Patent Publication Number: US-2015083924-A1

Title: Radiographic imaging device and radiation detector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of International Application No. PCT/JP2013/064673, filed May 27, 2013, the disclosure of which is incorporated herein by reference in its entirety. Further, this application claims priority from Japanese Patent Application No. 2012-123627, filed May 30, 2012, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a radiographic imaging device and radiation detector that generate a radiation image based on radiation passing through an imaging target region. 
     2. Description of the Related Art 
     In recent years, radiation detectors such as flat panel detectors (FPD) and the like have been realized. In an FPD, a radiation-sensitive layer is disposed on a thin film transistor (TFT) active matrix substrate. The FPD converts radiation directly to digital data. A portable radiographic imaging device (hereinafter referred to as an “electronic cassette”) that incorporates a radiation detector, electronic circuits including an image memory, and a power supply section, and that stores radiation image data from the radiation detector in the image memory, has also been realized. There are calls for the same radiation detector to be used for imaging both still images and video images (fluoroscopic images). In general, in cases of imaging still images, there are many cases in which a high definition image (high resolution) is required but a low frame rate (imaging interval) is acceptable. On the other hand, in cases of video imaging, there are many cases in which a high frame rate is required but a low resolution is acceptable. 
     Accordingly, there are technologies that enable the acquisition of high frame rate images or the acquisition of high definition images in accordance with objectives, such as, for example, the technology recited in Japanese Patent Application Laid-Open (JP-A) No. 2004-46143. JP-A No. 2004-46143 recites an image forming device that is provided with pixels arrayed in a two-dimensional matrix, a signal processing circuit part  15  that processes signals from the pixels, and a gate driver circuit part  17  that controls connections with the pixels. The gate driver circuit part  17  is connected to the pixels by gate lines  13 A and  13 B. The gate lines  13 A and  13 B include gate lines that are respectively connected to each pixel in a row or a column and gate lines that connect to pixels in plural rows or plural columns in common. 
     According to the technology recited in JP-A No. 2004-46143, if a switching element connected to a gate line of system A, which connects to all the pixels belonging to the same row, is driven, an image with a usual number of pixels is outputted, whereas if a switching element connected to a gate line of system B, which connects to all pixels in common across a plural number of rows, is driven, an image with one pixel for four of the usual pixels is outputted. 
     Thus, in a case in which four pixels at a time of high definition imaging become one pixel at a time of high speed driving, a defect that would correspond to one pixel has a size of four pixels. Therefore, in order to maintain consistent image quality at times of high-speed driving, a standard for determining whether or not a defect is acceptable must be specified more strictly, and it is difficult to maintain productivity. In particular, in a case in which there is a breakage in a gate line (a scan line), all pixels from the breakage portion of the gate line to an end portion become defective pixels, and the size of the defect is remarkably large. 
     The present invention provides a radiographic imaging device and a radiation detector in which a resolution may be switched and that may prevent the occurrence of defective pixels in a case in which a breakage occurs in a scan line. 
     SUMMARY OF THE INVENTION 
     A first aspect of the present invention is a radiographic imaging device including: a plurality of first scan lines and a plurality of second scan lines extending in a first direction; a plurality of signal lines extending in a second direction that crosses the first direction; a plurality of first switching elements provided in correspondence with intersection portions between the plurality of signal lines and the plurality of first scan lines, control terminals of the first switching elements being connected to the corresponding first scan lines and output terminals of the first switching elements being connected to the corresponding signal lines; a plurality of sensors, each of which is connected to an input terminal of a respective one of the first switching elements and that generates charges in accordance with intensities of irradiated radiation or intensities of light corresponding to the radiation; a plurality of second switching elements, each of which includes an input terminal connected to a respective one of the sensors and a control terminal connected to one of the second scan lines, respective output terminals of the plurality of the second switching elements, whose respective input terminals are connected to a plurality of the sensors, which sensors are adjacent in the first direction and the second direction, being connected to the same signal line; a first driving signal provision section that provides sequential driving signals to the plurality of first scan lines; a second driving signal provision section that provides sequential driving signals to the plurality of second scan lines; and a connection portion that electrically connects to one another a plurality of the second scan lines to which the same or identical driving signals are provided by the second driving signal provision section. 
     In a second aspect of the present invention, in the first aspect, the connection portion may be provided at second end portions of the second scan lines, the second end portions being at an opposite side of the second scan lines from first end portions at a side thereof at which the second driving signal provision section is connected. In a third aspect of the present invention, in the second aspect, the connection portion may be provided at the first end portions and the second end portions of the second scan lines. In a fourth aspect of the present invention, in the second or third that aspect, the connection portion may be provided between the first end portions and the second end portions of the second scan lines. 
     In a fifth aspect of the present invention, in the first aspect, the connection portion may be formed integrally with each of the second scan lines. In a sixth aspect of the present invention, in the first to fourth aspects, the connection portion may include a flexible member. 
     In a seventh aspect of the present invention, in the above aspects, the first driving signal provision section may provide driving signals to each of the first scan lines when in a first imaging mode, and the second driving signal provision section may provide driving signals to each of the second scan lines when in a second imaging mode. 
     In an eighth aspect of the present invention, in the above aspects, the first driving signal provision section and the second driving signal provision section may be formed in a single package. In a ninth aspect of the present invention, in the eighth aspect, the first driving signal provision section and the second driving signal provision section may be connected to end portions of the plurality of first scan lines and the plurality of second scan lines. 
     In a tenth aspect of the present invention, in the first to seventh aspects, the first driving signal provision section and the second driving signal provision section may be separately provided. In an eleventh aspect of the present invention, in the tenth aspect, the first driving signal provision section may be connected to the plurality of first scan lines at end portions at the opposite side thereof from connection portions that connect the plurality of second scan lines with the second driving signal provision section. 
     A twelfth aspect of the present invention, in the above aspects, may further include a signal processing section that is connected to each of the plurality of signal lines and that generates a radiation image in accordance with charges read out to the signal lines from the plurality of sensors in response to driving that turns on the first switching elements or the second switching elements. 
     A thirteenth aspect of the present invention is a radiation detector including: a plurality of first scan lines and a plurality of second scan lines extending in a first direction; a plurality of signal lines extending in a second direction that crosses the first direction; a plurality of first switching elements provided in correspondence with intersection portions between the plurality of signal lines and the plurality of first scan lines, control terminals of the first switching elements being connected to the corresponding first scan lines and output terminals of the first switching elements being connected to the corresponding signal lines; a plurality of sensors, each of which is connected to an input terminal of a respective one of the first switching elements and that generates charges in accordance with intensities of irradiated radiation or intensities of light corresponding to the radiation; a plurality of second switching elements, each of which includes an input terminal connected to a respective one of the sensors and a control terminal connected to one of the second scan lines, respective output terminals of the plurality of the second switching elements, whose respective input terminals are connected to a plurality of the sensors, which sensors are adjacent in the first direction and the second direction, being connected to the same signal line; and a connection portion that electrically connects to one another a plurality of the second scan lines to which the same or identical driving signals are provided. 
     According to the radiographic imaging device and radiation detector relating to the present invention, an occurrence of defective pixels may be prevented even in a case in which a breakage in a scan line occurs. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Detailed explanation follows regarding exemplary embodiments of the present invention, with reference to the following drawings. 
         FIG. 1  is a block diagram showing the configuration of a radiographic imaging system in accordance with an exemplary embodiment of the present invention. 
         FIG. 2  is a perspective view showing configurations of an electronic cassette that is one aspect of a radiographic imaging device in accordance with the exemplary embodiment of the present invention. 
         FIG. 3  is a sectional view showing the configurations of the electronic cassette that is one aspect of the radiographic imaging device in accordance with the exemplary embodiment of the present invention. 
         FIG. 4  is a sectional view for explaining penetration side sampling and irradiation side sampling. 
         FIG. 5  is a diagram showing electronic configurations of the radiographic imaging device in accordance with the exemplary embodiment of the present invention. 
         FIG. 6  is a diagram showing connection configurations between a radiation detector and a scan line driving circuit in accordance with the exemplary embodiment of the present invention. 
         FIG. 7  is a timing chart of driving signals in a high resolution mode of the radiographic imaging device in accordance with the exemplary embodiment of the present invention. 
         FIG. 8  is a timing chart of driving signals in a low resolution mode of the radiographic imaging device in accordance with the exemplary embodiment of the present invention. 
         FIG. 9  is a partial structural diagram of the radiation detector illustrating a case in which a breakage in a second scan line has occurred. 
         FIG. 10  is a diagram showing electronic configurations of a radiographic imaging device in accordance with an exemplary embodiment of the present invention. 
         FIG. 11  is a diagram showing connection configurations between a radiation detector and a scan line driving circuit in accordance with the exemplary embodiment of the present invention. 
         FIG. 12  is a diagram showing electronic configurations of a radiographic imaging device in accordance with an exemplary embodiment of the present invention. 
         FIG. 13  is a diagram showing electronic configurations of a radiographic imaging device in accordance with an exemplary embodiment of the present invention. 
         FIG. 14  is a diagram showing electronic configurations of a radiographic imaging device in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Herebelow, exemplary embodiments of the present invention are described in detail while referring to the drawings. Elements or portions that are substantially the same or equivalent are assigned the same reference numerals in the respective drawings. 
     First Exemplary Embodiment  
       FIG. 1  is a block diagram showing the configuration of a radiographic imaging system in accordance with an exemplary embodiment of the present invention. 
     A radiographic imaging system  200  includes a radiographic imaging device  100 , a radiation irradiation device  204  and a system control device  202 . The radiation irradiation device  204  irradiates radiation (for example, X-rays or the like) at an imaging subject  206 . The radiographic imaging device  100  generates radiation images that visualize radiation that has been irradiated from the radiation irradiation device  204  and passed through an imaging subject  206 . The system control device  202  commands the radiographic imaging device  100  and the radiation irradiation device  204  to image radiation images, and acquires radiation images generated by the radiographic imaging device  100 . The radiation irradiation device  204  irradiates radiation in accordance with control signals provided from the system control device  202 . Radiation that has passed through the imaging subject  206 , which is disposed at an imaging position, is irradiated onto the radiographic imaging device  100 . 
     The radiographic imaging device  100  images radiation images in different imaging modes: a high resolution mode and a low resolution mode. The high resolution mode is a mode that images radiation images with high resolution, and is applicable to, for example, imaging still images. The low resolution mode is a mode that images radiation images at a high frame rate but with a lower resolution than images generated in the high resolution mode, and is applicable to, for example, imaging video images. The system control device  202  provides commands to the radiographic imaging device  100  instructing which of the high resolution mode and the low resolution mode to select in accordance with, for example, instructions from a user. 
       FIG. 2  is a perspective view showing configurations of the radiographic imaging device  100  in accordance with the present exemplary embodiment. The radiographic imaging device  100  according to the present exemplary embodiment takes the form of an electronic cassette. The radiographic imaging device  100  is provided with a casing  10  formed of a material that transmits the radiation, and the radiographic imaging device  100  is configured to be waterproof and tightly sealed. A space A that accommodates various components is formed inside the casing  10 . Inside the space A, a radiation detector  20  that detects radiation X passing through the imaging subject and a lead plate  11  that absorbs back scattering of the radiation X are arranged in this order from an irradiated surface side of the casing  10  on which the radiation X is irradiated. A case  12  is disposed at one end of the interior of the casing  10 . The case  12  accommodates a power supply section and the like (not shown in the drawings) at a location that does not overlap with the radiation detector  20 . 
     As shown in  FIG. 3 , a support body  13  is disposed inside the casing  10  at the inner face of a rear face portion  10 B, which opposes a top plate  10 A. Between the support body  13  and the top plate  10 A, the radiation detector  20  and the lead plate  11  are arranged in this order in the direction of irradiation of the radiation X. With a view to weight reduction and tolerating dimensional variations, the support body  13  is configured of, for example, a foam material. The support body  13  supports the lead plate  11 . 
       FIG. 4  is a sectional diagram schematically showing a layer configuration of the radiation detector  20  in accordance with the present exemplary embodiment. The radiation detector  20  has a configuration in which a TFT substrate  22  and a scintillator  23  are layered. The TFT substrate  22  includes, on a glass substrate  50 , sensors  61 , which are described below, thin film transistors (TFTs  1  and TFTs  2 ) and the like (see  FIG. 5 ). The scintillator  23  includes a fluorescent material that converts irradiated radiation to light and emits the light. 
     In a case in which, as shown in  FIG. 4 , the radiation is irradiated from the side of the radiation detector  20  at which the scintillator  23  is formed and the radiation detector  20  reads the radiation image with the TFT substrate  22 , which is referred to as penetration side sampling (PSS), light is more strongly emitted from the side of the scintillator  23  of the face thereof on which the radiation is irradiated. In a case in which the radiation is irradiated from the side of the radiation detector  20  at which the TFT substrate  22  is formed and the radiation detector  20  reads the radiation image with the TFT substrate  22  provided at the side of the front face that is the face on which the radiation is incident, which is referred to as irradiation side sampling (ISS), light is more strongly emitted from the side of the scintillator  23  of the face thereof that is joined to the TFT substrate  22 . The below-described sensors  61  provided at the TFT substrate  22  receive the light produced by the scintillator  23  and generate electronic charges. Therefore, in a case in which the radiation detector  20  is of an ISS type, light emission positions of the scintillator  23  are closer to the TFT substrate  22  than in a case in which the radiation detector  20  is of a PSS type. As a result, the resolution of the radiation images obtained by imaging is higher. 
       FIG. 5  is a structural diagram showing electronic configurations of the radiographic imaging device  100  in accordance with the present exemplary embodiment. As shown in  FIG. 5 , the radiographic imaging device  100  includes the radiation detector  20 , a scan line driving circuit  30 , a signal processing circuit  35 , an image memory  36  and a control circuit  37 . Note that, in  FIG. 5 , the scintillator  23  is not shown in the drawing. 
     The radiation detector  20  includes a plural number of pixels  60  two-dimensionally arrayed on a glass substrate  50  in a predetermined first direction and a second direction that crosses the first direction. Each of the plural pixels  60  includes one of the sensors  61 , a first thin film transistor  1  (hereinafter referred to as the TFT  1 ), and a second thin film transistor  2  (hereinafter referred to as the TFT  2 ). The sensor  61  is formed with a photoelectric conversion element that receives light emitted from the scintillator  23  in response to the irradiation of radiation and generates charges, and that accumulates the generated charges. The first thin film transistor  1  (hereinafter referred to as the TFT  1 ) and the second thin film transistor  2  (hereinafter referred to as the TFT  2 ) read the charges accumulated in the sensor  61  out to a signal line D. 
     In each pixel  60 , the input terminals of the TFT  1  and the TFT  2  are connected to the sensor  61 . The TFTs  1  are switching elements that are driven when a radiation image is being imaged in the high resolution mode, and the TFTs  2  are switching elements that are driven when a radiation image is being imaged in the low resolution mode. In  FIG. 5 , the arrangement of the pixels  60  is shown simplified; the pixels  60  are arranged in lines of, for example, 1024 in the first direction and in the second direction (that is, 1024 by 1024 pixels). The sensors  61  of the pixels  60  are connected to common lines, which are not shown in the drawings, forming a configuration such that a bias voltage is applied via the common lines from a power supply section (not shown in the drawings). 
     The TFT substrate  22  includes plural first scan lines G (illustrated by lines G 1  to G 8  in  FIG. 5 ), plural second scan lines M (illustrated by lines M 1  to M 4  in  FIG. 5 ), and plural signal lines D (illustrated by lines D 1  to D 5  in  FIG. 5 ) on the glass substrate  50 . The first scan lines G and the second scan lines M extend in the first direction along the array of the pixels  60 . The signal lines D extend in the second direction orthogonally to the scan lines G and M. The scan lines G and the signal lines D are provided in correspondence with rows and columns of the pixels  60 . For example, in the case of an array of 1024 by 1024 of the pixels  60 , 1024 each of the first scan lines G and the signal lines D are provided. In the present exemplary embodiment, the second scan lines M are half the number of the first scan lines G. That is, in the aforementioned case, 512 of the second scan lines M are provided. 
     The control terminals (gates) of the plural TFTs  1  that are driven when a radiation image is being imaged in the high resolution mode are connected to the respective first scan lines G. More specifically, the control terminals (gates) of the TFTs  1  in plural pixels  60  that are in a line along the direction in which the first scan lines G extend are connected to the same first scan line G. For example, in the example shown in  FIG. 5 , the control terminals (gates) of the TFTs  1  in pixels  60 ( 1 ) to  60 ( 4 ) are connected to the first scan line G 1 , and the control terminals (gates) of the TFTs  1  in pixels  60 ( 5 ) to  60 ( 8 ) are connected to the first scan line G 2 . 
     The control terminals (gates) of a plural number of the TFTs  2  that are driven when a radiation image is being imaged in the low resolution mode are connected to each of the second scan lines M. More specifically, the control terminals (gates) of the TFTs  2  in plural pixels  60  that are in a line along the direction in which the second scan lines M extend and the TFTs  2  in pixels  60  that are adjacent thereto in the direction of extension of the signal lines D, are all connected to the same second scan line M. For example, in the example shown in  FIG. 5 , the control terminals (gates) of the TFTs  2  in pixels  60 ( 1 ) to  60 ( 8 ) are connected to the second scan line M 1 , and the control terminals (gates) of the TFTs  2  in pixels  60 ( 9 ) to  60 ( 16 ) are connected to the second scan line M 2 . 
     The output terminals of the TFTs  1  in a plural number of the pixels  60  that are in a line along the direction in which the signal lines D extend are connected to the same signal line D. For example, in the example shown in  FIG. 5 , the output terminals of the TFTs  1  in pixels  60 ( 1 ),  60 ( 5 ),  60 ( 9 ),  60 ( 13 ),  60 ( 17 ),  60 ( 21 ),  60 ( 25 ) and  60 ( 29 ) are connected to the signal line D 1 , and the output terminals of the TFTs  1  in pixels  60 ( 2 ),  60 ( 6 ),  60 ( 10 ),  60 ( 14 ),  60 ( 18 ),  60 ( 22 ),  60 ( 26 ) and  60 ( 30 ) are connected to the signal line D 2 . 
     The output terminals of the TFTs  2  in four pixels that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend, and that are connected to the same second scan line M, are connected to the same signal line D. For example, in the example shown in  FIG. 5 , the output terminals of the TFTs  2  that constitute a composite pixel  70 ( 4 ) formed of the pixels  60 ( 9 ),  60 ( 10 ),  60 ( 13 ) and  60 ( 14 ) are connected to the signal line D 2 , and the output terminals of the TFTs  2  that constitute a composite pixel  70 ( 2 ) formed of the pixels  60 ( 2 ),  60 ( 3 ),  60 ( 6 ) and  60 ( 7 ) are connected to the signal line D 3 . 
     The scan line driving circuit  30  is provided at one of two adjacent edges of the radiation detector  20 . The signal processing section  35  is provided at the other of the two adjacent edges. Each of the first scan lines G and each of the second scan lines M is connected to the scan line driving circuit  30  via a respective connection terminal  52 . 
       FIG. 6  is a diagram showing connection configurations between the radiation detector  20  and the scan line driving circuit  30 . The scan line driving circuit  30  includes a first driving signal generation circuit  31 , which generates driving signals when in the high resolution mode, and a second driving signal generation circuit  32 , which generates driving signals when in the low resolution mode. The first driving signal generation circuit  31  and the second driving signal generation circuit  32  are accommodated in a single integrated circuit or a single semiconductor package and are formed integrally. 
     The first driving signal generation circuit  31  includes a shift register circuit. The first driving signal generation circuit  31  is connected to each of the first scan lines G via the respective connection terminals  52 , and sequentially outputs driving pulses to each of the first scan lines G when in the high resolution mode. The TFTs  1  turn ON in response to the driving pulses provided via the first scan lines G, and output charges accumulated in the sensors  61  to the signal lines D. 
     The second driving signal generation circuit  32  also includes a shift register circuit. The second driving signal generation circuit  32  is connected to each of the second scan lines M via the respective connection terminals  52 , and sequentially outputs driving pulses to each of the second scan lines M when in the low resolution mode. The TFTs  2  turn ON in response to the driving pulses provided via the second scan lines M, and output charges accumulated in the sensors  61  to the signal lines D. 
     Thus, in the present exemplary embodiment, the first driving signal generation circuit  31  that operates in the high resolution mode and the second driving signal generation circuit  32  that operates in the low resolution mode are accommodated in the single scan line driving circuit  30 . Because the scan line driving circuit  30  is a single configuration, an imaging area may be enlarged compared to a case in which a scan line driving circuit is provided as plural configurations at both sides of the radiation detector  20  (see  FIG. 12 ), or the overall size of the radiographic imaging device  100  may be reduced. The first driving signal generation circuit  31  and the second driving signal generation circuit  32  may also be separated and disposed at one side of the radiation detector  20 . In this case, some ingenuity is required for routing the first scan lines G and the second scan lines M on the glass substrate  50 , as a result of which the wiring burden is greater and artifacts may result. In a case in which the radiographic imaging device  100  is employed as a portable electronic cassette, as in the present exemplary embodiment, it is desirable to form the scan line driving circuit  30  as a single configuration that is capable of handling both the high resolution mode and the low resolution mode, and providing the scan line driving circuit  30  at only one side of the radiation detector  20  is desirable with regard to assuring the imaging area and reducing the size, and in regard to avoiding an increase in the wiring burden. 
     In  FIG. 5 , a configuration is illustrated in which the single scan line driving circuit  30  is provided for all of the scan lines G and M. However, scan line driving circuits may be respectively provided for sets of predetermined numbers of scan lines. For example, in the case in which 1024 of the first scan lines G are provided on the glass substrate  50 , scan line driving circuits may be provided for sets of 256 thereof, in which case four of the scan line driving circuits are provided. The same possibility applies to the signal processing section  35 . 
     In the present exemplary embodiment, as described below, driving pulses with the same time width and the same signal level are provided from the scan line driving circuit  30  to the second scan lines M 1  and M 2  simultaneously. The second scan lines M 1  and M 2  that constitute a pair to which the same driving signals are provided simultaneously are electrically connected to one another by a redundant line R, at end portions of the scan lines M 1  and M 2  that are at the opposite side thereof from end portions at the side at which the scan line driving circuit  30  is disposed. Similarly, the second scan lines M 3  and M 4  constitute a pair to which driving signals with the same time width and the same signal level are simultaneously provided from the scan line driving circuit  30 . The pair formed of the second scan lines M 3  and M 4  are electrically connected to one another by a redundant line R at end portions of the scan lines M 3  and M 4  that are at the opposite side thereof from end portions at the side at which the scan line driving circuit  30  is disposed. The redundant lines R are functionally unnecessary for the radiation detector  20  to image radiation images. However, as described below, the redundant lines R prevent the occurrence of defective pixels when there is a breakage in a second scan line M. Herein, the first and second scan lines G and M, the signal lines D and the redundant lines R may be formed by, for example, using vapor deposition, sputtering or the like to form a film of a conductive material such as aluminium or the like on the glass substrate  50 , and then patterning the film. In this case, the redundant lines R are formed integrally with the second scan lines M. 
     The above term “end portions of the second scan lines M” includes not just the ends of the second scan lines M but also a range along each second scan line M from the end of the second scan line M to the TFT  2  that is connected closest to the end of the second scan line M. The term “end portions” does not indicate positions in the arrangement of the second scan lines M on the glass substrate  50 . 
     Each of the signal lines D is connected to the signal processing section  35 . The signal processing section  35  is equipped with an amplification circuit and a sample and hold circuit (neither of which is shown in the drawings) for each of the individual signal lines D. Each amplification circuit amplifies inputted electronic signals. After being amplified by the amplification circuits, the electronic signals transmitted through the individual signal lines D are retained at the sample and hold circuits. At the output side of the sample and hold circuits, a multiplexer and an analog-to-digital (A/D) converter (neither of which is shown in the drawings) are connected in this order. The electronic signals retained at the respective sample and hold circuits are sequentially (serially) inputted to the multiplexer, and are converted to digital image data by the A/D converter. 
     The image memory  36  stores image data outputted from the A/D converter of the signal processing section  35 . The image memory  36  has a storage capacity capable of storing a predetermined number of frames of image data. Each time a radiation image is imaged, image data obtained by the imaging is sequentially stored in the image memory  36 . 
     The control circuit  37  outputs control signals to the signal processing section  35  indicating timings of signal processing, and outputs controls signals to the scan line driving circuit  30  indicating timings of the output of driving signals. The control circuit  37  includes a microcomputer, and is provided with a central processing unit (CPU) and a memory including read-only memory (ROM) and random access memory (RAM), and a non-volatile storage section formed of flash memory or the like. 
     The radiographic imaging device  100  according to the present exemplary embodiment is provided with a radiation amount acquisition function that, in order to detect a radiation irradiation condition, acquires information representing a radiation amount of radiation irradiated from the radiation irradiation device  204 . This radiation amount acquisition function is realized by, for example, sensors for radiation amount acquisition being provided in the radiation detector  20  and signals outputted from these sensors being read out and analyzed. 
     Herebelow, radiation image imaging operations by the radiographic imaging device  100  according to the present exemplary embodiment are described. The radiographic imaging device  100  starts an imaging operation of a radiation image when the above-mentioned radiation amount acquisition function detects the start of an irradiation of radiation from the radiation irradiation device  204 . When the imaging operation is started, charges are accumulated in the sensors  61  of the pixels  60  of the radiation detector  20  in accordance with the irradiation of radiation thereon. The charges accumulated in the sensors  61  are outputted to the signal lines D via the TFTs  1  or the TFTs  2 , and image data is generated at the signal processing section  35 . The generated image data is stored in the image memory  36 . 
     The radiographic imaging device  100  images the radiation image in either the high resolution mode or the low resolution mode in accordance with control signals provided from the system control device  202 . 
       FIG. 7  is a timing chart of driving signals outputted from the scan line driving circuit  30  in a case in which the high resolution mode is selected. 
     In the high resolution mode, the first driving signal generation circuit  31  of the scan line driving circuit  30  provides driving pulses sequentially to the first scan lines G 1 , G 2 , G 3 , etc. When a driving pulse is provided to the first scan line G 1 , each of the TFTs  1  connected to the first scan line G 1  turns ON, and the charges accumulated in the sensors  61  in pixels  60 ( 1 ) to  60 ( 4 ) are outputted to the signal lines D 1  to D 4 , respectively. Then, when a driving pulse is provided to the first scan line G 2 , each of the TFTs  1  connected to the first scan line G 2  turns ON, and the charges accumulated in the sensors  61  in pixels  60 ( 5 ) to  60 ( 8 ) are outputted to the signal lines D 1  to D 4 , respectively. In this manner, in the high resolution mode the charges accumulated in the sensors  61  in the pixels  60  are outputted to mutually different signal lines D for the different pixels. Meanwhile, the second driving signal generation circuit  32  of the scan line driving circuit  30  does not generate driving signals in the high resolution mode. Therefore, all of the TFTs  2  connected to the respective second scan lines M stay in the OFF state in the high resolution mode. 
       FIG. 8  is a timing chart of driving signals outputted from the scan line driving circuit  30  in a case in which the low resolution mode is selected. 
     In the low resolution mode, the second driving signal generation circuit  32  of the scan line driving circuit  30  provides driving pulses sequentially to the pair formed by the second scan lines M 1  and M 2 , and the pair formed by the second scan lines M 3  and M 4 , etc. That is, the same driving signals are provided at the same timings to the second scan lines M 1  and M 2 , and then the same driving signals are provided at the same timings to the second scan lines M 3  and M 4 . When a driving pulse is provided to the second scan lines M 1  and M 2 , each of the TFTs  2  connected to the second scan lines M 1  and M 2  turns ON, and the charges accumulated in the sensors  61  in pixels  60 ( 1 ) to  60 ( 16 ) are outputted to the signal lines D 1  to D 5 . 
     More specifically, for example, the charges accumulated in the sensors  61  of the four pixels  60 ( 2 ),  60 ( 3 ),  60 ( 6 ) and  60 ( 7 ) that are connected to the second scan line M 1  and that are adjacent to one another in the direction in which the scan lines G and M extend and in the direction in which the signal lines D extend are respectively simultaneously outputted via the TFTs  2  in those pixels to the signal line D 3 . Further in this example, the charges accumulated in the sensors  61  of the four pixels  60 ( 9 ),  60 ( 10 ),  60 ( 13 ) and  60 ( 14 ) that are connected to the second scan line M 2  and that are adjacent to one another in the direction in which the scan lines G and M extend and in the direction in which the signal lines D extend are respectively simultaneously outputted via the TFTs  2  in those pixels to the signal line D 2 . 
     Then, when a driving pulse is provided to the second scan lines M 3  and M 4 , each of the TFTs  2  connected to the second scan lines M 3  and M 4  turns on, and the charges accumulated in the sensors  61  in pixels  60 ( 17 ) to  60 ( 32 ) are outputted to the signal lines D 1  to D 5 . More specifically, for example, the charges accumulated in the sensors  61  of the four pixels  60 ( 18 ),  60 ( 19 ),  60 ( 22 ) and  60 ( 23 ) that are connected to the second scan line M 3  and that are adjacent to one another in the direction in which the scan lines G and M extend and in the direction in which the signal lines D extend are respectively simultaneously outputted via the TFTs  2  in those pixels to the signal line D 3 . Further in this example, the charges accumulated in the sensors  61  of the four pixels  60 ( 25 ),  60 ( 26 ),  60 ( 29 ) and  60 ( 30 ) that are connected to the second scan line M 4  and that are adjacent to one another in the direction in which the scan lines G and M extend and in the direction in which the signal lines D extend are respectively simultaneously outputted via the TFTs  2  in those pixels to the signal line D 2 . 
     Meanwhile, the first driving signal generation circuit  31  of the scan line driving circuit  30  does not provide driving signals to any of the first scan lines G in the low resolution mode. Therefore, all of the TFTs  1  connected to the respective first scan lines G stay in the OFF state in the low resolution mode. 
     In this manner, in the low resolution mode the charges accumulated in the sensors  61  of a set of four pixels that are connected to the same second scan line M and that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend are simultaneously outputted to the same signal line D. That is, in the low resolution mode, the composite pixels  70  are configured by combinations of four individual pixels of the high resolution mode. In other words, four pixels in the high resolution mode become a single pixel in the low resolution mode, and the resolution in the low resolution mode is a quarter of the resolution in the high resolution mode. Further, in the present exemplary embodiment, because a driving pulse is provided simultaneously to the pair of second scan lines M 1  and M 2  and charges are read simultaneously from the pixels  60  of four rows, the frame rate in the low resolution mode is four times that in the high resolution mode. Thus, a high frame rate is achieved. 
       FIG. 9  is a partial structural diagram of the radiation detector  20  illustrating a case in which a breakage in a second scan line M has occurred. As an example, a case in which a breakage occurs at point A 1  of the second scan line M 1  between the composite pixels  70 ( 2 ) and  70 ( 3 ) is described below. In this case, a driving signal that the scan line driving circuit  30  outputs to the second scan line M 1  is provided as far as the composite pixel  70 ( 3 ), but is not provided to the composite pixels  70 ( 1 ) and  70 ( 2 ) at the far side of the composite pixel  70 ( 3 ). However, the driving signal that the scan line driving circuit  30  outputs to the second scan line M 2  is provided to the composite pixels  70 ( 1 ) and  70 ( 2 ) via the redundant line R. Therefore, even in the case in which a breakage has occurred at point A 1 , an occurrence of defective pixels may be avoided. If the redundant line R were not present, the composite pixels  70 ( 1 ) and  70 ( 2 ) would have become defective pixels. 
     As a further example, a case in which a breakage occurs at point A 2  of the second scan line M 2  between the composite pixel  70 ( 5 ) and the connection terminal  52  thereof is described below. In this case, a driving signal that the scan line driving circuit  30  outputs to the second scan line M 2  is not provided to any of the composite pixels  70  on the second scan line M 2 . However, the driving signal that the scan line driving circuit  30  outputs to the second scan line M 1  is provided to each of the composite pixels  70  on the second scan line M 2  via the redundant line R. Therefore, even in the case in which a breakage has occurred at point A 2 , an occurrence of defective pixels may be avoided. If the redundant line R were not present, all of the composite pixels  70  on the second scan line M 2  would have become defective pixels. 
     Thus, according to the radiographic imaging device  100  of the present exemplary embodiment, even in a case in which a breakage has arisen on a second scan line M that is a transmission path for driving signals in the low resolution mode, driving signals that are outputted to the other second scan line M constituting the pair are provided via the redundant line R, and thus occurrences of defective pixels may be prevented. Moreover, because the redundant lines R are provided at the end portions at the opposite side of the second scan lines M from the ends that are connected to the scan line driving circuit  30 , occurrences of defective pixels may be prevented regardless of breakage locations. 
     The scan line driving circuit  30  is a single configuration that includes the first driving signal generation circuit  31  that generates driving signals in the high resolution mode and the second driving signal generation circuit  32  that generates driving signals in the low resolution mode. Because the scan line driving circuit  30  is provided only at one side of the radiation detector  20 , the device may be reduced in size. Therefore, the radiographic imaging device  100  according to the present exemplary embodiment may be excellently employed in a portable electronic cassette. Further, because the scan line driving circuit  30  is disposed only at one side of the radiation detector  20 , structural portions that implement various additional functions may be provided at the opposite side of the radiation detector  20  from the side at which the scan line driving circuit  30  is disposed without leading to a reduction of the imaging area. Further, because the scan line driving circuit  30  is a single configuration capable of handling both the modes, the high resolution mode and the low resolution mode, an increase in a wiring burden due to routing of the first scan lines G and the second scan lines M on the radiation detector  20  may be prevented. 
     In the present exemplary embodiment, a case is illustrated in which each redundant line R is configured by a conductive body formed as a film on the glass substrate  50 . However, a redundant line R may be configured to include a flexible cable, and may be configured to include a flexible substrate. When at least a portion of a redundant line R is configured by a flexible member, there is no need to reserve space for the redundant line R to extend along the glass substrate  50 , and the device may be further reduced in size. For example, in a case in which another member (for example, a control circuit or the like) is disposed on the radiation detector, the redundant line R may be extended as far as the other member by the redundant line R featuring flexibility. 
     Second Exemplary Embodiment  
       FIG. 10  is a structural diagram showing electronic configurations of a radiographic imaging device  100   a  in accordance with a second exemplary embodiment of the present invention. The radiographic imaging device  100   a  according to the present exemplary embodiment differs from the first exemplary embodiment described above in the configuration of the second scan lines M in a radiation detector  20   a.  That is, in the present exemplary embodiment, the pair formed by the second scan lines M 1  and M 2  and the pair formed by the second scan lines M 3  and M 4  are each electrically connected to one another on the glass substrate  50 . 
       FIG. 11  is a diagram showing connection configurations between the radiation detector  20   a  and the scan line driving circuit  30  in accordance with the present exemplary embodiment. Each of the second scan lines M is connected to the scan line driving circuit  30  via a connection terminal  52  that is provided one for each of the pairs mentioned above. The scan line driving circuit  30  includes the first driving signal generation circuit  31  that operates when in the high resolution mode and the second driving signal generation circuit  32  that operates when in the low resolution mode. In the low resolution mode, the second driving signal generation circuit  32  outputs the same driving signals to the pairs of the second scan lines M. 
     As shown in  FIG. 10 , the second scan lines M 1  and M 2  and the second scan lines M 3  and M 4  that constitute pairs are each electrically connected to one another by the redundant lines R at the end portions that are at the opposite side from the end portions at the side at which the scan line driving circuit  30  is disposed. 
     Thus, in the radiographic imaging device  100   a  according to the present exemplary embodiment, the second scan lines M that constitute pairs are electrically connected, and in the low resolution mode the same driving signals are provided to the respective pairs. Therefore, the number of lines connecting the radiation detector  20   a  with the scan line driving circuit  30  may be half the number in the first exemplary embodiment. However, according to this configuration, capacitance loads at the scan line driving circuit  30  are increased, as a result of which rise times of the driving signals may be slower. In a case in which this would be a problem, a configuration that provides individual driving signals to the respective first scan lines M as in the first exemplary embodiment is preferable. 
     In the radiation detector  20   a  according to the present exemplary embodiment, similarly to the case of the first exemplary embodiment, imaging is possible in the high resolution mode and in the low resolution mode. Also similarly to the case of the first exemplary embodiment, even if a breakage occurs in a second scan line M, the driving signals outputted to the other second scan line M constituting that pair are provided via the redundant line R. Thus, occurrences of defective pixels may be prevented. 
     Third Exemplary Embodiment  
       FIG. 12  is a structural diagram showing electronic configurations of a radiographic imaging device  100   b  in accordance with a third exemplary embodiment of the present invention. In the radiographic imaging device  100   b  according to the present exemplary embodiment, a first scan line driving circuit  30   a  is disposed adjacent to one of two opposing edges of a radiation detector  20   b,  and a second scan line driving circuit  30   b  is disposed adjacent to the other of the two edges. That is, the first scan line driving circuit  30   a  and the second scan line driving circuit  30   b  are disposed so as to sandwich the radiation detector  20   b.    
     Each of the first scan lines G is connected to the first scan line driving circuit  30   a  via the respective connection terminal  52 . The first scan line driving circuit  30   a  includes a driving signal generation circuit that generates driving signals when in the high resolution mode, and sequentially outputs driving pulses to each of the first scan lines G. The TFTs  1  turn ON in response to the driving pulses provided via the first scan lines G, and output charges accumulated in the sensors  61  to the signal lines D. 
     Each of the second scan lines M is connected to the second scan line driving circuit  30   b  via the respective connection terminal  52 . The second scan line driving circuit  30   b  includes a driving signal generation circuit that generates driving signals when in the low resolution mode, and sequentially outputs driving pulses to each of the second scan lines M. The TFTs  2  turn ON in response to the driving pulses provided via the second scan lines M, and output charges accumulated in the sensors  61  to the signal lines D. Driving states in the high resolution mode and the low resolution mode are the same as in the first exemplary embodiment (see  FIG. 7  and  FIG. 8 ). 
     Thus, the present exemplary embodiment is configured in a mode in which the first scan line driving circuit  30   a  that operates when radiation images are being imaged in the high resolution mode and the second scan line driving circuit  30   b  that operates when radiation images are being imaged in the low resolution mode are separated from one another. In the present exemplary embodiment, the first scan line driving circuit  30   a  and the second scan line driving circuit  30   b  are disposed so as to sandwich the radiation detector  20   b.    
     The pair constituted by the second scan lines M 1  and M 2 , to which the same driving signals are provided at the same timings, are electrically connected by a redundant line R at the end portions at the side thereof at which the first scan line driving circuit  30   a  is disposed. Similarly, the pair constituted by the second scan lines M 3  and M 4  are electrically connected by a redundant line R at the end portions at the side thereof at which the first scan line driving circuit  30   a  is disposed. 
     Because the first scan lines G include wiring portions that extend toward the first scan line driving circuit  30   a,  the redundant lines R pass over the first scan lines G to be connected between the second scan lines M. Accordingly, in the present exemplary embodiment, the redundant lines R may be configured by jumper leads such as flexible cables or the like. Because the redundant lines R are configured by flexible cables or the like that are not formed integrally with the glass substrate  50 , the same TFT substrate may be used in a case in which scan line driving circuits are disposed at two sides of the radiation detector as in the present exemplary embodiment and a case in which a scan line driving circuit is disposed only at one side of the radiation detector as in the first exemplary embodiment. 
     Thus, in the radiographic imaging device  100   b  of the present exemplary embodiment with this configuration too, similarly to the case of the first exemplary embodiment, imaging is possible in the high resolution mode and in the low resolution mode. Also similarly to the case of the first exemplary embodiment, even if a breakage occurs in a second scan line M, the driving signals outputted to the other second scan line M constituting that pair are provided via the redundant line R. Thus, occurrences of defective pixels may be prevented. In the present exemplary embodiment, because the scan line driving circuits are provided at both sides of the radiation detector  20   b,  the size of the device is larger than in the first exemplary embodiment. Therefore, the radiographic imaging device  100   b  according to the present exemplary embodiment is excellent for application to a radiographic imaging device of a built-in type, which is incorporated in a standing table for imaging a radiation image in a standing position and a reclining table for imaging a radiation image in a reclining position, or the like. Further, according to the radiographic imaging device  100   b  in accordance with the present exemplary embodiment, because the first scan line driving circuit  30   a  that operates when radiation images are being imaged in the high resolution mode and the second scan line driving circuit  30   b  that operates when radiation images are being imaged in the low resolution mode are configured as separate bodies, switching between the high resolution mode and the low resolution mode may be achieved in a shorter duration than in a case in which these scan line driving circuits are integrally configured. 
     In  FIG. 12 , the single first scan line driving circuit  30   a  is provided for all the first scan lines G, and the second single scan line driving circuit  30   b  is provided for all the second scan lines M. However, the scan line driving circuits may be provided one for each of predetermined numbers of the scan lines G and M. As an example, in the case in which 1024 of the first scan lines G are provided in the radiation detector  20   b,  the first scan line driving circuit  30   a  may be provided one for each 256 lines. In this case, four of the first scan line driving circuit  30   a  are provided. In the present exemplary embodiment, because the number of the second scan lines M is half the number of the first scan lines G, in the case in which the number of the first scan lines G is 1024, the number of the second scan lines M is 512. Therefore, in a case in which the second scan line driving circuit  30   b  is provided one for each 256 of the second scan lines M, two of the second scan line driving circuit  30   b  are provided. Thus, the number of the second scan line driving circuits  30   b  may be smaller than the number of the first scan line driving circuits  30   a.  Therefore, at a time of a reset operation that is conducted before the start of imaging of a radiation image in order to clear out charges accumulated in the sensors  61 , power consumption may be reduced by using the second scan line driving circuits  30   b  that are fewer in number. Moreover, in a case in which the scan line driving circuits  30   b  are used to perform the reset operation, a duration required to complete the reset of the whole imaging area may be shorter than in a case in which the first scan line driving circuits  30   a  are used, and a duration from when an irradiation of radiation is started to when a charge accumulation mode is entered may be shortened. 
     Fourth Exemplary Embodiment  
       FIG. 13  is a structural diagram showing electronic configurations of a radiographic imaging device  100   c  in accordance with a fourth exemplary embodiment of the present invention. In the radiographic imaging device  100   c  according to the present exemplary embodiment, the first scan line driving circuit  30   a  is disposed adjacent to one of two opposing edges of a radiation detector  20   c,  and the second scan line driving circuit  30   b  is disposed adjacent to the other of the two edges. That is, the first scan line driving circuit  30   a  and the second scan line driving circuit  30   b  are disposed so as to sandwich the radiation detector  20   c . The first scan line driving circuit  30   a  is connected to each of the first scan lines G at end portions at the opposite side thereof from connection ends at which the second scan lines M are connected to the second scan line driving circuit  30   b.  Meanwhile, the second scan line driving circuit  30   b  is connected to each of the second scan lines M at end portions at the opposite side thereof from connection ends at which the first scan lines G are connected to the first scan line driving circuit  30   a.  Driving states of the radiation detector  20   c  are the same as in the third exemplary embodiment. 
     The pair constituted by the second scan lines M 1  and M 2 , to which the same driving signals are provided at the same timings, are electrically connected by a redundant line R 1  at the end portions at the side thereof at which the first scan line driving circuit  30   a  is disposed. In the present exemplary embodiment, the second scan lines M 1  and M 2  are also connected by a redundant line R 2  at the end portions at the side thereof at which the second scan line driving circuit  30   b  is disposed. Similarly, the pair constituted by the second scan lines M 3  and M 4  are electrically connected by a redundant line R 1  at the end portions at the side thereof at which the first scan line driving circuit  30   a  is disposed, and are electrically connected by a redundant line R 2  at the end portions at the side thereof at which the second scan line driving circuit  30   b  is disposed. 
     Thus, in the radiographic imaging device  100   c  according to the present exemplary embodiment, the respective scan lines M constituting pairs are electrically connected by the redundant lines R 1  and R 2  at both end portions thereof. Because the redundant lines are provided at plural locations, an occurrence of defective pixels may be prevented even if breakages occur at plural locations on a second scan line M. For example, as illustrated in  FIG. 13 , a case is described below in which a breakage occurs at point A 3  on the second scan line M 1 , between the composite pixels  70 ( 1 ) and  70 ( 2 ), and a breakage occurs at point A 4 , between the second scan line driving circuit  30   b  and the connection terminal  52 . In this case, the driving signals outputted by the second scan line driving circuit  30   b  to the second scan line M 1  are not provided to any of the composite pixels  70  on the second scan line M 1 . However, the driving signals outputted to the second scan line M 2  by the second scan line driving circuit  30   b  are provided via the redundant line R 1  to the composite pixel  70 ( 1 ) on the second scan line M 1 , and are provided via the redundant line R 2  to the composite pixels  70 ( 2 ) and  70 ( 3 ) on the second scan line M 1 . Therefore, an occurrence of defective pixels may be prevented even in the case in which breakages occur at point A 3  and point A 4 . If the redundant lines R 1  and R 2  were not present, all of the composite pixels  70  would have become defective pixels. 
     The present exemplary embodiment has a configuration in which the redundant lines R 1  and R 2  are provided at both end portions of the second scan lines M constituting a pair. However, the redundant line R 2  may be provided at a middle portion of the second scan lines M, between the composite pixels. Furthermore, the redundant lines may be both disposed at the two end portions of the second scan lines M and disposed at middle portions between the composite pixels. That is, the redundant lines may be provided at three or more locations on the second scan lines M constituting the pair. Thus, even in a case in which breakages occur at plural points on a second scan line, an occurrence of defective pixels may be prevented or an occurrence of defective pixels may be reduced in scale because the number of redundant lines is increased. This configuration in which two or more redundant lines connect the second scan lines M constituting a pair may also be applied to the radiation detectors according to the first and second exemplary embodiments. 
     Fifth Exemplary Embodiment  
       FIG. 14  is a structural diagram showing electronic configurations of a radiographic imaging device  100   d  in accordance with a fifth exemplary embodiment of the present invention. In a radiation detector  20   d  structuring the radiographic imaging device  100   d  according to the present exemplary embodiment, the mode of connection of the TFTs  2  that operate when in the low resolution mode to the second scan lines M and the signal lines D differs from the first to fourth exemplary embodiments described above. 
     The control terminals (gates) of the plural TFTs  1  that are driven when a radiation image is being imaged in the high resolution mode are connected to the respective first scan lines G. More specifically, the control terminals (gates) of the TFTs  1  in a plural number of the pixels  60  that are in a line along the direction in which the first scan lines G extend are connected to the same first scan line G. For example, in the example shown in  FIG. 14 , the control terminals (gates) of the TFTs  1  structuring pixels  60 ( 1 ) to  60 ( 4 ) are connected to the first scan line G 1 , and the control terminals (gates) of the TFTs  1  structuring pixels  60 ( 5 ) to  60 ( 8 ) are connected to the first scan line G 2 . 
     The control terminals (gates) of a plural number of the TFTs  2  that are driven when a radiation image is being imaged in the low resolution mode are connected to each of the second scan lines M. More specifically, the TFTs  2  in a plural number of the pixels  60  that are in a line along the direction in which the second scan lines M extend are connected to the same second scan line M. For example, in the example shown in  FIG. 14 , the gates of the TFTs  2  structuring pixels  60 ( 1 ) to  60 ( 4 ) are connected to the second scan line M 1 , and the control terminals (gates) of the TFTs  2  structuring pixels  60 ( 5 ) to  60 ( 8 ) are connected to the second scan line M 2 . 
     The output terminals of the TFTs  1  in a plural number of the pixels  60  that are in a line along the direction in which the signal lines D extend are connected to the same signal line D. For example, in the example shown in  FIG. 14 , the output terminals of the TFTs  1  in pixels  60 ( 1 ),  60 ( 5 ),  60 ( 9 ) and  60 ( 13 ) are connected to the signal line D 1 , and the output terminals of the TFTs  1  in pixels  60 ( 2 ),  60 ( 6 ),  60 ( 10 ) and  60 ( 14 ) are connected to the signal line D 2 . 
     The output terminals of the TFTs  2  in four pixels that are adjacent to one another in the direction in which the scan lines G and M extend and in the direction in which the signal lines D extend are connected to the same signal line D. For example, in the example shown in  FIG. 14 , the output terminals of the TFTs  2  that constitute the composite pixel  70 ( 1 ) formed of the pixels  60 ( 1 ),  60 ( 2 ),  60 ( 5 ) and  60 ( 6 ) are connected to the signal line D 1 , the output terminals of the TFTs  2  that constitute the composite pixel  70 ( 3 ) formed of the pixels  60 ( 9 ),  60 ( 10 ),  60 ( 13 ) and  60 ( 14 ) are connected to the signal line D 2 , the output terminals of the TFTs  2  that constitute the composite pixel  70 ( 2 ) formed of the pixels  60 ( 3 ),  60 ( 4 ),  60 ( 7 ) and  60 ( 8 ) are connected to the signal line D 3 , and the output terminals of the TFTs  2  that constitute the composite pixel  70 ( 4 ) formed of the pixels  60 ( 11 ),  60 ( 12 ),  60 ( 15 ) and  60 ( 16 ) are connected to the signal line D 4 . 
     In the low resolution mode, the scan line driving circuit  30  provides driving pulses sequentially to the pair formed of the second scan lines M 1  and M 2  and to the pair formed of the second scan lines M 3  and M 4 . That is, the same driving signals are provided at the same timings to the second scan lines M 1  and M 2 , and then the same driving signals are provided at the same timings to the second scan lines M 3  and M 4 . 
     When a driving pulse is provided to the second scan lines M 1  and M 2 , each of the TFTs  2  connected to the second scan lines M 1  and M 2  turns ON, and the charges accumulated in the sensors  61  in pixels  60 ( 1 ) to  60 ( 8 ) are outputted to the signal lines D 1  and D 3 . More specifically, for example, the charges accumulated in the sensors  61  of the four pixels  60 ( 1 ),  60 ( 2 ),  60 ( 5 ) and  60 ( 6 ) that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend are respectively outputted via the TFTs  2  in those pixels to the signal line D 1 . Further in this example, the charges accumulated in the sensors  61  of the four pixels  60 ( 3 ),  60 ( 4 ),  60 ( 7 ) and  60 ( 8 ) that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend are respectively outputted via the TFTs  2  in those pixels to the signal line D 3 . 
     Then, when a driving pulse is provided to the second scan lines M 3  and M 4 , each of the TFTs  2  connected to the second scan lines M 3  and M 4  turns ON, and the charges accumulated in the sensors  61  in pixels  60 ( 9 ) to  60 ( 16 ) are outputted to the signal lines D 2  and D 4 . More specifically, for example, the charges accumulated in the sensors  61  of the four pixels  60 ( 9 ),  60 ( 10 ),  60 ( 13 ) and  60 ( 14 ) that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend are respectively outputted via the TFTs  2  in those pixels to the signal line D 2 . Further in this example, the charges accumulated in the sensors  61  of the four pixels  60 ( 11 ),  60 ( 12 ),  60 ( 15 ) and  60 ( 16 ) that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend are respectively outputted via the TFTs  2  in those pixels to the signal line D 4 . 
     Operations when in the high resolution mode are the same as in the case of the first exemplary embodiment, so are not described here. 
     Thus, in the radiographic imaging device  100   d  according to the present exemplary embodiment, in the low resolution mode the charges accumulated in the sensors  61  of a set of four pixels that are adjacent to one another in the direction in which the scan lines G and M extend and the direction in which the signal lines D extend are simultaneously outputted to the same signal line D. That is, in the low resolution mode, the composite pixels  70  are configured by combinations of four individual pixels of the high resolution mode. In other words, four pixels in the high resolution mode become a single pixel in the low resolution mode, and the resolution in the low resolution mode is a quarter of the resolution in the high resolution mode. Further, in the present exemplary embodiment, because a driving pulse is provided simultaneously to the pair of second scan lines M 1  and M 2  and charges are read simultaneously from the pixels  60  of two rows, the frame rate in the low resolution mode is two times that in the high resolution mode. Thus, a high frame rate is achieved. 
     The second scan lines M 1  and M 2  that constitute a pair to which the same driving signals are provided from the scan line driving circuit  30  simultaneously are electrically connected to one another by a redundant line R, at the end portions of the scan lines M 1  and M 2  that are at the opposite side thereof from the end portions at the side at which the scan line driving circuit  30  is disposed. Similarly, the pair formed of the second scan lines M 3  and M 4  are electrically connected to one another by a redundant line R at the end portions of the scan lines M 3  and M 4  that are at the opposite side thereof from the end portions at the side at which the scan line driving circuit  30  is disposed. Thus, the same as in the exemplary embodiments described above, even in a case in which a breakage has occurred on a second scan line M that is a transmission path for driving signals in the low resolution mode, driving signals that are outputted to the other second scan line M constituting the pair are provided via the redundant line R, and thus occurrences of defective pixels may be prevented. 
     The exemplary embodiments described above illustrate a radiographic imaging device of an indirect conversion type in which irradiated radiation is converted to light by a scintillator to image a radiation image. However, the present invention is also applicable to a radiographic imaging device of a direct conversion type that directly converts radiation to charges in a semiconductor layer of amorphous selenium or the like. 
     Further, the exemplary embodiments described above illustrate a case in which four pixels in the high resolution mode serve as a single pixel in the low resolution mode. However, the resolution in the low resolution mode may be altered as appropriate, by modifying connection configurations between the TFTs  2  and the second scan lines M and signal lines D to increase the number of sensors from which charges are simultaneously read out into the same signal line (in other words, the number of the pixels  60  that constitute each composite pixel  70 ). In this case, if the number of the second scan lines to which the same or identical driving signals are provided in the low resolution mode is three or more, it is appropriate to provide redundant lines so as to connect each of these second scan lines to one another. 
     Configurations of the respective exemplary embodiments described above may be combined as appropriate. 
     In the exemplary embodiments described above, a case is illustrated in which X-rays are detected as the radiation that is the object of detection. However, the present invention is not limited thus. For example, the radiation that is the object of detection may be any of visible light, ultraviolet rays, infrared rays, alpha rays, gamma rays and the like. 
     In addition, configurations of the radiographic imaging system, configurations of the radiographic imaging device and so forth described in the above exemplary embodiments are examples, and may be suitably modified within a technical scope not departing from the spirit of the present invention. 
     The disclosures of Japanese Patent Application No. 2012-123627 are incorporated into the present specification by reference in their entirety. 
     All references, patent applications and technical specifications cited in the present specification are incorporated by reference into the present specification to the same extent as if the individual references, patent applications and technical specifications were specifically and individually recited as being incorporated by reference.