Paper surface roughness analyzer
CA 2112792 A1 · Owner: Westvaco Corporation · Inventors: Rogowski, Donald F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Subjective paper characteristics such as visual appearance and print quality are often objectively related to certain scales of surface roughness. Three dimensional topographic surface data is obtained from a paper sample secured by vacuum to a flat porous plate for translational movement in a grid pattern beneath a vertically compliant stylus that is resiliently suspended beneath a rigid, overhead support beam. Such surface data is mathematically filtered by a linear convolution technique or the distinctly alternative circular convolution technique to segregate the raw data characteristics of component surfaces that contain only certain frequencies of roughness. The root-mean-square …
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 January 4, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 4, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 4, 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.