| 摘要 |
<p>PURPOSE:To detect the recording medium reproduction speed based on the frequency of the recording medium reproduction signal such as cassette tapes and the scale frequency and to adjust the recording medium reproduction speed from the detecting result. CONSTITUTION:The reproduction signal of a cassette tape is inputted to a basic wave detection circuit 21. The circuit 21 detects the basic wave of the reproduction signal at its output to a phase comparator 25 and to a dividing ratio setting circuit 24. The circuit 24 sets the frequency ratio dividing a reference wave signal outputted by a reference frequency generation circuit 22 based on the scale frequency to be outputted to a frequency divider 23. The frequency divider circuit 23 divides the reference wave signal based on the dividing ratio and outputs a frequency dividing signal to the phase comparator 25. The phase comparator 25 compares the phase of the basic wave signal from the circuit 21 with the phase of the frequency signal from the frequency divider 23, outputting a deviation value signal. The deviation value signal corresponds to deviation value of the reproduction speed.</p> |
