Non-linear reflectance optical information recording layer irradiated by a light beam controlled with an amplitude filter
US5434840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1993 |
| Grant date | Jul 18, 1995 |
| Priority date | — |
| Expiry date | Sep 10, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is an optical disk player capable of suppressing the influence of side lobes of an irradiated spot on the reflected light from an optical disk, thereby ensuring an improved recording/reproducing characteristic. The optical disk player comprises an optical irradiation system for focusing a laser beam as a spot along an information recording portion of an optical disk, and an optical detection system for guiding reflected light from the spot to a photosensor, whereby recorded information is reproduced based on an output signal from the photosensor. The information recording portion is formed of a reflection film whose reflectance increases gradually or stepwise in accordance with an increase in intensity of incident light. The optical irradiation system has an amplitude filter or a phase filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.