Claims
- 1. A method of testing the authenticity of a document provided with at least one optico-diffractively effective metallized security indicium, comprising the steps of:
storing a signal representative of the security indicium of a genuine document; moving a document along a predetermined path; applying a voltage to the security indicium by capacitive coupling; measuring the voltage in the security indicium and deriving a signal representative of the measured voltage; and comparing the measured voltage signal against the stored signal.
- 2. The method of claim 1, further comprising the step of altering the movement of the document in response to a difference between the stored signal and the measured voltage signal.
- 3. The method of claim 1, wherein the optico-diffractively effective security indicium is a hologram comprising a plurality of discontinuous metallization segments.
- 4. The method of claim 1, wherein the optico-diffractively effective security indicium is a hologram comprising a plurality of metallization segments of different thicknesses.
- 5. The method of claim 1, wherein the optico-diffractively effective security indicium is a hologram comprising a plurality of discontinuous metallization segments with interspersed elements responsive to electromagnetic radiation of a predetermined frequency range.
- 6. The method of claim 5, wherein the electromagnetic radiation is ultra violet light and the responsive elements comprise a dye fluorescing when irradiated by ultra violet light.
- 7. The method of claim 5, wherein the responsive elements comprise a light absorbing substance.
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 18 916.4 |
Apr 1997 |
DE |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation in part of Application No.: 09/423,274, filed Jan. 27, 2000, now abandoned.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09423274 |
Jan 2000 |
US |
Child |
09931694 |
Aug 2001 |
US |