METHOD OF LEARNING REPRODUCTION POWER

摘要

PROBLEM TO BE SOLVED: To solve the problem that it is difficult for a conventional optical disk recording and reproducing apparatus to control reproduction power precisely since the apparatus cannot simply measure the power of a main beam focused on an information recording surface and contributing to recording and reproduction among laser beams outputted from an objective lens.

SOLUTION: The ratio of proper reproduction power to erasure threshold power is obtained in advance and in the case of learning the reproduction power by each drive apparatus, the erasure threshold power is measured and multiplied by the ratio to determine the reproduction power. The method of learning the reproduction power makes it possible to determine the proper reproduction power without regard to the variance of an optical pickup or the variance of sensitivity of a medium.

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