Fluorescent lamp lighting device
CA 2211054 C · Owner: Matsushita Electric Industrial Co. Ltd. · Inventors: Gyoten, Masayoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides for a starting switch circuit which is generally applicable to ballasts and fluorescent lamps having different normal rated power from each other. A starting switch circuit comprising: a serially-connected circuit having first rectifying means a, semiconductor switching element including a control terminal and first resistor means for detecting a current flowing to the semiconductor switching element, all connected in series; first timer means, connected in parallel to a series circuit of the semiconductor switching element and the first resistor means, for making the semiconductor switching element to OFF state after the semiconductor switching element is in …
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, 1997 and granted January 15, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 6, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 6, 2019.
- 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.