Patent ID: 8247779

Claim:
A radiation imaging apparatus comprising: a sensor array constructed by arranging, in a matrix form, a plurality of pixels each including a converting element configured to convert radiation into charges and a thin film transistor which has a control terminal and two main terminals and in which one of said two main terminals is connected to said converting element in order to output an electric signal according to the charges; a driving circuit configured to supply signals to said control terminals of said plurality of thin film transistors on a row-unit basis; a reading circuit configured to hold an electric signal read out through the other one of said two main terminals into a first sampling and holding circuit or a second sampling and holding circuit and output an image signal based on the electric signal; and a control unit configured to control said driving circuit and said reading circuit, wherein, for a period of time until an image signal according to a pulse-shaped radiation is output after termination of irradiation of said sensor array by the pulse-shaped radiation, said control unit allows said driving circuit to drive said thin film transistor of a predetermined pixel, thereby allowing a first electric signal to be output from said predetermined pixel, allows said driving circuit to drive said thin film transistor of said predetermined pixel in which the first electric signal has been output, thereby allowing a second electric signal to be output from said predetermined pixel, and allows said reading circuit to output the image signal based on an electric signal corresponding to a difference between the first electric signal held in the first sampling and holding circuit and the second electric signal held in the second sampling and holding circuit.