Security document
CA 1322015 C · Owner: Metal Box Plc · Inventors: Burnham, Audrey R.; Edwards, Christopher J.; Munn, Roger E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A security document has security printing formed as a moire pattern of two superimposed sets of generally parallel lines. In each line set the line spacing varies progressively along the length of the lines so that each line set has one or more areas in which the line frequency is low and individual lines can be seen with the naked eye, and one or more further areas of high line frequency in which individual lines can only be readily distinguished by using magnification. Furthermore the thickness of each line varies, progressively between relatively large and relatively small values corresponding respectively to the areas of low and high line frequency, the ratio of line spacing to line …
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
- Granted September 7, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 7, 2010.
- 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.