Method for encoding materials with a luminescent tag and apparatus for reading same

A method for verifying the authenticity of an object, the method comprising the steps of:

• associating a luminescent tag with the object;
• coding said luminescent tag by adjusting relative light intensities emitted thereby within at least two luminescence bands;
• and
• authenticating the object by triggering said luminescent tag, measuring a light spectrum emitted thereby and comparing said measured spectrum with a reference spectrum;
• wherein if said measured spectrum matches said reference spectrum, the object is authenticated.

A system for verifying the authenticity of an object, the system comprising:

• a luminescent tag to be associated with the object, said luminescent tag coded to emit light when triggered within at least two luminescence bands at predetermined relative light intensities;
• a reference tag representative of said predetermined intensities;
• and
• a monitoring station having access to said reference tag, said station comprising a spectrometer, a data processor and an output device and being configured to measure light intensities emitted within said luminescence bands by said coded tag via said spectrometer, compare said measured intensities with said predetermined intensities and indicate via said output device whether said measured intensities match said predetermined intensities.

An apparatus for authenticating a luminescent tag, the apparatus comprising:

• a reference tag representative of relative light intensities emitted within at least two luminescence bands;
• a spectrometer for measuring light intensities emitted from the luminescent tag within said luminescence bands;
• a data processor configured to compare said measured intensities with said representative intensities;
• and
• an output device for indicating whether the measured intensities match said representative intensities;
• wherein if said measured intensities match said representative intensities, the luminescent tag is authenticated.

A computer-readable storage medium having a computer-readable program embodied therein for directing operations of a computer system comprising a spectrometer, a data processor, a storage device and an output device, wherein the computer-readable program comprises instructions for operating the computer system to authenticate a luminescent tag associated with an object in accordance with the following:

• storing in the storage device a reference tag representative of relative light intensities emitted within at least two luminescence bands;
• measuring, via the spectrometer, light intensities emitted from the luminescent tag within said luminescence bands;
• using the processor, comparing said measured intensities with said representative intensities;
• and
• indicating, via the output device, whether said measured intensities match said representative intensities;
• wherein if said measured intensities match said representative intensities, the object is authenticated.

A method for incorporating a luminescent code into a material comprising the steps of:

• combining a donor luminescent substance with an acceptor luminescent substance, wherein an emission spectrum of said donor substance overlaps with an absorption spectrum of said acceptor substance;
• irradiating said combined substances with a high power source of ultraviolet radiation, said radiation comprising a wavelength which lies within an absorption spectrum of said donor substance;
• adjusting an energy of said radiation such that when said combined substances are subsequently irradiated with a low power source of ultraviolet radiation, an intensity of measurable emissions of said donor substance versus an intensity of peak measurable emissions of said acceptor substance is of a predetermined ratio;
• and
• combining said combined substances with said material.