Photographic simulation of density differences as changes of line direction
CA 1066109 A · Owner: Canadian Bank Note Company · Inventors: Merry, Trevor
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a photographic technique for generating a line pattern for use in creating medallion effects on printed documents or for anti-counterfeiting purposes and the like. A high-contrast line screen negative is prepared and a positive generated from the negative. The positive is then superposed on the negative but offset therefrom by the width of a thin line of the resulting image. The combined line pattern creates a medallion effect when the line spacing is comparable in dimensions to the image detail. The resulting pattern may also be used in conjunction with a finding screen or superimposed line pattern to regenerate visual information that appears in hidden or subdued …
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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
- Granted November 13, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 13, 1996.
- 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.