AUTO FOCUSING APPARATUS FOR CAMERA SYSTEM AND METHOD FOR SHORTENING FOCUSING TIME

摘要

PURPOSE: An apparatus for controlling a focus of a camera system automatically and a method for reducing a focus controlling time thereof are provided to reduce an auto focus controlling time by varying a moving speed of a lens. CONSTITUTION: A function f_a() signifies the first focus value and a function f_b() signifies the second focus value. The first and the second focus values are calculated by adding image signals passing through different frequency bands. The third focus value is calculated by adding the first and the second focus values. A moving speed of a lens varies in accordance with a relative distance from the final lens location to a present lens location.