Direct effect master/stamper for optical recording
CA 2020175 A1 · Owner: E.I. Du Pont De Nemours And Company · Inventors: Simmons, Howard E. Iii; Degraaf, Martinus J. M.; Degraaf, Martinus J. M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Title, DIRECT EFFECT MASTER/STAMPER, FOR OPTICAL RECORDING Abstract, A method for making optical recording media in which the optically readable information is embossed therein by means of an information master recording which is directly usable as a stamper.
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 29, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 29, 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.