Method and apparatus for controlling access to storage media
CA 2415047 A1 · Owner: Selinfreund, Richard H. · Inventors: Vig, Rakesh; Drew, Jeffrey M.; Selinfreund, Richard H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for preventing copying of data from optical storage media. A locus (410) on optical storage medium is initially read to produce a signal and is then re-read by a reader to produce a second signal. The signal detected upon re-reading is different from the signal that is detected upon initial sampling. A method and apparatus for controlling access to a storage medium such as an optically readable medium. Light sensitive or other materials (400) that are adapted to change state and affect reading of a storage medium are used to control access to data that may be stored on optical medium and/or to control use of the medium.
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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 30, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 30, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 30, 2023.
- 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.