Automatic exposure control method for photographed image and automatic exposure control apparatus using the method

摘要

An automatic exposure control method for an image produced on a solid-state image sensing device in which intensity of radiation light irradiated to an object to be examined from a radiation source is feedback controlled. The solid-state image sensing device comprises a picture element producing part where electric charges generated by way of photo-electric conversion when receiving exposure, and a dark current measuring part where a dark current is generated and stored without receiving exposure. The image is produced while performing radiography in a manner that the intensity of radiation light is feedback controlled so as to keep, within a predetermined density range, the amount value which is defined by removing the charge signals stored on a specified pixel element or a specified pixel element column in the dark current measuring part of the image sensing device from the charge signals stored on a specified pixel element or a specified pixel element column in the picture element producing part of the image sensing device.