Method and system for optical disc copy-protection
CA 2464808 A1 · Owner: Li, Junzhong · Inventors: Vig, Rakesh; Selinfreund, Richard H.; Miller, Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and system for providing copy-protected optical medium using a substrate having information stored therein in information pits (5) and information lands (10, 11), wherein the information lands (10,11) comprise lands in two different planes. A reflective layer (12) covers the information lands (10) and an optically-changeable security material (16) is applied over the reflective layer (12).
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 February 6, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 6, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 6, 2025.
- 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.