Optical head device and recording/reproduction device
US8036093B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2009 |
| Grant date | Oct 11, 2011 |
| Priority date | — |
| Expiry date | Dec 24, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical head device includes a first light source and a second light source respectively emitting a first light beam and a second light beam, a luminous flux separating section selectively separating the first and second light beams for which the same optical path is used, to first and second optical paths, respectively, and a first objective lens converging the first light beam that has been separated to the first optical path on the first optical information recording medium. Further, the optical head device includes a second objective lens made of resin and converging the second light beam separated to the second optical path on the second optical information recording medium, and a first filtering section formed on a beam exit face of the second objective lens and reducing the transmittance of the first light beam to be lower than transmittance of the second light beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.