Reproducing rate control apparatus for optical disk

Abstract

A reproducing rate control apparatus for an optical disk includes a synchronizing clock generating unit which generates a synchronizing clock pulse with a phase locked to a phase of a digital reproduction signal. A signal processing unit generates a demodulated data signal from the digital reproduction signal in accordance with the synchronizing clock pulse, wherein the demodulated data signal is written to a memory in accordance with the synchronizing clock pulse, the demodulated data signal is read from the memory in accordance with a read reference clock pulse, and the read demodulated data signal is processed through an error correction so that a processed demodulated data signal is output. A frequency detecting unit detects whether the frequency of the synchronizing clock pulse is within a predetermined range of frequencies centered at a standard frequency. A switching unit selectively outputs one of a first read-reference clock pulse having an initial frequency and a second read-reference clock pulse having a second frequency to the signal processing unit in accordance with a result of the detection by the frequency detecting unit.