| 摘要 |
A camera provided with a circuit for determining the closing of a focal plane shutter in accordance with a desired time interval includes additional control circuitry for enabling an exposure to be controlled by closure of the lens shutter in an objective lens assembly which is mounted to the camera body. The additional control circuitry includes a normally closed switch shunting a first pair of connector terminals to maintain operation of the control circuitry when the objective lens assembly is not mounted to the camera body. The normally closed switch is open with the objective lens assembly mounted to the camera body and mechanism for closing the lens shutter is energized through a normally open switch closed by the opening movement of the focal plane shutter. An additional switch is shunted across a pair of terminals interconnecting the lens assembly with the camera body and is closed with the lens shutter open to maintain energization of the focal plane shutter restraining control mechanism. With the objective lens assembly mounted to the camera the apparatus for determining the exposure time interval is set at a time greater than the exposure interval and the mechanism for closing the lens shutter is energized by the closing of the normally open switch and the opening of the additional switch closes the focal plane shutter by de-energizing the control circuit. In another embodiment an additional normally open switch shunting the integrating capacitor in the control circuit is closed with the mounting of said objective lens assembly to the camera body to automatically disable the control circuit enabling exposure to be effected by the lens shutter.
|
