Optical disc and optical disc address reading apparatus and method
CA 2706897 A1 · Owner: Ishida, Takashi · Inventors: Ishibashi, Hiromichi; Kobayashi, Yoshiharu; Ishida, Takashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical disc with a spiral or concentric track has a groove formed with a sinusoidal wobble along the track and a sector block disposed along the track. Sectors are formed by dividing each sector block into a plurality of , parts. A synchronization mark on the disc is formed in the first sector in each , sector block. Positive marks or negative marks on the discs are formed in sectors other than the first sector in each sector block. Each positive mark is , a first groove discontinuity creating a discontinuity of a first width W1 in the , track direction of the groove. Each negative mark is a second groove discontinuity creating a discontinuity of a second width W0 in the track …
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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 December 27, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 27, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 2022.
- 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.