| 摘要 |
PROBLEM TO BE SOLVED: To correctly discriminate and read data signals and sector information by eliminating errors in reading of land prepits indicating sector information and data pits on tracking guides indicating data signals at the time of optically reading high-density signals. SOLUTION: The optical information medium has a light-transmissible substrate 1 by which recording light is transmitted, a recording layer 12 which is formed on this translucent substrate 1 and a reflection layer which is formed on this recording layer 12 and reflects reproducing light and records the optical readable signals by the recording light made incident from the translucent substrate 1. This optical information medium has the spiral tracking guides 3 on the surface side formed with the recording layer 12 of the translucent substrate 1 and is formed with the land prepits 6 indicating the sector information on the addresses, etc., of the tracking guides 3 on the lands 8 between the tracking guides 3. The length of the land prepits 6 is set at 50 to 83% of the min. pit length and at the length for the clock components of 1.5 to 2.5. channels. The film thickness of the recording layer 12 in the land prepits 6 is varied from the film thickness of the recording layer 12 in the tracking guides 3. |
