Optical passband filter
CA 2130639 C · Owner: Wilson, Robert Woodrow · Inventors: Glance, Bernard; Wilson, Robert Woodrow
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical passband filter having a frequency transition that is several of orders or magnitude narrower than prior optical filters includes two frequency routing devices. The first frequency routing device has one input for receiving the input signal and at least N outputs where N corresponds to the number of, frequencies that compose the input signal. The N outputs of the first frequency routing device are each coupled to inputs of a second frequency routing device. The outputs of the second frequency device each correspond to one of the selected output frequency bands into which the input signal is to be divided. A multiplexed input signal containing several different frequency channels …
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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 22, 1994 and granted August 4, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 22, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 22, 2016.
- 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.