Method of reproducing signals recorded on a magnetooptic recording medium
CA 2058173 C · Owner: Sony Corporation · Inventors: Aratani, Katsuhisa; Ohta, Masumi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is intended to improve the track recording density and track density of a magnetooptic recording medium to prevent the deterioration of characteristics due to the variation of reproducing power. After recording information signals on a magnetooptic recording medium having at least a reproducing layer, an intermediate layer and a record hold layer, the direction of magnetization of the reproducing layer is turned in the direction of an initializing magnetic field. The reproducing layer is irradiated with a laser beam and a reproducing magnetic field is applied to the same simultaneously to heat the reproducing layer in a temperature distribution so that a region …
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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 20, 1991 and granted May 29, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 2013.
- 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.