| 摘要 |
PURPOSE:To reduce an effect due to the internal reflection of a filter and allow the easy demounting and cleaning thereof by providing a light reflective sensor near the detected surface of a travelling body, so as to keep distances from a filter end at the side of a light emitting element and a filter end at the side of a light receiving element different from each other. CONSTITUTION:A light emitting element 2 and a light receiving element 3 are laid in parallel and integrally molded, and a flat and light transmission filter 4 is laid on the surface of the molded product. A light reflective sensor 1 is thereby formed and laid near the detected surface of a photosensitive material 5. Also, the sensor 1 is laid, so that a distance between the surface end of the filter 4 at the side of the element 2 is different from a distance between the surface end of the filter 4 at the side of the element and the surface of the photosensitive material 5. In this case, the sensor 1 is laid with the shorter distance section positioned in front. As a result, the filter 4 can be confirmed in shape and cleaned without demounting the sensor 1. Also, light from the element 2 is irradiated to the surface of the material 5 and the reflection thereof is vertically received with the element 3 (incident angle Q1 = reflection angle Q2 for restraining the attenuation of light quantity. |
