Object lens for optical pickup and method for designing the same
US7260048B2 · kind B2 · utility
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6References
7Claims
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Key dates
| Filing date | Aug 7, 2003 |
| Grant date | Aug 21, 2007 |
| Priority date | — |
| Expiry date | Feb 8, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup records data in or reproduces data from optical recording media respectively having recording faces at different heights, and includes a semiconductor laser diode array having light emitting portions for respectively emitting laser beams of different wavelengths. A finite conjugate type object lens used in this optical pickup is designed so that the numerical aperture of the object lens can be controlled to be changed in accordance with switching between the different wavelengths for allowing a laser beam to be focused on each optical recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.