Optical head having a reproducing optical system and filter formed by light passing therethrough
US6178151A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1998 |
| Grant date | Jan 23, 2001 |
| Priority date | — |
| Expiry date | Apr 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10543
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical head includes: a light source; a photodetector for generating a prescribed signal based on light which the photodetector receives; a converging optical system for converging a light beam emitted from the light source to be incident upon a prescribed reflective member; and a reproducing optical system for guiding reflected light from the prescribed reflective member to the photodetector. The reproducing optical system is configured for converging light on a prescribed converging point, and a filter having a light transmissive region for allowing light in the vicinity of a center of the converged light to selectively pass therethrough is provided in the vicinity of the converging point. The light transmissive region of the filter is formed by light which has passed through at least a part of the reproducing optical system and has been converged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.