Optical lens and method of producing the same, method of producing optical lens array, focus error signal production method, and optical pickup apparatus
US6724544B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 2002 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Jan 23, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/22
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element, which is formed integrally with a substrate having a flat face, has a convex curved face that functions as an optical lens and is shaped such that the curvature on a first cross section and the curvature on a second cross section perpendicular to and intersecting with the first cross section are different from each other, whereby the focal lengths on the first and second cross sections are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.