Light diffusing apparatus
CA 2134902 C · Owner: Nortel Networks Limited · Inventors: Koens, Paul John; Bertignoll, Friedrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A light diffusing apparatus, which may be used as an elongate visual indicator in telephone sets, video cassette recorders etc provides, very even illumination (i.e. evenly diffused light without any discernible bright spots) when illuminated by spot light from one or two light emitting diodes. The apparatus includes a light guide having a light path of sufficient length to disperse the spot light from the emitting diodes. The dispersed light from the light guide then passes through a light diffuser. The light output end of the light guide and the light input surface of the light diffuser have uniform texture surfaces to further diffuse the dispersed light. The light diffuser may include …
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 2, 1994 and granted May 16, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 2, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 2, 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.