Record carrier with watermark
CA 2397242 A1 · Owner: Koninklijke Philips Electronics N.V. · Inventors: Werner, Antonius J. J.; Yntema, Gertjan; Kramer, Engelbertus P. G. M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a record carrier (1) comprising a pattern of substantially parallel tracks (2) for storing data in the form of marks in , which the data is encoded by means of a channel code. The record carrier further includes a watermark (3) which is provided by controlling the parameter of the channel code so as to introduce a predetermined run length distribution in the marks on the record carrier. Brightness differences are caused by introducing this run length distribution. The invention also relates to a device for reading a record carrier a method of providing a watermark on , the record carrier and a device for providing a watermark on a record carrier.
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 November 12, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 12, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 12, 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.