The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 2000
Filed:
Nov. 30, 1993
Hanspeter Hauser, Aesch, CH;
Werner Helmut Gerber, Riehen, CH;
Abul Iqbal, Arconciel, CH;
Pierre Maurer, Rixheim, FR;
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Abstract
In order to prevent or at least render difficult the copying of colored printed security papers, for example banknotes, the printing inks used for printing are so formulated that copies made using customary color copiers produce a markedly different color impression and can therefore easily be identified as being forgeries. This is achieved by using for the formulation of the printing inks dyes (pigments) that are as different as possible from the dyes (toners) customarily used in conventional color copiers. The choice of the dyes for the formulation of the printing inks is especially such that there is the greatest possible degree of metamerism between the printing ink in question and the match of the relevant master color using the dyes of the color copier. Preferably non-amorphous or anisotropic black dyes and effect dyes, especially fluorescent effect dyes, are co-used for the formulation of the printing inks.