Automatic focussing circuit for camera - has delay circuit to ensure lens is focussed before shutter release is effective

摘要

A delay system for a camera with automatic focussing prevents shutter release before the object is in focus. The delay unit is located between the camera shutter release and the exposure functions, i.e. the shutter and aperture mechanisms of an automatic camera, and the unit delays exposure until the lens focussing unit transmits a signal to indicate sharp focus. The lens focussing mechanism is on the output of the automatic range finder. A variation is to have the shutter release button directly feeding the range finder and the latter providing a trigger signal to a shutter release/aperture stop down control.