Optical information recording and reproduction apparatus
CA 2067654 C · Owner: Yamazaki, Koichi · Inventors: Yamazaki, Koichi; Nakamura, Eiichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The provision of an optical information recording and reproduction apparatus that correctly performs tracking control even if there is a step in the information recording surface in an apparatus that records and reproduces information to and from an information recording medium such as an optical card or the like. An optical information recording and reproduction apparatus which focusses a light spot from a laser (1), onto an optical information recording medium (7) which has a tracking track, and performs the recording and reproduction of information to required positions using said tracking track as a reference said, apparatus being characterized by reducing an optical output of said …
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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 April 30, 1992 and granted December 8, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 30, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 30, 2014.
- 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.