| 摘要 |
PROBLEM TO BE SOLVED: To record desired data by effectively utilizing an information recording surface and to enable the high-speed access thereof by setting the lengths of the irradiation loci of the laser beams corresponding to one bit in one data string to nearly specific angle intervals, thereby increasing the data quantity to be multiplexed with the outer peripheral side. SOLUTION: The optical disk is exposed by the laser beam LA and LB in a state such that the disk is rotationally driven at the constant angular speed by a spindle servo circuit 5. Modulation signals VpA and VpB for modulating these laser beams are formed on the basis of a clock BCLK for data transfer which is a specified frequency. As a result, the lengths of the grooves to which the data of one bit is allocated attain the equal angular intervals on the inner peripheral side and outer peripheral side of a master disk. Even when the inner peripheral side region and the outer peripheral side region are respectively accessed by rotationally driving the disk under the conditions of the constant angular speed, the meandering of the groove wall surfaces is detected and processed by the specified repetitive periods, by which the reproducing of the data recorded on the optical disk is made possible.
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