Optical pickup
US7453787B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2005 |
| Grant date | Nov 18, 2008 |
| Priority date | — |
| Expiry date | Jan 13, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup projects laser beams having the first to the third wavelengths, in response to the type of a recording medium which is an object to which recording or reproduction is to be performed, and reflecting light from the recording medium is received by a light-detecting element. In order to reduce the sizes of the optical pickup, light of the second and the third wavelengths is generated by a single dual-wavelength light source, and reflecting light of all the wavelengths is to be received by the single light-detecting element. A hologram element giving different optical effects to light of each wavelength is arranged between the light irradiating means and the light-detecting element. Thus, appropriate information recording and reproduction can be performed by using light of each wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.