Multi-bit cellular reflectivity modulation for optical media
CA 2085974 A1 · Owner: Ibm Canada Limited-Ibm Canada Limitee · Inventors: Lightstone, Sam Sampson
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical storage device comprising a disk, having a recording surface for reflecting laser light incident thereon, and a plurality of cells representing stored data. Each of the cells is characterized by one of 2N predetermined levels of effective reflectivity to the incident laser light, where N>1 and wherein N represents the number of bits stored per cell.
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 December 21, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 21, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 21, 2014.
- 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.