Patent ID: 9097811
Filing Date: 2015-08-04
Classification: G01T,H04N

Abstract:
1. A radiographic image detector comprising: an imaging device configured to detect a radiographic image of a subject from radioactive rays that penetrate through the subject after being radiated from a radiation source, wherein said imaging device has an imaging area in which a plurality of pixels are arranged in a matrix to accumulate signal charges corresponding to incident amounts of the radioactive rays therein, and a plurality of scanning lines for driving said pixels and a plurality of signal lines for reading out the signal charges from said pixels to output the radiographic image are provided in correspondence with lines and columns of said pixels respectively; a driving device configured to output a drive signal to a respective scanning line to turn a single switching transistor, associated with a respective pixel of said plurality of pixels, ON and OFF, the source terminal of said single transistor connected to a respective signal line of said plurality of signal lines, said single switching transistor configured to execute sequentially a pixel resetting operation, a charge accumulating operation for accumulating the signal charge in said pixel, and a signal charge reading operation for reading out the accumulated signal charge from said pixel, wherein said single switching transistor is turned ON in said pixel resetting operation to read out a dark charge through said respective signal line, the dark charge being generated in said pixel regardless of the radioactive rays, said single switching transistor is turned OFF in said charge accumulating operation, and said single switching transistor is turned ON in said signal charge reading operation to read out the signal charge through said respective signal line; a radiation detecting device configured to perform a radiation detecting operation for detecting the start of radiation of the radioactive rays by monitoring a charge leak from said pixel to said respective signal line while said single switching transistor is OFF, the amount of charge leak corresponding to the dark charge and the signal charge accumulated in said pixel; and a control device configured to control said radiation detecting device and said driving device to start said radiation detecting operation by turning said single switching transistor OFF before starting said charge accumulating operation, and to start said charge accumulating operation while keeping said single switching transistor OFF after said radiation detecting device detects the start of radiation of the radioactive rays.