| 摘要 |
<p>PURPOSE:To obtain the device capable of detecting the tape speed with high accuracy in a tape recorder, etc., and realizing the control of the tape speed with high accuracy by the detection. CONSTITUTION:In the tape speed detection mechanism in the tape recorder that a rotation roller 2 always rotating at the speed in proportion to the tape speed is provided, fringe patterns 8a, 8b are formed at a constant space on the surface without contacting a tape 1 in the rotation roller and an optical sensor 9 detecting the gradation of the fringe patterns is provided, it is characterized by having electrodes 3 in the almost all circumference on the side surface in contact with the tape in the rotation roller, by making the tape 1 attract in the rotation roller 2 with static electricity force generated by impressing the voltage on the electrodes and by eliminating the slip between the tape 1 and the rotating roller.</p> |
