Diffractive safety element
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Oct 5, 2004
Grant Date -
Jul 8, 2004
app pub date -
Nov 6, 2003
filing date -
Jun 8, 2001
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A security element is embedded in a layer composite of plastic material and has reflecting, optically variable surface patterns which can be visually recognized from predetermined observation directions and which are formed from a mosaic of surface elements occupied by optically active structures. A part of the surface pattern is additionally covered by a regularly arranged matrix of unit cells. Each unit cell is occupied by a single elementary surface or a group of identical surface portions that contain optically active structures which are independent of the mosaic of the surface pattern. The arrangement of the elementary surfaces and the surface portions in the matrix form an item of concealed information which is not perceptible to the naked eye, in the form of graphic or alphanumeric characters which however are reproduced in a color photocopy with a color or gray value contrast which is perceptible to the naked eye.
First Claim
Other Claims data not available
