Security paper with authenticity features in the form of substances luminescing only in the invisible region of the optical spectrum and process for testing the same
First Claim
1. A process for testing the authenticity of security documents secured with a luminescing substance without attracting attention, comprising:
- exciting the security document with light from the invisible region of the optical spectrum; and
sensing luminescence light emitted from said security document in the invisible region of the optical spectrum;
wherein the exciting and sensing steps are performed through a plate which is separate from said security document and opaque to visible light but which allows both excitation light and also luminescence light to pass through; and
wherein said exciting step is carried out by an exposure unit and said sensing step is carried out by a sensing unit and further including positioning said exposure unit and said sensing unit behind said plate so as to hide said exposure unit and said sensing unit from view.
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Accused Products
Abstract
Security paper with luminescing authenticity characteristics which after excitation with invisible light emit exclusively invisible light of different wavelengths as authenticity signal. The luminophores can be included in the printing ink used or they can be added to the paper material in the manufacture of the paper material. A corresponding test apparatus makes it possible to check the authenticity of the security paper in the presence of customers but unnoticed by them; thereby the invisibility of the test signal and the authenticity signal are taken advantage of and the test device is hidden behind a plate non-transmissive for visible light which however is transmissive for the test signal and for the authenticity signal.
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Citations
17 Claims
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1. A process for testing the authenticity of security documents secured with a luminescing substance without attracting attention, comprising:
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exciting the security document with light from the invisible region of the optical spectrum; and sensing luminescence light emitted from said security document in the invisible region of the optical spectrum; wherein the exciting and sensing steps are performed through a plate which is separate from said security document and opaque to visible light but which allows both excitation light and also luminescence light to pass through; and wherein said exciting step is carried out by an exposure unit and said sensing step is carried out by a sensing unit and further including positioning said exposure unit and said sensing unit behind said plate so as to hide said exposure unit and said sensing unit from view. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11)
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6. A device for testing the authenticity of security documents secured with a luminescing substance without attracting attention, comprising:
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an exposure unit for exciting the security document with light from the invisible region of the optical spectrum; a detector unit for sensing luminescence light emitted from the security paper in the invisible region of the optical spectrum; and a plate separating said exposure unit and said detector from a security document being tested, said plate being separate from said security document, opaque to visible light and allowing both excitation light and also luminescence light to pass through. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification