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US 6,271,967 B1Granted
Optically diffractive structure
AssigneeLeonard Kurz GmbH & Co.
InventorWilhelm Stork
Life of this patent
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AssigneeLeonard Kurz GmbH & Co.
InventorWilhelm Stork
Estimating the term…
The invention concerns a structure arrangement that includes surface regions having one or more structures having an optical-diffraction effect, in particular for visually identifiable, optical security elements for value-bearing documents, for example banknotes, credit cards, passes or check documents, or other items to be safeguarded; in order to make it more difficult to forge and in particular copy such a structure arrangement it is proposed in accordance with the invention that the structure arrangement is such that for the production of given items of optical information in given viewing directions in one or more of the surface regions (8, 30) of the structure arrangement there are provided sub-regions (10, 12, 14, 32, 34) with a structure (16, 18, 20; 36, 38) that is identical except for the structural parameter of optical depth and that the optical depth of the structure (16, 20; 36) is constant over the extent of a sub-region (10, 14; 32) but is different from the optical depth of the structure (18; 38) of another sub-region (12; 34).
A diffraction structure comprising a plurality of surface regions each having at least one structure having an optical-diffraction effect, wherein, among said plurality of surface regions, there is provided at least two surface regions for the production of given items of optical information in given viewing directions, each of said at least two surface regions having a grating structure that has a grating parameter of optical depth which is constant over the extent of the surface region of which it is a part, the grating structure of each of said at least two surface regions being identical to the grating structure of at least one other of said at least surface regions in every respect except that grating parameter of optical depth, and wherein said surface regions are immediately adjacent each other with parallel and non-collinear grating vectors and have their periods dephased relative to each other by a fraction of a grating period.
A diffraction structure comprising a plurality of surface regions each having at least one structure having an optical-diffraction effect, wherein, among said plurality of surface regions, there is provided at least two surface regions for the production of given items of optical information in given viewing directions, each of said at least two surface regions having a rectilinear grating structure that has a grating parameter of optical depth which is constant over the extent of the surface region of which it is a part, the grating structure of each of said at least two surface regions being identical to the grating structure of at least one other of said at least two surface regions in every respect except the grating parameter of optical depth, and said surface regions are immediately adjacent each other with parallel and non-collinear grating vectors and have their periods dephased relative to each other by a fraction of a grating period.
A diffraction structure used in combination with a machine for detecting light wavelength, said diffraction structure comprising a plurality of surface regions each having at least one structure having an optical-diffraction effect, wherein, among said plurality of surface regions, there is provided at least two surface regions for the production of given items of optical information in given viewing directions, each of said at least two surface regions having a grating structure that has a grating parameter of optical depth which is constant over the extent of the surface regions of which it is a part, the grating structure of each of said at least two surface regions being identical to the grating structure of at least one other of said at least two surface regions in every respect except the grating parameter of optical depth, and said surface regions are immediately adjacent each other with parallel and non-collinear grating vectors and have their periods dephased relative to each other within the plane of the surface regions by a fraction of a grating period, and wherein said optical depth of said respective grating structures are associated with a given machine-detectable light wavelength or wavelength range.
Dependencies are inferred from the claim text.