Identification article with pattern-form fresnel hologram, fabrication thereof, and verification thereof
US4677285A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 19, 1986 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | Feb 19, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H1/0236
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An identification article comprise a substrate and a pattern-form Fresnel hologram provided as an identification information providing layer on the surface or in the interior of the substrate structure. The pattern-form Fresnel hologram is formed by (a) forming a Fresnel hologram by exposing a photosensitive resin layer to an interference light obtained from interference between an object light beam and a reference light beam both obtained by dividing a single coherent light, (b) exposing the Fresnel hologram to light transmitted through a mask pattern, (c) fabricating a pattern-form Fresnel hologram by developing the Fresnel hologram, and (d) reconstructing the pattern-form Fresnel hologram thus obtained. The identification article is verified by projecting a monochromatic light onto the hologram to reproduce an image and projecting this image on a screen or detecting it with a light detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.