Patent · US Expired

Data storage card having a non-magnetic substrate and data surface region and method for using same

US6857569B1 · kind B1 · utility

18Cited by
190References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 15, 2000
Grant dateFeb 22, 2005
Priority date
Expiry dateNov 27, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/0033
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A data storage card includes a glass substrate having first and second edges. A data storage surface region is located on the glass substrate between the first and second edges. The data surface region includes a magnetic storage medium having at least one layer of high density, high coercivity magnetic material for storing magnetic signals. The data storage card may include a relatively hard, abradeable protective coating formed on the magnetic material layer. The protective coating has a thickness between a maximum thickness which would materially attenuate magnetic signals passing between the magnetic material layer and a transducer of a read device, and a minimum thickness enabling said protective coating to be abraded by usage in an ambient natural atmosphere operating environment for removing therefrom a known quantity of the protective coating.

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