Radiation imaging apparatus, radiation imaging system, and method of controlling radiation imaging apparatus

A radiation imaging apparatus capable of taking a moving picture by acquiring a plurality of radiation image signals on the basis of a plurality of times of irradiation with radiation pulses, the radiation imaging apparatus comprising:

• a radiation detector having a two-dimensional array of pixels for detecting electric signals based on incident radiation rays;
• a reading circuit configured to read image signals based on the electric signals;
• an analog-to-digital convener configured to convert the electric signals read by the reading circuit into digital signals;
• and
• a controller configured to switch an operation status of the analog-to-digital convener in a period between a start of an n-th time of irradiation with radiation pulse and a start of an (n+1)-th time of irradiation with radiation pulse, where n is a natural number,
• wherein the period includes at least a first period which includes an irradiation period in which the radiation detector is irradiated with the n-th time radiation pulse and a second period in which the reading circuit reads the image signals, and
• wherein the controller controls the analog-to-digital converter during the period so that power consumption of the analog-to-digital converter in the first period is smaller than power consumption of the analog-to-digital converter in the second period.