Security devices
US12187065B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 2020 |
| Grant date | Jan 7, 2025 |
| Priority date | — |
| Expiry date | Sep 24, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F2003/0257
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.