Security Device Formed By Printing With Special Effect Inks

Abstract

A security device is disclosed that has an image formed upon a substrate. The image has a first printed region and a second different printed region both printed with a same ink formulation of field alignable flakes. At least one of the printed regions has optically variable effects. One of the first and second printed regions at least partially surrounds the other. The second printed region is formed of thin parallel lines and the first printed region has substantially wider lines than are printed in the second printed region. The area density of the ink in a line in the first group of wider lines is greater than the area density of a line in the second group of narrower lines. A surprising effect of this image is that particles or flakes in the ink are field aligned so as to produce a visible kinematic dynamic effect visible in the first region and not visible in the second region when the image is tilted or rotated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will now be described in conjunction with the drawings, in which:

FIG. 1 a is a plan view of a security device showing the letter “B” printed in thick lines and having a background that surrounds the “B” in thinner parallel lines.

FIG. 1 b is a plan view of an alternative embodiment wherein the letter “B” is printed with a thicker ink coating than the background.

FIG. 2 is a plan view of an alternative embodiment of the invention wherein the letter “B” is printed in thick parallel lines in a first direction and wherein thinner parallel lines defining a background are at a different angle approximately 45 degrees to the thick parallel printed lines.

FIG. 3 a is a cross-sectional view of a printing plate for the images in FIG. 2.

FIG. 3 b is a cross-sectional view of the ink that is printed on the substrate using the printing plate in FIG. 3a before applying a magnetic field to align the flakes.

FIG. 4 is the cross-sectional view of FIG. 3b illustrating the orientation of the flakes in an applied magnetic field.

FIG. 5 is the perspective view of the image of FIG. 3b after the magnetic field has been applied.

FIG. 6 is a prior art cross-sectional view of a flip-flop.

FIGS. 7 and 8 are simplified plan views of a flip-flop as seen from different angles.

FIG. 9 is a prior art cross-sectional view of a rolling bar showing only some of the aligned flakes.

FIG. 10 is a top view of the rolling bar shown in FIG. 9.

Claims

1. A security device comprising an image formed upon a substrate having a first printed region and a second printed region, wherein at least one printed region has optically variable effects, wherein one of the first and second printed regions are at least partially surrounded by the other, wherein a same ink formulation having field alignable flakes therein is applied to the first and second printed regions, wherein the second printed region is comprised of thin parallel lines, wherein a) the first printed region is either a solid printed region or is comprised of substantially wider lines than are printed in the second printed region; orb) wherein the first printed region is either a solid printed region or is comprised of a first group of parallel lines and wherein the area density of the ink of the second group of substantially parallel lines is substantially less that the area density of solid printed region or the area density of the first group of parallel lines,

2. A security device as defined in claim 1, wherein both printed regions have optically variable effects.

3. A security device as defined in claim 2 wherein a plurality of parallel lines in the first region are at least twice a wide as the thin parallel lines of the second region and wherein the area density of the ink of the second group of substantially parallel lines is substantially less that the area density of the area density of the first group of parallel lines,

4. A security device as defined in claim 3, wherein the ink is comprised of magnetically aligned flakes.

5. A security device as defined in claim 3 wherein the ink consists of magnetically alignable flakes.

6. A security device as defined in claim 4, wherein the magnetically aligned flakes in the first and second regions is the same ink formulation and wherein the lines in the first region are at least two times wider than the lines in the second region.

7. A security device as defined in claim 6, wherein a contrast between the first region and second region forms discernible indicia.

8. A security device as defined in claim 7 wherein the magnetically aligned flakes are color shifting flakes.

9. A security device as defined in claim 7, wherein the magnetically aligned flakes are color switching flakes.

10. A security device as defined in claim 7, wherein the magnetically aligned flakes are diffractive flakes.

11. A security device as defined in claim 6 wherein the lines in the first region are parallel.

12. A security device as defined in claim 6 wherein the lines in the second region are parallel.

13. A security device as defined in claims 6 wherein the lines in the first and second regions are parallel.

14. A security device as defined in claim 6 wherein lines in one of the first and second regions are of different thicknesses.

15. A security device as defined in claim 4 wherein flakes in the first and second regions are magnetically aligned and wherein a strong dynamic effect that is a function of the alignment of the flakes is seen in the first printed region and is not seen in the second printed region.

16. A security device as defined in claim 3 wherein the height of the ink in the first region is greater than the height of the ink in the second regions.

17. A security device as defined in claim 3, wherein the weight of the ink in a line of a length of one unit in the first region is at least three times the weight of the ink in a line of a same length in the second region.

18. A security device as defined in claim 3 wherein the first region consists of a plurality of parallel printed lines of width WL.

19. A security device as defined in claim 18 wherein the second region consists of a plurality of parallel printed lines having a width of less than WL/2.

20. A security device as defined in claim 19, wherein a rolling bar is seen in the first region without magnification as the image is tilted, and wherein a rolling bar is not seen without magnification in the second region when tilting the image.

21. A security device as defined in claim 3, wherein the ink is applied to the first and one or more second regions by an Intaglio printing process.

22. A security device as defined in claim 1 wherein a plurality of adjacent pairs of parallel lines in the second region each have a visible unprinted line therebetween and wherein the unprinted line is wider than the printed lines next thereto.

23. A security device as defined in claim 1 wherein a plurality of adjacent pairs of parallel lines in the first region each have a visible unprinted line therebetween and wherein the unprinted line is narrower than the printed lines next thereto.

24. A security device as defined in claim 1, wherein the thin parallel lines in the second region are contiguous and form a single line.

25. A security device as defined in claim 1 wherein the wider lines in the first printed region are contiguous and form a single line.

26. A security device as defined in claim 1 wherein the thin parallel lines in the second region and the wider lines in the first printed region are contiguous and form a single line.

27. A security device as defined in claim 1 wherein the thin parallel lines in the second region and the wider lines in the first printed region appear to be contiguous and appear form a single line having a varying width and wherein the single line having a varying width is a dotted or pixelated line.

28. A method of forming a security device comprising the steps of: printing upon a substrate a first printed region and one or more second printed regions at least partially bordering the first printed region, wherein a same ink formulation having flakes therein is applied to the first and one or more second printed regions in lines of different thicknesses, and/or different heights, wherein the printed lines in the first printed region are substantially wider and or higher, than printed lines in the one or more second printed regions, and wherein particles or flakes in at least some of the ink is field aligned so as to produce a visible kinematic effect when the image is tilted or rotated, and wherein a contrast between the first and second printed regions as a function of their contrasting line widths, forms a discernible printed image.

29. A method as defined in claim 28 wherein the printing is Intaglio printing.

30. A method as defined in claim 29 wherein ink is applied so as to be more raised in the first region than in the second region.

31. A method as defined in claim 28 wherein the discernible printed image consists of a lined image formed of groups of parallel lines.