| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve the accuracy of evaluation of the reproduced quality of test pattern data for deciding optimum laser power at the time of recording data even if high speed test writing is performed. <P>SOLUTION: First, a changeover switch 19 is switched to a test pattern generating circuit 18 side to set laser power at the time of recording data to an optimum value, the prescribed test pattern data are generated by the test pattern generating circuit 18 and supplied to a laser diode 2, the laser power is varied for each prescribed data quantity (e.g. 1 sector), test writing is performed for the prescribed region of an optical disk 1 with rotation speed at the time of recording data. Next, this test pattern data are reproduced with rotation speed being lower than speed at the time of test writing of this test pattern data (e.g. 1/2 times), after it is amplified by ta pre-amplifier 4, it is supplied to a quality evaluating means 22. In the quality evaluating means 22, this reproduced test pattern data are sampled and taken in by an AD converter 23, the sample data are accumulated in a memory 24 to evaluate quality. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
