| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical encoder having a light source whose lifetime is long in comparison with conventional ones. Ž<P>SOLUTION: The optical encoder includes a light emitting part 4, a light receiving part 8 and an optical scale 1 having a reflecting part 2 and a non-reflecting part 3, wherein the light emitting part includes a resonator structure 41 which has a first reflecting layer 5 for reflecting light generated in an active layer 13 and a second reflecting layer 6 having the reflectivity lower than that of the first reflecting layer and preventing the light from being emitted while using only the light emitting part, and which is configured to cause a laser oscillation only when the light reflected by the reflecting part of above optical pattern is made incident. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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