Patent application number | Description | Published |
20100320480 | PHOSPHOR CONVERTING IR LEDS - 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. | 12-23-2010 |
20110069174 | AUTHENTICATION APPARATUS FOR VALUE DOCUMENTS - 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. | 03-24-2011 |
20110087440 | AUTHENTICATION SYSTEMS FOR DISCRIMINATING VALUE DOCUMENTS BASED ON VARIABLE LUMINESCENCE AND MAGNETIC PROPERTIES - 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. | 04-14-2011 |
20110121203 | AUTHENTICATION APPARATUS FOR MOVING VALUE DOCUMENTS - 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. | 05-26-2011 |
20110146930 | CONTROLLING THE DETECTABILITY OF AN ARTICLE AND METHOD FOR AUTHENTICATING THE ARTICLE - Cascading phosphors are described herein that produce emissions when they are excited by incident radiation. The cascading phosphors can be applied to articles, and can be useful in authenticating the article. The cascading phosphors include a host and at least three active ions. | 06-23-2011 |
20110147450 | METHOD AND AUTHENTICATION APPARATUS FOR AUTHENTICATING VALUE DOCUMENTS - 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. | 06-23-2011 |
20110147614 | REFRACTIVE INDEX MATCHED PHOSPHORS AND SUBSTRATES FOR SECURITY APPLICATIONS - 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. | 06-23-2011 |
20120104256 | VALUE DOCUMENTS AND OTHER ARTICLES HAVING TAGGANTS THAT EXHIBIT DELAYED MAXIMUM INTENSITY EMISSIONS, AND METHODS AND APPARATUS FOR THEIR AUTHENTICATION - Value documents or other articles having authentication features, authentication apparatuses, and methods of authentication are provided that relate to the use of taggants that absorb radiation from an illumination source and emit radiation in a manner that has a maximum intensity occurring a duration of time after the illumination source has been switched off. The taggants include a crystalline composition comprising a host crystal lattice doped with a first rare earth active ion, and in some examples a second rare earth active ion. | 05-03-2012 |
20120153184 | LUMINESCENT PHOSPHOR-CONTAINING MATERIALS, AND METHODS FOR THEIR PRODUCTION AND USE IN AUTHENTICATING ARTICLES - Embodiments of luminescent phosphor-containing materials include a medium and particles of a phosphor compound dispersed in the medium. The phosphor compound includes a host lattice comprising at least one alkaline earth element, manganese, and europium (e.g., divalent manganese and divalent europium). Embodiments of methods for producing such a phosphor-containing material include preparing a phosphor compound that includes the phosphor compound particles, and dispersing the particles in the medium to produce the phosphor-containing material. The material may then be incorporated into an article. Embodiments of a method for identifying a phosphor-containing material incorporated with an article include exposing a portion of the article to exciting radiation (e.g., light produced by a blue diode), and determining whether a detected emission produced as a result of the exciting radiation indicates a manganese emission following a europium absorption for at least a first time period after termination of the exposing step. | 06-21-2012 |
20130015369 | METHODS AND APPARATUS FOR AUTHENTICATING ARTICLES WITH LUMINESCENT PHOSPHOR COMPOUNDS - Methods and apparatus for article authentication include an exciting radiation generator that exposes an area of the article to exciting radiation, and at least two radiation detectors that detect emitted radiation from the area in a first band and in a second band that does not overlap the first band. The first band corresponds with a first emission sub-band of an emitting ion, and the second band corresponds with a second emission sub-band of the same emitting ion. A processing system calculates a comparison value that represents a mathematical relationship (e.g., a ratio) between a first intensity of the emitted radiation in the first band with a second intensity of the emitted radiation in the second band, and determines whether the comparison value compares favorably with an authentication parameter. When the comparison value compares favorably with the authentication parameter, the article is identified as being authentic. | 01-17-2013 |
20130015651 | LUMINESCENT PHOSPHOR COMPOUNDS, ARTICLES INCLUDING SUCH COMPOUNDS, AND METHODS FOR THEIR PRODUCTION AND USE - Embodiments include luminescent phosphor compounds that include one or more emitting ions and one or more disturbing ions, and methods for their production. An emitting ion in the compound may be characterized by a first decay time constant when the emitting ion is undisturbed. However, a corresponding disturbing ion in the compound, which is different from the emitting ion, causes the emitting ion to have a pre-defined, target disturbed decay time constant that is greater than zero and less than the first decay time constant. An embodiment of an authentication system is configured to measure the decay time constant of a phosphor compound applied to an article, and to determine whether the decay time constant corresponds to a phosphor compound that includes a particular disturbing ion (e.g., in order to determine whether or not the article is authentic). | 01-17-2013 |
20130119274 | LUMINESCENT BORATES, MATERIALS AND ARTICLES INCORPORATING SUCH BORATES, AND METHODS AND APPARATUS FOR THEIR PRODUCTION AND USE IN ARTICLE AUTHENTICATION - Embodiments include luminescent materials and associated production methods. The material includes a crystal borate having a first substitutable element, neodymium substituted for the first substitutable element at a first substitution percentage of at least about 20 percent, and ytterbium substituted for the first substitutable element at a second substitution percentage. The material also may include chromium substituted for a second substitutable element. The material also may include a medium within which particles of the borate are incorporated. The medium, with the luminescent material particles, may form a security feature of an article. Embodiments of methods for identifying whether such a luminescent material is incorporated with an article include exposing a portion of the article to excitation in a chromium absorption band, and determining whether a detected emission produced by the article as a result of the excitation indicates an ytterbium emission after termination of the exposing step. | 05-16-2013 |
20130122266 | LUMINESCENT BORATES, MATERIALS AND ARTICLES INCORPORATING SUCH BORATES, AND METHODS AND APPARATUS FOR THEIR PRODUCTION AND USE IN ARTICLE AUTHENTICATION - Embodiments include luminescent materials and associated production methods. The material includes a crystal borate having a first substitutable element and a second substitutable element, one or more rare earth ions substituted for the first substitutable element, and chromium substituted for the second substitutable element. The one or more rare earth ions are selected from a group consisting of neodymium and ytterbium. The material also may include a medium within which particles of the borate are incorporated. The medium, with the luminescent material particles, may form a security feature of an article. Embodiments of methods for identifying whether such a luminescent material is incorporated with an article include exposing a portion of the article to excitation in a chromium absorption band, and determining whether a detected emission produced by the article as a result of the excitation indicates an ytterbium emission after termination of the exposing step. | 05-16-2013 |
20130181144 | ARTICLES INCORPORATING THERMOGRAPHIC PHOSPHORS, AND METHODS AND APPARATUS FOR AUTHENTICATING SUCH ARTICLES - Embodiments include methods and apparatus for identifying a thermographic phosphor (e.g., Er:YIG) incorporated on or within an article. The method and apparatus embodiments include an excitation energy generator selectively exposing the article to excitation energy in an absorption band of the thermographic phosphor. An emitted radiation detector detects first emission characteristics of first emitted radiation from the article within an emission band of the thermographic phosphor when the article has a first temperature, and detects second emission characteristics of second emitted radiation from the article within the emission band when the article has a second temperature that is different from the first temperature. A temperature adjustment element is configured to adjust the temperature of the article. Embodiments further include a processing system determining whether the first emission characteristics are sufficiently different from the second emission characteristics. | 07-18-2013 |
20140021369 | ARTICLES, METHODS OF VALIDATING THE SAME, AND VALIDATION SYSTEMS EMPLOYING DECAY CONSTANT MODULATION - 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. | 01-23-2014 |
20140151997 | LUMINESCENT BORATES, LUMINESCENT MATERIALS AND ARTICLES INCORPORATING SUCH BORATES - 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 B | 06-05-2014 |