Optical information recording medium and methods for recording, reading, and erasing information thereupon
US6606293B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 2000 |
| Grant date | Aug 12, 2003 |
| Priority date | — |
| Expiry date | Jan 6, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/24316
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is disclosed an optical information recording medium having phase-change recording films whose the transmittance can be made substantially uniform irrespective of the presence or absence of recording. There are also disclosed methods for recording, reading, and erasing information well at a high density on such a medium. Each of the phase-change recording films other than the top one has a phase-change recording film for recording and erasing information by a phase change caused by illumination of laser light. A transparent upper protective film is formed on the phase-change recording film to protect the phase-change recording film mainly against thermal deformation during recording and erasing of information. A transparent lower protective film is formed under the phase-change recording film to protect the phase-change recording film mainly against thermal deformation during recording and erasing of information. A foundation interference film is formed under the transparent lower protective film to adjust the transmittance of the phase-change recording film for the laser light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.