| 摘要 |
<p>PURPOSE:To reduce the time from the release action to the start motion of the shutter in a simple constitution by suspending the drive of diaphragm blades when the phototometric output reaches the value corresponding to the proper diaphragm value, and concurrently moving the mobile mirror to the photographic position. CONSTITUTION:When diaphragm lever 20 is moved clockwise via lever 23 by the depression of shutter button, sector gear 22 spring-connected is rotated to ratate ratchet wheel 28, but its speed is reduced by anchor 30 and escape wheel 29 so that stopping-down is carried out at at low speed. The light of object which passes it is incident onto photodetector PD1 via mirror 31 and pentaprism 41, etc., and its aperture is stopped down to the proper aperture, whereupon magnet Mg1 is operated so that locking lever 21 locks the ratchet wheel 28 to decide the diaphragm aperture. At the same time, magnet Mg2 works to raise the mirror 31 and move it to the observation position of the object to the photographic position. Accordingly, the time from release action to start of shutter can be reduced.</p> |
