Reading-writing pickup head
US6343059B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1999 |
| Grant date | Jan 29, 2002 |
| Priority date | — |
| Expiry date | Aug 16, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1359
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention concerns a reading-writing pickup head for data access on optical record media. The pickup head of the present invention includes a birefringent prism and a quarter-wave plate where the birefringent prism is made of double-refraction material with different refraction indices on different polarizations, and it is used to split the incident and reflection beams of the pickup head. According to the present invention, the prism and the polarized beam splitter of a pickup head of the related art are replaced with the birefringent prism. Consequently, the number of optical elements of the pickup head according to the present invention is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.