Magneto-optical recording medium and manufacturing method thereof
CA 2087288 C · Owner: Hirokane, Junji · Inventors: Katayama, Hiroyuki; Hirokane, Junji; Mieda, Michinobu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A magneto-optical recording medium has a recording layer including at least two magnetic layers. The magneto-optical recording medium satisfies a condition of ?A1.K1 - A2.K2 ? < 2.0 (erg2/cm4) wherein A1 K1, A2, and, K2 respectively represent an exchange constant of a first magnetic layer, a perpendicular magnetic anisotropy of a first magnetic layer, an exchange constant of a second magnetic layer, and a perpendicular magnetic anisotropy of a second magnetic layer. First and Second magnetic layers are made of TbFeCo.
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 January 14, 1993 and granted July 8, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 14, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 14, 2015.
- 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.