Method for manufacturing read-only optical disc medium and read-only optical disc medium
US8634287B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2008 |
| Grant date | Jan 21, 2014 |
| Priority date | — |
| Expiry date | Nov 17, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/268
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An information signal area on an information signal recording surface is provided as pits on a mirror in accordance with modulated information data, and is covered with a metal alloy reflective film. Sections that do not include pits corresponding to the information data are provided in the information signal area, and portions of the metal alloy reflective film on the sections are formed as perforated marks corresponding to the information data. In this case, the reproduction signal amplification level of a prepit signal and the reproduction signal amplitude level of a perforated mark signal can be obtained as substantially equal values by adjusting the depth and width of pits and/or adjusting the width and length of perforated marks. Hence, waveform distortion due to a waveform equalization circuit and variations in binary signals due to displacement of the slice level are reduced so that signals can be stably and reliably detected with the same reading apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.