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:
Apr. 14, 1992
Filed:
Nov. 27, 1990
Gregor Antes, Hirzel, CH;
Ohannes Minnetian, Luzern, CH;
Landis & Gyr Betriebs AG, Zug, CH;
Abstract
An interlaminar sandwich comprises first and second lacquer layers, a diffraction structure embedded between the first and second lacquer layers, a heat activated adhesive layer disposed one one of the lacquer layers, and a transparent stabilization layer disposed over the other lacquer layer, the stabilization layer distributing heat evenly through the interlaminar sandwich so that when heat is applied to the stabilization layer, the adhesive layer will bond the interlaminar sandwich to a substrate. Preferably, the interlaminar sandwich also contains an intermediary layer between the stabilization layer and the first lacquer layer which bonds these layers together. At temperatures below 170.degree. C., the adhesive layer is bonded so intimately to the substrate that the interlaminar sandwich cannot be removed from the substrate without tearing it. At temperatures above 150.degree. C., the lacquer layers soften, thus destroying the diffraction structure. After being built up on a film, the interlaminar sandwich can be punched out in the form of a tag and attached to an identification document thereby protecting the document against attempts to remove the tag.