| 摘要 |
PURPOSE:To prevent a control signal from misdiscrimination immediately even if burst-like pulse missing or the like is generated in the reproduced output of a control signal by storing at least 3 discrimination results of recording speed obtain by detecting the ratio of the frequency of the reproduced output of the control signal to that of an FG signal in time series and finding out the majority of these stored results. CONSTITUTION:The compared outputs S8, S9 of size comparators 15, 16 are inputted to shift registers 21, 27 and a signal S2 outputted from a sequence generating circuit 12 is used as shift clocks for the shift registers 21, 22. In said constitution, the compared outputs S8, S9 corresponding to the stages of the registers 21, 22, i.e. the discriminated results corresponding to the stages, are stored in the registers 21, 22. The plural discriminated results stored in the registers 21, 22 are processed by a majority discrimination circuit 23 to find out the majority, so that final discrimination is performed. When a recording mode is to be discriminated on the basis of the majority of 3 discriminated results, a recording speed discriminated twice or more out of the 3 discriminated results is regarded as a regular recording speed.
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