| 摘要 |
PROBLEM TO BE SOLVED: To reduce noise sound by deciding a drive speed of a focus adjustment lens means depending on a drive amplitude so as to reduce the drive speed in comparison with a conventional device thereby making number of fields required for the movement the same as the conventional device. SOLUTION: A camera control microcomputer 115 moves a focus lens 105 so as to maximize an output signal from an AF evaluation value processing circuit 114 extracting a high frequency component used for focus detection from an output signal from a CCD 106 so as to adjust the focus automatically. In the case that an aperture 103 is open, since the depth of field is shallow, the lens 105 is moved with a small amount because a focus voltage is changed regardless of a small movement, and conversely in the case that the aperture 103 is closed, the movement amount of the lens 105 is set larger. Then the drive speed is decided by calculating a time required for the movement of the setting moving amount based on the moving time of the setting moving amount when a focus compensation lens motor 114 is driven at a highest speed (to what number of fields the moving time is equivalent) so as to drive the lens 105. Since the lens 105 has only to reach an object position just before the start of a succeeding field, the slower drive speed than that of a conventional device is adopted. |
