Optical information medium and a method of manufacturing the medium
CA 2435652 C · Owner: Koninklijke Philips Electronics N.V. · Inventors: Hendriks, Bernardus H. W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical information medium (20) for recording such as DVR-blue, and a , method for manufacturing such a medium (20) is provided. Reading from and recording onto the medium (20) is performed by means of a focused radiation beam (10) having a radiation wavelength & and a numerical aperture NA. Said medium has a substrate (1), and a stack (2) of layers provided thereon. The stack (2) comprises at least a first recording stack (3) and k radiation beam transmissive layers (4, 5). Each transmissive layer (4 5) has a refractive , index ni and an average thickness di ~m and 1 = i = k and k = 2. The thickness dk of layer k (5) is determined by a simple formula which depends on the …
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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 December 20, 2001 and granted June 7, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 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.