Laser control circuit
CA 2073430 C · Owner: Roberts, Kim Byron · Inventors: Roberts, Kim Byron; Burley, Gregory Stephen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A laser diode control circuit maintains a desired average output power of the laser diode (10) by detecting (18) the optical output, amplifying (24) the detected output and controlling a bias current (14) of the laser diode accordingly. A pilot tone (20) is combined with the detected output (18) and amplified therewith and the amplified (24) level of the tone is detected (22) and used to control (26) a modulation current (16) for the laser diode. In one described arrangement the laser diode (10) is controlled to have a high extinction ratio with the bias current at the knee (42) of the diode's characteristic curve and in another arrangement a, lower extinction ratio is provided with the …
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 November 30, 1990 and granted March 31, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 30, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2012.
- 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.