Abstract:
A value document authentication apparatus and system that includes value document substrates having a uniform distribution of one or more phosphors that emit infrared radiation in one or more wavelengths, which can be measured at the same location on the value document that is illuminated by a phosphor exciting light source when the document passes the light source with a uniform velocity. The illumination and measurement locations on the value document can be offset. The measured infrared radiation as a series of overlapped measurements along a pre-selected track in the value document represents an intensity profile, which can be normalized after removing high variations. The normalized intensity profile of a test value document can be compared with normalized intensity profile from valid reference documents to authenticate the test value document.
Abstract:
Phosphor compositions are provided that can be incorporated into or onto plastic substrates as covert security features. The plastic substrates can be transparent and the phosphor compositions have a refractive index that effectively matches the refractive index of the plastic substrate to maintain the transparency. The phosphor compositions have absorption in the infrared, thus enabling excitation and detection of the compositions with an infrared emitting source.
Abstract:
Taggants can be incorporated into or onto value documents. The taggants comprise a crystalline taggant doped with two rare earth ions. The substrate or printed matter into which the taggant can be incorporated has a minimal absorption infrared wavelength window and the taggant is excited by incident infrared radiation in this wavelength range. Suitable first rare earth ions function as efficient broad band absorbers of incident infrared radiation and passes energy non-radiatively to a second rare earth ion, which the emits infrared radiation at a wavelength greater than the incident infrared radiation. The emitted infrared radiation is also in the minimal absorption transmission window of the printed matter or the substrate into which the taggant is incorporated. Methods of authenticating the value document include detection of the emitted radiation at pre-determined values.
Abstract:
A value document authentication system comprising a value document substrate having a luminescent compound disposed on or in at least a portion of the value document substrate, wherein the luminescent compound (i) comprises a host lattice having at least one metallic ion with magnetic properties and is doped with at least one rare earth ion capable of emitting infrared radiation with at least one distinct infrared wavelength when excited with an exciting light source having sufficient energy to excite emission from the luminescent compound and (ii) has a pre-determined ratio of metallic ions to rare earth ions such that the ratio corresponds to a parameter of a pre-selected decision criteria, both of which properties are measured at the same location on the value document and used to authenticate the value document.
Abstract:
An authentication apparatus used to authenticate a moving value document with uniform or non-uniform distribution of a pre-selected covert composition that includes an active ion that emits optical radiation at a pre-selected wavelength when excited by exciting incident light. The optical radiation is imaged onto at least one photodetector having first and second detector elements. The imaged intensities are captured at pre-determined times relating to the velocity of the value document. The ratio between the second detector element and the first detector element measured at the same image location or different image locations represents the characteristic decay time intensity data of the pre-selected wavelength emission. The authenticity of the value document is rejected when the pre-selected wavelength emission is not received by the at least one photodetector or when the output electronic signal ratio does not meet expected value.
Abstract:
The production of light of various wavelengths using IR phosphor down conversion techniques using existing LED emissions to pump sensitizer-rare earth ions that emit at other wavelengths. A sensitizer absorbs an LED chip pump emission and then transfers that energy with high quantum efficiency to dopant ions that then emits at their characteristic wavelength.
Abstract:
A method and system for identifying, tracking, and/or authenticating objects that is simple to apply and to use by an intended user, but is extremely difficult to counterfeit or compromise by an unintended user. Also disclosed is a multi-color, co-planar indicium made of a combination of printed patterns of multiple inks. The printed patterns may be modified by software-generated masks to ensure that the patterns are co-planar. The indicium is undecipherable unless irradiated with specified wavelengths of light radiation, filtered through specified spectral filters, and read and decoded by an electronic image reader. The indicium may be visible or covert. The indicium encodes unique true information about the object and may encode nonsensical or intentionally incorrect information as a further deterrent to unauthorized use. The method permits the indicia to be applied to objects at high processing speeds possible with inkjet printing.
Abstract:
Articles, methods of validating the articles, and validating systems are provided herein. In an embodiment, an article includes a substrate and a security feature on the substrate. The security feature includes a first region that has a first ink composition and a second region that has a second ink composition. The first ink composition includes a first luminescent phosphor and the second ink composition includes a second luminescent phosphor that is different from the first luminescent phosphor. The first luminescent phosphor and the second luminescent phosphor have indistinguishable excitation energy wavelengths, indistinguishable emission wavelengths, and distinguishable temporal decay properties.
Abstract:
Luminescent borates, luminescent materials, and articles incorporating such borates are provided herein. An embodiment of a luminescent borate includes a host borate that has a B9O16-comprising crystal lattice. Neodymium and/or ytterbium are present within the host borate, and one or more substitutable elements are optionally present along with the neodymium and/or ytterbium within the host borate. The one or more substitutable elements are different from neodymium and ytterbium.