| 摘要 |
PROBLEM TO BE SOLVED: To reproduce and output an accurate form clock from a binary signal outputted from an optical disk device corresponding to speed-up of the optical disk device. SOLUTION: A phase comparator (PD1) 1 outputs a phase error signal limited at a coming out timing of a rising edge of a binary signal. A phase comparator (PD2) 2 outputs a phase error signal limited at coming out timing of a falling edge of the binary signal. Respective outputs of the phase comparators (PD1) 1, (PD2) 2 and a frequency meter (FD) 3 are summed at the pre-stage of a low-pass filter(LPF) 4. A voltage controlled oscillator(VCO) 5 controls an oscillation frequency according to the output signal of the low-pass filter(LPF) 4, and reproduces and outputs a clock signal having an N-fold frequency of the clock signal (PLCK). A frequency divider (1/N) 6 divides the output signal of the above-mentioned voltage controlled oscillator and outputs the clock signal (PLCK). |
