Semiconductor laser driving circuit
CA 2011168 C · Owner: Fujitsu Limited · Inventors: Fukudome, Fujito
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A semiconductor laser driving circuit is arranged so that a predetermined number of transistors can be selected from a group of transistors disposed in parallel according to the characteristics of a semiconductor laser and the selected transistors are connected in parallel between the semiconductor laser and a current source. An optimum current is allowed to flow through the semiconductor laser to cause it to generate a required light output. Moreover a, collector current which provides the optimum characteristics flows through each of the selected transistors. Therefore, an optimum high-speed response can always be realized irrespective of the magnitude of the driving pulse current of 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 February 28, 1990 and granted February 1, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 28, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 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.