Optically variable and machine-readable device for use on security documents
CA 2088960 C · Owner: Neitman, Robert L. · Inventors: Neitman, Robert L.; Castle, William J.; 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 optically variable device for use on security documents to deter unauthorized reproduction is provided which contains a warning message that is not readily apparent to an observer but that reproduces as a visible warning message when copied. The device comprises a pattern of light reflecting surfaces which comprise a reflection diffraction grating having a plurality of grooves that vary in orientation and blaze angle. In an alternative embodiment, a machine-readable optically variable device is provided in which the pattern of specularly light-reflecting surfaces produces a machine-readable message in response to light impinging on the device.
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 February 5, 1993 and granted April 4, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 5, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 5, 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.