Low pressure discharge lamp having sintered "cold cathode" discharge electrodes
CA 2103695 C · Owner: Philips Electronics N.V. · Inventors: Goldburt, Efim; Woodward, David R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fluorescent low pressure discharge lamp is provided with axially mounted cold-cathode electrodes consisting of a sintered shaped mixture of inorganic, material including about 50-90% by weight off tungsten and the remainder BaO or a, mixture of BaO, Ca0 and SrO and oxides of Y Zr or Hf or the rare earths. The, electrodes have a uniform density throughout with a porosity of less than 10%.
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 August 6, 1993 and granted April 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 6, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 6, 2015.
- 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.