SECURITY FEATURE COMPRISING A PERFORATION PATTERN

• US 20020027359A1
• Filed: 07/20/1999
• Published: 03/07/2002
• Est. Priority Date: 11/05/1996
• Status: Active Grant

• Current Assignee: Industrial Automation Integratorsb V
• Original Assignee: Cobben
• Inventors: ELENBAAS, ABRAHAM, COBBEN, JOHANNES I.M.
• Granted Patent: US 6,739,627 B2
• Time in Patent Office: Days
• US Class Current: 283/67
• CPC Class Codes: B42D 25/24 Passports
• CPC Class Codes: B42D 25/346 Perforations
• CPC Class Codes: B42D 25/435 using electromagnetic radiation, e.g. laser
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: Y10S 283/902 Anti-photocopy

Abstract

The invention relates to a document to be protected against forgery comprising a security feature in the form of a perforation pattern, wherein the perforation pattern extends over a surface of the document and represents an image comprising brightness tones. The perforation pattern is herein formed such that, for instance when the thus treated document is held up to the light or placed on a light box, an image becomes visible at the location of the perforation pattern. It will be apparent that arrangement of such an image representing brightness tones requires extremely advanced technologies. Such technologies are not easily accessible to potential forgers, so that documents thus provided with such a perforation pattern are very difficult to forge. The perforation pattern is preferably applied by means of laser light.

Claims

1. Document to be protected against forgery, comprising a security feature in the form of a perforation pattern, characterized in that the perforation pattern extends over a closed surface of the document and represents a depiction comprising brightness tones from a continuous scale, and that the perforation pattern is applied by means of laser light.

2. Document as claimed in claim 1, characterized in that the depiction is visible when the document is illuminated from the rear.

3. Document as claimed in claim 1 or 2, characterized in that the perforation pattern is a representation of a depiction arranged on the document by means of a different technique.

4. Document as claimed in claim 3, characterized in that the depiction arranged by means of a different technique is specific to the document.

5. Document as claimed in claim 4, characterized in that the document is a passport and that the depiction is a passport photograph.

6. Document as claimed in claim 5, characterized in that the security feature is applied on a page of the passport other than the page on which the passport photograph is arranged.

7. Document as claimed in any of the foregoing claims, characterized in that the brightness tones of the depiction are realized by varying the size of the perforations.

8. Document as claimed in any of the foregoing claims, characterized in that the brightness tones are realized by varying the density of the perforations.

9. Document as claimed in claim 7 or 8, characterized in that the light tones are realized by varying large perforation holes respectively a high density of perforation holes and that dark tones are represented by small perforation holes respectively a low density of perforation holes.

10. Method for applying a security feature in the form of a perforation pattern in a document, characterized in that the perforation pattern is applied by a laser device which is adapted to successively apply the perforation pattern in the document, wherein the size of the perforation holes or the density of the perforation holes is controlled by means of an electronic representation of the depiction.

11. Method as claimed in claim 10, characterized in that the document is a passport and that a perforation pattern is applied in the passport which is a representation of the passport photograph arranged in the passport.

12. Method as claimed in claim 11, characterized in that the passport photograph is put into digital form by means of an optical electronic device and that the perforation pattern is applied on the basis of the digital reproduction of the passport photograph.

13. Method as claimed in claim 12, characterized in that the passport photograph is arranged in printed form in the passport.

14. Device for performing the method as claimed in any of the claims 10-13.