High pressure discharge lamp with incandescent filament for starting
CA 2005582 C · Owner: Gte Products Corporation · Inventors: Thibault, Paul; Michael, Joseph Darryl; Biblarz, Oscar
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high pressure sodium arc tube assembly includes a light-transmitting arc tube containing a fill material including sodium and mercury, a pair of electrodes sealed in opposite ends of the arc tube and a filament or other resistive member located within the arc tube and extending between opposite ends thereof. The filament is electrically connected to the electrodes. The filament provides a sufficient electric field and an abundance of electrons dispersed throughout the discharge region to initiate an arc discharge when the electrodes are energized. The filament is selected to produce an electric field in the discharge region prior to initiation of arc discharge of at least 20 volts per …
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 14, 1989 and granted May 10, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 2011.
- 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.