| 摘要 |
PROBLEM TO BE SOLVED: To provide a photoelectric encoder dispensing with a dedicated optical sensor or the like in order to detect a reference position or the like in a feed roller or the like of a printer. SOLUTION: The photoelectric encoder includes: a moving body 2 composed to alternately arrange a translucent region 3 and a shading region 2a being a prescribed same size together with length of a moving direction; a light emitting part 6 and a light receiving part 7; a cyclic pulse signal generation part; and a reference pulse signal generation part. The moving body 2 is moved so as to cross a separation space of the light emitting part 6 and the light receiving part 7, and light emitted from the light emitting part 6 transmits the translucent region of the moving body 2 to receive light in the light receiving part 7. The specific translucent region 3 indicating the reference position of the moving body 2 is formed in lower transmittance than the other translucent region 3. Two sets of light receiving element groups 7a and 7b composed of four light receiving elements of a first light receiving element as the front position, a second light receiving element, a third light receiving element and a fourth light receiving element are adjoined to compose the light receiving part 7. The photoelectric encoder is composed by regarding the width of all the light receiving elements as a half of the prescribed size. COPYRIGHT: (C)2008,JPO&INPIT
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