| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk unit equipped with a phase error correction mechanism for a phase locked loop(PLL) which can always set the optimal corrected value on an optional position of a disk and can stabilize pull-in operation by the phase locked loop(PLL) circuit. SOLUTION: In this phase error correction mechanism for PLL, a phase comparator output (PDO) circuit 3 sets a PDO signal at a fixed value and a control circuit 6 sets a PESP signal outputted from a phase error correction output (PESP) circuit 2 at a variable correction value, Thus, control (VCTL) signals outputted from a low-pass filter(LPF) 5 are superposed and synthesized to set correction values in all areas of a disk at variable values thereby making the correction values optimal even when differences are generated between inner circumference part and outer circumference part of the disk. Consequently, pulling-in of read-in signals from the disk is always made stable at read operation by the PLL circuit shown in a rough sketch. |
