Optical recording medium
CA 2070221 A1 · Owner: Kitagawa, Nobuhisa · Inventors: Kitagawa, Nobuhisa; Hirose, Sumio; Mizukuki, Tadahiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical recording medium of a single plate type comprises a substrate having a groove, a recording layer containing a dye overlying the substrate a reflective, layer overlying the recording layer and a protective layer overlying the reflective layer, wherein the recording layer is formed by a spin-coating method and the dimension of the groove varies from the center portion of the substrate toward the outer periphery thereof.
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 2, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 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.