JP2011156241A - Radiographic imaging device, and radiographic imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiographic imaging device which can remove exactly an offset portion caused by a lag, from image data, when carrying out continuous imaging such as animation radiographing and long radiographing. <P>SOLUTION: The radiographic imaging device 1 includes a plurality of radiation detecting elements 7 arrayed two-dimensionally in each area r partitioned by a plurality of scanning lines 5 and a plurality of signal lines 6 arranged to be crossed each other, a reading circuit 17 equipped with an amplifying circuit 18 for converting a charge accumulated in each radiation detecting element 7 into an output signal V in response to a charge amount Q thereof, and a control means 22 for controlling the reading circuit 17, to perform reading processing of the charge from each radiation detecting element 7, and the control means 22 makes variable a saturated charge amount Qrsat of the reading circuit 17 and a saturated charge amount Qpsat of the radiation detecting element 7, in response to a radiographing mode set before the radiographic imaging, and changes a relative level relation between the saturated charge amount Qrsat of the reading circuit 17 and the saturated charge amount Qpsat of the radiation detecting element 7. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radiographic image capturing apparatus and a radiographic image capturing system, and more particularly to a radiographic image capturing apparatus and a radiographic image capturing system capable of performing continuous imaging.

  A so-called direct type radiographic imaging device that generates electric charges by a detection element in accordance with the dose of irradiated radiation such as X-rays and converts it into an electrical signal, or other radiation such as visible light with a scintillator or the like. Various types of so-called indirect radiographic imaging devices have been developed that convert charges into electromagnetic signals after they have been converted into electromagnetic waves of a wavelength, and then generated by photoelectric conversion elements such as photodiodes in accordance with the energy of the converted and irradiated electromagnetic waves. Yes. In the present invention, the detection element in the direct type radiographic imaging apparatus and the photoelectric conversion element in the indirect type radiographic imaging apparatus are collectively referred to as a radiation detection element.

  This type of radiographic imaging apparatus is known as an FPD (Flat Panel Detector), and conventionally formed integrally with a support base (or a bucky apparatus) (see, for example, Patent Document 1). A portable radiographic imaging device in which an element or the like is housed in a housing has been developed and put into practical use (see, for example, Patent Documents 2 and 3).

  In addition, unlike conventional screen film and CR (Computed Radiography) devices that do not allow over-shooting, there is no need to change the film or photostimulable phosphor sheet for each radiographic image. Alternatively, it is configured such that image data for every several tens of images can be stored in a storage means such as a DRAM (Dynamic RAM) built in the apparatus.

  Therefore, using a radiographic image capturing device, for example, so-called moving image capturing in which a subject (that is, a subject) is continuously irradiated with radiation while gradually changing the direction of the subject (ie, a subject) relative to the radiographic image capturing device. For example, it is possible to perform so-called long photographing in which a wide range of the subject's body is photographed while changing the position of the photographing apparatus (see, for example, Patent Document 4). Note that, hereinafter, a series of radiographic image capturing such as moving image shooting and long-length shooting is collectively referred to as continuous shooting.

  By the way, at the time of radiographic imaging, when radiation is irradiated to such a radiographic imaging device through a subject, an electromagnetic wave converted from the radiation by a radiation detecting element irradiated with the radiation, a scintillator or the like is incident. A charge is generated in the radiation detection element according to the dose of the irradiated radiation, and after imaging, this charge is read out and detected as image data for each radiation detection element.

  Also, in each radiation detection element, so-called dark charges are constantly generated due to thermal excitation of each radiation detection element itself by heat, etc., and at the time of image reading processing for reading image data from each radiation detection element, each radiation detection element Since dark charges are read out in addition to charges that are true image data generated by radiation irradiation from the detection element, the read image data includes an offset due to dark charges.

  Therefore, in order to obtain true image data by subtracting the offset due to dark charges from the read image data, it is formed with a thin film transistor (hereinafter referred to as TFT) or the like at the time of radiographic image capturing. The switch means is turned off for the same amount of time as the charge storage state in each radiation detection element when the switch means of each radiation detection element is turned off, but the radiation imaging apparatus is not irradiated with radiation. In some cases, a so-called offset reading process (also referred to as a dark reading process) is performed in which the radiation image capturing apparatus is left unattended.

  In this offset reading process, the TFT is turned off for the same time as when radiographic images are captured. Therefore, the same amount of dark charge as that accumulated in each radiation detecting element during radiographic image capturing is applied to each radiation detecting element. It can be stored in the image, and by reading it, an offset amount (that is, an offset correction value) due to dark charges superimposed on the true image data can be obtained. Then, true image data can be obtained by subtracting the offset correction value from the read image data.

  That is, for example, as shown in FIG. 20, in order to obtain the offset correction value O, when the TFT is turned off without irradiating the radiation imaging apparatus (see “TFToff” on the left side in the figure), each radiation detection is performed. Dark charges generated in the elements (see da in the figure) start to be accumulated in the respective radiation detection elements from that time, and the charge amount Q in each radiation detection element increases with time. In addition, Qa in the figure is a base charge accumulated in each radiation detection element, but this charge is not read out.

  Then, after the TFT is turned off for the same period of time as radiographic imaging, the TFT is turned on (see “TFTon” in the figure), the offset reading process is started, and the TFT is turned off. Until the image reading process ends (see “TFToff” on the right side of the figure), the charge O indicated by the oblique lines in the figure is read as the offset correction value O.

  Also during radiographic imaging, for example, as shown in FIG. 21, dark charges (see “TFToff” on the left side of the figure) generated in each radiation detection element when the TFT is turned off (see the figure). (See da)) starts to be accumulated in each radiation detection element, and the charge amount Q in each radiation detection element increases with time. When the radiation image capturing apparatus is irradiated with radiation, charges are generated in each radiation detection element during that time, and the charges are also accumulated in each radiation detection element.

After the radiation irradiation is finished, the TFT is turned on (see “TFTon” in the figure), the image reading process is started, the TFT is turned off, and the image reading process is finished (in the figure). (See “TFToff” on the right side), the charge d in the hatched portion in the figure is read as image data d, and the image data d includes the offset correction value O resulting from the dark charge described above. . Therefore, the true image data d ^* generated by radiation irradiation in radiographic imaging is basically
d ^* = d−O (1)
As described above, the offset correction value O can be subtracted from the read image data d.

  However, in the case of continuous shooting such as moving image shooting or long shooting as described above in which a plurality of radiographic images are continuously captured in a short time using a radiographic image capturing apparatus, In addition to the offset correction value O due to the dark charge as described above, the offset Olag due to the so-called lag, which is generated in the same continuous shooting, is superimposed on the image data d read out in the above. It is known that there are cases.

  Further, even if the dark charge remains in each radiation detection element without being read out during the image readout process, the reset process of each radiation detection element is repeated during a short interval between each radiographic image capture in continuous imaging. However, the above lag does not disappear easily even if the reset process of each radiation detection element is repeatedly performed during a short interval, and is offset during the next image reading process. It is known to appear as a minute Olag.

  Then, as shown in FIG. 22, the lag lag remains even if the reset process is repeated after the first imaging, and after the radiation is irradiated in the second imaging, the TFT is turned on and the image is read out. During the period from the start of processing until the TFT is turned off and the image reading process is completed, the charge in the hatched portion d in the figure is read as image data d. Includes the charge indicated by the hatched portion O in the figure as the offset correction value O described above, and also includes the offset Olag due to the lag.

  Similarly, although not shown, for example, when the third shooting is performed, the image data d of the third shooting is caused by the lag generated in the first shooting in addition to the offset correction value O. Not only the offset amount Olag but also the offset amount Olag due to the lag generated in the second shooting is superimposed. Thus, the offset Olag due to the lag generated in the previous imaging is superimposed on the image data read from each radiation detection element in the second and subsequent imaging.

  In addition, it is known that the offset Olag due to the lag increases as the dose of radiation applied to the radiation detection element increases in the imaging performed before the continuous imaging such as movie shooting or long shooting. .

  As described above, when the offset Olag due to the lag generated in the previous radiographic imaging in the series of radiographic imaging performed in the continuous imaging is superimposed on the image data d obtained in the current radiographic imaging, An image obtained by radiographic imaging is in a state in which an afterimage due to lag generated in radiographic imaging before that is reflected in an original image resulting from radiographic imaging this time. For example, in the case of long imaging, an afterimage of the chest image taken before that is reflected in the waist image of the subject imaged in this radiographic imaging.

  For this reason, the obtained radiographic image becomes very difficult to see. For example, when a radiographic imaging device is used to capture a radiographic image for medical use, a doctor who viewed such a radiographic image overlooks the lesion. Or, there is a risk of misdiagnosis if there is a lesion in a non-lesioned portion.

In this way, when performing continuous shooting such as moving image shooting or long shooting using a radiographic image capturing device, the previous image capturing in a series of radiographic image capturing is performed from the image data d obtained in each radiographic image capturing. It is desirable that the offset Olag due to the lag generated in step 1 can be accurately eliminated. And if offset Olag due to lag can be detected,
d ^* = d-O-Olag (2)
By performing this calculation, it is possible to accurately obtain true image data d ^* for each radiographic image capturing.

  Therefore, for example, in Patent Document 5, in a series of radiographic imaging performed in continuous imaging, in the second and subsequent imaging, each radiation detection element is in a stage where radiation is not applied to the apparatus before imaging is performed. A technique is described in which afterimage data remaining in is read out and an offset Olag due to a lag generated by photographing performed before that is calculated.

JP-A-9-73144 JP 2006-058124 A JP-A-6-342099 JP 2007-260027 A JP 2009-204310 A

  However, in the technique disclosed in Patent Document 5, it may not always be easy to construct an interface between a radiation generation apparatus that emits radiation and a radiographic imaging apparatus. There is a possibility that radiation is emitted from the radiation generation apparatus while the imaging apparatus is performing the afterimage data reading process.

Therefore, in each radiographic image capturing in a series of radiographic image capturing performed in continuous imaging such as moving image capturing or long-length capturing, the size of the image data d itself obtained by the radiographic image capturing performed before the current radiographic image capturing is performed. Then, the size of the offset Olag due to the lag superimposed on the image data d obtained by the current radiographic image capturing is estimated, and the offset Olag due to the estimated lag is substituted into the above equation (2), It may be configured to calculate true image data d ^* for each radiographic image capturing in imaging.

  However, such a configuration has the following problems.

  The radiographic imaging apparatus is configured to read out charges accumulated in a radiation detection element such as a photodiode with a readout circuit including an amplifier circuit configured with a charge amplifier circuit as shown in FIG. 23, for example. . In this case, the amplifier circuit Amp is composed of an operational amplifier Oa and a capacitor Con having a capacitance Cf connected in parallel thereto, and an output signal V having a voltage value corresponding to the charge amount Q stored in the capacitor Con is downstream. It is designed to output. Hereinafter, the capacitance Cf of the capacitor Con in the amplifier circuit Amp configured by the charge amplifier circuit is referred to as a charge amplifier capacitance Cf. The output signal V corresponds to the image data d and the offset correction value O described above.

  On the other hand, in the photodiode, as shown in the upper graph of FIG. 24, the irradiation radiation dose I (including the case where the irradiation radiation is converted into electromagnetic waves by a scintillator or the like. The same applies to the following). The accumulated charge quantity Q increases almost linearly, but the accumulated charge quantity Q is saturated when the dose I of the irradiated radiation is very strong. Hereinafter, the saturated charge amount Q is referred to as a saturated charge amount Qpsat of the radiation detection element. In each graph of FIG. 24, the radiation dose I on the horizontal axis, the charge amount Q on the vertical axis, and the output signal V are represented on a log scale.

  For example, when a radiographic image capturing apparatus is used as a medical radiographic image capturing apparatus that captures a lesioned part or the like of a patient, the lesioned part or the like of a patient whose subject is the radiation emitted from the radiation generating apparatus. It is photographed in an image area that has passed through the body and the like, and has been absorbed and scattered by the patient's body and then arrived at the radiographic apparatus. In the graph shown in the upper side of FIG. 24, the image is taken in a region of the radiation dose I such that the charge amount Q accumulated in the radiation detection element increases or decreases almost linearly.

  Therefore, in the readout circuit of the radiographic imaging apparatus, sufficient quantization can be performed on the region of the radiation dose I corresponding to the charge amount Q in such a range that increases or decreases substantially linearly. In addition, as shown in the upper graph of FIG. 24, the maximum value of the charge amount Q that can be detected by the readout circuit is normally set to be smaller than the saturation charge amount Qpsat of the original radiation detection element. Yes. Hereinafter, the maximum value of the charge amount Q that can be detected by the readout circuit is referred to as a saturation charge amount Qrsat of the readout circuit.

  Since the readout circuit is configured in this way, as shown in the lower graph of FIG. 24, the amount of charge Q in the radiation detection element is as long as the dose I of the irradiation beam irradiated to the radiation detection element is small. The output signal V from the readout circuit corresponding to the charge amount Q read from the radiation detection element increases substantially linearly with respect to the radiation dose I.

  However, the dose I of radiation applied to the radiation detection element increases, and the charge amount Q accumulated in the radiation detection element reaches the saturation charge amount Qrsat of the readout circuit to output the maximum value Vmax of the output signal V. Then, the readout circuit is constant even if the amount of radiation I to be irradiated increases more than that and the amount of charge Q accumulated in the radiation detection element increases beyond the saturation charge amount Qrsat of the readout circuit. Only the maximum value Vmax of the output signal V, that is, the output signal V is output.

  As described above, the offset Olag due to the lag should increase as the dose I of the radiation applied to the radiation detection element increases, but the charge amount Q accumulated in the radiation detection element as described above increases. In the region of the radiation dose I that is equal to or higher than the saturation charge amount Qrsat of the readout circuit, the output signal V from the readout circuit, that is, the image data d becomes a constant value (that is, the maximum value Vmax of the output signal V). The value does not increase.

  Therefore, in a series of radiographic imaging performed in continuous imaging, if the image data d obtained in the previous imaging is the maximum value Vmax of the output signal V from the readout circuit or a value very close thereto, There arises a problem that the size of the offset Olag due to the lag superimposed on the image data d obtained by the current radiographic imaging cannot be estimated from the size of the image data d itself.

  In particular, when intense radiation having a dose I in such a region is irradiated, the charge amount Q accumulated in the radiation detection element becomes equal to or greater than the saturation charge amount Qrsat of the readout circuit, and radiographic imaging from the next time onward. It remains as a big lag. If the offset Olag due to the lag cannot be accurately excluded from the image data d, the previous radiographic imaging is included in the radiographic image generated based on the image data d that cannot completely eliminate the offset Olag due to the lag. Afterimages appear, and problems such as oversight of a lesion as described above occur.

Therefore, for radiographic imaging devices and radiographic imaging systems, a series of images are taken at short intervals, such as continuous shooting such as movie shooting and long shooting, and even if the lag is likely to remain, It is desirable that the offset image Olag due to the lag can be accurately excluded from the data d and the true image data d ^* for each radiographic image can be obtained accurately.

  The present invention has been made in view of the above-described problems, and radiographic imaging capable of accurately eliminating an offset due to lag from image data when performing continuous imaging such as movie shooting or long shooting. An object is to provide a device and a radiographic imaging system using the same.

In order to solve the above-described problem, the radiographic imaging device of the present invention includes
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 readout circuit including an amplification circuit that converts the charge accumulated in each radiation detection element into an output signal corresponding to the amount of the charge;
Control means for controlling at least the readout circuit to perform readout processing of the charge from each of the radiation detection elements;
With
The control means varies the saturation charge amount of the readout circuit and / or the saturation charge amount of the radiation detection element according to the imaging mode set before radiographic imaging, and the saturation charge amount of the readout circuit And the relative magnitude relationship between the saturation charge amount of the radiation detecting element is changed.

Moreover, the radiographic imaging device of the present invention is
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 readout circuit including an amplification circuit that converts the charge accumulated in each radiation detection element into an output signal corresponding to the amount of the charge;
Control means for controlling at least the readout circuit to perform readout processing of the charge from each of the radiation detection elements;
A sensor panel comprising:
Moving means for relatively displacing the positional relationship between the sensor panel and the subject;
With
The control means varies the saturation charge amount of the readout circuit and / or the saturation charge amount of the radiation detection element according to the imaging mode set before radiographic imaging, and the saturation charge amount of the readout circuit And the magnitude relation between the saturation charge amount of the radiation detecting element is changed.

Moreover, the radiographic imaging system of the present invention is
A radiographic imaging apparatus of the present invention comprising a communication means capable of transmitting and receiving information;
A radiation generator comprising a radiation source for irradiating the radiation imaging apparatus with radiation;
A console that calculates true image data for each of the radiation detection elements based on the image data transmitted from the radiation imaging apparatus and the offset correction value;
With
The console is
When the image data and the offset correction value are obtained in the normal imaging mode, the offset correction value is subtracted from the image data to calculate true image data for each radiation detection element. And
In the case where the image data and the offset correction value are obtained in the continuous imaging mode, in the continuous imaging, the radiation detection element in the radiographic imaging before the radiographic imaging in which the image data to be processed is obtained. Estimate the dose of radiation irradiated to the radiation detection element from the image data obtained for, estimate the offset due to the lag superimposed on the image data to be processed, and read the offset from the image data to be processed Subtracting the offset correction value read out in step 1 and the offset due to the lag to calculate true image data for each of the radiation detection elements.

  According to the radiographic imaging apparatus and radiographic imaging system of the present invention, the saturation charge amount Qrsat of the readout circuit and the saturation charge amount Qpsat of the radiation detection element or both can be changed according to the set imaging mode. Since the relative magnitude relationship between the saturation charge amount Qrsat of the readout circuit and the saturation charge amount Qpsat of the radiation detection element is changed, in the normal imaging mode in which normal single radiographic imaging is performed, the readout circuit In a state in which the saturation charge amount Qrsat is relatively smaller than the saturation charge amount Qpsat of the radiation detection element, it is possible to obtain normal image data by performing normal radiographic imaging by a known method, and based on the image data. A radiographic image can be accurately generated.

  Further, in a continuous imaging mode in which a series of radiographic images are taken continuously at a relatively short interval, such as moving image shooting and long-time shooting, the saturation charge amount Qrsat of the readout circuit is relatively larger than the saturation charge amount Qpsat of the radiation detection element. As shown in the lower graph of FIG. 15 and the lower graph of FIG. 19 described later, the output is output from the readout circuit in accordance with the dose I of the radiation irradiated to the radiation detection element. The output signal V, that is, the image data d, falls within the maximum value Vmax of the output signal V, and the radiation dose I and the output signal V from the readout circuit can be associated one-to-one.

  For this reason, it is possible to accurately estimate the dose I of the radiation applied to the radiation detection element 7 at that time from the image data d obtained in the previous radiographic imaging, and the offset due to the lag generated in the previous radiography. Olag can be accurately estimated. Therefore, by subtracting the offset amount Olag due to the lag accurately estimated from the image data d, it becomes possible to accurately eliminate the offset amount Olag due to the lag from the image data d. However, it is possible to accurately prevent the occurrence of such a phenomenon.

It is a perspective view which shows the structure of the radiographic imaging apparatus which concerns on each embodiment. It is sectional drawing which follows the XX line in FIG. It is a top view which shows the structure of the board | substrate of the sensor panel of a radiographic imaging apparatus. 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 the sensor panel of FIG. It is sectional drawing which follows the YY line in FIG. It is a side view explaining the sensor panel formed by attaching COF, a PCB board, etc. to a board. It is a block diagram showing the equivalent circuit of the sensor panel of a radiographic imaging apparatus. It is a block diagram showing the equivalent circuit about 1 pixel which comprises the detection part of a sensor panel. It is a timing chart which shows an example of the timing which switches the voltage applied to each scanning line between ON voltage and OFF voltage in the reset process of each radiation detection element. It is a timing chart which shows the timing which switches the voltage applied to each scanning line between an ON voltage and an OFF voltage in an image reading process and an offset reading process. It is a figure which shows the whole structure of the radiographic imaging system which concerns on each embodiment. (A) is a figure which shows the structure of an operation switch, (B) is a state which the button part was half-pressed, (C) is a figure explaining the state by which the button part was fully pressed. It is the schematic which shows the structure of the elongate imaging device which concerns on each embodiment. It is the schematic which shows another structural example of a elongate imaging device. The upper graph is a graph for explaining that the saturation charge amount of the readout circuit is varied in the first embodiment, and the lower graph is a graph for explaining that the output signal from the readout circuit is less than the maximum value. is there. It is a timing chart showing each timing of reception of an irradiation start signal, reset processing for one surface, transmission of an interlock release signal, and irradiation of radiation. It is a timing chart showing the procedure of processing in continuous photography mode. It is a figure which shows the example of the table which defined the relationship between the dose I of the irradiated radiation, and the offset part by the lag after predetermined time. The upper graph is a graph for explaining that the saturation charge amount of the radiation detection element is varied in the second embodiment, and the lower graph is a graph for explaining that the output signal from the readout circuit is less than the maximum value. It is. It is a graph explaining the offset correction value read by the dark charge which generate | occur | produces and accumulate | stores in each radiation detection element, and an offset correction process. It is a graph explaining the change of the electric charge amount in each radiation detection element at the time of radiographic imaging, the image data read by image read-out processing, and the offset correction value contained in it. It is a graph explaining the lag remaining after radiographic imaging, the image data read by the image reading process, and the offset correction and the offset due to the lag included therein. It is an equivalent circuit diagram of the amplifier circuit comprised with the charge amplifier circuit. The upper graph shows the relationship between the amount of charge in normal imaging and the saturation charge amount of the radiation detection element and readout circuit, and the lower graph shows that the output signal from the readout circuit is constant above a predetermined dose of radiation. It is a graph explaining what becomes.

  Embodiments of a radiographic imaging apparatus and a radiographic imaging system according to the present invention will be described below with reference to the drawings.

[First Embodiment]
[Configuration of Radiation Imaging System]
The above-described radiographic image capturing apparatus that performs long imaging for capturing a wide range of the subject's body while changing the position of the radiographic image capturing apparatus with respect to the subject will be described later. A radiographic image capturing apparatus capable of capturing a moving image that is captured while changing the orientation of a subject as a subject with respect to the radiographic image capturing apparatus will be described.

  In the following description, a radiographic imaging apparatus capable of performing long imaging with a sensor panel moving means as described later is distinguished from a general radiographic imaging apparatus without a moving means. Is called a long photographing device.

  Also, in the following, a radiographic imaging apparatus that performs continuous imaging such as moving image shooting and long shooting 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. Although the case of a so-called indirect type radiographic imaging apparatus will be described, the present invention can also be applied to a direct type radiographic imaging apparatus.

  Furthermore, in the following, a case where the radiographic image capturing apparatus that can perform moving image capturing and can be used for long-length capturing is described as being portable, a so-called installation formed integrally with a support stand or the like. The present invention is also applied to a radiographic imaging apparatus of a type.

  FIG. 1 is an external perspective view of a radiographic imaging apparatus according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line XX of FIG. As shown in FIGS. 1 and 2, the radiographic imaging apparatus 1 according to the present embodiment is configured by housing a sensor panel Sp including a scintillator 3, a substrate 4, and the like in a housing 2.

  The housing 2 is formed of a material such as a carbon plate or plastic that at least the radiation incident surface R transmits radiation. 1 and 2 show a case in which the housing 2 is a so-called lunch box type formed by the frame plate 2A and the back plate 2B. However, the housing 2 is integrally formed in a rectangular tube shape. It is also possible to use a so-called monocoque type.

  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. In the present embodiment, communication means for transmitting / receiving information such as image data d to / from an external device such as a console 58 (see FIG. 11) described later in a wireless manner is provided on the side surface of the lid member 38. An antenna device 39 is embedded.

  The installation position of the antenna device 39 is not limited to the side surface portion of the lid member 38, and the antenna device 39 can be installed at an arbitrary position of the radiographic image capturing apparatus 1. The number of antenna devices 39 to be installed is not limited to one, and a plurality of antenna devices 39 may be provided. Furthermore, information such as image data d can also be configured to be transmitted / received to / from an external device in a wired manner. In this case, for example, as a communication means, a LAN (Local Area Network) cable, USB ( (Universal Serial Bus) A connection terminal or the like for connecting a cable or the like is provided on the side surface of the radiation image capturing apparatus 1 or the like.

  As shown in FIG. 2, a base 31 is disposed inside the housing 2 via a lead thin plate (not shown) on the lower side of the substrate 4 of the sensor panel Sp. A PCB substrate 33, a buffer member 34, and the like on which are disposed are mounted. 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.

  The scintillator 3 is attached to a detection unit P, which will be described later, of the substrate 4. As the scintillator 3, for example, a scintillator 3 that has a phosphor as a main component and converts it into an electromagnetic wave having a wavelength of 300 to 800 nm, that is, an electromagnetic wave centered on visible light when it receives incident radiation, is used.

  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.

  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.

  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 switch means, 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 a turn-on voltage is applied to the connected scanning line 5 by the scanning drive means 15 described later, and is applied to the gate electrode 8g, and is stored in the radiation detection element 7. The electric charge that is present is emitted to the signal line 6. Further, the TFT 8 is turned off when the off voltage is applied to the connected scanning line 5 and the off voltage is applied to the gate electrode 8g, and the emission of the charge from the radiation detecting 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.

  Here, the structure of the radiation detection element 7 and the TFT 8 in this embodiment will be briefly described with reference to the cross-sectional view shown in FIG. FIG. 5 is a cross-sectional view taken along line YY 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 silicon nitride (laminated on the gate electrode 8g and the surface 4a). The first electrode 74 of the radiation detecting element 7 is connected to the upper portion of the gate electrode 8g on the gate insulating layer 81 made of SiN _x ) or the like via the semiconductor layer 82 made of hydrogenated amorphous silicon (a-Si) or the like. The formed source electrode 8s and the drain electrode 8d 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 (SiN _x ) 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.

  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.

  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.

  At the time of radiographic imaging, radiation enters from the radiation incident surface R of the housing 2 of the radiographic imaging apparatus 1 and is converted into electromagnetic waves such as visible light by the scintillator 3, and the converted electromagnetic waves are irradiated from above in the figure. Then, the electromagnetic wave reaches the i layer 76 of the radiation detection element 7, and electron-hole pairs are generated in the i layer 76. In this way, the radiation detection element 7 converts the electromagnetic waves irradiated from the scintillator 3 into electric charges.

  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.

A bias line 9 for applying a bias voltage Vbias 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 A second passivation layer 79 made of silicon nitride (SiN _x ) or the like is covered from above.

  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.

  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 Film) 12 in which a chip such as a gate IC 12 a constituting a gate driver 15 b of the scanning drive unit 15 described later is formed on a film. They are connected via an anisotropic conductive adhesive material 13 such as an anisotropic conductive adhesive film or an anisotropic 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. In the present embodiment, the sensor panel Sp of the radiographic image capturing apparatus 1 is formed as described above. In FIG. 6, illustration of the electronic component 32 and the like is omitted.

  Here, the circuit configuration of the sensor panel Sp of the radiation image capturing apparatus 1 will be described. FIG. 7 is a block diagram showing an equivalent circuit of the sensor panel Sp of the radiographic image capturing apparatus 1 according to the present embodiment, and FIG. 8 is a block showing an equivalent circuit for one pixel constituting the detection unit P of the sensor panel Sp. FIG.

  As described above, each radiation detection element 7 of the detection unit P of the sensor panel Sp has the bias line 9 connected to the second electrode 78, and each bias line 9 is bound to the connection 10 to be the bias power supply 14. It is connected to the. The bias power supply 14 applies a bias voltage Vbias 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 the bias voltage Vbias applied from the bias power source 14 to each radiation detection element 7.

  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 applies 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 Vbias 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 the gate driver 15b of the scanning driving means 15 to be 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 means 15 is a power supply circuit 15a that supplies an on voltage and an off voltage to the gate driver 15b via the wiring 15c, and a voltage applied to each line L1 to Lx of the scanning line 5 between the on voltage and the off voltage. A gate driver 15b that switches between the on state and the off state of each TFT 8 is provided.

  Then, the scanning drive unit 15 performs reset processing of each radiation detection element 7 that discharges charges remaining in each radiation detection element 7, image read processing for reading image data d from each radiation detection element 7, and the like. When a trigger signal is received from the control means 22 to be described later, switching between the on-voltage and the off-voltage of the voltage applied to each line L1 to Lx of the scanning line 5 from the gate driver 15b is started.

  In the present embodiment, when the scanning drive unit 15 receives the trigger signal from the control unit 22 during the reset process of each radiation detection element 7, for example, as shown in FIG. 9, the scan drive unit 15 applies the trigger signal from the gate driver 15b. The lines L1 to Lx of the scanning line 5 for switching the voltage between the on voltage and the off voltage are sequentially switched to perform the reset process Rm for one surface, and the reset process Rm for the one surface is repeatedly performed as necessary. The reset processing of each radiation detection element 7 is performed while adjusting them. In addition, in the reset process of each radiation detection element 7, for example, the reset process is performed by simultaneously applying the on-voltage to all the lines L <b> 1 to Lx of the scan line 5 from the gate driver 15 b of the scan drive unit 15. It is also possible to configure so that

  In the present embodiment, the scanning drive unit 15 receives the trigger signal from the control unit 22 during the image reading process or the offset reading process described later, and applies it from the gate driver 15b as shown in FIG. The radiation detection elements connected to the lines L1 to Lx of the scanning line 5 through the TFTs 8 by sequentially switching the lines L1 to Lx of the scanning line 5 for switching the voltage to be switched between the on voltage and the off voltage. 7, the image data d and the offset correction value O are read out.

  As shown in FIGS. 7 and 8, each signal line 6 is connected to each readout circuit 17 formed in the readout IC 16. In the present embodiment, 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 and a correlated double sampling circuit 19. An analog multiplexer 21 and an A / D converter 20 are further provided in the reading IC 16. 7 and 8, the correlated double sampling circuit 19 is represented as CDS. In FIG. 8, the analog multiplexer 21 is omitted.

  In the present embodiment, the amplifier circuit 18 is configured by a charge amplifier circuit, and is configured by connecting an operational amplifier 18a, capacitors C1 to C4 connected in parallel to the operational amplifier 18a, and a charge reset switch Sw1. . The amplifier circuit 18 is connected to a power supply unit 18b for supplying power to the charge amplifier circuit 18a.

Further, the signal line 6 is connected to the inverting input terminal on the input side of the operational amplifier 18 a of the amplifier circuit 18, and the reference potential V ₀ is applied to the non-inverting input terminal on the input side of the amplifier circuit 18. ing. Note that the reference potential V ₀ is set to an appropriate value.

  The charge reset switch Sw <b> 1 of the amplifier circuit 18 is connected to the control unit 22 and is controlled to be turned on / off by the control unit 22. When the charge reset switch Sw1 is turned off and the TFT 8 of the radiation detection element 7 is turned on at the time of image readout processing or offset readout processing from each radiation detection element 7, the radiation detection element 7 emits light. The charged charge Q flows into the capacitors C1 to C4 via the signal line 6 and is accumulated, so that the voltage value V corresponding to the accumulated charge amount Q, that is, the output signal V is output from the output side of the operational amplifier 18a. It has become.

  In this way, the amplifier circuit 18 converts the charge amount Q output from each radiation detection element 7 into a charge voltage and outputs an output signal value V corresponding to the charge amount Q. When the charge reset switch Sw1 is turned on, the input side and the output side of the amplifier circuit 18 are short-circuited, and the charge Q accumulated in the capacitors C1 to C4 is discharged to reset the amplifier circuit 18. It is like that. 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.

  Switches Sw 2 to Sw 4 are connected in series to the capacitors C 2 to C 4 of the amplifier circuit 18, respectively, and on / off of the switches Sw 2 to Sw 4 is controlled by the control means 22. As will be described later, in the present embodiment, the control unit 22 changes the charge amplifier capacitance Cf by switching the switches Sw2 to Sw4 that are turned on in the normal shooting mode and the continuous shooting mode, respectively. It has become. In the present embodiment, the charge amplifier capacitance Cf corresponds to the total value of the capacitances of the capacitor C and the capacitor C1 corresponding to the switch Sw that is turned on among the capacitors C2 to C4.

  When the image reading process or the offset reading process is performed from each radiation detection element 7, the switches Sw <b> 2 to Sw <b> 4 in which the charge Q emitted from each radiation detection element 7 is turned on among the capacitor C <b> 1 and the switches Sw <b> 2 to Sw <b> 4. Are distributed and accumulated in the capacitors C2 to C4 corresponding to.

  Note that a switch may be connected to the capacitor C1 in series. Further, as the capacitors C1 to C4, for example, if capacitors having capacitances of 0.5 [pF], 0.5 [pF], 1 [pF], and 2 [pF] are used, the switches Sw2 to Sw4 are turned on / off. By switching, the charge amplifier capacitance Cf can be set from 0.5 [pF] to 4 [pF] in increments of 0.5 [pF].

  A correlated double sampling circuit (CDS) 19 is connected to the output side of the amplifier circuit 18. In this embodiment, the correlated double sampling circuit 19 has a sample and hold function. The sample and hold function in the correlated double sampling circuit 19 is turned on / off by a pulse signal transmitted from the control means 22. To be controlled.

  Then, the control means 22 controls the amplification circuit 18 and the correlated double sampling circuit 19 in the image reading process and the offset reading process from each radiation detecting element 7, and the electric charges released from each radiation detecting element 7 are controlled. Charge voltage conversion is performed by the amplifier circuit 18, and the output signal V subjected to charge voltage conversion is sampled by the correlated double sampling circuit 19 and output to the downstream side as image data d or an offset correction value O.

  The output signal V output from the correlated double sampling circuit 19, that is, the image data d and the offset correction value O of each radiation detection element 7 are transmitted to the analog multiplexer 21 (see FIG. 7), and sequentially A / D from the analog multiplexer 21. It is transmitted to the converter 20. Then, it is digitized sequentially by the A / D converter 20 and outputted to the storage means 40 so as to be stored in sequence.

  The image data d and the offset correction value O read from each radiation detection element 7 are stored in an image storage area (not shown) of the storage means 40 according to an instruction of a memory controller (not shown) controlled by the control means 22. It is like that.

  The control means 22 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface connected to the bus, an FPGA (Field Programmable Gate Array), or the like (not shown). It is configured. It may be configured by a dedicated control circuit. And the control means 22 controls operation | movement etc. of each member of the radiographic imaging apparatus 1. Further, as shown in FIG. 7 and the like, the control means 22 is connected with a storage means 40 composed of a DRAM or the like.

  In the present embodiment, the above-described antenna device 39 is connected to the control unit 22, and each member such as the detection unit P, the scanning drive unit 15, the readout circuit 17, the storage unit 40, the bias power supply 14, and the like. A battery 41 for supplying electric power is connected. 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.

  As described above, the control unit 22 controls the bias power supply 14 to set the bias voltage Vbias applied from the bias power supply 14 to each radiation detection element 7, or the charge reset switch Sw <b> 1 of the amplifier circuit 18 of the readout circuit 17. Various processes such as controlling the on / off of the sample and hold function and controlling the on / off of the sample and hold function by transmitting a pulse signal to the correlated double sampling circuit 19 are executed.

  In addition, the control unit 22 performs any processing on the scanning driving unit 15 at the time of reset processing of each radiation detection element 7 or at the time of image reading processing from each radiation detection element 7 after radiographic imaging. A signal for instructing these is transmitted as a trigger signal for starting these processes. As a signal for instructing the process, a different signal is transmitted in each of the above processes.

  When a signal instructing processing is received as a trigger signal from the control unit 22, the scanning driving unit 15 performs the reset processing of each radiation detection element 7 at the timing shown in FIG. At the time of the reading process, for example, at the timing shown in FIG. 10, the voltage applied from the gate driver 15b to each of the lines L1 to Lx of the scanning line 5 is switched between the on voltage and the off voltage, and the on voltage is applied. The lines L1 to Lx of the line 5 are sequentially switched.

  Further, as described above, in the present embodiment, the control unit 22 turns on the amplifier circuit 18 of the readout circuit 17 when the normal shooting mode is set and when the continuous shooting mode is set. The switches Sw2 to Sw4 are switched to change and set the charge amplifier capacitance Cf. In this regard, the configuration of the radiographic image capturing system 50 and the radiographic image capturing apparatus that performs long imaging (that is, the radiographic image capturing apparatus) The configuration of the above-described long photographing apparatus 100 will be described later.

[Configuration of radiation imaging system]
FIG. 11 is a diagram illustrating an overall configuration of the radiographic image capturing system according to the present embodiment. As shown in FIG. 11, the radiographic imaging system 50 includes, for example, an imaging room R1 that irradiates radiation and images a subject (part of the patient's imaging target) that is a part of a patient (not shown), and a radiographer or the like. The anterior chamber R2 where the operator performs various operations such as control of the start of radiation applied to the subject, and the outside thereof are arranged.

  In the radiographing room R1, a bucky device 51 that can be loaded with the radiographic imaging device 1 described above, a radiation source 52 that includes an X-ray tube (not shown) that generates radiation to irradiate a subject, and a radiation generation device 55 that controls the radiation source In addition, when the radiographic image capturing apparatus 1 and the radiation generating apparatus 55 and the console 58 communicate wirelessly, a base station 54 provided with a wireless antenna 53 that relays these communications is provided.

  11 shows a case where the portable radiographic imaging device 1 is used by being loaded into the cassette holding part 51a of the bucky device 51. However, as described above, the radiographic imaging device 1 is used as the bucky device 51. Or may be formed integrally with a support base or the like. Further, as described above, when communication between the radiographic imaging apparatus 1 and an external apparatus is performed via a cable such as a LAN cable, these cables are connected to the base station 54 as shown in FIG. It is also possible to configure such that information such as data can be transmitted / received by cable communication via a cable or the base station 54.

  The base station 54 is connected to the radiation generating device 55 and the console 58, and signals for LAN communication when transmitting information between the radiographic image capturing device 1 and the console 58 are transmitted to the base station 54. Is converted into a signal for transmitting information to and from the radiation generating device 55, and a converter (not shown) that performs the reverse conversion is incorporated.

  In the present embodiment, the front room R2 is provided with an operation console 57 for the radiation generating device 55. The operation console 57 is operated by an operator such as a radiologist to transmit radiation to the radiation generating device 55. An exposure switch 56 for instructing the start of irradiation is provided.

  For example, as shown in FIG. 12A, the exposure switch 56 includes a rod-shaped button portion 56a having a predetermined stroke, and a housing that supports the button portion 56a so as to be movable in the stroke direction indicated by an arrow S in the drawing. It is comprised with the body part 56b. The button part 56a of the exposure switch 56 includes, for example, a cylindrical part 56a1 protruding upward from the casing part 56b and a columnar part 56a2 protruding further upward from the inside thereof.

  Then, as shown in FIG. 12B, when the column portion 56a2 is pushed in the stroke direction S up to the upper end portion of the cylindrical portion 56a1 (that is, when a so-called half-press operation is performed), the exposure switch 56 is operated. An activation signal is transmitted to the radiation generator 55 via the table 57. Upon receiving this activation signal, the radiation generating device 55 places the radiation source 52 in a standby state by starting rotation of the anode of the X-ray tube of the radiation source 52.

  Further, as shown in FIG. 12C, when both the cylindrical portion 56a1 and the columnar portion 56a2 of the exposure switch 56 are pushed to the upper end portion of the housing portion 56b (that is, when a so-called full pushing operation is performed). The exposure switch 56 transmits an irradiation start signal to the radiation generator 55 via the console 57.

  When the radiation generation device 55 receives this irradiation start signal from the exposure switch 56, the radiation generation device 55 transmits the irradiation start signal to the radiographic imaging device 1 via the base station 54 by a wireless method or a wired method. In this embodiment, when receiving the interlock release signal transmitted from the radiographic imaging apparatus 1 via the base station 54 as described later, the radiation generator 55 receives the X-ray tube from the radiation source 52. It is designed to emit radiation.

  In addition to this, the radiation generating device 55 moves the radiation source 52 to a predetermined position so that the radiation image capturing device 1 loaded in the designated bucky device 51 can be appropriately irradiated with radiation, or the radiation direction thereof. Adjusting a diaphragm or a collimator (not shown) so that the radiation is irradiated in a predetermined region of the radiographic imaging apparatus 1, or adjusting the radiation source 52 so that an appropriate dose of radiation is irradiated. Various controls such as adjustment are performed on the radiation source 52. In addition, you may comprise so that operators, such as a radiographer, may perform these processes manually.

  In addition, the radiation generator 55 irradiates the radiation from the radiation source 52 by, for example, stopping the X-ray tube of the radiation source 52 when a predetermined time has elapsed from the start of radiation irradiation from the radiation source 52. Is supposed to stop.

  The configuration and the like of the radiographic image capturing apparatus 1 are as described above. However, in the present embodiment, the radiographic image capturing apparatus 1 may be used by being mounted on the bucky device 51 as described above. 51 is not loaded and can be used alone.

  That is, the radiation image photographing apparatus 1 is disposed on the upper surface side in a single state, for example, in a bed provided in the photographing room R1 or in a bucky device 51B for lying position photographing 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 source 52B or the like via a subject.

  In the present embodiment, the radiographic image capturing apparatus 1 is loaded from the radiation source 52 of the radiation generating apparatus 55 with respect to the radiographic image capturing apparatus 1 while being loaded on the bucky apparatus 51 or placed on the bed. The subject can be continuously photographed by continuously irradiating radiation while changing the orientation of the body of the subject (not shown) that is the subject with respect to the irradiation direction of the radiation, or without changing the orientation or the like. It has become.

  In the present embodiment, the image data d is processed based on the image data d transmitted from the radiation image capturing apparatus 1, and is configured by a computer or the like that can generate a final radiation image. A console 58 is provided outside the imaging room R1 and the front room R2. It is also possible to configure the console 58 so as to be provided, for example, in the front chamber R2. In addition, the console 58 is connected to or includes a storage means 59 composed of an HDD (Hard Disk Drive) or the like.

  For example, a preview image based on the image data d acquired by radiographic imaging is displayed on the console 58, or the radiographic imaging apparatus 1 is set between a wake-up state and a sleep state. Or a function that allows an operator such as a radiographer to create or select imaging order information that represents the contents of radiographic imaging performed in the imaging room R1. It is also possible to configure so that it is configured appropriately.

[Configuration of long-length imaging device]
In addition, the radiographic image capturing apparatus 100 that performs long-length imaging in which, for example, a wide range of the subject's body is imaged while the positional relationship between the sensor panel Sp and the subject being the subject is relatively displaced in the imaging room R1, That is, it is possible to provide the long photographing apparatus 100.

  For example, as shown in FIG. 13, the long photographing apparatus 100 includes a sensor panel Sp, and a moving unit 101 that relatively displaces the positional relationship between the sensor panel Sp and the subject Hu. In the present embodiment, the long imaging device 100 is configured to move the sensor panel Sp housed inside the support 102. For example, the portable radiographic imaging device 1 described above is used. The radiographic image capturing apparatus 1 may be configured to be mounted on the long image capturing apparatus 100 and moved.

  The configuration of the sensor panel Sp is the same as that described in the configuration of the radiation image capturing apparatus 1 described above, and the description thereof is omitted. Hereinafter, each functional unit of the sensor panel Sp will be described using the same reference numerals as those used in the description of the radiographic image capturing apparatus 1 described above.

  In the present embodiment, the sensor panel Sp is housed integrally in the support body 102. The support 102 has, for example, a length longer than that of a general adult, and the moving unit 101 is used to move the sensor panel Sp along the longitudinal direction (the direction of the arrow shown in FIG. 13). A moving mechanism 101a and a moving mechanism control means 101b are provided.

  The moving mechanism 101a includes a motor or the like (not shown). Further, the moving mechanism control means 101b controls the start and stop of the moving mechanism 101a, and controls the moving mechanism 101a to move the sensor panel Sp so that it is within the photographing target range of the subject Hu. The positional relationship between the sensor panel Sp and the subject Hu is relatively displaced. Although the shooting target range of the subject Hu is different for each shooting, the moving unit 101 can move the sensor panel Sp within a range from a general adult's head to the tip of the foot so that any shooting can be handled. It is preferable that it is comprised.

  In FIG. 13, the sensor panel Sp is moved in the longitudinal direction of the support body 102 (that is, the vertical direction in this case), and the image is taken three times, thereby taking a long image from the head of the subject who is the subject Hu to the toes. However, the present invention is not limited to this, and the number of times of imaging performed by moving the sensor panel Sp in the longitudinal direction is appropriately set according to the vertical length of the sensor panel Sp, the distance to be moved, and the like. Is done.

  In this embodiment, the movement mechanism control means 101b is connected to the control means 22 on the sensor panel Sp in addition to the movement mechanism 101a, and the base station 54 (see FIG. 11) by a wired system such as a cable (not shown). It is connected to the.

  Then, as described above, when the irradiation start signal is transmitted from the radiation generator 55 that has received the irradiation start signal from the exposure switch 56 via the base station 54, the moving mechanism control unit 101b receives the irradiation start signal. Is transmitted to the control means 22 of the sensor panel Sp, and as will be described later, when an interlock release signal is received from the control means 22 of the sensor panel Sp, radiation is generated via the base station 54. The data is transmitted to the device 55.

  In the long photographing apparatus 100 of the present embodiment, data, signals, etc. between the sensor panel Sp and external devices such as the radiation generator 55 and the console 58 are thus provided via the moving mechanism control means 101b of the moving means 101. Therefore, the moving mechanism control unit 101b constitutes a communication unit capable of transmitting / receiving information to / from an external device. Therefore, in this case, it is not always necessary to provide the antenna device 39 on the sensor panel Sp.

  Further, FIG. 13 shows the standing long photographing apparatus 100 that performs photographing by raising the subject who is the subject Hu in front of the support 102, that is, the radiation source 52 side. For example, as shown in FIG. 14, a long-sided photographing apparatus 100 in a prone position that photographs a subject who is not shown in the lying state on the support 102 may be used.

  In the case of the upright long photographing apparatus 100, the sensor panel Sp housed in the support 102 or the loaded radiographic image photographing apparatus 1 is installed as in the case of the standing long photographing apparatus 100 shown in FIG. It is also possible to perform a plurality of times of imaging while moving in the longitudinal direction of the support 102, and as shown in FIG. 14, the position of the sensor panel Sp and the radiographic imaging device 1 are fixed. The support 102 is configured to move in the longitudinal direction thereof (see, for example, the arrow in the drawing), or both the support 102 and the sensor panel Sp and the radiographic image capturing apparatus 1 are moved, respectively. The positional relationship between Hu and the sensor panel Sp can be relatively displaced.

  It should be noted that the long photographing apparatus 100 as described above is used for normal photographing (that is, photographing in a normal photographing mode to be described later) with the sensor panel Sp being fixed in position without moving the sensor panel Sp in the longitudinal direction of the support 102. ) Or video shooting.

[About shooting mode settings and saturation charge variation]
Hereinafter, radiation based on a set imaging mode when performing continuous imaging such as moving image shooting or long imaging using the above-described radiographic image capturing apparatus 1 or long image capturing apparatus 100 or when performing normal single image capturing. A description will be given of variable saturation charge amounts Qpsat and Qrsat of the detection element 7 and the readout circuit 17, estimation of offset Olag due to lag from the read image data, calculation of true image data d ^* , and the like. The operation of the radiographic image capturing apparatus 1 (including the long image capturing apparatus 100) and the radiographic image capturing system 50 according to the present embodiment will also be described.

  In addition, the control configuration of each process in the control means 22 of the sensor panel Sp in the radiographic imaging apparatus 1 and the control configuration of each process in the control means 22 of the sensor panel Sp in the long imaging apparatus 100 are basically. These are the same, and will be described together below. However, needless to say, it does not mean that imaging using the radiographic imaging device 1 and imaging using the long imaging device 100 are performed simultaneously.

[Shooting mode settings]
In this embodiment, prior to radiographic imaging, normal radiographic imaging is performed on the radiographic imaging apparatus 1 and the long imaging apparatus 100 described above, or a series of radiographic imaging is continuously performed. It is possible to select and set whether to perform continuous shooting such as moving image shooting or long shooting.

  In the present embodiment, the operator can perform normal imaging mode set when normal single radiographic imaging is performed on the console 58, and video imaging or long-length imaging in which a series of radiographic imaging is continuously performed. A case will be described in which one of the continuous shooting modes set in the case of shooting can be selected. However, it is also possible to configure such that the radiographic image capturing apparatus 1 or the long image capturing apparatus 100 is directly input and set, and an appropriate method can be adopted as a method for setting the image capturing mode.

[Variation of saturation charge amount of readout circuit]
When one of the normal imaging mode and the continuous imaging mode is selected and set on the console 58, the console 58 is set to the radiographic image capturing apparatus 1 or the long imaging apparatus 100 in which the imaging mode is set. Thus, a signal representing the imaging mode set via the base station 54 or the like (see FIG. 11) is transmitted.

  When the control means 22 of the sensor panel Sp of the radiographic image capturing apparatus 1 or the long image capturing apparatus 100 receives a signal representing the image capturing mode transmitted from the console 58, according to the set image capturing mode, in the present embodiment. By varying the saturation charge amount Qrsat of the readout circuit 17 of the sensor panel Sp, the magnitude relationship between the saturation charge amount Qrsat of the readout circuit 17 and the saturation charge amount Qpsat of the radiation detection element 7 is changed.

  In the present embodiment, the control unit 22 controls on / off of the switches Sw2 to Sw4 (see FIG. 8) of the amplifier circuit 18 configured by the charge amplifier circuit of the readout circuit 17 according to the set photographing mode. Then, it is set which of the capacitors C2 to C4 is connected in parallel with the capacitor C1 to the operational amplifier 18a, and the total value of the capacitors connected in parallel to the operational amplifier 18a, that is, the charge amplifier capacitance Cf is set. The saturation charge amount Qrsat of the readout circuit 17 is varied by varying the value.

  Then, when the normal imaging mode is set as the imaging mode, the control unit 22 varies the saturation charge amount Qrsat of the readout circuit 17 as described above, and the saturation charge amount Qrsat of the readout circuit 17 becomes radiation. The saturation charge amount Qpsat of the detection element 7 is set to be relatively smaller.

  As described above (see FIG. 24), the radiographic imaging apparatus 1 and the long imaging apparatus 100 perform sufficient quantization on the region of the radiation dose I where the lesioned part of the patient as the subject is imaged. In order to achieve this, the saturation charge amount Qrsat of the readout circuit is set in advance so as to be smaller than the saturation charge amount Qpsat of the radiation detection element.

  Therefore, when the normal shooting mode is set as the shooting mode, the control unit 22 selects the capacitors C2 to C4 in the amplification circuit 18 of the readout circuit 17 in accordance with the normal setting (that is, default setting), and performs charging. The amplifier capacitance Cf is set to an initial value, and the saturation charge amount Qrsat of the readout circuit 17 is set.

  Note that adjusting the value of the charge amplifier capacitance Cf by appropriately selecting the capacitors C2 to C4 within a range in which the saturation charge amount Qrsat of the readout circuit is smaller than the saturation charge amount Qpsat of the radiation detection element, etc. , As necessary.

  On the other hand, when the continuous shooting mode is set as the shooting mode, the control unit 22 changes the saturation charge amount Qrsat of the reading circuit 17 by changing the charge amplifier capacitance Cf as described above, and reads out. The saturation charge amount Qrsat of the circuit 17 is set so as to be relatively larger than the saturation charge amount Qpsat of the radiation detection element 7.

  In this case, in the image reading process or the like, the TFT 8 is turned on, so that the charge accumulated in the radiation detection element 7 is released to the signal line 6, and the capacitor C 1 of the amplifier circuit 18 of the reading circuit 17 is turned on. Accumulated in the capacitor C corresponding to the switched switch Sw. An output signal V corresponding to the charge amount Q accumulated in the radiation detection element 7 is output from the amplifier circuit 18 in accordance with the relationship V = Q / Cf.

The maximum value Vmax of the analog output signal V to which the maximum value 2 ¹⁶ (when the signal value is 16 bits) is assigned by the A / D converter 20 (see FIGS. 7 and 8) is determined. , Q = Cf × V, the value of Q corresponding to the maximum value Vmax of the output signal V is determined. The value of Q corresponding to the maximum value Vmax of the output signal V from the readout circuit 17 is determined as described above. This is the saturation charge amount Qrsat of the readout circuit 17.

That is, between the saturation charge amount Qrsat of the readout circuit 17 and the maximum value Vmax of the output signal V,
Qrsat = Cf × Vmax (3)
The relationship is established. Since Vmax is a fixed value as described above, the saturation charge amount Qrsat of the readout circuit 17 can be varied by changing the charge amplifier capacitance Cf.

  Therefore, in the present embodiment, when the continuous shooting mode is set as the shooting mode, the control unit 22 controls on / off of the switches Sw2 to Sw4 (see FIG. 8) of the amplifier circuit 18 to thereby charge the charge amplifier capacitance Cf. It is set to be variable so that the value of is increased. Then, by changing the value of the charge amplifier capacitance Cf so as to increase, the saturation charge amount Qrsat of the readout circuit 17 is increased in accordance with the above equation (3), and the saturation charge amount Qrsat of the readout circuit 17 is It is made variable so as to be relatively larger than the saturation charge amount Qpsat.

  This will be described with reference to a graph. As shown in the upper graph of FIG. 15, the saturation charge amount Qrsat of the readout circuit 17 is changed to the saturation of the radiation detection element 7 by changing the value of the charge amplifier capacitance Cf to be large. It becomes relatively larger than the charge amount Qpsat. When the charge amplifier capacitance Cf increases, the value of the output signal V from the read circuit 17 becomes relatively small due to the relationship V = Q / Cf.

  Therefore, as indicated by a solid line in the lower graph of FIG. 15, the output signal V output from the amplifier circuit 18 of the readout circuit 17 is not saturated with the maximum value Vmax of the output signal V, that is, the radiation dose I. The output signal V from the readout circuit 17 does not output only the maximum value Vmax in spite of the increase, and the readout circuit 17 responds to the dose I with respect to all the doses I of the irradiated radiation. It is possible to output the changing output signal V.

  The control means 22 of the sensor panel Sp of the radiographic image capturing apparatus 1 or the long image capturing apparatus 100, as described above, switches Sw2 to Sw4 of the amplifier circuit 18 of the readout circuit 17 according to the set imaging mode (see FIG. 8), the saturation charge amount Qrsat of the readout circuit 17 is variably set and the magnitude relationship between the saturation charge amount Qrsat of the readout circuit 17 and the saturation charge amount Qpsat of the radiation detection element 7 is determined. If changed, each processing is subsequently performed according to the set photographing mode.

[Processing in normal shooting mode]
Since radiographic imaging in the normal imaging mode is normal single radiographic imaging and can be performed by a known procedure, it will be briefly described below.

  When the control means 22 controls the on / off of the switches Sw2 to Sw4 (see FIG. 8) of the amplifier circuit 18 of the readout circuit 17 as described above and variably sets the saturation charge amount Qrsat of the readout circuit 17, Alternatively, when a signal indicating that reset processing of each radiation detection element 7 is started is received from the console 58, an on-voltage is subsequently applied from the gate driver 15b of the scanning drive means 15, as shown in FIG. The lines L1 to Lx of the scanning line 5 are sequentially switched, and the reset process Rm for one surface is repeated a predetermined number of times to reset each radiation detection element 7.

  Then, an operator such as a radiologist finishes the alignment of the subject who is the subject Hu with the radiographic image capturing apparatus 1 or the long image capturing apparatus 100, moves from the photographing room R1 to the front room R2, and operates the console. When the exposure switch 56 of the exposure switch 56 is operated and the button part 56a of the exposure switch 56 is pressed halfway (see FIG. 12B), an activation signal is sent from the exposure switch 56 to the radiation generator 55 via the console 57. Sent. When receiving the activation signal, the radiation generation device 55 places the radiation source 52 in a standby state by starting rotation of the anode of the X-ray tube of the radiation source 52.

  Subsequently, as shown in FIG. 12C, when the operator fully presses the button portion 56a of the exposure switch 56, the radiation generator 55 starts irradiation from the exposure switch 56 via the console 57. A signal is transmitted. When the radiation generation device 55 receives the irradiation start signal from the exposure switch 56, the radiation generation device 55 transmits the irradiation start signal to the radiographic imaging device 1 or the long imaging device 100 via the base station 54 by a wireless method or a wired method. To do.

  When receiving the irradiation start signal from the radiation generator 55, the control means 22 of the radiographic imaging device 1 or the long imaging device 100 performs a reset process Rm for one surface at that time as shown in FIG. When the process is completed, an interlock release signal is transmitted to the radiation generator 55.

  Further, the control means 22 is in a state in which the off voltage is applied to all the lines L1 to Lx of the scanning line 5 from the gate driver 15b of the scanning driving means 15 when the reset process Rm for the last one surface is completed. Then, all the TFTs 8 of the sensor panel Sp are turned off, and each radiation detection element 7 is shifted to a charge accumulation state in which charges generated therein are held.

  When receiving the interlock release signal transmitted from the radiation imaging apparatus 1 or the long imaging apparatus 100 via the communication means or the base station 54, the radiation generation apparatus 55 emits radiation from the X-ray tube of the radiation source 52. Irradiate. Then, the radiation generator 55 irradiates the radiation from the radiation source 52 by, for example, stopping the X-ray tube of the radiation source 52 when a predetermined time has elapsed from the start of radiation irradiation from the radiation source 52. Stop.

  The control means 22 of the radiographic image capturing apparatus 1 or the long image capturing apparatus 100 irradiates the radiation from the radiation source 52 when a predetermined time has elapsed from the time when the interlock release signal is transmitted to the radiation generating apparatus 55. As a result, the trigger signal is transmitted to the scanning drive unit 15, and the voltage applied to each line L1 to Lx of the scanning line 5 from the gate driver 15b to the scanning drive unit 15 at the timing shown in FIG. The line is switched between the on-voltage and the off-voltage, and the lines L1 to Lx of the scanning line 5 to which the on-voltage is applied are sequentially switched. In this way, the image reading process is performed, and image data d for each radiation detection element 7 is obtained.

  In addition, it may be configured to transmit a signal indicating that the radiation has been terminated from the radiation generator 55 to the radiographic imaging apparatus 1 or the long imaging apparatus 100 when radiation irradiation from the radiation source 52 has been completed. The radiation image capturing apparatus 1 or the long image capturing apparatus 100 itself may be configured to detect the end of radiation irradiation. Further, the radiation image capturing apparatus 1 or the long image capturing apparatus 100 itself may be configured to detect the start of radiation irradiation.

  At this time, since the imaging mode is set to the normal imaging mode, each readout circuit 17 outputs an output signal V that has a correspondence relationship as shown in FIG. That is, in this case, image data d is output.

  Further, the control means 22 obtains an offset correction value O that is an offset due to dark charges included in the image data d for each radiation detection element 7 obtained as described above before or after radiographic imaging. The offset reading process is performed.

  In the offset reading process, as described above, the control unit 22 turns off the TFTs 8 for the same time as the time during which charges are accumulated in the radiation detection elements 7 with the TFTs 8 turned off during radiographic imaging. In the meantime, the radiation image capturing apparatus 1 and the long image capturing apparatus 100 are left without being irradiated with radiation.

  When the time elapses, the control means 22 transmits a trigger signal to the scanning driving means 15 and each of the scanning lines 5 from the gate driver 15b at the timing shown in FIG. 10 as in the case of the image reading processing. The voltage applied to the lines L1 to Lx is switched between the on voltage and the off voltage, and each line L1 to Lx of the scanning line 5 to which the on voltage is applied is sequentially switched to correct the offset for each radiation detection element 7. The value O is obtained.

  The offset reading process is performed a plurality of times, a plurality of offset correction values O for each radiation detection element 7 are averaged, and the average value is set as an offset correction value O for each radiation detection element 7. It is also possible.

[Processing for image data obtained in normal shooting mode]
The console 58 that has received the transmission of the image data d and the offset correction value O from the radiographic imaging device 1 or the long imaging device 100, the radiographic imaging device 1 or the like receives each radiation according to the above equation (1). For each detection element 7, the offset correction value O is subtracted from the image data d to calculate true image data d ^* generated by radiation irradiation in radiographic imaging.

[Processing in continuous shooting mode]
On the other hand, the continuous shooting mode is set as the shooting mode, and the on / off of the switches Sw2 to Sw4 (see FIG. 8) of the amplifier circuit 18 of the readout circuit 17 is controlled as described above to control the saturation charge amount Qrsat of the readout circuit 17. Then, the control means 22 of the sensor panel Sp of the radiographic image capturing apparatus 1 or the long image capturing apparatus 100 performs each process according to the timing chart shown in FIG.

  In the following description, a case where long photographing is mainly performed using the long photographing apparatus 100 will be described as an example of continuous photographing. However, a series of cases using the radiographic image photographing apparatus 1 and the long photographing apparatus 100 will be described. The same applies to the case of moving image shooting or the like in which radiation image shooting is performed continuously. In the following, as shown in FIG. 17, a case where radiographic imaging is performed three times while moving the sensor panel Sp (see FIG. 13) with the long imaging apparatus 100 will be described. The same applies to the case where more radiographic images are continuously taken.

  As shown in FIG. 17, first, the control means 22 sequentially switches the lines L1 to Lx of the scanning line 5 to which the ON voltage is applied from the gate driver 15b of the scanning driving means 15 and performs the reset process Rm for one surface a predetermined number of times. After repeatedly performing reset processing of each radiation detection element 7 (see “Reset” in the figure), the apparatus is left for a predetermined time as described above and scanned from the gate driver 15b at the timing shown in FIG. The voltage applied to the lines L1 to Lx of the line 5 is switched between the on voltage and the off voltage, and the lines L1 to Lx of the scanning line 5 to which the on voltage is applied are sequentially switched to perform the reading process (A). By doing so, an offset reading process for reading the offset correction value O for each radiation detection element 7 is performed.

  In this case as well, the offset reading process is performed a plurality of times, a plurality of offset correction values O obtained for each radiation detection element 7 are averaged, and the average value is offset correction value O for each radiation detection element 7. It is also possible to configure as follows.

  Further, in continuous shooting such as moving image shooting and long shooting, when offset reading processing is performed after a series of radiographic imaging, an offset amount Olag (see FIG. 22) due to a lag lag generated in the series of radiographic imaging is obtained. Since it is superimposed on the offset correction value O, it is necessary to remove the offset Olag due to the lag from the offset correction value O. However, as shown in FIG. 17, the offset readout process is performed before a series of radiographic imaging. When this is done, there is an advantage that the offset correction value O does not include the offset Olag due to the lag, so that the removal process becomes unnecessary.

  In this case, since the shooting mode is set to the continuous shooting mode, the charge amplifier capacitance Cf of the amplifier circuit 18 of the readout circuit 17 is set to be variable to a value larger than the charge amplifier capacitance Cf in the normal shooting mode. ing. Therefore, when the long imaging device 100 and the radiographic imaging device 1 are left for a predetermined time as described above, even if the charge amount Q of the dark charge accumulated in each radiation detection element 7 is the same, it is continuously In the shooting mode, the output signal V output from the readout circuit 17 in accordance with the charge amount Q is smaller than that in the normal shooting mode, as can be seen from the relationship V = Q / Cf.

  Therefore, even when the dark charge amount Q accumulated in each radiation detection element 7 is the same, the offset correction value O obtained in the continuous imaging mode is the offset correction value obtained in the normal imaging mode. A value smaller than O.

  As shown in FIG. 17, the control unit 22 then sequentially switches the lines L1 to Lx of the scanning line 5 to which the on-voltage is applied from the gate driver 15b of the scanning driving unit 15 again, thereby resetting one surface. Is repeated to reset each radiation detection element 7 before continuous imaging (see “Reset” second from the left in the figure).

  After the operator such as a radiographer finishes the alignment of the subject who is the subject Hu with the radiographic imaging device 1 or the long imaging device 100, the button 56a of the exposure switch 56 of the console 57 is half-pressed. Then (see FIG. 12B), when the radiation source 52 is put on standby and the button portion 56a of the exposure switch 56 is fully pressed (see FIG. 12C), the radiation generator 55 to the long imaging device 100 or An irradiation start signal is transmitted to the radiation image capturing apparatus 1.

  When receiving the irradiation start signal, the control unit 22 of the long image capturing apparatus 100 or the radiographic image capturing apparatus 1 ends the reset process Rm for one surface at that time as shown in FIG. Then, an interlock release signal is transmitted to the radiation generator 55, and the state in which the off voltage is applied to all the lines L1 to Lx of the scanning line 5 from the gate driver 15b of the scanning driving means 15 is maintained.

  When receiving the interlock release signal transmitted from the long imaging apparatus 100 or the radiographic imaging apparatus 1 via the communication means or the base station 54, the radiation generating apparatus 55 emits radiation from the X-ray tube of the radiation source 52. Irradiate. Then, the radiation generator 55 irradiates the radiation from the radiation source 52 by, for example, stopping the X-ray tube of the radiation source 52 when a predetermined time has elapsed from the start of radiation irradiation from the radiation source 52. Stop.

  When the irradiation of the radiation is completed, the control unit 22 of the long image capturing device 100 or the radiographic image capturing device 1 transmits a trigger signal to the scan driving unit 15 and the gate of the scan driving unit 15 at the timing shown in FIG. The voltage applied to each line L1 to Lx of the scanning line 5 from the driver 15b is switched between the on voltage and the off voltage, and the lines L1 to Lx of the scanning line 5 to which the on voltage is applied are sequentially switched and read processing is performed. By performing (A), an image reading process for reading image data d for each radiation detection element 7 is performed.

  In addition, it may be configured to transmit a signal indicating that the radiation has been terminated from the radiation generator 55 to the radiographic imaging apparatus 1 or the long imaging apparatus 100 when radiation irradiation from the radiation source 52 has been completed. The radiation image capturing apparatus 1 or the long image capturing apparatus 100 itself may be configured to detect the end of radiation irradiation, and the radiation image capturing apparatus 1 or the long image capturing apparatus 100 itself may start the radiation irradiation. As described above, it can be configured to detect.

  At this time, since the imaging mode is set to the continuous imaging mode, each readout circuit 17 has a correspondence relationship as shown in the lower graph of FIG. Output signal V, that is, image data d in this case is output.

  That is, also in this case, the shooting mode is set to the continuous shooting mode, and the charge amplifier capacitance Cf of the amplifier circuit 18 of the readout circuit 17 is set to be larger than the charge amplifier capacitance Cf in the normal shooting mode. Therefore, even if the charge amount Q of the charge generated and accumulated in each radiation detection element 7 by the radiation image capturing is the same, it is output from the readout circuit 17 according to the charge amount Q in the continuous capturing mode. As can be seen from the relationship V = Q / Cf, the output signal V is smaller than that in the normal photographing mode.

  Therefore, even if the charge amount Q of the charges generated and accumulated in each radiation detection element 7 is the same, the image data d obtained in the continuous photographing mode is the image data d obtained in the normal photographing mode. It becomes a smaller value.

  When the image reading process ends, the control unit 22 performs a reset process for each radiation detection element 7 that repeats the reset process Rm for one surface for the next imaging. In the case of the long photographing apparatus 100 shown in FIG. 13, the control unit 22 moves the sensor panel Sp to the moving mechanism control unit 101 b of the moving unit 101 during the reset process of each radiation detection element 7. An instruction is issued to activate the moving mechanism 101a to move to the position. Then, the movement mechanism control unit 101b activates the movement mechanism 101a to move the sensor panel Sp to the next predetermined position.

  In the long photographing apparatus 100 shown in FIG. 13, the control means 22 reads out the image data d for each radiographic image photographing performed three times while moving the sensor panel Sp as described above, and performs long photographing. It has become. In the following, image data d read out in the n-th (n = 1 to 3 in the above example) image reading process in continuous shooting such as long shooting or moving image shooting is referred to as image data d (n ).

[Estimation of offset by lag and calculation of true image data]
The console 58 that has received the transmission of the image data d (n) and the offset correction value O from the long photographing apparatus 100 and the radiographic imaging apparatus 1, the control means 22 of the long photographing apparatus 100, etc. In addition, based on the image data d, the offset correction value O, and the like, true image data d ^* generated by radiation irradiation in radiographic image capturing is calculated.

  As described above, in the case of continuous imaging, unlike the case of normal imaging described above, the image data d (n) obtained in the second and subsequent radiographic imaging in continuous imaging is used for imaging performed before that time. The offset Olag due to the lag generated in step 1 is superimposed. That is, the offset Olag due to the lag generated in the first photographing is superimposed on the image data d (2) obtained in the second photographing, and the image data d (3) obtained in the third photographing is superimposed on the image data d (3) obtained in the third photographing. The offset Olag due to the lag generated in the first and second shootings is superimposed.

Therefore, the console 58 that has received the transmission of the image data d (n) and the offset correction value O from the long photographing apparatus 100, the control means 22 of the radiographic image photographing apparatus 1, the long photographing apparatus 100, etc. is in the continuous photographing mode. In this case, for the image data d (1) for each radiation detection element 7 obtained in the first radiographic imaging in continuous imaging, offset correction is performed from the image data d (1) according to the above equation (1). By subtracting the value O, true image data d ^* generated by radiation irradiation in radiographic imaging is calculated.

Further, for the image data d (n) for each radiation detection element 7 obtained in the second and subsequent radiographic imaging in continuous imaging, offset correction is performed from the image data d (n) according to the above equation (2). By subtracting the offset Olag due to the value O and lag, true image data d ^* generated by radiation irradiation in radiographic imaging is calculated.

  In order to perform this subtraction process, offset offset Olag data due to lag is required. In this embodiment, as shown in FIG. 18, the dose of irradiated radiation I and the first time shown in FIG. Each time when the reset process Rm for one surface is repeated for a time corresponding to the time between the first shooting and the second shooting (the time between the second shooting and the third shooting is also substantially the same time). The relationship between the offset Olag due to the lag read from the detection element 7 is experimentally obtained in advance, and a table of the offset Olag due to the lag generated in the previous photographing is created.

  Although not shown, each radiation detection element 7 is reset between the first imaging and the second imaging shown in FIG. 17 and is left and read out for a time corresponding to the second imaging (A ), And the offset Olag due to the lag read from each radiation detection element 7 at the time of performing the reset processing of each radiation detection element 7 between the second imaging and the third imaging, and irradiation at the first imaging A relationship with the radiation dose I is experimentally obtained in advance, and a table of offset Olag due to lag generated in the previous imaging is created.

  These tables are stored in advance in the memory or storage means 40 of the CPU or FPGA constituting the control means 22 or in the memory or storage means 59 of the CPU constituting the console 58. Further, the memory or the like also stores in advance a table representing the relationship between the radiation dose I represented by the graph shown in the lower side of FIG. 15 and the output signal V from the readout circuit 17, that is, the image data d.

  Then, the control means 22 and the console 58, for example, in the second radiographic imaging in the continuous imaging, for the image data d (2) obtained for a certain radiation detection element 7, the radiation detection is performed in the first imaging. From the image data d (1) obtained for the element 7, the radiation dose I corresponding to it is estimated according to the table shown in the lower part of FIG. Then, the offset Olag value corresponding to the radiation dose I estimated as described above is estimated with reference to the offset Olag table generated by the previous imaging shown in FIG.

Then, the second image data d (2) is substituted for d in the above equation (2), the offset correction value O for the radiation detection element 7 is substituted for O, and the lag estimated as described above is assigned to Olag. The true image data d ^* (2) generated in the radiation detection element 7 due to the irradiation of radiation in the second radiographic imaging is calculated by substituting the offset Olag. This calculation process is performed for all the radiation detection elements 7.

  Further, the control means 22 and the console 58, for example, with respect to the image data d (3) obtained for a certain radiation detection element 7 in the third radiographic imaging in the continuous imaging, From the image data d (2) obtained for the radiation detection element 7 in the second imaging, the radiation dose I corresponding to the radiation data I is estimated according to the table shown in the lower part of FIG.

  Then, the offset Olag value corresponding to the radiation dose I estimated as described above is estimated with reference to the offset Olag table generated by the previous imaging shown in FIG. The offset Olag due to the lag is expressed as Olag (2) in the sense of the offset generated in the second shooting.

  Further, the radiation dose I corresponding to the radiation detection element 7 is estimated from the image data d (1) obtained for the radiation detection element 7 in the first imaging two times before according to the table shown in the lower part of FIG. Then, with reference to a table of offset Olag due to the lag generated in the previous imaging, not shown, the offset Olag value due to the lag corresponding to the radiation dose I estimated as described above is estimated. The offset Olag due to the lag is expressed as Olag (1) in the sense of the offset generated in the first shooting.

Then, the third image data d (3) is substituted for d in the above equation (2), the offset correction value O for the radiation detection element 7 is substituted for O, and the lag estimated as described above is assigned to Olag. Substituting the total value Olag (1) + Olag (2) of the offset Olag (1) and Olag (2) by the above, it is generated in the radiation detection element 7 when radiation is irradiated in the third radiographic imaging. The true image data d ^* (3) is calculated. This calculation process is performed for all the radiation detection elements 7.

In the present embodiment, as described above, the true image data d ^* in all radiographic imaging from the first to the third imaging in the continuous imaging is calculated.

  In the conventional method, as described above, a series of radiographic imaging is performed without changing the charge amplifier capacitance Cf of the amplifier circuit 18 of the readout circuit 17 even in the continuous imaging mode. Therefore, as shown in the lower graph of FIG. 24, the image data d (n) obtained in the previous or previous radiographic imaging is the maximum value Vmax of the output signal V of the readout circuit 17 (or a value close thereto). In this case, it is not possible to estimate the radiation dose I irradiated to the radiation detection element 7 in the previous or previous radiographic imaging from the previous or previous image data d (n). Moreover, the offset Olag due to the lag generated in the previous shooting could not be estimated.

  On the other hand, in the present embodiment, as described above, in the continuous imaging mode, the charge amplifier capacitance Cf of the amplifier circuit 18 of the readout circuit 17 is varied so that the saturation charge amount Qrsat of the readout circuit 17 is saturated with the radiation detection element 7. It is configured to be variable so as to be relatively larger than the charge amount Qpsat.

  Therefore, as shown in the lower graph of FIG. 15, an output signal V (that is, image data d (n)) output from the readout circuit 17 is output according to the dose I of the radiation applied to the radiation detection element 7. The signal dose V falls below the maximum value Vmax of the signal V, and the radiation dose I and the output signal V from the readout circuit 17 can be associated one-to-one. Then, it becomes possible to accurately estimate the dose I of the radiation irradiated to the radiation detection element 7 in the previous or previous imaging from the image data d (n) obtained in the previous or previous radiographic imaging. It is possible to accurately estimate the offset Olag due to the lag generated in the previous shooting.

  Note that, as described above, it is possible to separately provide a table of offset Olag due to lag generated in the previous and previous shootings, but for example, the offset Olag due to lag has the lag. In the case where the number of times the reset process Rm for one surface is repeated after the radiographic image has been generated and the time t decreases continuously, only one table is created in advance, and the reduction rate α (t ), The offset Olag due to the lag superimposed on the image data d (n) obtained by the current radiographic image capturing can be estimated.

  That is, in this case, in the same manner as described above, a lag that is read out from each radiation detection element 7 after the reset process of each radiation detection element 7 is repeated for a unit time of, for example, 1 second after that. A table (see, for example, FIG. 18) is created by experimentally obtaining the relationship between the offset Olag and the dose I of the irradiated radiation, and is stored in the CPU memory or the like. Further, a decrease rate α (t) of the offset Olag due to the lag with respect to the elapsed time t after the previous radiographic image capturing is experimentally obtained in advance, and this is also stored in the memory of the CPU or the like.

  For example, for the image data d (2) obtained for a certain radiation detection element 7 in the second radiographic imaging in the continuous imaging, the image data obtained for the radiation detection element 7 in the first imaging. From d (1), the radiation dose I corresponding to it is estimated according to the table shown in the lower part of FIG. Then, referring to the table, the value of the offset Olag (1) due to the lag corresponding to the estimated radiation dose I is estimated.

Then, the offset Olag (1) due to the estimated lag is multiplied by a decrease rate α (t1-2) corresponding to the elapsed time t1-2 from the first radiographic image capturing to the second radiographic image capturing. And
d ^* (2) = d (2) −O−α (t1-2) × Olag (1) (4)
The true image data d ^* (2) generated in the radiation detection element 7 due to the irradiation of radiation in the second radiographic imaging is calculated.

  Further, for example, for the image data d (3) obtained for a certain radiation detection element 7 in the third radiographic imaging in the continuous imaging, the radiation detection is performed in the previous second imaging in the same manner as described above. From the image data d (2) obtained for the element 7, the dose I of the radiation corresponding thereto is estimated according to the table shown in the lower part of FIG. Then, with reference to the table, the value of the offset Olag (2) due to the lag corresponding to the estimated radiation dose I is estimated. Further, the offset Olag (2) due to the estimated lag is multiplied by a decrease rate α (t2-3) corresponding to the elapsed time t2-3 from the second radiographic image capturing to the third radiographic image capturing.

  Further, the radiation dose I corresponding to the radiation detection element 7 is estimated from the image data d (1) obtained for the radiation detection element 7 in the first imaging two times before according to the table shown in the lower part of FIG. Then, referring to the table, the value of the offset Olag (1) due to the lag corresponding to the estimated radiation dose I is estimated. Further, the offset Olag (1) due to the estimated lag is multiplied by a decrease rate α (t1-3) corresponding to the elapsed time t1-3 from the first radiographic image capturing to the third radiographic image capturing.

And
d ^* (3) = d (3) −O− {α (t2-3) × Olag (2) + α (t1-3) × Olag (1)} (5)
The true image data d ^* (3) generated in the radiation detection element 7 due to the irradiation of radiation in the third radiographic imaging is calculated. Such a configuration is also possible.

  As described above, according to the radiographic imaging apparatus 1 and the radiographic imaging system 50 including the long imaging apparatus 100 according to the present embodiment, the saturation charge amount Qrsat of the readout circuit 17 is set according to the set imaging mode. The relative magnitude relationship between the saturation charge amount Qrsat of the readout circuit 17 and the saturation charge amount Qpsat of the radiation detection element 7 is changed according to the set imaging mode.

  Therefore, in the normal imaging mode in which normal single radiographic imaging is performed, normal radiographic imaging is known in a state where the saturation charge amount Qrsat of the readout circuit 17 is relatively smaller than the saturation charge amount Qpsat of the radiation detection element 7. It is possible to obtain effective image data d by performing the above method, and it is possible to accurately generate a radiation image based on the image data d.

  Further, in the continuous imaging mode in which a series of radiographic image capturing is performed continuously at a relatively short interval, such as moving image capturing or long image capturing, the saturation charge amount Qrsat of the readout circuit 17 is greater than or equal to the saturation charge amount Qpsat of the radiation detection element 7. To be relatively large.

  Therefore, as shown in the lower graph of FIG. 15, the output signal V, that is, the image data d (n) output from the readout circuit 17 in accordance with the dose I of the radiation applied to the radiation detection element 7 is the output signal V. Therefore, the radiation dose I and the output signal V from the readout circuit 17 can be associated with each other on a one-to-one basis. Therefore, it is possible to accurately estimate the dose I of the radiation irradiated to the radiation detecting element 7 at that time from the image data d (n) obtained by the previous radiographic imaging, and the lag caused by the previous radiographic imaging. It is possible to accurately estimate the offset Olag due to.

  Therefore, by subtracting the offset Olag due to the lag accurately estimated from the image data d (n), it becomes possible to accurately eliminate the offset Olag due to the lag from the image data d (n). In continuous shooting, a phenomenon in which an afterimage due to lag is reflected in a radiation image is likely to occur, but it is possible to accurately prevent such a phenomenon from occurring.

In addition, in this embodiment and 2nd Embodiment mentioned later, although it demonstrated on the assumption that radiographic imaging of 3 times is performed continuously as continuous imaging, it is not limited to this. When more radiographic images are taken continuously, for example, a table for associating the radiation dose I with the offset Olag due to the lag is prepared in advance, or from the above equation (5) As can be inferred, α (tm−n) × Olag (m) (m = 1 to n−1) is a necessary number from the value obtained by subtracting the offset correction value O from the nth image data d (n). The true image data d ^* (n) can be calculated by subtracting the value obtained by adding only the values.

[Second Embodiment]
In the first embodiment, the readout circuit 17 changes the relative magnitude relationship between the saturation charge amount Qrsat of the readout circuit 17 and the saturation charge amount Qpsat of the radiation detection element 7 according to the set imaging mode. The charge amplifier capacitance Cf of the amplifying circuit 18 is varied by controlling on / off of the switches Sw2 to Sw4 (see FIG. 8) of the amplifying circuit 18 composed of the charge amplifier circuit of FIG. The case of varying the above has been described.

  However, instead of changing the saturation charge amount Qrsat of the readout circuit 17 or with the change of the saturation charge amount Qrsat of the readout circuit 17, the saturation charge amount Qpsat of the radiation detection element 7 is changed, so that the set imaging mode is achieved. Accordingly, the relative magnitude relationship between the saturation charge amount Qrsat of the readout circuit 17 and the saturation charge amount Qpsat of the radiation detection element 7 can be changed.

  In the second embodiment of the present invention, it will be described that the saturation charge amount Qpsat of the radiation detection element 7 is varied as described above. Also in the present embodiment, the configurations of the radiographic image capturing apparatus 1, the long image capturing apparatus 100, and the radiographic image capturing system 50 are the same as in the case of the first embodiment described above, and a description thereof is omitted. Each functional unit will be described with the same reference numerals as those shown in the first embodiment.

  In the present embodiment, the control means 22 of the radiographic image capturing apparatus 1 or the long image capturing apparatus 100 determines the potential difference between the two electrodes of the radiation detection element 7, that is, the first electrode 74 and the second electrode, according to the set imaging mode. The saturation charge amount Qpsat of the radiation detection element 7 is varied by varying the potential difference between the electrodes 78 (see FIG. 8 and the like).

Specifically, as shown in FIG. 8, in the normal state, that is, the normal imaging mode, the bias voltage Vbias is applied to the second electrode 78 of the radiation detection element 7 from the bias power supply 14 via the bias line 9 and its connection 10. The reference potential V ₀ is applied to the radiation detection element 74 from the amplifier circuit 18 of the readout circuit 17 via the TFT 8. Therefore, a potential difference of V ₀ −Vbias is generated between the first electrode 74 and the second electrode 78 of the radiation detection element 7.

Now, assuming that the parasitic capacitance of the radiation detection element 7 is C, the radiation detection element 7 can accumulate a charge amount Q calculated by C × (V ₀ −Vbias). This is the saturation charge amount Qpsat of the radiation detection element 7. That is, the saturation charge amount Qpsat of the radiation detection element 7 is
Qpsat = C × (V ₀ −Vbias) (6)
Is calculated by

Therefore, the saturation charge amount Qpsat of the radiation detection element 7 can be varied by varying the potential difference V ₀ -Vbias between the first electrode 74 and the second electrode 78 of the radiation detection element 7.

As described above, in the present embodiment, the control unit 22 controls the bias power supply 14 to set the bias voltage Vbias applied from the bias power supply 14 to each radiation detection element 7. Therefore, in the present embodiment, the control unit 22 varies the potential difference V ₀ −Vbias between the first electrode 74 and the second electrode 78 of the radiation detection element 7 by varying the bias voltage Vbias to be set, The saturation charge amount Qpsat of the radiation detection element 7 is made variable. It is also possible to make the reference potential V ₀ variable.

  In the present embodiment, when the shooting mode is set based on the instruction from the console 58 or the like as described above, the control unit 22 sets the bias to be set in the bias power source 14 according to the set shooting mode. The voltage Vbias is varied to vary the saturation charge amount Qpsat of the radiation detection element 7.

  When the normal imaging mode is set as the imaging mode, the control means 22 sets the bias voltage Vbias to be set to the bias voltage Vbias in normal radiographic image imaging, and is shown in the graph on the upper side of FIG. As described above, the saturation charge amount Qrsat of the readout circuit 17 is set to be relatively smaller than the saturation charge amount Qpsat of the radiation detection element 7.

  Therefore, in this case, the relationship between the radiation dose I applied to the radiation detection element 7 and the output signal V from the readout circuit 17 is as shown in the lower graph of FIG.

On the other hand, when the continuous imaging mode is set as the imaging mode, the control unit 22 applies the bias voltage Vbias set to the bias power source 14 as described above to the first electrode 74 and the second electrode of the radiation detection element 7. The potential difference V ₀ −Vbias between the electrodes 78, that is, the saturation charge amount Qpsat of the radiation detection element 7 is varied to be small, and the saturation charge amount Qrsat of the readout circuit 17 is relatively larger than the saturation charge amount Qpsat of the radiation detection element 7. In other words, the saturation charge amount Qpsat of the radiation detection element 7 is set to be relatively smaller than the saturation charge amount Qrsat of the readout circuit 17.

  As described above, when the saturation charge amount Qpsat of the radiation detection element 7 becomes small, the charge amount Q generated in each radiation detection element 7 can be accumulated only up to the saturation charge amount Qpsat. Even if the charge amount Q accumulated in each radiation detection element 7 increases, the saturation is caused by the saturation charge amount Qpsat.

  As described above, since the saturation charge amount Qpsat of the radiation detection element 7 is relatively smaller than the saturation charge amount Qrsat of the readout circuit 17, the charge accumulated in each radiation detection element 7 is reduced. The quantity Q does not exceed the saturation charge quantity Qrsat of the readout circuit 17.

  In this case, the relationship between the radiation dose I applied to the radiation detection element 7 and the output signal V from the readout circuit 17 is as shown in the lower graph of FIG. Output signal V falls within the range below the maximum value Vmax of output signal V, and radiation dose I and output signal V from readout circuit 17 can be in a one-to-one correspondence.

  Therefore, in the radiographic image capturing apparatus 1, the long image capturing apparatus 100, and the radiographic image capturing system 50 according to the present embodiment, as in the case of the first embodiment, reading is performed by a series of radiographic image capturing in continuous imaging. The radiation dose I irradiated to the radiation detection element 7 is accurately estimated from the one-to-one relationship from the value of the image data d (n) for each radiation detection element 7 that has been output, and the estimated radiation It is possible to accurately estimate the offset Olag due to the lag based on the dose I.

In addition, the radiation detection element 7 is calculated by performing an operation according to the above-described equations (4) and (5) from the image data d (n), the offset correction value O, and the offset Olag due to the accurately estimated lag. True image data d ^* (n) can be accurately calculated.

  As described above, the radiation image capturing apparatus 1 and the radiation image capturing system 50 including the long image capturing apparatus 100 according to the present embodiment can accurately exhibit the same effect as that of the first embodiment. It becomes.

  That is, in the present embodiment, the two electrodes (first electrode 74) of the radiation detection element 7 are changed by varying the bias voltage Vbias applied from the bias power source 14 to each radiation detection element 7 according to the set imaging mode. And the second electrode 78), the saturation charge amount Qpsat of the radiation detection element 7 is varied by varying the potential difference generated between the second electrode 78) and the saturation charge amount Qpsat of the readout circuit 17 and the saturation charge amount Qpsat of the radiation detection element 7. It was configured to change the relative magnitude relationship with.

  Therefore, in the normal imaging mode in which normal single radiographic imaging is performed, normal radiographic imaging is known in a state where the saturation charge amount Qrsat of the readout circuit 17 is relatively smaller than the saturation charge amount Qpsat of the radiation detection element 7. It is possible to obtain effective image data d by performing the above method, and it is possible to accurately generate a radiation image based on the image data d.

  Further, in the continuous imaging mode in which a series of radiographic image capturing is performed continuously at a relatively short interval, such as moving image capturing or long image capturing, the saturation charge amount Qrsat of the readout circuit 17 is greater than or equal to the saturation charge amount Qpsat of the radiation detection element 7. In other words, the saturation charge amount Qpsat of the radiation detection element 7 is varied so as to be relatively smaller than the saturation charge amount Qrsat of the readout circuit 17.

  Therefore, as shown in the lower graph of FIG. 19, the output signal V, that is, the image data d (n) output from the readout circuit 17 in accordance with the dose I of the radiation applied to the radiation detection element 7 is the output signal V. Therefore, the radiation dose I and the output signal V from the readout circuit 17 can be associated with each other on a one-to-one basis. Therefore, it is possible to accurately estimate the dose I of the radiation irradiated to the radiation detecting element 7 at that time from the image data d (n) obtained by the previous radiographic imaging, and the lag caused by the previous radiographic imaging. It is possible to accurately estimate the offset Olag due to.

  Therefore, by subtracting the offset Olag due to the lag accurately estimated from the image data d (n), it becomes possible to accurately eliminate the offset Olag due to the lag from the image data d (n). In continuous shooting, a phenomenon in which an afterimage due to lag is reflected in a radiation image is likely to occur, but it is possible to accurately prevent such a phenomenon from occurring.

  It is possible to configure the first embodiment and the second embodiment to be combined.

  That is, when the set imaging mode is the normal imaging mode, the charge amplifier capacitance Cf of the amplification circuit 18 of the readout circuit 17 and the two electrodes (the first electrode 74 and the second electrode 78) of the radiation detection element 7 are used. Is set as in a normal case, and when the set shooting mode is the continuous shooting mode, the charge amplifier capacitance Cf is varied so as to increase the saturation charge amount Qrsat of the readout circuit 17. The bias voltage Vbias is varied to vary the potential difference between the two electrodes of the radiation detection element 7 so as to reduce the saturation charge amount Qpsat of the radiation detection element 7.

  In this way, it is also possible to vary the saturation charge amount Qrsat of the readout circuit 17 so as to be relatively larger than the saturation charge amount Qpsat of the radiation detection element 7.

  In the first and second embodiments described above, the radiation detection element 7 is once irradiated from the image data d (m) for each radiation detection element 7 obtained by previous radiographic imaging such as the previous time. The case where the radiation dose I is estimated and the offset Olag due to the lag is estimated from the estimated radiation dose I has been described.

  However, the offset Olag by the lag superimposed on the image data d (n) of the current radiographic image capture from the image data d (m) of each radiation detection element 7 obtained by the previous radiographic image capture such as the previous time is calculated. It is also possible to configure so as to perform direct estimation, and it is also possible to configure so that a table for direct estimation is stored in a CPU memory or the like.

DESCRIPTION OF SYMBOLS 1 Radiographic imaging apparatus 5, L1-Lx Scan line 6 Signal line 7 Radiation detection element 14 Bias power supply 17 Reading circuit 18 Amplifying circuit 18a Operational amplifier 22 Control means 39 Antenna apparatus (communication means)
50 radiation imaging system 52 radiation source 55 radiation generator 58 console 74 first electrode (electrode of radiation detection element)
78 Second electrode (electrode of radiation detection element)
100 Long imaging device (radiological imaging device)
101 Moving means C1-C4 Capacitor Cf Charge amplifier capacity (capacitor capacity)
d, d (n) Image data d ^* , d ^* (n) True image data Hu Subject I Radiation dose O Offset correction value Olag Offset due to lag Q Charge amount Qpsat Saturation charge amount Qrsat of radiation detection element Saturated charge amount r Region Sp Sensor panel V Output signal V ₀ -Vbias Potential difference Vbias bias voltage between two electrodes of radiation detection element

Claims (9)

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 readout circuit including an amplification circuit that converts the charge accumulated in each radiation detection element into an output signal corresponding to the amount of the charge;
Control means for controlling at least the readout circuit to perform readout processing of the charge from each of the radiation detection elements;
With
The control means varies the saturation charge amount of the readout circuit and / or the saturation charge amount of the radiation detection element according to the imaging mode set before radiographic imaging, and the saturation charge amount of the readout circuit And a radiation image capturing apparatus, wherein a relative magnitude relationship between a radiation amount and a saturation charge amount of the radiation detection element is changed. 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 readout circuit including an amplification circuit that converts the charge accumulated in each radiation detection element into an output signal corresponding to the amount of the charge;
Control means for controlling at least the readout circuit to perform readout processing of the charge from each of the radiation detection elements;
A sensor panel comprising:
Moving means for relatively displacing the positional relationship between the sensor panel and the subject;
With
The control means varies the saturation charge amount of the readout circuit and / or the saturation charge amount of the radiation detection element according to the imaging mode set before radiographic imaging, and the saturation charge amount of the readout circuit A radiographic imaging apparatus, wherein the magnitude relationship between the saturation charge amount of the radiation detection element is changed.   The imaging modes that can be set are the normal imaging mode that is set when normal single radiographic imaging is performed, and the video shooting or long-time imaging in which a series of radiographic imaging is performed continuously. The radiographic image capturing apparatus according to claim 1, wherein the continuous image capturing mode is included.   When the normal imaging mode is set as the imaging mode, the control unit varies the saturation charge amount of the readout circuit and / or the saturation charge amount of the radiation detection element to change the saturation charge amount of the readout circuit. Is set to be relatively smaller than the saturation charge amount of the radiation detection element, and when the continuous imaging mode is set, the saturation charge amount of the readout circuit and / or the saturation charge amount of the radiation detection element The radiographic image capturing apparatus according to claim 3, wherein the saturation charge amount of the readout circuit is set to be relatively larger than the saturation charge amount of the radiation detection element by varying. The amplification circuit of the readout circuit is composed of a charge amplifier circuit formed by connecting a capacitor in parallel with an operational amplifier,
The control means varies the saturation charge amount of the readout circuit by varying the capacitance of the capacitor of the charge amplifier circuit in accordance with the imaging mode set before radiographic imaging. The radiographic imaging apparatus according to any one of claims 1 to 4, wherein a relative magnitude relationship between a charge amount and a saturation charge amount of the radiation detection element is changed.   The control means varies the saturation charge amount of the radiation detection element by varying a potential difference between the two electrodes of the radiation detection element in accordance with an imaging mode set before radiographic imaging. 6. The radiographic imaging apparatus according to claim 1, wherein a relative magnitude relationship between a saturation charge amount of a circuit and a saturation charge amount of the radiation detection element is changed. The radiation detection element has a bias voltage applied to one of the electrodes from a bias power source,
The control means controls the bias power supply in accordance with an imaging mode set before radiographic imaging, and varies the bias voltage applied to the electrode of the radiation detection element, so that 2 of the radiation detection element. The radiographic imaging apparatus according to claim 6, wherein a potential difference between the two electrodes is varied. The control means includes
When the normal imaging mode is set as the imaging mode, the offset correction value read out by the offset readout process is subtracted from the image data obtained by radiographic imaging to obtain a true value for each radiation detection element. Calculate the image data,
When the continuous imaging mode is set as the imaging mode, in the continuous imaging, the radiation is obtained from the image data obtained for the radiation detection element in the radiographic imaging before the radiographic imaging in which the image data to be processed is obtained Estimate the dose of radiation irradiated to the detection element and estimate the offset due to the lag superimposed on the image data to be processed. From the image data to be processed, the offset correction value read by the offset read process and The radiographic image capturing apparatus according to claim 1, wherein true image data for each of the radiation detection elements is calculated by subtracting the offset due to the lag. The radiographic imaging apparatus according to any one of claims 1 to 7, further comprising a communication unit capable of transmitting and receiving information;
A radiation generator comprising a radiation source for irradiating the radiation imaging apparatus with radiation;
A console that calculates true image data for each of the radiation detection elements based on the image data transmitted from the radiation imaging apparatus and the offset correction value;
With
The console is
When the image data and the offset correction value are obtained in the normal imaging mode, the offset correction value is subtracted from the image data to calculate true image data for each radiation detection element. And
In the case where the image data and the offset correction value are obtained in the continuous imaging mode, in the continuous imaging, the radiation detection element in the radiographic imaging before the radiographic imaging in which the image data to be processed is obtained. Estimate the dose of radiation irradiated to the radiation detection element from the image data obtained for, estimate the offset due to the lag superimposed on the image data to be processed, and read the offset from the image data to be processed A radiographic imaging system, wherein true image data for each of the radiation detection elements is calculated by subtracting the offset correction value read in step 1 and the offset due to the lag.

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