Information recording medium
US4956213A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 1989 |
| Grant date | Sep 11, 1990 |
| Priority date | — |
| Expiry date | Feb 15, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/913
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improvement of an information recording medium comprising a disc-shaped resin substrate having an inner-side non-recording zone and an outer-side non-recording zone, a laser-sensitive recording layer, and a flexible resin film (for protection of the recording layer, having protruded and depressed portions on at least the surface facing the recording layer is disclosed. The improvement comprises joining the substrate and the flexible resin to each other on the inner-side and outer-side non-recording zones through fusion by ultrasonic welding or thermal welding in such manner that at least one joining of the flexible resin film to the substrate on the outer-side non-recording zone and the inner-side non-recording zone is effected through a fused portion in the form of a discontinuous ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.