Smooth-surfaced magnetic recording medium
CA 2024867 A1 · Owner: Hmt Technology Corporation · Inventors: Eltoukhy, Atef H.; Tsai, Hsiao-Chu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high-density thin-film magnetic disc and method of producing the disc. In forming the disc chromium is, sputtered onto a smooth-surfaced non-metallic substrate, such as a glass substrate first at room temperature, to, form a substratum with a random structure then at a high, temperature, to form a chromium underlayer with anisotropic crystal orientation. A cobalt-based alloy is sputtered onto the underlayer to form the thin film magnetic layer. The disc has high coercivity low bit shift, and can be, operated at a flying height of between 2-4 µinches.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed September 7, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 7, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.