Access controlled optical disc and method therefor
CA 2492336 A1 · Owner: H.T.A. High Tech Applications Holdings Limited · Inventors: Wijnen, Arie Marinus; Knox, Alistair John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical disc is disclosed having a set of primary tracks and a set of alternate tracks. At least some of the primary and alternate tracks are associated. When a CD-DA reader accesses the optical disc it locates only the , primary tracks. By contrast when a data reader such as a CD-Rom drive accesses the disc, modifications to the Table of Contents (TOC) cause the data reader not to access a given primary track but instead to be directed to its associated alternate track. This alternate track may contain audio (CD-DA) data which may or may not correspond with the CD-DA data in the associated primary track. The alternate tracks may be copy protected and/or may include , compressed …
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 July 8, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 8, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 8, 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.