Measurement of fiber diameters and detection of defects
CA 2083969 A1 · Owner: Corning Incorporated · Inventors: Lee, Patrick Shiu Key; Button, Leslie James; Reding, Bruce Warren
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Methods for measuring the diameters of transparent filaments with high precision are provided. The methods involve determining the average spatial frequency of the farfield interference pattern produced by illuminating the filament with a beam of laser light using discrete sequence Fourier transforms (DSFTs). Methods are also provided for making the diameter measurement insensitive to filament ellipticity by determining the diameter at two locations which are spaced apart by an amount such that a plot of diameter versus angle of rotation for an elliptical filament calculated at the first location is approximately 90° out of phase from the same plot calculated at the second location. Methods …
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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 November 27, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 27, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 27, 2014.
- 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.