Optical security element
US11292283B2 · kind B2 · utility
0Cited by
4References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2018 |
| Grant date | Apr 5, 2022 |
| Priority date | — |
| Expiry date | Dec 4, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/1866
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
The invention relates to a thin optical security element comprising a reflective or refractive light-redirecting surface having a relief pattern operable to redirect incident light from a light source and form a projected image on a projection surface, the optical parameters of this optical security element fulfilling a specific projection criterion such that the projected image comprises a caustic pattern reproducing a reference pattern that is easily visually recognizable by a person. The invention also relates to a method for designing a relief pattern of an optical security element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.