Identification matter
CA 1108666 A · Owner: Post Office · Inventors: Ferro, Berkeley M.; Walker, Aubrey D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A credential, such as a passport or an identification card, is provided, for example by impregnation or coating with a phosphorescent composition which includes at least two phosphorescence activators which exhibit different emission characteristics both with respect to wavelength and lifetime so that, when the composition is irradiated the initial afterglow changes colour, for example from green to blue.
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 8, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 8, 1998.
- 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.