| 摘要 |
PURPOSE:To prevent hunting, etc., of video signals so as to always obtain a properly exposed image, by holding a video image pickup device at the operating state just before a mirror is lifted up over the mirror-up period at the time of shutter releasing and releasing the image pickup device from the operating state when the mirror is returned to the original state and light is made incident to a finder. CONSTITUTION:The holding circuit 34 of an auto-iris controlling circuit 30 continues the input to an iris error amplifier 35 by holding the detecting DC voltage of a detecting circuit 32 by means of hold signals outputted from a timer circuit 40 at the timing of shutter releasing. The detecting DC voltage just before mirror-up is performed is continuously inputted to the iris error amplifier 35 even after the light to a finder is intercepted and the detecting circuit 32 does not make any output. Accordingly, an auto-iris 7 is fixed to the operating state just before the mirror-up. When the hold signal of the timer circuit 40 is interrupted after a prescribed shutter time has passed, a quick return mirror 1 is returned and light is made incident to the finder, and then, the holding circuits 26 and 34 are released from their held states.
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