US 11,747,268 B2
Coded polymer substrates for banknote authentication
Nabil Lawandy, Saunderstown, RI (US)
Assigned to Spectra Systems Corporation, Providence, RI (US)
Filed by Spectra Systems Corporation, Providence, RI (US)
Filed on Mar. 1, 2018, as Appl. No. 15/909,170.
Claims priority of provisional application 62/465,587, filed on Mar. 1, 2017.
Prior Publication US 2018/0252637 A1, Sep. 6, 2018
This patent is subject to a terminal disclaimer.
Int. Cl. G01N 21/23 (2006.01); G07D 7/1205 (2016.01); B42D 25/29 (2014.01); B42D 25/36 (2014.01); G01N 21/31 (2006.01); G07D 7/12 (2016.01); G07D 7/202 (2016.01); G01N 21/552 (2014.01); G07D 7/10 (2006.01); B42D 25/351 (2014.01)
CPC G01N 21/31 (2013.01) [G01N 21/554 (2013.01); G07D 7/10 (2013.01); G07D 7/12 (2013.01); G07D 7/1205 (2017.05); G07D 7/205 (2013.01); B42D 25/29 (2014.10); B42D 25/351 (2014.10); B42D 25/36 (2014.10); G07D 2207/00 (2013.01)] 20 Claims
OG exemplary drawing
 
13. A system for authenticating an item, comprising:
the item including a polymer substrate comprising a polymer material and a doping material, the polymer substrate being transparent to visible spectrum radiation, the polymer material and the doping material configured to transmit radiation through the polymer substrate, and the doping material capable of absorbing and scattering radiation of at least one specific wavelength to generate a spectral signature including a notched pattern in a spectral band of wavelengths of the transmitted radiation;
a radiation source for irradiating the item with incident radiation characterized by a spectral band of wavelengths spanning a band of wavelengths including the at least one specific wavelength absorbed and scattered by the doping material, the polymer substrate absorbing and scattering radiation of the incident radiation to generate the spectral signature in the spectral band of wavelengths of the incident radiation and transmitting the radiation having the generated spectral signature through the polymer substrate; and
a sensor configured to detect the spectral signature after the radiation is transmitted through the polymer substrate.