Patent ID: 9749518
Date: 2017-08-29
CPC Classifications: G02B,G03B,G06K,H04N

Claim:
1. A focusing device comprising: an image capturing unit that captures a subject image formed via an optical system including a lens for executing focus adjustment and outputs an output signal; an edge detection unit that detects an edge signal among the output signal in correspondence to each color component among a plurality of color components contained in an image based upon the output signal; a calculation unit that calculates edge differential values each of which is a differential value of the edge signal in correspondence to the each color component; and a control unit that controls a moving direction along which the lens is to move based upon a comparison of the edge differential values, wherein the control unit calculates two ratios of the edge differential values in correspondence to different color components among the plurality of color components and determines a direction, for a position at which the two ratios match each other or along Which a difference between the two ratios is getting smaller, as the moving direction.