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US 5,886,798 AGranted
Information carriers with diffraction structures
AssigneeLandis & Gyr Technology Innovation AG
InventorsRene Staub, Wayne Robert Tompkin
Life of this patent
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AssigneeLandis & Gyr Technology Innovation AG
InventorsRene Staub, Wayne Robert Tompkin
Estimating the term…
An information carrier has at least one diffraction pattern which is formed from microscopically fine relief structures and which, upon being illuminated with coherent light, produces in two spatially separate directions, a first and a second image of an object. The images can be rendered visible on a screen or analysed by means of photodetectors. The two images have strong-light and/or weak-light picture elements and includes a symmetry insofar as a weak-light picture element of the second image can be associated with a strong-light picture element of the first image and vice-versa. Such information carriers are suitable as security elements for documents of all kinds such as, for example, banknotes, passes, identity cards, credit cards, etc., wherein at least a part of the security information is not visible under incoherent illumination conditions.
An information carrier having at least one diffractive pattern containing diffractive structures of microscopically fine relief structures, wherein light diffracted from said information carrier, upon being illuminated with coherent light, is rendered visible on a screen and produces a first image of an object in a first direction and a second image of said object in a second angularly separated direction, wherein said diffractive pattern is such that the first image has at least strong-light picture elements, the second image has at least weak-light picture elements, wherein a weak-light picture element of the second image is associated with a strong-light picture element of the first image, and wherein said diffractive pattern comprises the superimposition of one of a Fourier and kinoform hologram on a diffractive structure having an asymmetrical profile shape, serving as a carrier profile.
An information carrier having at least two diffractive patterns containing diffractive structures of microscopically fine relief structures, wherein light diffracted from said information carrier, upon being illuminated with coherent light, is rendered visible on a screen and produces first image of an object in a first direction and a second image of said object in a second angularly separated direction, wherein said diffractive pattern is such that the first image has at least strong-light picture elements, the second image has at lest weak-light picture elements, wherein a weak-light picture element of the second image is associated with a strong-light picture element of the first image, wherein the first image comprises a strong-light representation of a first object and a weak-light representation of a second object, said first image representations at least partially overlapping, and wherein the second image contains a weak-light representation of the first object and a strong-light representation of the second object, said second image representations at least partially overlapping.
Dependencies are inferred from the claim text.