Value or security product with luminescent security elements and method for the production and use thereof in respect to visual and machine-operated detection of authenticity

• US 6,530,527 B1
• Filed: 11/16/1999
• Issued: 03/11/2003
• Est. Priority Date: 03/04/1997
• Status: Expired due to Term

• Current Assignee: Bundesdruckerei GmbH (Government of Germany)
• Original Assignee: Bundesdruckerei GmbH (Government of Germany)
• Inventors: Schmidt, Wolfgang, Ahlers, Benedikt, Franz-Burgholz, Arnim, Kappe, Frank, Gutmann, Roland
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): Nowlin, April
• Application Number:
  US09/380,501
• Time in Patent Office: 1,211 Days
• Field of Search: 235/491, 235/494, 235/488, 235/470, 235/454, 235/487, 283/72, 283/83, 427/7, 101/150
• US Class Current: 235/491
• CPC Class Codes: B41M 1/10 Intaglio printing ; Gravure printing
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: D21H 21/48 Elements suited for physical verification, e.g. by irradiation
• CPC Class Codes: G07D 7/06 using wave or particle radiation
• CPC Class Codes: G07D 7/12 Visible light, infrared or ultraviolet radiation
• CPC Class Codes: G07D 7/128 Viewing devices

Abstract

A value or security product such as a banknote, ID card or the like, is provided with luminescent security elements which are excitable in an electromagnetic alternating field. A production method of applying the required colors and substances to the value or security product is also provided. Also included is a respective security technology arrangement for visual and machine-operated detection of authenticity, where electrical fields in particular and optical radiation, preferably in the UV wavelength range, are used to excite so-called phosphorous colors, and additional optical effects in the visible UV wavelength range can be achieved by secondary excitation mechanisms.

Claims

1. A value/security instrument with embedded security elements containing substances that have electroluminescent (EL) properties and that emit radiation within an alternating electric field, said instrument comprising:

an essentially planar electrode arrangement is placed on said instrument; and

electrodes located on approximately the same plane lying adjacent to one another formed with a field gap between them, wherein the EL substances are penetrated by the field lines of the alternating electric field produced within the field gap.

2. The instrument according to claim 1, wherein said EL substances are placed approximately flat on top of and parallel to said electrodes at least near said field gap.

3. The instrument according to claim 1 or 2, wherein said EL substances are placed flat beneath and parallel to said electrodes at least near said field gap.

4. The instrument according to claim 1 or 2, wherein said electrode arrangement consists of electrode fingers that mesh into one another, said electrode fingers forming a meandering field gap between them.

5. The instrument according to claim 1 or 2, wherein the EL substances form a printed EL picture that emits either visible or invisible primary radiation.

6. The instrument according to claim 1 or 2, and further comprising additional illuminating dyes to form pigments added to a mixture of print dyes and binders.

7. The instrument according to claim 5, wherein the printed picture containing said EL substances is covered with translucent print dyes.

8. The instrument according to claim 7, and further comprising a UV filter added to said translucent print dyes, or is provided in the form of encapsulated pigments.

9. A process to manufacture a security document, printed using steel plate deep-engraved intaglio printing with a number of deep-engraved intaglio dyes, wherein the process comprises the steps of:

graphical structuring of substrates, in particular special security paper of up to 200 gr/m² surface weight using intaglio printing techniques, screen printing techniques and other printing processes;

printing of lateral electrodes using conducting pastes, said electrodes having electrical connector sites;

printing of an isolation dye;

printing of an EL substance at least partially over the electrodes;

printing passivating, electrically conducting dyes onto the electrical connector sites in the form of conducting dyes or pastes, in particular based on carbon and gold;

printing of an elastic, transparent, friction-resistant protective layer, in particular based on aqueous polyurethane dispersions; and

hardening of the printed material following the printing process.

10. The process according to claim 9, and comprising the further step, prior to printing, of applying adhesive agent in the form of an aqueous polyurethane dispersion to achieve optimal adhesion and embedding of the printed layers to follow.

11. The process according to claim 9, wherein the isolation dye applied in the isolation dye printing step contains aqueous polyurethane dispersion systems and/or barium titanate (BaTiO₂), said dye having a dielectric constant which is raised by said dispersion systems and/or BaTiO₂.

12. The process according to claim 9, wherein EL substances printed in the EL substance printing step consist of multi-colored electroluminescent pastes to which “

range spacers”

are added, if needed, thereby forming microencapsulated light pigments, said spacers preventing the microencapsulated light pigments from being damaged by the high pressures during printing.

13. The process according to claim 9, wherein after the EL substance is printed in the EL substance printing step, translucent dyes are printed above or below the EL substance to achieve additional graphical and security structure.

14. The process according to claim 9, and comprising the further step of applying a thermal press at temperatures up to 200°

C. and pressures up to 500 N/cm² after the last process step to stabilize and improve the quality of the security document.

15. A testing device to visually and/or machine test the authenticity of value/security documents that have EL-active security features at certain points thereon, said features containing electroluminescent substances, the testing device comprising:

two supports on the testing device parallel to one another between which the document to be tested is placed, at least one of said supports being transparent;

an electrode arrangement on at least one of said supports, said electrode arrangement being capable of producing an alternating electric field that penetrates the value/security instrument at least at those points where the EL-active security features are located, thus exciting the EL-active security features so that they emit photons that can be evaluated either visually or by machine.

16. The testing device according to claim 15, wherein both electrodes are located on one side of one of said stationary supports in the form of a common electrode arrangement.

17. The testing device according to claim 15 or 16, wherein said electrode arrangement is essentially planar with electrodes located in approximately the same plane and lying adjacent to one another that form a field gap between each other, wherein the EL-active security features are penetrated by the field lines of the alternating electric field produced in the field gap.

18. The testing device according to claim 17, wherein said electrode arrangement consists of electrode fingers that mesh with one another, said electrode fingers forming a meandering field gap between each other.

19. The testing device according to claim 15 or 16, wherein said electrode arrangement is applied onto an isolation layer.

23. The testing device according to one of claims 15, 16, 20, 21 or 22, wherein at one of said support plates a fluorescent layer is located that produces secondary radiation in the visible range from primary radiation (visible or invisible) emitted from one of the EL-active security features.

20. A testing device to visually and/or machine test the authenticity of value/security documents having EL active security features at certain points thereon, said features containing electroluminescent substances, the testing device comprising:

two supports parallel to one another between which the document to be tested is placed, at least one of said supports being transparent;

electrodes located at both said supports and producing an alternating electric field between each other similar to a plate condenser, said electric field penetrating the value/security instrument at least at the points where the EL-active security features are located, resulting in the EL-active security features being excited to the point of emitting photons that can be visually or mechanically evaluated.

21. The testing device according to claim 20, wherein both said electrodes are located opposite one another on said supports and the value/security instrument is placed in an inlet gap between said electrodes.

22. A testing device to visually and/or machine test the authenticity of value/security documents having EL active security features located at certain points thereon, said features containing electroluminescent substances, the testing devices comprising:

two supports parallel to one another between which the document to be tested is placed, at least one of said supports being transparent;

a first electrode located on the value/security instrument; and

a second electrode located on one of said supports resulting in an alternating electric field being produced between said two electrodes that penetrates the value/security instrument at least at the points where the EL-active security features are located, thus resulting in the EL-active security features being excited to the point of emitting photons that can be visually or mechanically evaluated.

24. A value and security product with an area comprising:

a printed layer comprising;

a print dye having at least one electroluminescent substance embedded therein as a security feature, wherein said electroluminescent substance emits an electromagnetic radiation in the form of electroluminescence by excitation within an alternating electric field produced by an essentially planar electrode arrangement having electrodes located on approximately the same plane and adjacent to each other, said electrodes forming a field gap between them and penetrate said electroluminescent substance with electric field lines; and

a thickness selected such that the electroluminescence is excitable by means of the alternating electric field.

25. The value and security product according to claim 24, wherein the printed layer is produced by means selected from the group consisting of intaglio printing, offset printing and screen-printing.

26. The value and security product according to claim 24, wherein the electroluminescent layer is provided in microencapsulated condition.

27. The value and security product according to claim 24, and further comprising a UV filter in the encapsulation.