| 摘要 |
PROBLEM TO BE SOLVED: To record information under the optimum condition by setting a supplying electric power, in which the fluctuation amount in the time base of a signal reproduced under test and extracted becomes minimum, to be the optimum recording power. SOLUTION: A pickup device 2 irradiates a phase transition type disk DK with a light beam having intensity complied with a supplying electric power and converts the beam to an electric signal proportional to the intensity of the reflected. returned light beam. A positional information detecting device 6 detects the position of the pickup device 2 in the radial direction of the disk based on a RF signal and a servo circuit 7 performs various servo operations such as a tracking servo. A laser power controller 8 supplys an erasing power Pe, a recording power Pw and a reproducing power Pp to a laser diode of the pickup device 2 by the contorl of a microcomputer 1, respectively. Coarse adjustment is performed for setting the optimum erasing power and a recording power for a present for the loaded disk DK and then fine adjustment is performed for setting the optimum recording power. |
