| 摘要 |
PURPOSE:To eliminate the need for electromagnet and considerably lower production costs by performing holding of a movable lens group for focus controlling in a focus coincidence position by means of a ratchet and a pawl member. CONSTITUTION:The lens frame 3 of a camera is mounted to an immobile member 2 of the camera by means of helicoid gears 3a, 2a. When the frame 3 is turned by a cam ring 7, a pawl part 21a successively rides over the teeth of a ratchet part 18a and engages with the tooth on the far right end corresponding to a focal length, for example, 0.8m, because the pawl member 21 is held energized by a spring 23. Since a terminal 34d for detecting the turning angle at which the cam ring opposes to 0.8m and a common terminal 33 are connected, a control circuit 35 compares this state with the distance information having been stored based on the depression of a pushbutton switch 36d, and detects the coincidence to cause a motor 8 to invert and the cam ring 7 to return to the home position. |
