Reflection type compound prism and optical pickup apparatus employing the same
US7088664B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2002 |
| Grant date | Aug 8, 2006 |
| Priority date | — |
| Expiry date | Dec 12, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/124
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A reflection type compound prism and an optical pickup apparatus employing the same. As a light beam is passed through the compound prism, a size of the light beam in a direction perpendicular to a reference plane is reduced by a first reflection surface, propagated toward an objective lens by second and third reflection surfaces and the size restored by reflecting the light beam from a fourth reflection surface forming an angle less than 45° with respect to the reference plane so that a height of an optical system is reducible to obtain a small thin optical pickup with a desired NA. The second and third reflection surfaces are spaced apart in a direction perpendicular to the reference plane by an amount close to a diameter of the light beam at a point of incidence of the light beam with the compound prism.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.