Photoelectric encoder and electronic device

摘要: PROBLEM TO BE SOLVED: To provide an inexpensive photoelectric encoder having excellent operation accuracy and little characteristic dispersion, even when a light receiving quantity is fluctuated. SOLUTION: Since negative feedback circuit 12 negatively feeds back DC output of differential amplifier 7 to the input side diodes 5, 6 forming logarithm compression section, this can reduce offset signal based on fluctuating itself. Hereby, be reduced surely if dispersion optical system or exists. A current added from acquired by amplifying photodiodes 1, 2 amplifiers 3, 4 into 6. since impedance lowered, reduced, coupling capacity small especially at low-speed time like removal AC in insufficient. COPYRIGHT: (C)2008,JPO&INPIT