Patent · US Expired

Information record stampers

US4262875A · kind A · utility

13Cited by
10References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 17, 1979
Grant dateApr 21, 1981
Priority date
Expiry dateAug 17, 1999

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S425/81
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

Video disc nickel stampers are coated with a very thin, e.g., 100-250 angstroms, non-grainy layer of chromium which imparts increased scratch resistance to carbon-filled polyvinylchloride resins during compression molding.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.