Optical recording medium and optical pickup device
US6930976B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 16, 2001 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | Feb 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0943
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording medium is arranged such that respective information recorded on lands and grooves are reproducible by either of a light beam of a first wavelength λ1 and a light beam of a second wavelength λ2 which is shorter than the first wavelength λ1. The groove depth d of the optical recording medium is such that tracking error signals of not less than a predetermined level can be ensured for respective wavelengths λ1 and λ2 without generating distortion in waveform, irrespectively of differences in receiving light sensitivity of a photodetector provided in a optical pickup devices for use in recording and reproducing information on and from such optical recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.