Optical recording medium
US5246758A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1992 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | Apr 2, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording medium, including a substrate and a recording film disposed thereon, wherein an optical shutter layer is disposed in front of the recording film with respect to the direction of an incident reading light beam or recording light beam which is to be supplied to the optical recording medium; and the optical shutter layer comprises, as a main component, a substance having a shutter property such that the substance is in a state where it develops a color thereof until the substance is irradiated with a reading light beam, but when the substance is irradiated with the reading light beam, the substance irradiated with the reading light beam is heated up over a certain temperature so that the substance is decolored and a central portion of the optical shutter layer irradiated with the reading light beam is caused to have a light transmission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.