AUTOMATIC FOCUS DETECTING DEVICE FOR CAMERA

摘要

PURPOSE:To shorten an arithmetic time and to improve tracking performance for an object by performing focusing arithmetic operation based upon the shift quantity limited almost in a focusing state by a block which obtains a signal indicating the nearest focus state selected by last focusing detection arithmetic operation. CONSTITUTION:A microcomputer 30 stores the block whose gap between images is largest by the last focusing arithmetic operation and performs focusing detection arithmetic operation by the zone arithmetic routine of the 1st time for the block at the time of refocusing arithmetic operation. Then the 1st focusing detection correlative arithmetic is performed by a flow branched by set (n) and the focusing detection arithmetic operation after temporary focusing detecting operation is speeded up. Further, when the block whose gap between images is largest is selected preferentially in block fractionization focusing detection arithmetic operation, the number of times of correlation arithmetic for the focusing detection of following blocks is decreased to improve the response of focusing adjustment.