Security devices
AssigneeOptrical Limited
InventorNavin Suyal
Life of this patent
Estimating the term…
Abstract
A security device (1) comprising an optically transparent layer (3) including a repeating first array of separate optical focussing elements (3) (e.g. having translational symmetry) wherein a pitch distance between repeated elements in the first array is a first pitch value (A). The device also includes a repeating second array of separate image elements (6) (e.g. having translational symmetry) collectively defining an image viewable through the first part. The device is structured such that a pitch distance between repeated or successive elements in the second array is a second pitch value (B) wherein the ratio (A/B) of the first pitch value and the second pitch value has a value, A/B=n±Δ, that differs from a positive integer value, n, according to an absolute difference, Δ, not exceeding 0.01 and not less than 0.001.
Claims18
A security device comprising:
- a first part including an optically transparent layer including a repeating first array of separate optical focusing elements including lenticular lenses having translational symmetry wherein a pitch distance between repeated elements in the first array is a first pitch value (A);
- a second part separate from the first part and including a repeating second array of separate image elements having translational symmetry and collectively defining an image viewable through the first part wherein a pitch distance between repeated elements in the second array is a second pitch value (B);
- and
- wherein the optical focusing elements are aligned with respect to the separate image elements to reveal a blended whole image together with one or more Moire fringes that show 3-dimensional (3D) depth as the image viewing angle changes, wherein the blended whole image is different from each of the separate image elements,
- wherein the ratio (A/B) of the first pitch value and the second pitch value has a value A/B=n+Δ, that differs from a positive integer value, n, according to an absolute difference, Δ, not exceeding 0.01 and not less than 0.001.
A method of manufacturing a security device comprising:
- providing a first part including an optically transparent layer including a repeating first array of separate optical focusing elements including lenticular lenses having translational symmetry wherein a pitch distance between repeated elements in the first array is a first pitch value (A);
- providing a second part including a repeating second array of separate image elements having translational symmetry and collectively defining an image viewable through the first part wherein a pitch distance between repeated elements in the second array is a second pitch value (B) wherein the ratio A/B=n+Δ, that differs from a positive integer value, n, according to an absolute difference, Δ, not exceeding 0.01 and not less than 0.001,
- wherein the optical focusing elements aligned with respect to the separate image elements to reveal a blended whole image together with one or more Moire fringes that show 3-dimensional (3D) depth as the image viewing angle changes, wherein the blended whole image is different from each of the separate image elements.
A security device comprising:
- an optically transparent layer including a repeating first array of separate optical focusing elements including lenticular lenses having translational symmetry wherein a pitch distance between repeated elements in the first array is a first pitch value (A);
- a repeating second array of separate image elements having translational symmetry and collectively defining an image viewable through the first part wherein a pitch distance between repeated elements in the second array is a second pitch value (B);
- and
- an optically transparent release layer between the first part and the second part which retains the optical focusing elements aligned with respect to the separate image elements to reveal a blended whole image together with one or more Moire fringes that show 3-dimensional (3D) depth as the image viewing angle changes, wherein the blended whole image is different from each of the separate image elements, and wherein a width dimension of the blended whole image is at least twice as large as an aperture width of each optical focusing element,
- wherein the ratio (A/B) of the first pitch value and the second pitch value has a value A/B=n+Δ, that differs from a positive integer value, n, according to an absolute difference, Δ, not exceeding 0.01 and not less than 0.001,
- wherein the repeating second array of separate image elements comprises two or more sub-arrays of separate image elements, each one of which collectively presents a distinct respective image, the two or more sub-arrays including a first sub-array having separate image elements complying with the ratio A/B=n+Δ and a second sub-array having image elements complying with the ratio A/B=n−Δ, and wherein the second sub-array is adjacent the first sub-array or embedded within the first sub-array.
Dependencies are inferred from the claim text.