Radiation imaging method and apparatus

This invention discloses a radiation imaging apparatus. According to the radiation imaging apparatus of this invention, any separate automatic exposure controller (AEC) sensor need not be prepared. If an AEC sensor is arranged on the radiation imaging apparatus, as in the prior art, the image quality degrades because an image sensor receives radiation that is attenuated by the AEC sensor. This can be avoided in this invention. Additionally, the apparatus main body can be made compact. To accomplish this, the radiation imaging apparatus has a first optical conversion element that converts incident radiation into an electrical signal, and generates image information on the basis of the electrical signal output from the first optical conversion element. Below a portion that is aligned to the gap between the first optical conversion elements, a plurality of second optical conversion elements which detect the incident amount of the radiation from the gap are formed. Exposure control for the radiation or control of the optical conversion elements is executed on the basis of the detection result by the second optical conversion element.