PURPOSE: To prevent a photographic lens from moving for a prescribed time by providing a timer circuit which inhibits the driving of the photographic lens until at least a prescribed time elapses since a focusing signal is annhilated by the retreat operation of a mirror.
CONSTITUTION: A counter 13 is constituted of plural FF circuits 10W12, is cleared by the focusing signal of a detector 3, and counts the pulse outputs of a pulse generator 8 via an OR circuit 9 after the focusing signal annhilates. A timer circuit is constituted of the pulse generator 8, the OR circuit 9 and the counter 13. A switch 14 performs opening on the way of retreating of a quick return mirror to the outside of the photographic optical path, and performs closing on the way of resetting of the quick return mirror into the photographic optical path. While this switch is open, it disables the focus detector 3.
OGASAWARA AKIRA
TERUI NOBUHIKO
HOSHINO KUNIHISA
UTAGAWA TAKESHI
| JPS5587128A | 1980-07-01 | |||
| JPS52126225A | 1977-10-22 |
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