| 摘要 |
PROBLEM TO BE SOLVED: To provide an autofocus method and an autofocus device by which the peak position of an AF evaluated value can be detected in a shorter time without drastically lowering the detecting accuracy of a focusing position in contrast detection type autofocus control. SOLUTION: In a system, the AF evaluated value is calculated based on a high frequency component included in an output signal from a CCD at respective positions while a focus lens is moved in an optical axis direction by a stepping motor, and the focus lens is moved to the peak position where the AF evaluated value is the largest. The focus lens is continuously moved within a searching range and exposure is performed by the CCD in a specified cycle in course of the movement of the focus lens. By shortening an AF evaluation cycle for acquiring the AF evaluated value, the speed-up of autofocus operation is realized. Besides, since the vibration of the focus lens is not increased for every AF evaluation cycle, the operation noise of the focus lens at the time of autofocus control is decreased. COPYRIGHT: (C)2003,JPO |
