OPTICAL RECORDING AND REPRODUCING MEDIUM, ITS ORIGINAL PLATE, METHOD OF MANUFACTURING AND DEVICE FOR OPTICAL RECORDING AND REPRODUCING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an optical recording and reproducing medium that can make tracking servo control without degrading its recording and reproducing characteristics even when it is required to set a plurality of track pitches.

SOLUTION: The optical recording and reproducing medium has two or more track pitches formed with hill and dale patterns on the surface of a disk base, and the recording and reproducing light is radiated to the patterns along their tracks. The track pitches of the patterns 11 and 12 having different pitches are made larger than 1.00 time or but 6.25 times or smaller the track pitch of the minimum track pitch pattern 13 out of the patterns 11 to 13. Further, the region between the patterns having different track pitches is used as a transition region for changing the track pitch and the tracks are formed into spirals.

COPYRIGHT: (C)2004,JPO