AUTOMATIC FOCUSING APPARATUS FOR AUTOMATICALLY ADJUSTING FOCUS IN RESPONSE TO VIDEO SIGNAL BY FUZZY INFERENCE

摘要

The autofocus device of the video camera performs focusing automatically based on the video signal obtained from the imaging session. The autofocus device detects the level of the high frequency component of the video signal and supplies a focus evaluation value that takes a maximum at the focus matching position. The focus motor control circuit executes the auto focus operation by the climbing servo method based on this focus evaluation value. The initial setting of the lens movement direction at the start of the autofocus operation, the selection of the focus region among the plurality of regions, and the restart of the autofocus operation due to the subject change after the autofocus operation is completed once are determined using fuzzy inference.