| 摘要 |
PURPOSE:To eliminate erroneous detection and to improve detection precision by fixing a pattern recorded in the specified area of an optical disk to a best pattern at the time of detecting recording power. CONSTITUTION:Two-OR circuits 2a which OR-operate a prescribed bit and a gate signal from a control circuit 3 among output data of an A/D converter 5 is provided for a logical circuit 2. A two-NOR circuit 2b which inversely inputs the other bits of the above data, ORs inversed input and the gate signal and inverts a logical result is provided. The best pattern as against recording power detection can be obtained by combining the two-OR circuits 2a and the two-NOR circuit 2b. The pattern is recorded in the specified area of the optical disk 1 and the average level of the reproduction signal is compared with a reference level so as to detect recording power. The number of pulse edges is much and a DC component is not included in the reproduction signal and therefore highly precise detection is realized without. |
