Patent ID: 8107588

Claim:
A radiation imaging apparatus comprising: a detection unit for detecting as an image signal radiation that is emitted from a radiation generator has passed through an object; a read-out unit for amplifying and reading out the image signal detected by said detection unit; and a control unit for controlling at least one of the radiation generator, said detection unit said read-out unit to cause the image signal to have an S/N ratio required for the image signal, wherein when a radiation dosage at which the S/N ratio required for the image signal is achieved is within a first range, in which a first noise component relating to the radiation dosage is dominant among noise components in the image signal, said control unit adjusts the radiation dosage, and when the radiation dosage at which the S/N ratio required for the image signal is achieved is within a second range, in which a second noise component inherent in said detection unit or said read-out unit is dominant among noise components in the image signal, and when the radiation dosage within the second range is smaller than the radiation dosage within the first range, said control unit adjusts at least one of an amplification ratio of said detection unit and an amplification ratio of said read-out unit.