Object authentication
View Patent ↗A device detects multi-spectral imaging by using scan elements. The device may include an illumination module and a detection module to detect light scattered from an object illuminated by the illumination module. The device may also include an array of light sources to produce light at a plurality of different wavelengths, and create a line of illumination with each of the different wavelengths. The light detection may be applied to authenticate and validate documents, such as banknotes moving along a document conveyer.
1. A method for authenticating an object, comprising:
modulating a plurality of wavelengths of light from a plurality of light-emitting sources, wherein modulating the plurality of wavelengths of light comprises simultaneously modulating the plurality of wavelengths of light using a plurality of orthogonal sequence codes, and wherein modulating the plurality of wavelengths of light illuminates the object;
detecting a light signal from the illuminated object with plurality of photodiodes;
producing a reflectance spectrum from the light signal, wherein producing the reflectance spectrum comprises demodulating the light signal using the plurality of orthogonal sequence codes;
comparing the reflectance spectrum to a template reflectance spectrum of an authentic object; and
determining if the illuminated object is authentic as a function of the comparison.
2. The method of claim 1 , wherein modulating the plurality of wavelengths of light comprises employing a time division multiplexing(TDM).
3. The method of claim 1 . wherein modulating the plurality of wavelengths of light comprises employing a direct sequence spread spectrum modulation (DSSM).
4. The method of claim 1 , wherein producing the reference spectrum comprises generating a multi-spectrum image of at least a specified portion of the illuminated object.
5. The method of claim 4 , wherein the multi-spectrum image comprises a plurality of images of the specific portion of the illuminated object associated with one or more of the plurality of wavelengths of light.
6. The method of claim 1 , wherein the reflectance spectrum comprises one or more intensity levels associated with one or more of the plurality of wavelengths of light.
7. A method for authenticating an object, comprising:
illuminating the object with a plurality of wavelengths of light from a plurality of light-emitting sources wherein illuminating the object comprises simultaneously modulating the light-emitting sources using a plurality of orthogonal sequence codes;
detecting light scattered from the illuminated object with a plurality of photodiodes to create a multi-spectrum image of at least a specified portion of the illuminated object, wherein creating the multi-spectrum image comprises demodulating the light scattered from the illuminated object using the plurality of orthogonal sequence codes, and wherein the multi-spectrum image comprises a plurality of images associated with one or more of the plurality wavelengths;
comparing the multi-spectrum image to a template multi-spectrum image of an authentic object; and
determining if the illuminated object is authentic based on the comparison.
8. The method of claim 7 , wherein the plurality of light-emitting sources and the plurality of photodiodes are optically coupled such that the plurality of wavelengths of light are simultaneously directed to the plurality of photodiodes.
9. The method of claim 7 , wherein detecting the light scattered from the illuminated object comprises producing a reflectance spectrum for the detected scattered light.
10. The method of claim 7 , wherein the illuminating is performed as a line scan illumination of the object, wherein the line scan illumination is performed as the object moves past the plurality of light emitting sources.
11. The method of claim 7 , wherein the plurality of light-emitting sources and the plurality of photodiodes are optically coupled via a multi-lens optical system, and wherein the multi-lens optical system comprises a detector lens assembly configured to collect the light scatted from the illuminated object and direct the collected light onto the plurality of photodiodes.
12. An apparatus for authenticating an object comprising:
a memory;
a processor coupled to the memory, and configured to:
modulate a plurality of wavelengths of light from a plurality of light-emitting sources, wherein modulating the plurality of wavelengths of light comprises simultaneously modulating the plurality of wavelengths of light using a plurality of orthogonal sequence codes, and wherein modulating the plurality of wavelengths of light illuminates the object;
detect a light signal from the illuminated object with a plurality of photodiodes;
produce a reflectance spectrum from the light signal, wherein producing the reflectance spectrum comprises demodulating the light signal using the plurality of orthogonal sequence codes;
compare the reflectance spectrum to a template reflectance spectrum of an authentic object; and
determine if the illuminated object is authentic as a function of the comparison.
13. The apparatus of claim. 12 , wherein modulating the plurality of wavelengths of light comprises employing a time division multiplexing (TDM).
14. The apparatus of claim 12 , wherein modulating plurality of wavelengths of light comprises employing a direct a direct sequence spread spectrum modulation (DSSM).
15. The apparatus of claim 12 , wherein producing the reflectance spectrum comprises generating a multi-spectrum image of at least a specified portion of the illuminated object, and wherein the multi-spectrum image comprises a plurality of images of die specific portion of the illuminated object associated with one or more of the plurality of wavelengths of light.
16. The method of claim 1 . wherein each of the plurality of wavelengths light is uniquely associated with one of the plurality of orthogonal sequence codes.
17. The method of claim 1 , wherein the light signal comprises a plurality of wavelengths.
18. The method of claim 7 , wherein each of the plurality of wavelengths of light is uniquely associated with one of the plurality of orthogonal sequence codes.
19. The method of claim 7 , wherein the light signal comprises a plurality of wavelengths.
20. The apparatus of claim 12 , wherein demodulating the light signal using the plurality of orthogonal sequence codes produces a plurality of signals that are each associated with one of the plurality of wavelengths of light.