Optical recording medium and method for making
US5252370A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1992 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Feb 14, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A recording thin film, a dielectric thin film, and a reflective thin film are stacked on a surface of a substrate in the described order. Upon exposure to recording laser light, an inorganic compound in the recording thin film decomposes to release a gas, creating a space in the recording thin film. Since the substrate is also heated and softened, a recess is created in the substrate surface due to the pressure of evolving gas. The space and recess cause a change of optical conditions, resulting in a substantial lowering of reflectivity where the laser light is irradiated. This enables reproduction in accordance with the CD standard. The use of an inorganic compound which decomposes to release a gas upon heating rather than organic dyes ensures better light resistance, leading to highly reliable information storage. Recording sensitivity is high.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.