| 摘要 |
PURPOSE:To execute smoothly a switching operation of a focal distance and a focusing by constituting simply a switching mechanism of a focal distance and a focusing mechanism of a photographing optical system. CONSTITUTION:When a telephoto-standard changeover switch is set to a standard side, a lens barrel earth plate 3 moves to the rear direction of a camera by using a supporting bar 2 as a guide, and when a pattern detected by a contact piece 22 is cut, an electric conduction to a motor 11 is also cut, and said plate is held in its position. When a release operation is executed, the lens barrel earth plate 3 is fed in the front direction, and a prescribed number of pulses corresponding to distance information is counted by contact pieces 18a, 18b, the electric conduction to the motor 11 is turned off, and the focusing is ended. When said switch is set to a telephoto side, the lens barrel earth plate 3 moves to the front direction of the camera, and when a pattern detected by contact pieces 20, 21 is cut, the electric conduction to the motor 11 is cut. In this case, a sub-lens 4 is placed onto a photographing optical axis. When the release operation is executed, a prescribed number of pulses is counted by contact pieces 17a, 17b, the feeding of the lens barrel earth plate 3 is stopped and the focusing is ended. |
