Abstract: A blade type focal plane shutter wherein an exposure aperture is made to be always covered with a front blade group and rear blade group in a mirror-down state by operatively connecting a quick return mirror and a blade opening and closing controlling mechanism with each other in order to obtain a high light shielding property with the front blade group and rear blade group except when an exposure is made.

Abstract: A shutter blade is actuatable by a driver which can be locked in a shutter setting position by a locking lever assembly comprising a first lever having a bent end engageable with the driver and a second lever having an iron member attractable by an electromagnet which, when energized, causes the first and second levers to be angularly moved in unison in a direction to release the driver for actuating the shutter blade. The second lever is lockable against movement to actuate the driver by a reciprocable follower movable in response to operation of a quick return mirror mechanism. When a shutter button is depressed to move the mirror upwardly for starting an exposure operation, the second lever is disengaged from the follower, and attracted by the electromagnet as energized to release the driver. When the exposure operation is finished, the mirror is lowered to enable the follower to lock the second lever against movement.