| 摘要 |
<p>PURPOSE:To detect tape velocity without providing an exclusive tape guide by providing a medium, for which a pattern or form is changed with a fixed pitch in a circumferential direction, on the end face of a roller to be rotated synchronously with tape feeding velocity. CONSTITUTION:A guide roller 1, around which a traveling tape 2 is wound, is rotated integrally with a rotary roller 3. Accordingly, the rotary roller 3 is rotated synchronously with the feeding velocity of the tape. In a reflecting type photosensor 10, light from a light emitting element 8 is reflected on the bottom of a circular recessed part 4, which is provided on the lower end face of the rotary roller 3, and reaches a photodetector 9. On the other hand, when a part to reflect the emitted light is not the bottom part of the recessed part 4, the light to reach the photodetector 9 is made weak. By detecting these two states, the motion of the recessed part 4 is detected and the rotating speed of the guide roller 1 is detected. Accordingly, the tape feeding velocity can be precisely detected. Instead of the recessed part 4, a sheet drawing the pattern of various reflection factor can be used as well.</p> |
