Optical memory disc manufacture
US4957603A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 23, 1989 |
| Grant date | Sep 18, 1990 |
| Priority date | — |
| Expiry date | Oct 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/26
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of making an optical memory disc replica that includes the steps of injection molding a PMMA substrate having a surface with information recorded thereon as a series of surface undulations, and depositing a film of optically reflective metallic construction over the information surface such that the information recorded on the surface may be optically read through the substrate as a function of reflectivity from the film. The reflective film is sputter-deposited onto the information surface in the presence of carbon at said surface in excess of that in the polymer molecular structure by subjecting the surface to a plasma that includes carbon-rich ions to prepare the surface for chemical bonding with the metal of the film and the underlying substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.