OPTICAL POSITION MEASURING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical position measuring device capable of generating a reference pulse signal more reliably than the conventional technique even when the scanning interval is large or scattered light is incident. SOLUTION: This optical position measuring device largely diverging a beam bundle emitted from a light source uses relatively fine reference mark structural bodies 10, 20 on the side of a graduation plate M and a scanning plate A in relation with relatively coarsely patterned detecting elements D1-D3. Signals RIT and RIGT generated at the reference position are finally introduced to both input ends of a differential amplifier DIF to generate the reference pulse signal RIZ further processed arithmetically. Both input signals RIT and RIGT are subtracted from each other in the amplifier DIF to form the difference between both signals. The desired reference pulse signal RIZ is generated at the output end of the differential amplifier DIF, and the signal is transferred to an evaluation unit for further arithmetic process.