| 摘要 |
PURPOSE:To decrease the time until arrival of focusing point when the diaphragm of lens is stopped deeply by selecting a closed loop driver when a level of a high frequency component is maximized and then decreased to the movement of lens to bring the mode to the closed loop mode. CONSTITUTION:When a search driver 106 or a direction discriminating driver 107 is selected, the closed loop driver 108 is not selected soon and a peak passing detector 112 selects the closed loop driver 108 when the high frequency detection output level is maximized and then decreased to bring the mode to the closed loop mode. When the driver 108 is selected already and the mode is in the closed loop mode, a level change detector 114 detects whether or not a high frequency detected output has a large level change. If a large level change is detected, the mode is transited to the direction discriminating mode forcibly. That is, a direction discriminating hold device 101 discriminates the focusing direction and applies the drive direction signal 2 to a direction discrimination driver 107 to select the driver 107 and then the closed loop is set. |
