METHOD AND DEVICE FOR DETECTING RECORDING LASER POWER, RECORDING LASER POWER CONTROL METHOD, AND RECORDING DEVICE AND RECORDING AND REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To make settable a recording laser power by recording a reference signal for examination of a predetermined pattern on a recording medium while changing the laser power, obtaining the reproducing signal of the recorded reference signal for examination and detecting the change information of the laser power as information on a change in a phase difference from the examination reference signal. SOLUTION: An APC area reference signal generating circuit 17 outputs a reference signal for examination in a fixed cycle and a system controller 10 writes a pattern corresponding to the reference signal for examination on the APC area of a magneto- optical disk 1 while controlling the output laser power of the semiconductor layer of an optical pickup 4 through a laser power control circuit 6. A phase difference detecting circuit 23 compares the phase of the reference signal for examination with the reproducing signal of the recorded reference signal for examination, supplies an exclusive OR output to a proper power determining circuit 24, sends step information to be the optimum phase difference to a system controller 10 and controls the optimum laser power.