Optical disk, and information recording/reproduction apparatus
CA 2125331 C · Owner: Satoh, Isao · Inventors: Satoh, Isao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In an optical disk having a recording plane with a spiral first track and a spiral second track information being recorded into and/or reproduced from said first and second tracks the first track is formed in a groove-like shape the second track is formed between adjacent first tracks and in a land-like shape and information is recorded in the first and second tracks in different modulation methods.
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 June 7, 1994 and granted January 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 7, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 7, 2016.
- 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.