Magneto-optical recording device
CA 2048499 C · Owner: Sharp Kabushiki Kaisha · Inventors: Takahashi, Akira; Murakami, Yoshiteru; Ohta, Kenji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A magneto-optical recording device having a light source and external magnetic field applying apparatus which, records information on a magneto-optical recording medium with a magnetic field modulation method. The device has a controller which stops the irradiation of a light beam when switching the direction of applying external magnetic field during recording. This allows an area where information is recorded with a low external magnetic field to be smaller, and thereby achieving a reproduced signal of improved quality.
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 August 6, 1991 and granted November 9, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 6, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 6, 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.