Patent ID: 7994481

Claim:
A radiation imaging apparatus comprising: an area sensor for reading out an electric signal accumulated in a plurality of pixels arranged in a matrix, line by line, wherein the area sensor operates in a first operation for deriving radiation image data by reading a signal accumulated during irradiation with radiation, and a second operation for deriving offset data by reading a signal accumulated during non-irradiation with radiation, alternately, and wherein a frame rate is an inverse number of a sum of a time for the first operation and a time for the second operation; and a control unit for controlling the area sensor, wherein each of the first and second operations includes a waiting operation for accumulating the electric signal in the plurality of pixels of the area sensor and a read-out operation for reading out the electric signal accumulated in the plurality of pixels of the area sensor, and wherein the control unit switches the frame rate after the end of the read-out operation in the first operation and before an end of the read-out operation in the second operation which is continuous to the end of the read-out operation in the first operation.