Method of making a laminated recorded disc
US4390487A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1982 |
| Grant date | Jun 28, 1983 |
| Priority date | — |
| Expiry date | Jan 26, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/81
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A laminated recorded disc of the type having a core material surrounded by a surface layer of a conductive material is made from a preform having a core surrounded by the conductive material. The preform is made in a mold in which the conductive material is first injected into the mold and then the core material is injected into the conductive material. The disc is made from the preform by placing the preform between the platens of a compression mold and closing the heated platens against the preform. The heated platens heat and apply pressure to the preform to cause the materials of the preform to flow radially outwardly until the materials fill the mold cavity formed by the completely closed platens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.