Passive hidden imaging
First Claim
1. A printed mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through a predetermined optical processor.
1 Assignment
0 Petitions
Accused Products
Abstract
In a secure imaging system for securing documents or encrypting images, an image comprises an array of printed positions formed using a group of inks each having a predetermined spectrum. The positions are selected to form a predetermined image, either real or virtual, when the image is viewed through an optical processor. An image formed using inks having the same colors as experienced by the human eye, but not sharing exactly the same spectra, will fail to form the correct predetermined image.
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Citations
76 Claims
- 1. A printed mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through a predetermined optical processor.
- 19. A document carrying a mark, the mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through an optical processor.
- 21. Packaging, carrying a mark, the mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through an optical processor.
- 23. Electronically readable data storage medium, carrying a mark, the mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through an optical processor.
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28. A banknote carrying a mark, the mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through an optical processor.
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30. Apparatus for defining a source object comprising an array of printed positions using a group of inks each having a predetermined spectrum, the apparatus comprising:
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an image definer for defining an image, a reverse optical processor, associated with said image definer, for calculating a source image that leads via predetermined optical processing to said image, and an output, associated with said reverse optical processor for providing at least a definition for printing said source object. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
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- 43. Image forming apparatus for forming an image from a source object, the source object comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions and the inks having been selected to form a predetermined image with an optical processor, the apparatus comprising such an optical processor, and a source item holder, said source item holder being located to define a predetermined distance between said optical processor and a source object in said source item holder, thereby to form an image to correspond to said predetermined image.
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58. A method of defining a source object for a predetermined image comprising:
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carrying out reverse optical processing of said predetermined image, using said reverse optical processing to select pixel positions for printing said source object, and using said reverse optical processing to select ones from a group of inks each having a predetermined spectrum, for said selected pixel positions, thereby to define said source object. - View Dependent Claims (59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70)
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71. A method of verifying authenticity of a mark-bearing item, the mark comprising an array of printed positions each formed from one of a group of inks each having a predetermined spectrum, the positions being selected such as to form a predetermined image when said printed positions are viewed through an optical processor, the method comprising:
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applying said optical processor to form an image, comparing said formed image with said predetermined image, and if said formed image coincides with said predetermined image then authenticating said image bearing item. - View Dependent Claims (72, 73, 74, 75, 76)
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Specification