Optical disk structure, method of manufacturing the same, and apparatus for manufacturing the same
CA 2190285 C · Owner: Mori, Mikio · Inventors: Tomita, Takashi; Amano, Minami; Hagio, Takeshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A structure for optical disk, which has clear durable indications around the center hole of a disk in such a manner that it does not affect a reference surface for clamping. In order to realize such a disk structure a first optical, disk (11) and a second optical disk (12) respectively having transparent substrates (11a) and (12a) with a center hole (10) and reflecting coatings (11b) and (12b) on one side are integrally joined with an adhesive layer (13) in such a manner that the reflective coatings on the substrates are opposed to each other and thus a composite optical disk (100) is formed. Flat areas of the substrates around the hole (10) are provided with indications (11d) and (12d) by …
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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 March 13, 1996 and granted January 4, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 13, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 13, 2018.
- 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
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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.