Reflection scanner e.g. for object position sensing - has photosensitive elements connected in pairs in antiparallel, and arranged so that one element of one pair lies between two elements of other pair

摘要

The reflection scanner is equipped on the receiver side with at least four photo sensitive elements (13-16). The elements are connected in anti-parallel pairs, and are assigned spatially to each other so that between two elements (13,15 or 14,16) forming a receiving channel (26,27), one element (15,15) of another pair is arranged. The output signals of the two receiving channels (26,27), after current-voltage conversion are supplied respectively to frequency selective amplifiers (30,31). The gains of the amplifiers are adjusted steplessly by means of control voltages (USA,USB) applied at the control leads (37,38). ADVANTAGE - Scanning range of light scanners is enlarged. Operating reliability is increased and mounting simplified.