| 摘要 |
PURPOSE:To facilitate automtion and to align mecahnically and precisely a small stop to an optical axis by switching the small stop by an intermitting the conduction to an electromagnet. CONSTITUTION:When a release button is pressed down, an external surface cam 4 rotates counterclockwise through the operation of a motor M to press and rotate the bent part 2c of a stop blade 2 clockwise against a spring 7 by a projection part 4b, and an open aperture stop 2a is positioned closely to an aperture part 1. At this time, the electromagnet 8 attracts and holds an attraction part 2d. Further, a cam 4 is rotated and the magnet 8 is powered off to close the aperture part 1. The magnet 8 is not conducted to a small aperture, a change from a state right before the attracting operation of the magnet to the counterclockwise rotation is made following up the rotation of the cam 4 and the blade contacts a stop pin 9 on a substrate. The cam 4 further rotates continuously to perform exposure by a shutter blade before starting contacting the bent part 2C. |
