| 摘要 |
PROBLEM TO BE SOLVED: To obtain high quality RF signal and tracking error signal even when a usual optical pickup is used as it is by making maximum optical depth in a phase pit recording information within a prescribed range. SOLUTION: The conditions forming the phase pit on a polycarbonate substrate 1 are selected so that a pit opening width 3 is 0.40μm or below, a pit bottom part width 4 is 0.25μm or above, and pit depth 5 is from a 1/3.5 wavelength to a 1/4.2 wavelength, and further, a track pitch 6 is 1.15μm or above. Then, resist with prescribed thickness is applied onto a glass master disk to be dried, and a stamper is formed. The substrate 1 is injection molded using the stamper. On the injection molded substrate 1, an aluminum reflection film 2 is formed on the side formed with the pit, and further, a protection coat 7 protecting the reflection film 2 is formed on the film 2 to prescribed thickness. |
