| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk unit which can stably record information by optimizing the recording power of recording to a CD-RW over the entire disk area. <P>SOLUTION: Two sub-beams 53 and 55 are generated as +1st-order diffracted light and -1st-order diffracted light in an optical pickup together with a main beam 51 as zero-order diffracted light. Adjacent land tracks 59 and 61 on both the sides of a groove track 57 irradiated with the main beam are irradiated with the two sub-beams. The reflected light intensities of those two sub-beams are measured and on the basis of the measurement result, the recording power of the main beam is suitably controlled. The intensity of the reflected light beams from the land tracks irradiated with the sub-beams varies under the influence of curvature of the disk, temperature in recording, laser wavelength variation, etc., however not influenced by a last recording state, thus high- accuracy running OPC (optimum power control) is realized in the recording to the CD-RW and information can be recorded stably over the entire disk area. <P>COPYRIGHT: (C)2003,JPO |
