| 摘要 |
PURPOSE:To obtain an optical encoder which reduces the trouble of the precise positioning of a light emitting means and a slit window and has superior mass- productivity and is easily manufactured, by allowing a light emitting means to turn around its axis. CONSTITUTION:An encoder is provided with a scale 13 having a light and shade stripe pattern with specified pitch while the ratio of light parts and dark parts of the stripe pattern is specified, and the light emitting and photodetecting means formed by packaging a light emitting means 2 which moves relatively to said scale 13 and also illuminates said scale 13 through the slit window 5 and a photodetecting means 1 which photodetects reflected light from the scale 13. Further, the light emitting and photodetecting means is turned around its axis by a driving means to set the maximum sensitivity point of the photodetecting means 1 at the center position of the slit window 5. |
