| 摘要 |
<p>PURPOSE:To simplify a circuit and to relieve the load of the software of a microcomputer or the like by applying phase control of a capstan servo system with a pseudo control signal at rewrite of a program-search signal during reproduction. CONSTITUTION:A frequency generator 1 detects the rotation of a capstan shaft. In the case of the reproduction of the standard mode, a frequency divider circuit 2 applies 1/3N frequency division, a frequency divider circuit 3 applies 1/3N frequency division in the case of the thrice mode reproduction to form a pseudo control signal S2. The signal S2 is synchronized with a control signal S3 reproduced from a tape by a control head 7. The signal S2 is inputted to a changeover circuit 4, which is switched by a mode selection signal S6, the output is inputted to one input of a comparison switching circuit 5, the control signal S3 is inputted to the other input, the circuit 5 receives a level switching signal S4 to supply the pseudo control signal S2 to a phase comparator circuit 6, it is compared with a reference signal S7, a voltage to a phase difference is sent and the pseudo control signal S2 is used to attain the phase control of a capstan during program-search signal rewrite.</p> |
