Optical information medium, stamper for manufacturing transparent substrate therefor and recording method therefor
US6504815B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2000 |
| Grant date | Jan 7, 2003 |
| Priority date | — |
| Expiry date | Feb 15, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/263
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information medium is made up of a transparent substrate for a recording laser beam to penetrate therethrough, a recording layer formed on the transparent substrate, and a reflective layer for reflecting reproducing laser beam formed thereupon enabling the recording of optically readable signals by means of an incident recording laser from the transparent substrate. The transparent substrate has spiral-like tracking guides on the surface of the transparent substrate on which is formed the recording layer, and pre-pits indicative of address information are formed on a land portion defined between the tracking guides. The pre-pits are formed shifted from a center of the land. With this construction, the pre-pits open to a side of the tracking guide neighboring the land. With this, it is possible to read out address signals from the pre-pits with certainty when recording, and also to suppress errors due to mixing between the signals obtained from the pre-pits indicative of the address information and the recorded data read out from the pits on the tracking guides when reading the recorded optically readable signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.