| 摘要 |
PURPOSE:To easily high dimensional accuracy with regard to a slit and a guide hole by providing the slit which is formed in the peripheral edge part of a plate body in one body and where a light beam passes and the guide hole for alignment which is formed integrally in the center part of the plate body. CONSTITUTION:The plate body 1 has a code plate molded out of plastic or glass which is opaque enough not to pass the light of, for example, a light emitting diode and the peripheral edge part 1a of the plate body 1 having the slit 2 is improved more in size accuracy and formed thinly so as to reduce the influence of light interference and diffraction while the center part 1b is formed thickly so as to secure the strength. A light emitting part emits light to a light receiving part and when a plate for an optical encoder rotates, the light passes through only the slit 2, so the light is received by the light receiving part as a pulses the this light signal is converted into an electric signal by the light receiving part.
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