| 摘要 |
<p>PURPOSE:To detect failure in photosensitive part quickly, by means of a logical circuit, by adding an optical reflection index within a lower or upper half of a magnetic tape width at the tape end, adding it to almost all the tape width at the beginning end and detecting the index of lower or upper half. CONSTITUTION:At the beginning end of a magnetic tape 1, an optical reflection index BOT2 indicating the beginning end is attached. The BOT2 has a size over almost the full width of the magnetic tape. An optical reflecting index EOT3 indicating the end of tape is attached at the end of the magnetic tape 1, and the width is taken as upper half the tape width. A photosensitive part 5 detecting the lower half of the magnetic tape 1 and a photosensitive part 6 detecting the upper half are provided. The output of the photosensitive part 5, photosensitive part 6 and a signal line 17 indicating that the magnetic head is located before the BOT2, are operated at the logical circuit, and a failure signal of the parts 5, 6 is outputted at terminals 18, 19. Thus, the photosensitive part in failure can be detected completely when winding is made at the position of BOT.</p> |
