Optical determination of velocity
CA 2002809 A1 · Owner: Carr, Robert J. G. · Inventors: Carr, Robert J. G.; Al-Shukri, Sumaia; Clarke, David J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Particle velocity is determined optically through the use of crossed interference fringe patterns. The fringe patterns are produced by passing laser beams of distinct. wavelength along a common optical fibre and through two crossed diffraction gratings which are bonded to the free end of the fibre. Each diffraction grating is constructed in the manner of an interference filter so as to produce interference fringes at one wavelength but to transmit the other wavelength substantially uniformly across the grating. Other interference elements can be used in place of diffraction gratings and the use of a single diffraction grating is envisaged in certain circumstances. An indication of the sense …
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 10, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 10, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 10, 2011.
- 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.