EQUIPMENT FOR ACCUMULATION TIME CONTROL AND ACCUMULATION SIGNAL PROCESSING FOR PHOTOELECTRIC CONVERSION ELEMENT

摘要

PURPOSE:To improve responsiveness, to expand a luminance range possible to be read, and to improve the accuracy of an image signal, by terminating charging and the accumulation operation of a transducer at a time when a voltage arrives at a reference voltage whose value is set in advance at the value not exceeding the dynamic range of an A/D conversion part, etc. CONSTITUTION:When a various kinds of signals representing indication to start the accumulation operation of the image signal are sent from a microcomputer 3, the peak signal Vp and the dark signal Vd of the image signal at that time are calculated at a line sensor 1, and those signals are outputted to a signal processing circuit 2. The signal processing circuit 2, after, for example, starting the accumulation operation based on a various kinds of signals such as a BUS1 and a BUS2, etc., continues the accumulation operation until a peak detecting signal Vi arrives at the reference voltage V1 when the vi does not arrive at the V1 even after the lapse of a prescribed time To, and afterwards, terminates accumulation at a time t3 when the Vi arrives at the reference voltage V2. In such a way, it is possible to improve the accuracy of the accumulation signal in low luminance as improving not only the responsiveness in high luminance but the responsiveness in the low luminance.