Optical apparatus for optically reading and recording information
US5602383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1353
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical head for use in an optical recording apparatus contains a lens element that permits independent setting of the magnification and numerical aperture for a forward optical system and a rearward optical system. The optical head includes a light beam emitting assembly that emits a beam of light and a light beam separating assembly. A light beam focusing element focuses a forward light beam onto an optical recording medium. The light beam emitted from the light beam emitting assembly follows a forward optical path passing through the light beam separating assembly as a non-diffracted light beam and is focused onto the optical recording medium. A rearward light beam is reflected from the optical recording medium and follows a rearward optical path passing through the focusing element and the light beam separating assembly such that the rearward light beam is deflected to a light detection device. The lens element is positioned in at least one of the forward optical path and the rearward optical path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.