| 摘要 |
PURPOSE:To prevent light from a light emitting element from being received by a photodetector of the own device by providing a cover for preventing light leakage to a tip of an optical guide guiding the light from the light emitting element and adhering closely the cover to the inside face of a filter. CONSTITUTION:The light emitting element 16 and the photodetector 14 are incorporated in a main body case 6, the optical filter 13 is provided on one side face of the case 6, the entire device is constituted to attain light emission and photodetection via the filter 13, and the light emitting element 16 is constituted by mounting the light emitting element 16 in a light guide cylinder 15 preventing spread. For example, a rubber-made cover 17 for preventing leakage of light is provided to the surrounding of the end of the optical guide cylinder 15 while being adhered closely to the inner face of the filter 13. Thus, the light is not leaked from the gap between the optical guide 15 and the filter 13 and made incident on the adjacent photodetector 14, and the light from the light emitting element 16 is transmitted externally via the filter 13 surely. |
