Limbach & Limbach L.L.P.
Disc recording method wherein a segment is recorded with reference data to control the phase of a data clock
 A method of recording data on a disc on a disc pre-recorded with servo control data, with the servo control data being pre-recorded in the form of convex and concave pits at intervals along substantially concentric tracks, the servo control data recorded in alignment in a diametrical direction of the disc. The method includes the steps of dividing the disc into a plurality of zones in the radial direction, dividing the tracks into a plurality segments such that there is an equal number of segments in each interval between adjacent pre-recorded servo control data. The method further includes the step of recording reference data on at least one segment of the plurality of segments in each interval between adjacent servo control data, with the reference data being utilized to adjust a gain and a phase of a read-out clock upon reproduction of the disc. The method further includes the step of recording digital data on at least one segment of the plurality of segments in each interval between adjacent servo control data, with the digital data being recorded at a constant angular velocity and with the constant angular velocity being different for each zone. 
Sony Corporation
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Yoichiro Tamotsu Tetsu
Sako Yamagami Watanabe