Water-proof optical switching device for controlling flash light emission

摘要

An optical switching device comprises a light emitting device, a reflector for reflecting a light emitted by the light emitting device and having a plurality of set states, a reflected light distribution being changed by switching the set state, a pair of photo-sensing devices for sensing a light from the reflector, and a detector for detecting a difference between light amounts sensed by the photo-sensing devices. The set state of the reflector is discriminated based .on the detection output of the detector.