| 摘要 |
PURPOSE:To surely detect the end of a magnetic tape, by providing an optical fiber between a light emitting device and a photodetector for the detection of the end of a magnetic tape. CONSTITUTION:An optical fiber 7 is provided between a light emitting device insertion hole 5 in which a light emitting element such as a lamp and a light emitting diode is provided and a photodetector insertion hole 6 in which a photodetector such as a photo transistor and a photo diode is contained. For the optical fiber 7, quartz or high polymer fibers are used and the large aperture such as >=1mm. is used for the ease of adjustment of optical axis. |
