Method of forming a security device
US12384189B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2020 |
| Grant date | Aug 12, 2025 |
| Priority date | — |
| Expiry date | Sep 1, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2260/12
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A method of forming a security device includes: a holographic image layer, diffusion element, and barrier layer. A region of the barrier layer includes a heat-transformable material. The method further includes selectively applying heat at a plurality of positions within the region of the barrier layer, in accordance with a predetermined pattern, so as to modify the heat-transformable material such that the region of the barrier layer is selectively rendered passable to the diffusible substance at each of the plurality of positions, thereby permitting diffusion of the diffusible substance between the regions of the diffusion element and the holographic image layer such that, at a plurality of positions within the region of the holographic image layer and corresponding to the predetermined pattern, the volume hologram is dimensionally modified so as to become viewable in a second observable colour, different from the first observable colour.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.