| 摘要 |
PURPOSE:To secure the large control range without changing the loop gain as well as enhance the interchangeability by securing the different phase for the reference signal to be supplied to the capstan control system from the phase to be supplied to the drum control system. CONSTITUTION:The tracking circuit consists of capstan control system 1, drum control system 2 and reference signal generation circuit 3 each. In such constitution, the phase is made to gain by 1/4 cycle for reference signal 4B which is supplied to trapezoid wave generator 13 of system 1 in comparison with the reference signal which is supplied to delay mono-multi 22 of system 1. As a result, the variable width of the delay amount of delay output 23 becomes about the half of synchronization of reference signal 4A. In other words, the central value of the delay amount is equivalent to about the half of the delay cycle, and thus the variable width becomes identical between the plus and minus directions. And thus the delay variable range covers almost entire cycle. Accordingly, the tracking control range can be increased to nearly entire cycle. In such way, the tracking dispersion can be absorbed to enhance the interchangeability of the VTR. |
