3等の基板4の両面に直接設けられる全ての構成(図2における筐体2の内部構成全体)が既に搭載又は形成された状態であって、COF12、基板33、走査駆動手段15、読み出しIC16、制御手段22、記憶手段40、アンテナ装置39等も全て搭載されており、電源が供給されれば放射線画像の撮影が可能な状態である。以下の説明では、これらの構成を総括的に「検出機能部4A」というものとする。
 なお、基板4には、通常、リチウムイオンキャパシタ等の電気二重層キャパシタ、リチウムイオン電池等の二次電池がバッテリ41として搭載されるが、これらは、欠陥画素マップ作成におけるエイジングステップ(後述)における加熱による破壊、劣化などの影響を回避するために、バッテリ41は事前に取り外すか搭載前の段階で欠陥画素マップ作成を行う。
FIG. 18 is a diagram showing the overall configuration of the defective pixel map creation system 200. As shown in FIG.
As shown in the figure, the defective pixel map creation system 200 creates a defective pixel map for the substrate 4 at the previous stage stored in the housing 2 of the radiation imaging apparatus 1.
That is, the substrate 4 is in a state where all the configurations (the entire internal configuration of the housing 2 in FIG. 2) directly provided on both surfaces of the substrate 4 such as the detection unit P and the scintillator 3 are already mounted or formed. The COF 12, the substrate 33, the scanning drive unit 15, the readout IC 16, the control unit 22, the storage unit 40, the antenna device 39, and the like are all mounted, and a radiographic image can be captured when power is supplied. In the following description, these configurations are collectively referred to as “detection function unit 4A”.
Note that an electric double layer capacitor such as a lithium ion capacitor and a secondary battery such as a lithium ion battery are usually mounted on the substrate 4 as a battery 41. These are in an aging step (described later) in creating a defective pixel map. In order to avoid influences such as destruction and deterioration due to heating, the battery 41 is removed in advance or a defective pixel map is created at a stage before mounting.
 欠陥画素マップ作成システム200は、主に、上記検出機能部4Aを格納する加温部としての恒温槽210と、欠陥画素マップ作成装置220とから構成される。
 恒温槽210は、内部に検出機能部4Aを収容することが可能であり、高い密閉性と断熱性とを備え、また、外部からの可視光、放射線を含む電磁波を遮断して内部を暗室とすることが可能となっている。
 また、恒温槽210は、内部を昇温させるヒータ211と、内部の温度検出を行う温度センサ212と、収容された検出機能部4Aに対して各部に必要な電力を供給するための電源回路213と、収容された検出機能部4Aのアンテナ装置39を通じて無線通信を行う通信部214とを備えている。
The defective pixel map creation system 200 mainly includes a thermostatic chamber 210 as a heating unit that stores the detection function unit 4A and a defective pixel map creation device 220.
The thermostatic chamber 210 can accommodate the detection function unit 4A inside, has high sealing property and heat insulation, and blocks electromagnetic waves including visible light and radiation from the outside to make the inside a dark room. It is possible to do.
The thermostatic chamber 210 includes a heater 211 that raises the temperature inside, a temperature sensor 212 that detects the temperature inside, and a power supply circuit 213 that supplies necessary power to each part of the housed detection function unit 4A. And a communication unit 214 that performs wireless communication through the antenna device 39 of the housed detection function unit 4A.
 ヒータ211及び温度センサ212はコントローラ215に接続されており、当該コントローラは恒温槽210の内部温度の設定入力を行うことが可能である。そして、コントローラは、温度センサ212の検出温度に基づいてヒータ211の加熱制御を行い、恒温槽210内を設定温度に維持する制御を行う。 The heater 211 and the temperature sensor 212 are connected to the controller 215, and the controller can input the setting of the internal temperature of the thermostat 210. The controller performs heating control of the heater 211 based on the temperature detected by the temperature sensor 212, and performs control to maintain the constant temperature bath 210 at a set temperature.
 また、前述したように、検出機能部4Aは、バッテリ41を搭載しない状態で恒温槽210内に収容される。このため、電源回路213は、恒温槽210内に収容された検出機能部4Aが放射線画像撮影を実行可能となるように、検出機能部4Aに電源の供給を行う。電源回路213は、恒温槽210の外部に配置され、配線を通じて槽内の給電コネクタ213Aを介して検出機能部4Aに給電を行う。なお、給電コネクタ213Aは、バッテリ41を基板4に接続するコネクタと同型のものであり、バッテリ41を外した状態で替わりに給電コネクタ213Aを接続することができ、これにより、検出機能部4Aの各部に電源の供給が行われる。 As described above, the detection function unit 4A is accommodated in the thermostatic chamber 210 without the battery 41 mounted. For this reason, the power supply circuit 213 supplies power to the detection function unit 4A so that the detection function unit 4A housed in the thermostat 210 can execute radiographic image capturing. The power supply circuit 213 is disposed outside the thermostatic chamber 210 and supplies power to the detection function unit 4A through a power supply connector 213A in the bath through wiring. Note that the power supply connector 213A is the same type as the connector that connects the battery 41 to the substrate 4, and the power supply connector 213A can be connected instead of the battery 41 being removed, and thus the detection function unit 4A can be connected. Power is supplied to each part.
 通信部214は、恒温槽210の内部にアンテナを配した無線装置であって、検出機能部4A側のアンテナ装置39を通じて当該検出機能部4Aとの無線の送信及び受信を可能としている。そして、この通信部214は、欠陥画素マップ作成装置220に通信ケーブルで接続されており、後述する欠陥画素マップ作成装置220の制御手段221から検出機能部4Aへ制御指令を送信したり、検出機能部4Aが取得した暗画像データを受信して欠陥画素マップ作成装置220に送信することを可能としている。 The communication unit 214 is a wireless device in which an antenna is arranged inside the thermostat 210, and enables wireless transmission and reception with the detection function unit 4A through the antenna device 39 on the detection function unit 4A side. The communication unit 214 is connected to the defective pixel map creation device 220 via a communication cable, and transmits a control command to the detection function unit 4A from the control unit 221 of the defective pixel map creation device 220 described later, or a detection function. The dark image data acquired by the unit 4A can be received and transmitted to the defective pixel map creating apparatus 220.
 欠陥画素マップ作成装置220は、恒温槽210内で加熱された状態の検出機能部4Aを制御してエイジング処理と各放射線検出素子7の出力異常判定のための暗画像データBH3,BH4を取得する処理とを順番に実行させ、取得した暗画像データBH3,BH4から出力異常の放射線検出素子7を特定し、出力異常の放射線検出素子7について欠陥画素マップMの作成を行う。 The defective pixel map creation device 220 controls the detection function unit 4A heated in the thermostat 210 to acquire dark image data BH3 and BH4 for aging processing and output abnormality determination of each radiation detection element 7. The processing is executed in order, the radiation detection element 7 with abnormal output is identified from the acquired dark image data BH3 and BH4, and the defective pixel map M is created for the radiation detection element 7 with abnormal output.
 欠陥画素マップ作成装置220は、制御手段221と各種データの記憶手段230とを備え、当該制御手段221は、CPU222,RAM223,ROM224を備えている。
 また、この制御手段221は、プログラムメモリ225を具備しており、後述するエイジング処理を検出機能部4Aに実行させるためのエイジング制御プログラム227と各放射線検出素子7の出力異常判定のための暗画像データBH3,BH4を取得するためのデータ取得処理を検出機能部4Aに実行させるための暗画像データ取得制御プログラム228と、取得した暗画像データBH3,BH4から出力異常の放射線検出素子7を特定し、出力異常の放射線検出素子7について欠陥画素マップMの作成を行う出力異常判定プログラム229とを記憶している。
The defective pixel map creating apparatus 220 includes a control unit 221 and various data storage units 230, and the control unit 221 includes a CPU 222, a RAM 223, and a ROM 224.
The control means 221 includes a program memory 225, and an aging control program 227 for causing the detection function unit 4A to execute an aging process described later, and a dark image for determining an output abnormality of each radiation detection element 7. A dark image data acquisition control program 228 for causing the detection function unit 4A to execute a data acquisition process for acquiring the data BH3 and BH4, and specifying the radiation detection element 7 having an abnormal output from the acquired dark image data BH3 and BH4 An output abnormality determination program 229 for creating a defective pixel map M for the radiation abnormality detecting element 7 with an abnormality in output is stored.
(欠陥画素マップ作成方法)
 以下、制御手段221のCPU222が、上記エイジング制御プログラム227、暗画像データ取得制御プログラム228、出力異常判定プログラム229を順番に実行することにより行われる欠陥画素マップ作成方法について、図19のフローチャートに基づいて説明する。
(Defective pixel map creation method)
Hereinafter, a defective pixel map creation method performed by the CPU 222 of the control unit 221 executing the aging control program 227, the dark image data acquisition control program 228, and the output abnormality determination program 229 in order will be described with reference to the flowchart of FIG. I will explain.
 まず、制御手段221は、エイジング制御プログラム227を実行することにより、ヒータ211による恒温槽210内の設定温度(例えば摂氏60度)への加温を開始させると共に、通信部214を通じて、検出機能部4Aの制御手段22にエイジング処理を実行させる制御指令を送信する(ステップS31:エイジングステップ)。 First, the control unit 221 executes the aging control program 227 to start heating the heater 211 to a set temperature (for example, 60 degrees Celsius) in the thermostatic chamber 210, and through the communication unit 214, the detection function unit A control command for executing the aging process is transmitted to the control means 22 of 4A (step S31: aging step).
 上記エイジング処理は、各放射線検出素子7の蓄積電荷のリセットと、電荷の蓄積と、電荷の読み出し動作(電荷の放出動作)とを所定の継続時間中に繰り返し実行する処理である。具体的には、検出機能部4Aは、走査線5のラインL1~LxへのON電圧の印加と各電荷リセット用スイッチ18cのON状態への切り替えとによる各放射線検出素子7の蓄積電荷のリセットと、各電荷リセット用スイッチ18cのOFF及び各TFT8へのOFF電圧の印加により各放射線検出素子7による電荷の蓄積と、各TFT8へのON電圧の印加による各放射線検出素子7の蓄積電荷の読み出し(電荷の放出)とを複数回繰り返し実行させる。
 制御手段221は、検出機能部4Aに対して、上記リセット、電荷蓄積、電荷の読み出しを繰り返し実行させることにより、「エイジング制御部」として機能するものである。
The aging process is a process of repeatedly executing the reset of accumulated charges, the accumulation of charges, and the charge reading operation (charge releasing operation) within a predetermined duration. Specifically, the detection function unit 4A resets the accumulated charge of each radiation detection element 7 by applying an ON voltage to the lines L1 to Lx of the scanning line 5 and switching each charge reset switch 18c to the ON state. Then, charge accumulation by each radiation detection element 7 is performed by turning off each charge reset switch 18 c and application of an OFF voltage to each TFT 8, and readout of charge accumulated in each radiation detection element 7 by application of an ON voltage to each TFT 8. (Discharge of electric charge) is repeatedly executed a plurality of times.
The control unit 221 functions as an “aging control unit” by causing the detection function unit 4A to repeatedly execute the reset, charge accumulation, and charge readout.
 上記リセット、蓄積、読み出しの各動作は実際の放射線画像の通常の撮影時の動作よりも短いサイクルで実行される。また、上記サイクルは所定時間繰り返して実行される。かかる繰り返しの継続時間は例えば、10から20時間程度である。
 また、上記各放射線検出素子7の電荷の蓄積は、恒温槽210内において放射線の非照射状態で行われるため、暗電荷が蓄積されることなるが、エイジング処理における各放射線検出素子7の電荷の蓄積は暗電荷に限るものではなく、例えば、放射線の照射状態で行っても良い。
 また、各放射線検出素子7の蓄積電荷の読み出し動作は、データ取得を目的とするものではなく、電荷の放出動作を行わせることが目的であるため、A/D変換及び変換されたデータの保存は行われない。
The reset, storage, and readout operations are executed in a shorter cycle than the operation at the time of normal imaging of an actual radiation image. The cycle is repeatedly executed for a predetermined time. The repetition time is about 10 to 20 hours, for example.
Further, since the charge accumulation of each radiation detection element 7 is performed in the thermostatic chamber 210 in a non-irradiated state, dark charges are accumulated, but the charge of each radiation detection element 7 in the aging process is accumulated. Accumulation is not limited to dark charges, and may be performed in a radiation irradiation state, for example.
Further, the read operation of the accumulated charges of each radiation detection element 7 is not intended to acquire data but is intended to perform the discharge operation of charges, so A / D conversion and storage of the converted data are performed. Is not done.
 上記エイジング処理によって、加温された状態で、リセット、電荷の蓄積、電荷の読み出しが繰り返し行われることにより、各放射線検出素子7の中で、例えば、成膜時に異物が混入して素子の電極間でリークパスが発生しつつある欠陥画素の予備軍となる放射線検出素子7に対してリークを進行させ、出力異常を進行させることが可能である。
 即ち、後発的に出力異常を生じる放射線検出素子7について、出力異常の早期発見が可能となる。
By repeatedly performing reset, charge accumulation, and charge readout in the heated state by the aging process, for example, foreign substances are mixed in each radiation detection element 7 during film formation, and the electrode of the element It is possible to advance leakage to the radiation detection element 7 serving as a reserve for defective pixels for which a leak path is occurring between them, and to advance output abnormality.
That is, it is possible to detect an output abnormality early on the radiation detection element 7 that causes an output abnormality later.
 次に、暗画像データ取得制御プログラム228を実行することにより、制御手段221は、ヒータ211をOFFすると共に、通信部214を通じて、検出機能部4Aの制御手段22に、暗画像データBH3,BH4の取得制御を行わせる制御指令を送信する(ステップS32:暗画像データ取得ステップ)。
 上記暗画像データBH3,BH4の取得制御は、図10A及び図10Bに示した暗画像データBH1,BH2の取得の場合とほぼ同様の動作制御が行われる。
Next, by executing the dark image data acquisition control program 228, the control unit 221 turns off the heater 211 and transmits the dark image data BH3 and BH4 to the control unit 22 of the detection function unit 4A through the communication unit 214. A control command for performing acquisition control is transmitted (step S32: dark image data acquisition step).
The acquisition control of the dark image data BH3 and BH4 is almost the same operation control as the acquisition of the dark image data BH1 and BH2 shown in FIGS. 10A and 10B.
 即ち、検出機能部4Aの制御手段22は、各放射線検出素子7の電荷のリセットを行い、放射線の非照射状態で第三の蓄積時間で暗画像の電荷の蓄積を行い、各放射線検出素子7について読み出し処理を実行する。
 このとき、上記第三の蓄積時間は、撮影時の蓄積時間は撮影時の蓄積時間よりも長くする。具体的には、第三の蓄積時間は図10Aの第一の蓄積時間と同じ10[s]に設定されている。
 そして、各放射線検出素子7の第三の蓄積時間に基づく出力異常判定のための暗画像データBH3を取得すると、アンテナ装置39を通じて暗画像データBH3を欠陥画素マップ作成装置220の制御手段221に送信する。
 これにより、制御手段221は、暗画像データBH3を記憶手段230に保存する。
That is, the control means 22 of the detection function unit 4A resets the charge of each radiation detection element 7, accumulates the charge of the dark image in the third accumulation time in the non-irradiated state, and each radiation detection element 7 Read processing is executed for.
At this time, the third accumulation time is set so that the accumulation time at the time of shooting is longer than the accumulation time at the time of shooting. Specifically, the third accumulation time is set to 10 [s], which is the same as the first accumulation time in FIG. 10A.
When the dark image data BH3 for output abnormality determination based on the third accumulation time of each radiation detection element 7 is acquired, the dark image data BH3 is transmitted to the control means 221 of the defective pixel map creation device 220 through the antenna device 39. To do.
Accordingly, the control unit 221 stores the dark image data BH3 in the storage unit 230.
 次いで、検出機能部4Aの制御手段22は、各放射線検出素子7の電荷のリセットを行い、放射線の非照射状態で第四の蓄積時間で暗画像の電荷の蓄積を行い、各放射線検出素子7について読み出し処理を実行し、各放射線検出素子7の第四の蓄積時間に基づく出力異常判定のための暗画像データBH4を取得し、欠陥画素マップ作成装置220の制御手段221に送信する。
 なお、第四の蓄積時間は、第三の蓄積時間と異なる長さで、且つ、撮影時の蓄積時間より長い時間に設定されている。具体的には、第四の蓄積時間は図10Bの第二の蓄積時間と同じ20[s]に設定されている。
 そして、制御手段221は、暗画像データBH4を記憶手段230に保存する。
 制御手段221は、検出機能部4Aから、出力異常判定のための暗画像データBH3,BH4を取得する制御を実行することにより、「暗画像データ取得制御部」として機能するものである。
Next, the control means 22 of the detection function unit 4A resets the charge of each radiation detection element 7, accumulates the charge of the dark image in the fourth accumulation time in the non-irradiated state, and each radiation detection element 7 Is read out, and dark image data BH4 for output abnormality determination based on the fourth accumulation time of each radiation detection element 7 is acquired and transmitted to the control means 221 of the defective pixel map creation device 220.
The fourth accumulation time is set to a length different from the third accumulation time and longer than the accumulation time at the time of shooting. Specifically, the fourth accumulation time is set to 20 [s], which is the same as the second accumulation time in FIG. 10B.
Then, the control unit 221 stores the dark image data BH4 in the storage unit 230.
The control means 221 functions as a “dark image data acquisition control unit” by executing control for acquiring dark image data BH3 and BH4 for output abnormality determination from the detection function unit 4A.
 次に、出力異常判定プログラム229を実行することにより、制御手段221は、記憶手段230から二つの暗画像データBH3,BH4の読み出しを行い、それらを差分して差分データΔBH2を算出する(ステップS33:差分ステップ)。
 即ち、暗画像データBH4から暗画像データBH3が減算され、各放射線検出素子7ごとの出力値の差分値からなる差分データΔBH2が算出される。
Next, by executing the output abnormality determination program 229, the control unit 221 reads out the two dark image data BH3 and BH4 from the storage unit 230, and calculates the difference data ΔBH2 by subtracting them (step S33). : Difference step).
That is, the dark image data BH3 is subtracted from the dark image data BH4, and difference data ΔBH2 including the difference value of the output value for each radiation detection element 7 is calculated.
 これにより、前述した図13の場合と同様にして、複数ある読み出し回路17の読み取りの際の特性の違いによるばらつきがキャンセルされ、後に行われる各放射線検出素子7の出力異常の判定において、出力異常の値を顕著に見いだすことが可能である。
 制御手段221は、暗画像データBH3とBH4の差分算出を行うことにより、「差分算出部」として機能するものである。
As a result, similarly to the case of FIG. 13 described above, the variation due to the difference in characteristics at the time of reading by the plurality of readout circuits 17 is canceled, and in the subsequent determination of the output abnormality of each radiation detection element 7, the output abnormality It is possible to find the value of.
The control unit 221 functions as a “difference calculation unit” by calculating a difference between the dark image data BH3 and BH4.
 次いで、制御手段221は、出力異常判定プログラム229により、各放射線検出素子7の差分データΔBH2が求まると、これら各差分データΔBH2の平均値μと標準偏差σとから、出力異常の判定のための差分データΔBH2の上限の閾値μ+5σ、下限の閾値μ-5σを算出する(ステップS34)。
 なお、この場合も、σの係数は「5」に限らず、設定手段を設けて任意に設定入力可能としても良い。また、閾値そのものを任意に設定可能としても良い。
 さらに、制御手段221は、上記の閾値が設定されると、各放射線検出素子7の差分データΔBH2について順番に出力異常の判定を行う(ステップS35:判定ステップ)。
Next, when the difference data ΔBH2 of each radiation detection element 7 is obtained by the output abnormality determination program 229, the control unit 221 determines the output abnormality from the average value μ and the standard deviation σ of each difference data ΔBH2. The upper limit threshold μ + 5σ and the lower limit threshold μ−5σ of the difference data ΔBH2 are calculated (step S34).
In this case as well, the coefficient of σ is not limited to “5”, and setting means may be provided to allow arbitrary setting input. Further, the threshold value itself may be set arbitrarily.
Further, when the above threshold value is set, the control means 221 sequentially determines the output abnormality for the difference data ΔBH2 of each radiation detection element 7 (step S35: determination step).
 前述したように、この欠陥画素マップ作成システム200では、検出機能部4Aに対してエイジング処理を行ってから暗画像データを取得している。
 図20Aは検出機能部4Aにエイジング処理を行っていない場合の各放射線検出素子7の出力値とその頻度(素子数)の対応関係を示す線図であり、図20Bは検出機能部4Aにエイジング処理を行った場合の各放射線検出素子7の出力値とその頻度(素子数)の対応関係を示す線図である。
 これらの線図を比較すると分かるように、例えば、異物混入により小さなリークパスを生じているが、まだ異常といえない値d4を出力しているような放射線検出素子7に対して、エイジング処理で蓄積、読み出し等を繰り返すことにより、リークを積極的に進行させて、明らかに異常と識別することが可能な値d5を出力させることができる。
つまり、正常な範囲に閾値を近づけることなく、後発的に異常を生じる放射線検出素子7を識別することが可能となり、正常な放射線検出素子7まで出力異常と判定される可能性が低減され、判定精度の向上を図ることが可能となる。
As described above, in this defective pixel map creation system 200, the dark image data is acquired after performing the aging process on the detection function unit 4A.
FIG. 20A is a diagram showing a correspondence relationship between the output value of each radiation detection element 7 and its frequency (number of elements) when the detection function unit 4A is not subjected to the aging process, and FIG. 20B is an aging diagram for the detection function unit 4A. It is a diagram which shows the correspondence of the output value of each radiation detection element 7 at the time of processing, and its frequency (element number).
As can be seen from a comparison of these diagrams, for example, a small leak path is generated due to contamination of foreign matter, but the radiation detection element 7 that outputs a value d4 that cannot be said to be abnormal is accumulated by aging processing. By repeating reading and the like, it is possible to actively advance the leak and output a value d5 that can be clearly identified as abnormal.
In other words, it is possible to identify the radiation detection element 7 that subsequently causes an abnormality without bringing the threshold value close to the normal range, and the possibility that an output abnormality is detected up to the normal radiation detection element 7 is reduced. The accuracy can be improved.
 なお、上記図20A及び図20Bの例では、エイジング処理の有無による出力値の分布を例示したが、二つの暗画像データBH3,BH4の差分値である差分データΔBH2から各放射線検出素子7の出力異常を判定する場合についても同様のことがいえる。
 制御手段221は、暗画像データBH3,BH4の差分データから各放射線検出素子7の出力異常判定を行うことにより、「判定部」として機能するものである。
20A and 20B exemplify the distribution of output values depending on the presence or absence of the aging process, but the output of each radiation detection element 7 from the difference data ΔBH2 that is the difference value between the two dark image data BH3 and BH4. The same applies to the case of determining an abnormality.
The control means 221 functions as a “determination unit” by determining the output abnormality of each radiation detection element 7 from the difference data of the dark image data BH3 and BH4.
 次いで、制御手段221は、出力異常判定プログラム229を実行することにより、出力異常と判定した放射線検出素子7について、記憶手段230内の欠陥素子マップMに対してその放射線検出素子7の登録を行う(ステップS36:欠陥画素マップ作成ステップ)。
 欠陥素子マップが例えば、出力異常である放射線検出素子7の位置情報を記録したものでも良いし、全ての放射線検出素子7について正常か異常か(いずれの放射線検出素子7が異常であるか)を示す情報を記録したものでもよい。
 制御手段221は、欠陥画素マップの登録を行うことにより「欠陥画素マップ作成部」として機能するものである。
Next, the control unit 221 executes the output abnormality determination program 229 to register the radiation detection element 7 in the defect element map M in the storage unit 230 for the radiation detection element 7 determined to be output abnormality. (Step S36: defective pixel map creation step).
For example, the defect element map may be a record of the position information of the radiation detection elements 7 that are abnormal in output, and whether all the radiation detection elements 7 are normal or abnormal (which radiation detection element 7 is abnormal). The information shown may be recorded.
The control means 221 functions as a “defective pixel map creation unit” by registering a defective pixel map.
 以上のように、欠陥画素マップ作成システム200では、検出機能部4Aに対してエイジング処理を実行してから各放射線検出素子7の出力値の異常の判定を行うので、当初の段階では、異常出力とは見なされない後発的に異常出力を生じるであろう放射線検出素子7の異常状態を積極的に進行させて早期発見を行うことが可能となる。
 そして、後発的に異常となる放射線検出素子7の発生数を低減することができるため、使用開始以降の放射線画像撮影装置1のメンテナンス負担を低減することが可能である。
As described above, in the defective pixel map creation system 200, the abnormality of the output value of each radiation detection element 7 is determined after the aging process is performed on the detection function unit 4A. It becomes possible to detect early by actively proceeding with an abnormal state of the radiation detecting element 7 which will cause an abnormal output later, which is not considered to be.
And since the generation | occurrence | production number of the radiation detection element 7 which becomes abnormal later can be reduced, it is possible to reduce the maintenance burden of the radiographic imaging apparatus 1 after a use start.
 また、検出機能部4Aを収容する恒温槽210を備え、検出機能部4Aに対するエイジング処理を高温状態で行うことができるため、少ない処理繰り返し数でエイジングを効率的に進行させることができ、各放射線検出素子7の異常の発見精度を向上させることが可能である。
 なお、恒温槽210による検出機能部4Aの温度設定については、通常の使用環境温度である常温よりも高ければ良く、前述の例に限定されるものではない。また、設定温度は、放射線画像撮影装置1の複数回の使用時に検出機能部4Aの各構成の発熱により到達する筐体2内の連続使用温度と等しく設定しても良い。
Moreover, since the thermostat 210 which accommodates the detection function part 4A is provided and the aging process with respect to the detection function part 4A can be performed in a high temperature state, the aging can be efficiently advanced with a small number of process repetitions. It is possible to improve the detection accuracy of the abnormality of the detection element 7.
Note that the temperature setting of the detection function unit 4A by the thermostatic chamber 210 is not limited to the above-described example as long as it is higher than the normal temperature that is the normal use environment temperature. Further, the set temperature may be set equal to the continuous use temperature in the housing 2 that is reached by the heat generation of each component of the detection function unit 4A when the radiographic imaging device 1 is used a plurality of times.
 なお、本発明は上記の実施形態及び他の例に限定されず、本発明の趣旨から逸脱しない限り、適宜変更可能であることはいうまでもない。 Note that the present invention is not limited to the above-described embodiment and other examples, and it is needless to say that the present invention can be appropriately changed without departing from the gist of the present invention.
 放射線画像撮影を行う分野(特に医療分野)において利用可能性がある。 It may be used in the field of radiographic imaging (especially in the medical field).
1,100 放射線画像撮影装置
4A 検出機能部
5 走査線
6 信号線
7 放射線検出素子(画素)
17 読み出し回路
22 制御手段
39 アンテナ装置(通信手段)
40記憶手段
50 放射線画像撮影システム
53 無線アンテナ(通信手段)
58 コンソール(外部装置、出力異常判定手段、登録手段)
59 記憶手段
122 制御手段(出力異常判定手段、登録手段)
200 欠陥画素マップ作成システム
210 恒温槽(加温部)
220 欠陥画素マップ作成装置
221 制御手段
B 実写画像データを補正するための暗画像データ
BH1,BH2,BH3,BH4 放射線検出素子の出力異常判定のための暗画像データ
ΔBH,ΔBH2 差分データ
G 画像データ
J 実写画像データ
M 欠陥素子マップ
P 検出部
DESCRIPTION OF SYMBOLS 1,100 Radiation imaging device 4A Detection function part 5 Scan line 6 Signal line 7 Radiation detection element (pixel)
17 Reading circuit 22 Control means 39 Antenna device (communication means)
40 storage means 50 radiographic imaging system 53 wireless antenna (communication means)
58 Console (external device, output abnormality judgment means, registration means)
59 Storage means 122 Control means (output abnormality determination means, registration means)
200 Defect Pixel Map Creation System 210 Constant Temperature Bath (Heating Unit)
220 Defective pixel map creation device 221 Control means B Dark image data BH1, BH2, BH3, BH4 for correcting actual image data Dark image data ΔBH, ΔBH2 for determining an output abnormality of the radiation detection element Difference data G Image data J Real image data M Defect element map P Detector

Claims (14)

  1.  互いに交差するように配設された複数の走査線および複数の信号線と、前記複数の走査線および複数の信号線により区画された各領域に二次元状に配列された複数の放射線検出素子とを備える検出部と、
     前記放射線検出素子から前記信号線を通じて電荷を読み出し、前記放射線検出素子ごとに前記電荷を電気信号に変換してデータとして出力する読み出し回路と、
     放射線が照射される撮影時に前記各放射線検出素子が所定の蓄積時間で蓄積した電荷に基づいて前記読み出し回路が前記データとして実写画像データを出力すると共に、当該撮影に付随して前記放射線の非照射時に前記各放射線検出素子が前記撮影時と同じ蓄積時間で蓄積した電荷に基づいて前記読み出し回路が前記実写画像データを補正するための暗画像データを出力するよう制御する制御手段と、
     外部装置との間でデータを通信する通信手段と、
    を備える放射線画像撮影装置であって、
     前記制御手段は、放射線の非照射時に前記各放射線検出素子が前記撮影時よりも長い蓄積時間で蓄積した電荷に基づいて、前記読み出し回路が放射線検出素子の出力異常判定のための暗画像データを出力するよう制御することを特徴とする
    放射線画像撮影装置。
    A plurality of scanning lines and a plurality of signal lines arranged so as to intersect with each other; a plurality of radiation detecting elements arranged in a two-dimensional manner in each region partitioned by the plurality of scanning lines and the plurality of signal lines; A detector comprising:
    A readout circuit that reads out charges from the radiation detection elements through the signal lines, converts the charges into electrical signals for each radiation detection element, and outputs the data as data.
    The readout circuit outputs actual image data as the data based on the charges accumulated by the respective radiation detection elements at a predetermined accumulation time at the time of imaging in which radiation is irradiated, and non-irradiation of the radiation accompanying the imaging Control means for controlling the readout circuit to output dark image data for correcting the actual captured image data based on the electric charge accumulated by the radiation detecting elements at the same accumulation time as that at the time of imaging.
    A communication means for communicating data with an external device;
    A radiographic imaging device comprising:
    The control means is configured so that the readout circuit generates dark image data for determining an output abnormality of the radiation detection element based on the charge accumulated in each radiation detection element during the non-irradiation with a longer accumulation time than during the imaging. A radiographic imaging apparatus that is controlled to output.
  2.  前記制御手段は、前記各放射線検出素子について、蓄積時間がそれぞれ異なる複数の前記出力異常判定のための暗画像データを前記読み出し回路が出力するよう制御することを特徴とする請求項1記載の放射線画像撮影装置。 2. The radiation according to claim 1, wherein the control unit controls the radiation detection element so that the readout circuit outputs a plurality of dark image data for determining the output abnormality with different accumulation times. Image shooting device.
  3.  前記制御手段は、前記各放射線検出素子について、前記複数の出力異常判定のための暗画像データの内のいずれか二つのデータを差分してなる差分データを求めることを特徴とする請求項1又は2記載の放射線画像撮影装置。 The said control means calculates | requires the difference data formed by subtracting any two data in the said dark image data for said output abnormality determination about each said radiation detection element, or characterized by the above-mentioned. 2. The radiographic imaging apparatus according to 2.
  4.  前記制御手段は、前記各放射線検出素子の前記出力異常判定のための暗画像データを、一定の蓄積時間に基づいて複数回取得すると共にそれらを平均化することで取得することを特徴とする請求項1から3のいずれか一項に記載の放射線画像撮影装置。 The said control means acquires the dark image data for the said output abnormality determination of each said radiation detection element in multiple times based on fixed accumulation time, and acquires them by averaging them. Item 4. The radiographic image capturing device according to any one of Items 1 to 3.
  5.  前記各放射線検出素子について、前記出力異常判定のための暗画像データ又は前記差分データにより、前記各放射線検出素子の出力異常を判定する出力異常判定手段と、
     いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥素子マップと、
     前記出力異常判定手段により出力異常と判定された放射線検出素子について前記欠陥素子マップに登録する登録手段とを備えることを特徴とする請求項1から4のいずれか一項に記載の放射線画像撮影装置。
    For each radiation detection element, output abnormality determination means for determining an output abnormality of each radiation detection element based on dark image data or the difference data for the output abnormality determination,
    A defect element map for storing which radiation detection element has an output abnormality or a position of the radiation detection element to be an output abnormality;
    5. The radiographic imaging apparatus according to claim 1, further comprising: a registration unit that registers, in the defect element map, a radiation detection element that has been determined to have an output abnormality by the output abnormality determination unit. .
  6.  請求項1記載の放射線画像撮影装置と、
     前記放射線画像撮影装置との間でデータを通信する通信手段を備えるコンソールと、
     を備える放射線画像撮影システムであって、
     前記コンソールは、
     前記出力異常判定のための暗画像データから、前記各放射線検出素子の出力異常を判定する出力異常判定手段と、
     いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥素子マップと、
     前記出力異常判定手段により出力異常と判定された放射線検出素子について前記欠陥素子マップに登録する登録手段とを有することを特徴とする放射線画像撮影システム。
    The radiographic imaging device according to claim 1;
    A console comprising communication means for communicating data with the radiographic imaging device;
    A radiographic imaging system comprising:
    The console is
    From the dark image data for the output abnormality determination, output abnormality determination means for determining the output abnormality of each radiation detection element,
    A defect element map for storing which radiation detection element has an output abnormality or a position of the radiation detection element to be an output abnormality;
    A radiographic imaging system, comprising: a registration unit that registers, in the defect element map, a radiation detection element that has been determined to have an output abnormality by the output abnormality determination unit.
  7.  前記放射線画像撮影装置の制御手段は、前記各放射線検出素子について、蓄積時間がそれぞれ異なる複数の前記出力異常判定のための暗画像データを前記読み出し回路が出力するよう制御を行い、
     前記出力異常判定手段は、前記各放射線検出素子について、前記複数の出力異常判定のための暗画像データの内のいずれか二つのデータを差分してなる差分データを求め、当該差分データから前記各放射線検出素子の出力異常を判定することを特徴とする請求項6記載の放射線画像撮影システム。
    The control means of the radiographic imaging apparatus performs control so that the readout circuit outputs a plurality of dark image data for determining the output abnormality with different accumulation times for each radiation detection element,
    The output abnormality determination means obtains difference data obtained by subtracting any two data of the plurality of dark image data for output abnormality determination for each radiation detection element, The radiation image capturing system according to claim 6, wherein an output abnormality of the radiation detection element is determined.
  8.  前記出力異常判定のための暗画像データとして、複数回取得すると共に平均化したものを用いることを特徴とする請求項6又は7記載の放射線画像撮影システム。 The radiographic imaging system according to claim 6 or 7, wherein the dark image data for determining the output abnormality is obtained a plurality of times and averaged.
  9.  互いに交差するように配設された複数の走査線および複数の信号線と前記複数の走査線および複数の信号線により区画された各領域に二次元状に配列された複数の放射線検出素子とを備える検出部と、前記放射線検出素子から前記信号線を通じて電荷を読み出し、前記放射線検出素子ごとに前記電荷を電気信号に変換してデータとして出力する読み出し回路とを備える放射線画像撮影装置について、いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥画素マップを作成する欠陥画素マップ作成方法であって、
     前記複数の放射線検出素子の各々に対する電荷の蓄積と前記読み出し回路による電荷の読み出しとを繰り返し行うエイジングステップと、
     前記エイジングステップの後に、前記各放射線検出素子が、放射線の非照射状態で撮影時よりも長い蓄積時間で電荷を蓄積し、蓄積した電荷から放射線検出素子の出力異常判定のための暗画像データを取得する暗画像データ取得ステップと、
     前記放射線検出素子の出力異常判定のための暗画像データに基づいて、前記各放射線検出素子の出力異常を判定する判定ステップと、
     前記各放射線検出素子の出力異常の判定に基づいて、当該出力異常となる放射線検出素子を登録した前記欠陥画素マップを作成する欠陥画素マップ作成ステップと、
     を備えることを特徴とする放射線画像撮影装置の欠陥画素マップ作成方法。
    A plurality of scanning lines and a plurality of signal lines arranged so as to cross each other, and a plurality of radiation detecting elements arranged in a two-dimensional manner in each region partitioned by the plurality of scanning lines and the plurality of signal lines For any radiographic imaging apparatus comprising: a detection unit that includes: a readout circuit that reads out charges from the radiation detection elements through the signal lines, converts the charges into electrical signals for each radiation detection element, and outputs the signals as data. A defective pixel map creating method for creating a defective pixel map for storing a position of a radiation detecting element in which the radiation detecting element has an output abnormality or an output abnormality,
    An aging step for repeatedly accumulating charges for each of the plurality of radiation detection elements and reading the charges by the readout circuit;
    After the aging step, each of the radiation detection elements accumulates a charge in a longer accumulation time than that at the time of photographing in a non-irradiated state, and dark image data for determining an output abnormality of the radiation detection element is stored from the accumulated charge. A dark image data acquisition step to be acquired;
    A determination step for determining an output abnormality of each radiation detection element based on dark image data for output abnormality determination of the radiation detection element;
    Based on the determination of the output abnormality of each radiation detection element, a defective pixel map creation step for creating the defective pixel map in which the radiation detection element that causes the output abnormality is registered;
    A method for creating a defective pixel map of a radiographic image capturing apparatus.
  10.  前記暗画像データ取得ステップにおいて、前記蓄積時間の長さが異なる二以上の前記出力異常判定のための暗画像データを取得し、
     前記各放射線検出素子について、前記二以上の出力異常判定のための暗画像データの内、いずれか二つの暗画像データについて差分を行う差分ステップを備え、
     前記判定ステップでは、前記蓄積時間の異なる二つの暗画像データの差分から求まる差分データに基づいて、前記各放射線検出素子の出力異常を判定することを特徴とする請求項9記載の放射線画像撮影装置の欠陥画素マップ作成方法。
    In the dark image data acquisition step, two or more dark image data for the output abnormality determination with different accumulation times are acquired,
    For each of the radiation detection elements, a difference step of performing a difference for any two dark image data among the dark image data for the two or more output abnormality determinations,
    The radiographic image capturing apparatus according to claim 9, wherein in the determination step, an output abnormality of each of the radiation detection elements is determined based on difference data obtained from a difference between two dark image data having different accumulation times. Defect pixel map creation method.
  11.  前記エイジングステップは、前記検出部を通常使用環境温度よりも高温の状態に置いて行うことを特徴とする請求項9又は10記載の放射線画像撮影装置の欠陥画素マップ作成方法。 11. The method for creating a defective pixel map of a radiographic imaging apparatus according to claim 9 or 10, wherein the aging step is performed by placing the detection unit at a temperature higher than a normal use environment temperature.
  12.  互いに交差するように配設された複数の走査線および複数の信号線と前記複数の走査線および複数の信号線により区画された各領域に二次元状に配列された複数の放射線検出素子とを備える検出部と、前記放射線検出素子から前記信号線を通じて電荷を読み出し、前記放射線検出素子ごとに前記電荷を電気信号に変換してデータとして出力する読み出し回路とを備える放射線画像撮影装置について、いずれの放射線検出素子が出力異常であるか又は出力異常とする放射線検出素子の位置を記憶する欠陥画素マップを作成する欠陥画素マップを作成する欠陥画素マップ作成システムにおいて、
     前記複数の放射線検出素子の各々に対する電荷の蓄積と前記読み出し回路による電荷の読み出しとを繰り返し行うエイジング制御部と、
     前記電荷の蓄積と前記電荷の読み出しとが繰り返し行われた前記各放射線検出素子が、放射線の非照射状態で撮影時よりも長い蓄積時間で電荷を蓄積し、蓄積した電荷から放射線検出素子の出力異常判定のための暗画像データを取得する暗画像データ取得制御部と、
     前記放射線検出素子の出力異常判定のための暗画像データに基づいて、前記各放射線検出素子の出力異常を判定する判定部と、
     前記各放射線検出素子の出力異常の判定に基づいて、当該出力異常となる放射線検出素子を登録した前記欠陥画素マップを作成する欠陥画素マップ作成部と、
     を備えることを特徴とする放射線画像撮影装置の欠陥画素マップ作成システム。
    A plurality of scanning lines and a plurality of signal lines arranged so as to cross each other, and a plurality of radiation detecting elements arranged in a two-dimensional manner in each region partitioned by the plurality of scanning lines and the plurality of signal lines For any radiographic imaging apparatus comprising: a detection unit that includes: a readout circuit that reads out charges from the radiation detection elements through the signal lines, converts the charges into electrical signals for each radiation detection element, and outputs the signals as data. In a defective pixel map creating system for creating a defective pixel map for creating a defective pixel map for storing a position of a radiation detecting element that is an abnormal output or an abnormal output of the radiation detecting element,
    An aging control unit that repeatedly performs charge accumulation for each of the plurality of radiation detection elements and charge readout by the readout circuit;
    Each of the radiation detection elements in which the charge accumulation and the charge readout are repeatedly performed accumulates charges in a non-radiation state in a longer accumulation time than during imaging, and outputs the radiation detection elements from the accumulated charges. A dark image data acquisition control unit for acquiring dark image data for abnormality determination;
    Based on the dark image data for output abnormality determination of the radiation detection element, a determination unit for determining an output abnormality of each radiation detection element,
    Based on the determination of the output abnormality of each of the radiation detection elements, a defective pixel map creation unit that creates the defective pixel map in which the radiation detection element that causes the output abnormality is registered;
    A defect pixel map creating system for a radiographic image capturing apparatus.
  13.  前記暗画像データ取得制御部が、前記蓄積時間の長さが異なる二以上の前記出力異常判定のための暗画像データを取得し、
     前記各放射線検出素子について、前記蓄積時間の長さが異なる二以上の出力異常判定のための暗画像データの内、いずれか二つの暗画像データについて差分を求める差分算出部を備え、
     前記判定部は、前記蓄積時間の異なる二つの暗画像データの差分から求まる差分データに基づいて、前記各放射線検出素子の出力異常を判定することを特徴とする請求項12記載の放射線画像撮影装置の欠陥画素マップ作成システム。
    The dark image data acquisition control unit acquires two or more dark image data for output abnormality determination with different accumulation times,
    For each of the radiation detection elements, a difference calculation unit for obtaining a difference for any two of the dark image data among the dark image data for two or more output abnormality determinations having different accumulation time lengths,
    The radiographic image capturing apparatus according to claim 12, wherein the determination unit determines an output abnormality of each radiation detection element based on difference data obtained from a difference between two dark image data having different accumulation times. Defective pixel map creation system.
  14.  前記複数の放射線検出素子に対する電荷の蓄積と前記読み出し回路による電荷の読み出しとを繰り返し行う際に、前記検出部を通常使用環境温度よりも高温の状態に維持する加温部を備えることを特徴とする請求項12又は13記載の放射線画像撮影装置の欠陥画素マップ作成システム。 A heating unit is provided that maintains the detection unit at a temperature higher than a normal use environment temperature when repeatedly accumulating charges in the plurality of radiation detection elements and reading out charges by the readout circuit. The defect pixel map production system of the radiographic imaging device of Claim 12 or 13.
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