Brightness control circuit for a vacuum fluorescent display
CA 1137664 A · Owner: General Electric Company · Inventors: Fisler, Charles F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A circuit for controlling the brightness of a vacuum fluorescent display having filament terminals and connected to anode or segment biasing means includes a transformer having a filament winding connected to the filament terminals. The transformer is driven by a 60cycle power source. An electronic switch including a, transistor, is connected between a center tap of the filament and the anode biasing means (at a common ground) and circuit means open and close the switch at a 60cycle rate. The ratio of time during which the switch is closed to the time during which the switch is open is variable to control the brightness of the display.
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
- Granted December 14, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 14, 1999.
- 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.