Objective lens for optical pickup device, and optical pickup device
US8125873B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2008 |
| Grant date | Feb 28, 2012 |
| Priority date | — |
| Expiry date | Feb 22, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1374
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Provided is an objective lens for an optical pickup apparatus. The objective lens collects diffracted light generated by an optical path difference giving structure onto the information recording surface of an optical information recording medium as a spot and suppresses fluctuation of diffraction efficiency due to a change of using wavelength. The optical pickup apparatus using such objective lens is also provided. The total diffraction efficiency can be improved by adjusting a wavelength at which the diffraction efficiencies of a plurality of basic structures forming the optical path difference giving structure in the objective lens are maximum, in accordance with a basic structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.