Optical information recording/reproducing optical system and optical information recording/reproducing apparatus
US8339925B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2010 |
| Grant date | Dec 25, 2012 |
| Priority date | — |
| Expiry date | Apr 22, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1376
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information recording/reproducing optical system, comprising a light source; an optical element converting a laser beam into a substantially collimated beam; and an objective lens, wherein a wavelength λ (unit: nm) of the laser beam falls within a range of 400<λ<410, the optical element and the objective lens are made of same resin materials or different resin materials having a glass transition temperature of Tg>115° C., each of optical surfaces is configured not to have an optical thin film which contains at least one of or elements of titanium, tantalum, hafnium, zirconium, niobium, molybdenum and chromium, each of optical surfaces of the optical element is provided with an antireflection film made of one of or a mixture of at least two of silicon oxide, aluminum oxide, aluminum fluoride and magnesium fluoride, and a following condition is satisfied
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.