| 摘要 |
PURPOSE:To eliminate interference by leaked light flux while reducing the man- hour of assembly and the number of parts by forming a slit of an index scale on a light receiving surface of a photoelectric conversion element to nullify the distance to the light receiving surface. CONSTITUTION:An encoder is made up of a main scale 1, a light emitting element 5, a photoelectric conversion element 7 in which slits the same as the pitch between slits of the main scale 1 are formed on the light receiving surfaces of light receiving elements 7A and 7B with a light shielding thin film 8 and a base 6. When the light receiving elements 7A and 7B of the photoelectric conversion element 7 are made bright or dark respectively, as there is no distance between the light shielding thin film 8 and the photoelectric conversion element 7, light fluxes 11A and 11B fail to be received with the light receiving elements 7A and 7B thereby eliminating interference of a leaked light flux with other photoelectric conversion elements. Besides, this allows the concurrent use of an insulator between the light receiving elements 7A and 7B and a light shielding film with a slit to reduce the man-hour of assembly and the number of parts. |
