| 摘要 |
<p>PURPOSE:To eliminate the bad influence of chattering upon a dimming circuit by starting dimming operation in response to the separation of the movable contact of a bipolar switch which operates when a shutter is fully open and by starting the flashing of an electric flash when the contact touches the other electrode. CONSTITUTION:A transistor (TR) 11 is initially in an on-state, but turns off when the terminals A and C of a bipolar switch 13 separates from each other on the completion of a front curtain run. Consequently, charging a capacitor 10 is started with a current from a dimming circuit 9 including a photodetecting element 20 which photodetects reflected light from a film surface. When the terminal A comes into contact with the terminal B, an X contact terminal 16 is grounded and an electric flash starts flashing. As the integral value of the capacitor 10 reaches a prescribed value, a comparing circuit 14 outputs a light-emission stop signal. The terminals C and B differ in operation period, so dimming circuits 9 and 10 have no influence of the chattering of the terminals B and A.</p> |
