| 摘要 |
PURPOSE:To prevent human's eyes from being injured by detecting a current supplied to a semiconductor laser or the like used as a projecting means for an automatic focusing device, and interrupting outputted light by a protective cover when the detected value exceeds a prescribed value. CONSTITUTION:A bodytube 2 of a lens 1 is delivered to the front of a camera by using a bar 3 and a guiding pin 6 as guides at the completion of charging. The projective cover 7 is rotated by a spring 8 and held at the position where the cover 7 is abutted on a stopper pin 12 to cover the front surfaces of a projection lens 1a, a photodetecting means 1b and a photographing lens 1. A magnet 9 is turned on by the 1st stroke for release and excited by the 2nd stroke, so that the cover 7 is removed from the front of the lenses 1, 1a, 1b and a semiconductor laser 4 is emitted. The reflected light is detected by a photodetector 5 to control the bodytube 2. If an excessive current is made flow into the laser 4, the current is not supplied to the magnet 9, so that the protective cover 7 is not opened. |
