Magnetic recording medium
CA 2033004 C · Owner: Okazaki, Iwao · Inventors: Okazaki, Iwao; Nakajima, Shoji; Abe, Koichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A magnetic recording medium with excellent S/N ratio and durability is disclosed. The magnetic recording medium comprises a substrate film and a magnetic layer formed on at least one surface of the substrate film. The maximum depth of depressiones in the surface of the magnetic layer being larger than maximum height of peaks on the surface of the magnetic layer.
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 December 21, 1990 and granted March 7, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 21, 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.