| 摘要 |
PURPOSE:To detect electrically the position of a movable lens and to realize high-accuracy power focusing by providing a movable lens cylinder, a driving part, a position sensor part, a position decision part, a position setting part, and a position indication part. CONSTITUTION:The movable lens cylinder 5 provided in a fixed cylinder 5 so that it can move forth and back freely is driven by a driving part 61 with a motor 8, the position decision part 21 which decides and indicates the position of the movable lens cylinder 5 is connected to the position sensor part 41 which has an electrostatic capacity sensor 15 for detecting the position of the movable lens cylinder 5, and the position indication part 50 is provided which compares the outputs of both the position decision part 21 and the position setting part 45 outputting a position where the movable lens cylinder 5 is expected to move and then indicates the position where the movable lens cylinder 5 is expected to move to a driving part 61. Thus, the device is obtained which has a power focusing function for driving parts except a front lens by controlling the position of the movable lens while measuring the movement size accourately. |
