| 摘要 |
PURPOSE:To accurately detect a phase error between a clock pit signal and a clock signal even when a level of an RF signal reproduced from a magneto- optical disk is fluctuated or an optical MTF is fluctuated. CONSTITUTION:A sample-and-hold circuit 4 samples and holds a differentiated, signal (b) resulting from differentiating a clock pit signal (a) by a differentiation device 3 at an edge c1 at a prescribed timing of the clock signal generated by a PLL circuit 5. A detection circuit 12 detects a tilt in the differentiated signal (b) outputted from the differentiation device 3 and outputs a detected tilt alphai to a divider 11. The divider 11 divides a level phii at a prescribed timing of the differentiated signal (b) outputted from the sample-and-hold circuit 4 with the tilt alphai outputted from a sample-and-hold circuit 22 and outputs the quotient to the PLL circuit 5. The PLL circuit 5 generates the clock signal corresponding to the signal inputted from the divider 11. |
