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:
Oct. 20, 1998
Filed:
Jan. 23, 1997
Applicant:
Inventors:
Guenther Dausmann, Erding, DE;
Klaus Gnaedig, Munich, DE;
Assignee:
Bundesdruckerei GmbH, Berlin, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ; G03H / ; G03H / ; G03H / ;
U.S. Cl.
CPC ...
359-2 ; 359 10 ; 359 12 ; 359 29 ; 359 33 ;
Abstract
A method for the production of holograms proof against copying and imitation possessing authenticity features, which are copies of a master hologram. In accordance with the invention as a master hologram a hologram of a randomly structured optical element, as for example a diffusion plate, which constitutes the authenticity feature, is recorded and each hologram copy produced from the master hologram is provided with a layer having at least one layer with a color succession and/or the hologram copy produced on a thick light sensitive layer is caused to shrink or to expand.