Varying tone security document
CA 2112641 C · Owner: Standard Register Company (The) · Inventors: Mowry, William H. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved security document according to the present invention includes a substrate having a surface for carrying indicia. The document has background printed matter consisting, of a pattern of elements of a first size and frequency printed, at a first density on the surface. The document further has a cancellation term, consisting of a pattern of elements of a second size and frequency, printed at a second density on the surface. Elements of one of the first size or the second size are sufficiently small such that they are not reproduced by a color copier at a particular copier setting and elements of the, other of the first size or the second size are sufficiently large such that they …
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 December 30, 1993 and granted October 6, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 30, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 30, 2015.
- 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.