| 摘要 |
PROBLEM TO BE SOLVED: To obtain RF signals of high quality at an approximately twice higher recording density and a stable track error signal by forming information in the form of phase pits on a disk and selecting the track pitch of information tracks at a prescribed range or below. SOLUTION: The track pitch 6 is so selected as to attain about >=1.1 to <=1.25μm as a condition for forming the phase pits on the polycarbonate substrate 1. Further, the pits are so formed that the shortest mark length 18 attains >=0.6 to <=0.7μm. The pitch depth is determined by applying a resist on a glass master disk at a prescribed thickness and cutting the dried glass master disk to form a stamper. The injection molding of the substrate 1 having 1.2mm thickness is executed by using this stamper. An aluminum reflection film 2 is formed on the side formed with the pits of the injection molded substrate 1. Further, a protective coat 7 for protecting the reflection film 2 is formed at the prescribed thickness, by which the optical recording medium is formed. |
