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Proceedings Paper

Optical inspection techniques for security instrumentation
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Paper Abstract

This paper reviews four optical inspection systems, in which development TNO Institute of Applied Physics was involved: (1) intaglio scanning and recognition, (2) banknote quality inspection, (3) visualization and reading of a finger pattern, and (4) 3DAS authentication. (1) Intaglio is reserved for high security printing. It renders a tactile relief that can be recognized by a laser scanning technique. This technique is applied by various national banks to detect counterfeit banknotes returning from circulation. A new system is proposed that will detect intaglio on arbitrary wrinkled banknotes. (2) A banknote fitness inspection system (BFIS) that inspects banknotes in specularly reflected light is described. As modern banknotes are provided increasingly with reflective security foils, a new system is proposed that inspects banknotes in specular and diffuse reflection, as well as in transmission. (3) An alternative visualization method for visualization of finger patterns is described, employing a reflective elastomer. A CD scanning system reads the finger patterns. (4) A nonwoven structure has two advantageous properties for card authentication: a random structure which renders each few square millimeters of the pattern uniqueness (identification) and a 3D structure which makes it virtually impossible to be counterfeited (authentication). Both properties are inspected by an extremely simple lenseless reader.

Paper Details

Date Published: 15 March 1996
PDF: 9 pages
Proc. SPIE 2659, Optical Security and Counterfeit Deterrence Techniques, (15 March 1996);
Show Author Affiliations
Rudolf L. van Renesse, TNO Institute of Applied Physics (Netherlands)

Published in SPIE Proceedings Vol. 2659:
Optical Security and Counterfeit Deterrence Techniques
Rudolf L. van Renesse, Editor(s)

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