The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 2015
Filed:
Mar. 11, 2009
Charles Douglas Macpherson, Santa Barbara, CA (US);
Denis Gerard Vendette, Embrun, CA;
Gilles Girouard, Orleans, CA;
A Oliver Stone, Ottawa, CA;
Charles Douglas MacPherson, Santa Barbara, CA (US);
Denis Gerard Vendette, Embrun, CA;
Gilles Girouard, Orleans, CA;
A Oliver Stone, Ottawa, CA;
NANOTECH SECURITY CORP., Burnaby, CA;
Abstract
A security device for authenticating bank notes, documents and other items, comprises a luminescent material for producing luminescent radiation of first and second wavelengths. The security device includes an optically variable structure for controlling emission of luminescent radiation of at least one of the first and second wavelengths from the security device, the security device being arranged to permit, from an area of the optically variable structure, emission of luminescence of the first and second wavelengths from the security device. The optically variable structure causes the relative emissivity of the security device for luminescent radiation of the first and second wavelengths to change with a change in emission angle, so that the security device produces an angle-dependent color shift in the emitted luminescent radiation. The optically variable structure may comprise an optical interference stack that controls transmission of luminescent radiation therethrough in response to the wavelength of luminescent radiation.