Printed document having a value and comprising a luminescent authenticity feature

• US 6,503,603 B1
• Filed: 12/10/1999
• Issued: 01/07/2003
• Est. Priority Date: 02/02/1998
• Status: Expired due to Term

• Current Assignee: Giesecke & Devrient (Giesecke & Devrient GmbH)
• Original Assignee: Giesecke & Devrient GmbH
• Inventors: Kaule, Wittich, Schwenk, Gerhard, Stenzel, Gerhard
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): BLACKWELL, GWENDOLYN
• Application Number:
  US09/381,642
• Time in Patent Office: 1,124 Days
• Field of Search: 428/67, 428/80, 428/199, 428/204, 428/207, 428/211, 428/333, 428/403, 428/464, 428/537.7, 428/690, 428/913, 428/916, 283/57, 283/74, 283/113, 283/114, 283/107, 283/901, 283/904, 427/7
• US Class Current: 428/195.1
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: C09K 11/7701 Chalogenides
• CPC Class Codes: C09K 11/7708 Vanadates; Chromates; Molybdates; Tungstates
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: C09K 11/7776 Vanadates; Chromates; Molybdates; Tungstates
• CPC Class Codes: Y10S 283/901 Concealed data
• CPC Class Codes: Y10S 283/904 Credit card
• CPC Class Codes: Y10T 428/22 Nonparticulate element embedded or inlaid in substrate and visible
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24835 including developable image or soluble portion in coating or impregnation [e.g., safety paper, etc.]

Abstract

The invention relates to a printed valuable document with at least one authenticity mark in the form of a luminescent substance based on a host lattice doped with at least one rare earth metal. The host lattice largely absorbs in the visible region of the spectrum and is excitable in the visible region of the spectrum, and is transparent in at least parts of the IR spectral region. The rare earth metal is holmium. The luminescent substance is present in the volume of the valuable document in such a concentration that the properties of the valuable document just remain unimpaired.

Claims

1. Printed valuable document with at least one authenticity mark in the form of a luminescent substance based on a host lattice doped with at least one rare earth metal, which largely absorbs light and is excitable in the visible region of the spectrum, and is transparent in at least parts of the IR spectral region, whereby the rare earth metal is holmium and the luminescent substance is present in the volume of the valuable document in a concentration of no more than 5 percent by weight.

2. Printed valuable document according to claim 1, wherein the valuable document consists of paper and the luminescent substance is present in the paper in a concentration of between 0.05 and 1% by weight.

7. Printed valuable document according to claim 1, wherein the optically transparent range of the host lattice doped with rare earth metals lies in the region between 1 μ

m and 10μ

m.

8. Printed valuable document according to claim 1, wherein the host lattice contains iron or chromium as absorptive elements.

9. Printed valuable document according to claim 1, wherein the host lattice has a garnet or perovskite structure.

10. Printed valuable document according to claim 1, wherein the garnet structure can be described by the general formula

11. Printed valuable document according to claim 10, wherein the index x fulfills the condition 0.5<

x<

2.

12. Printed valuable document according to claim 10, wherein the luminescent substance can be described by the formula

13. Printed valuable document according to claim 9, wherein the garnet structure can be described by the general formula

14. Printed valuable document according to claim 13, wherein the luminescent substance can be described by the formula

15. Printed valuable document according to claim 9, wherein the perovskite structure can be described by the general formula

16. Printed valuable document according to claim 15, wherein the luminescent substance can be described by the formula

17. Printed valuable document according to claim 15, wherein the luminescent substance can be described by the formula

18. Printed valuable document according to claim 1, wherein the luminescent substance has a quantum yield of 50 to 90%.

26. Printed valuable document according to claim 12, wherein the luminescent substance can be described by the formula

27. Printed valuable document according to claim 13, wherein the garnet structure can be described by the general formula

28. Printed valuable document according to claim 14, wherein the luminescent substance can be described by the formula

29. Printed valuable document according to claim 16, wherein the luminescent substance can be described by the formula

30. Printed valuable document according to claim 17, wherein the luminescent substance can be described by the formula

3. Printed valuable document with at least one authenticity mark in the form of a luminescent substance based on a host lattice doped with at least one rare earth metal, which largely absorbs light and is excitable in the visible region of the spectrum, and is transparent in at least part ranges of the IR spectral region, whereby the rare earth metal is holmium and the luminescent substance is present in a layer applied to the valuable document in a concentration between 1 and 40% by weight.

4. Printed valuable document according to claim 3,wherein the luminescent substance is provided as an invisible and at least partial coating on the valuable document.

5. Printed valuable document according to claim 3, wherein the luminescent substance is mixed into a printing ink, which contains additional visible colour additives.

6. Printed valuable document according to claim 3, wherein the coating takes the form of one or more stripes.

25. Printed valuable document according to claim 3, wherein the layer applied to the valuable document is a printing ink, in which the luminescent substance is present in a concentration of between 10 and 30% by weight.

19. Security element, which features at least one substrate material and one luminescent substance, based on a host lattice doped with at least one rare earth metal, which largely absorbs and is excitable in the visible region of the spectrum and is transparent at least in parts of the IR spectral region, whereby the rare earth metal is holmium and the luminescent substance is present in the volume of the substrate material in a concentration of no more than 6 percent by weight and said substrate material consists of paper.

20. Security element according to claim 19, wherein the substrate material consists of plastic, and the luminescent substance is present in the plastic in a concentration of no more than 10% by weight.

22. Security element according to claim 19, wherein the security element has the form of a stripe or band.

23. Security element according to claim 22, wherein the substrate material is formed as a security thread or mottling fiber.

24. Security element according to claim 19, wherein the security element is in the form of a label.

31. Security element according to claim 19, wherein the substrate material consists of paper and the luminescent substance is present in the paper in a concentration of no more than between 0.05 and 1% by weight.

21. Security element, which features at least one substrate material and one luminescent substance, based on a host lattice doped with at least one rare earth metal, which largely absorbs and is excitable in the visible region of the spectrum and is transparent in at least parts of the IR spectral region, whereby the rare earth metal is holmium and the luminescent substance is present in a layer applied onto the substrate material in a concentration in the range between 1 and 40% by weight;

with the proviso that said luminescent substance is present in a printing ink.

32. Security element according to claim 21, wherein the luminescent substance is present in a printing ink in a concentration of between 10 and 30% by weight.