Nonabrasive magnetic recording tape
CA 1290199 C · Owner: Ellsworth, Arthur J. · Inventors: Ellsworth, Arthur J.; Woolley, Karen M.; Kim, Chong-Yong J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Magnetic recording tape is suitable for data recording mechanisms equipped with brass or other soft heads when its magnetizable layer is based on ferromagnetic iron oxide particles and contains titanium dioxide or other soft head cleaning agent which has a hardness approximating or slightly exceeding that of the iron oxide. The magnetizable layer preferably is free from but may also, contain unusually small amounts of hard head cleaning agent such as alumina.
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
- Granted October 8, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 8, 2008.
- 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.