| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve trial writing accuracy accompanying the achievement of a higher speed and to secure reproduction compatibility in a recording type optical disk device having a PRML system introduced thereto. <P>SOLUTION: The device includes a circuit 30 for correcting the phase of a reproducing signal 21 subjected to A/D conversion by timing sandwiching an edge using an FIR filter 31 of an even-number tap, and integrating the level of an edge point and its absolute value to measure edge shifting and jitters. Thus, the edge shifting of the reproducing signal is measured even in the vicinity of zero edge shifting corresponding to the achievement of a higher speed, and the learning accuracy of trial writing is improved. <P>COPYRIGHT: (C)2007,JPO&INPIT |
