Optical recording apparatus
CA 2022005 C · Owner: Yamada, Noboru · Inventors: Mizuno, Sadao; Yamada, Noboru; Satoh, Isao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical recording apparatus comprises optical recording mediums each of which comprises a single plate substrate and recording layers which are formed on both sides of the substrate and available for recording and reproduction or for recording erasing and, reproduction with irradiation of laser beams both, surfaces of the recording medium being available for the simultaneous access, and floating type optical thin heads which are provided at every side of the recording mediums and float from the respective surfaces of the recording mediums with maintaining specific distances therefrom for irradiating laser beams onto the recording mediums when the recording mediums are rotated. …
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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 July 26, 1990 and granted February 13, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 26, 2012.
- 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.