Radiation image capturing apparatus, radiation image capturing system, and method of controlling radiation image capturing apparatus

A radiation image capturing apparatus, comprising:

• an image capturing unit comprising a plurality of pixels and configured to capture a radiation image, a part of the plurality of the pixels which is used as a detection element configured to detect radiation for obtaining an accumulated value of irradiated radiation incident on the radiation image capturing apparatus separately from obtaining the radiation image, and
• a processor configured to calculate the accumulated value of irradiated radiation based on a signal from the part of the plurality of the pixels, wherein the processor is configured to:
• perform an operation of repeatedly resetting the plurality of the pixels before receiving an exposure request from a user;
• perform a reset operation of resetting the part of the plurality of pixels in accordance with the exposure request, where pixels, of the plurality of the pixels, other than the part of the plurality of the pixels are not reset;
• and
• calculate the accumulated value of irradiated radiation based on the signal from the part of the plurality of the pixels after the reset operation of resetting the part of the plurality of the pixels.