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Proceedings Paper

New OVD based on interferential photography recorded in holographic materials
Author(s): Hans I. Bjelkhagen
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Paper Abstract

A new Optical Variable Device (OVD) based on an old color photographic technique (Lippmann photography, invented in 1891) is presented. Today, this type of photography can be applied as a unique security device on security documents, such as, e.g., identification cards, passports, credit cards, and other documents where a high degree of security is needed. A Lippmann photograph is very similar to holograms, currently used in this field; a unique recording of each document can be made to achieve a degree of security higher than that with mass-produced holograms. The recording of Lippmann photographs requires a special type of photosensitive medium in contact with a reflecting layer. Panchromatic silver-halide or photopolymer materials can be used and, after being recorded and processed, laminated to security documents. A special type of recording equipment is required. Lippmann photographs are virtually impossible to copy and, certainly, cannot be copied by conventional photography or color copying machines.

Paper Details

Date Published: 23 March 1999
PDF: 9 pages
Proc. SPIE 3638, Holographic Materials V, (23 March 1999); doi: 10.1117/12.342808
Show Author Affiliations
Hans I. Bjelkhagen, De Montfort Univ. (United Kingdom)


Published in SPIE Proceedings Vol. 3638:
Holographic Materials V
T. John Trout, Editor(s)

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