Optical head device with diffraction grating for separating a light beam incident on an optical recording medium from a light beam reflected therefrom
US4733065A · kind A · utility
88Cited by
6References
20Claims
0Family size
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Key dates
| Filing date | Jun 24, 1985 |
| Grant date | Mar 22, 1988 |
| Priority date | — |
| Expiry date | Jun 24, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10576
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical head device comprises a light source, condensing optics for condensing a light beam emitted from the light source on an optical recording medium, a photodetector for detecting the light of the light beam reflected from the recording medium, and a beam splitter having a diffraction grating arranged in the optical path of the light beam entering the recording medium from the light source along a plane substantially perpendicular to the optical axis of the incident light beam to cause the light reflected light from the recording medium to be diffracted by the diffraction grating and directed to the photodetector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.