Infrared phosphor and material having latent images and optical reading system using said phosphor
CA 2123274 C · Owner: Takeuchi, Yoji · Inventors: Takeuchi, Yoji; Fukao, Ryuzo; Kanzaki, Hisao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides a phosphor excited by infrared rays to emit infrared rays which has a particle shape of nonacicular and a particle size of 4 µm or smaller after synthesized. The phosphor preferably comprises an oxoacid salt-containing compound containing at least one element selected from the group consisting of Nd, Yb and Er. The invention further provides a material having a latent image pattern comprising said phosphor and an optical reading system which use the material having a latent image pattern.
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 May 10, 1994 and granted December 9, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 10, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 10, 2016.
- 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.