| 摘要 |
PROBLEM TO BE SOLVED: To automatically adjust the focus of a camera at high speed. SOLUTION: First an optical system is moved by a prescribed amount N towards a far FAR distance direction and based on an increasing/decreasing tendency of a level change in a high-frequency component, the succeeding moving direction of the optical system is decided (O-Q section). Then the optical system is moved at a high speed, the level of the high frequency component is changed from an increasing tendency into a decreasing tendency, and the optical system is moved at a low speed in the opposite direction at a point R the level is decreased just by a prescribed levelα. Then after confirming that a position maximizing the level of the high frequency component, that is, a focal position P is passed by low-speed movement (after the arrival of a point S), the optical system is returned to the focal position P at high speed. |
