Objective optical system for optical pick-up
US6829105B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 2002 |
| Grant date | Dec 7, 2004 |
| Priority date | — |
| Expiry date | Sep 25, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10543
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A single-element objective lens for an optical pick-up is configured to converge substantially parallel light rays incident thereon onto a data recording surface of an optical recording medium. The objective lens includes, a first surface, which is a light incident side surface, and a second surface, which is an optical recording medium side surface. The first surface is an aspherical surface having a positive power, and the second surface is an aspherical surface having positive or negative power. The objective lens is designed such that paraxial wavefront aberration is 0.07&lgr; rms or less when a decentering amount between the first and second surfaces is 2 &mgr;m or less so as to converge the incident light substantially to a diffraction limit. A numerical aperture of the objective lens is 0.8 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.