LASER MODULATION TYPE OPTICAL ENCODER, LASER MODULATION TYPE MAGNETIC ENCODER, AND OPTICAL INTEGRATED CIRCUIT TYPE ENCODER

摘要

PURPOSE: To prevent signal accumulation error when a rotary plate has an eccentricity and to accurately detect an angle by a rotary encoder which is constituted at a relatively rough pitch. ;CONSTITUTION: The laser modulation type optical encoder is provided with interferometers 2-5 with a semiconductor laser 1 as a light source, a first photo detector 6 for detecting the interference signal of the interferometers, and an injection current control means 7 of the semiconductor laser 1. Also, it is provided with a traveling lattice 10 rotating or moving linearly, and a fixed lattice 11, a light source 8 for casting nearly parallel light to the traveling lattice 10 and the fixed lattice 11, and a second photo detector 12 for detecting the change in light quantity due to the move of the traveling lattice 10. The injection current control means 7 is driven by the output signal of the second photo detector 12.;COPYRIGHT: (C)1995,JPO