Optical memory having narrowed track pitch
US5586109A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1994 |
| Grant date | Dec 17, 1996 |
| Priority date | — |
| Expiry date | Dec 12, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0938
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A transparent substrate of an optical memory is produced by injection molding using a stamper. Grooves and lands are alternately arranged on the optical memory, for tracking of light converged on the optical memory. The groove width is set in the range of 0.3 .mu.m to 0.4 .mu.m and the groove depth is set in the rage of 80 nm to 100 nm. A decrease in the width of a land at each edge is restrained to 0.2 .mu.m in maximum. With such dimensions, even when the track pitch is set to about 1.4 .mu.m, it is possible to obtain a track crossing signal with intensity sufficient for performing an access operation to a target track. Moreover, since the dimensions bring about an improved reflectance at a land, the optical memory achieves an improved C/N and recording density.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.