| 摘要 |
PROBLEM TO BE SOLVED: To provide a photoelectric encoder that has stable and accurate phase difference and duty ratio, and provides an output signal of high-resolution even when optical dispersion by light emission, a moving body, or the like exists. SOLUTION: The photoelectric encoder comprises: a light emitting element; and a plurality of light receiving elements arranged in one direction D in a region at which light from the light emitting element arrives. When the moving body 40 alternately having optical ON sections X and optical OFF sections Y at a constant pitch P passes in one direction D, the outputs A1+, A2+, ..., A4- of respective light emitting elements have values according to incoming or non-incoming of the light from the light emitting element. The photoelectric encoder comprises subtracters 21, 22, 23 and 24 having difference between outputs of different phases by 180°, among the outputs of the plurality of light receiving elements. Differential signals obtained by respective subtracters 21, 22, 23 and 24 are alternately classified into a first group and second group according to the arrangement order of the light receiving elements, and are added for every group by adders 31 and 32. COPYRIGHT: (C)2008,JPO&INPIT
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