| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical encoder for avoiding a phase difference from being generated between signals due to a gate delay, and detecting a mobile body using signals excellent in the duty accuracy and the period accuracy. SOLUTION: The optical encoder includes: an OR circuit 21 for inputting received optical signals A+, B+; an OR circuit 22 for inputting received optical signals A-, B-; and an AND circuit 23 for inputting an output signal C from the OR circuit 21 and an output signal D from the OR circuit 22. In the optical encoder, a phase of the received optical signal A- is shifted from a phase of the received optical signal A+ by 180°, and a phase of the received optical signal B- is shifted from a phase of the received optical signal B+ by 180°. The received optical signals A-, B- are input to the OR circuit 22 in a signal processing circuit 15. Accordingly, the signal processing circuit 15 does not need NOT circuits for inverting the received optical signals A+, B+. COPYRIGHT: (C)2009,JPO&INPIT
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