Security device and method of manufacture thereof

Patent metadata

Field	Value
Publication number	US-2022144006-A1
Application number	US-202017438330-A
Country	US
Kind code	A1
Filing date	Mar 27, 2020
Priority date	Mar 28, 2019
Publication date	May 12, 2022
Grant date	—

Abstract

A security device includes a luminescent material arranged in a first region, wherein the material luminesces in response to irradiation one excitation wavelength wherein the first region exhibits a luminescent visible colour; an array of viewing elements; and a masking layer positioned between the decorative layer and the array of viewing elements, the masking layer partially overlaps with first region, including first pattern elements defined by the masking material, and second pattern elements defined by the absence of the masking material wherein the decorative layer is visible through the second pattern elements; the masking material is non-luminescing in response to one excitation wavelength, and when the security device illuminates by at least one wavelength, where the array of pattern elements overlaps with the first region, the second pattern elements exhibit the luminescent visible colour, and the first pattern elements exhibit a visual appearance that's different to the luminescent visible colour.

First claim

1 . A security device comprising:
a decorative layer comprising a luminescent material arranged in a first region, wherein the luminescent material luminesces in response to irradiation at at least one excitation wavelength such that the first region exhibits a luminescent visible colour when illuminated by said at least one excitation wavelength; an array of viewing elements; and, a masking layer comprising masking material positioned between the decorative layer and the array of viewing elements, the masking layer arranged as an array of pattern elements at least partially overlapping with said first region, and comprising first pattern elements defined by the presence of the masking material, and second pattern elements defined by the absence of the masking material such that the decorative layer is visible through the second pattern elements, wherein; the masking material is non-luminescing in response to the at least one excitation wavelength and is such that, when the security device is illuminated in the absence of the at least one excitation wavelength, at least where the array of pattern elements overlaps with the first region the first and second pattern elements have substantially the same visual appearance, and when the security device is illuminated by said at least one excitation wavelength, where the array of pattern elements overlaps with the first region, the second pattern elements exhibit the luminescent visible colour, and the first pattern elements exhibit a visual appearance that is different to the luminescent visible colour; and wherein, the array of pattern elements cooperates with the array of viewing elements such that when the security device is illuminated with the at least one excitation wavelength, the security device exhibits an optically variable effect.

2 . The security device of claim 1 , wherein, when illuminated in the absence of the at least one excitation wavelength, the first region exhibits a non-luminescent visible colour.

3 . The security device of claim 2 , wherein the non-luminescent visible colour exhibited by the first region when illuminated in the absence of the at least one excitation wavelength is different to the luminescent visible colour exhibited by the first region when illuminated by said at least one excitation wavelength.

4 . The security device of claim 1 , wherein, when illuminated in the absence of the at least one excitation wavelength, the first region is substantially colourless.

5 . The security device of claim 1 wherein, when the masking material is illuminated in the absence of the at least one excitation wavelength, the masking material is substantially transparent and substantially colourless such that the decorative layer is visible through the first pattern elements.

6 . The security device of any of claim 2 , wherein each first pattern element is arranged laterally within the first region and, when illuminated in the absence of the at least one excitation wavelength, the masking material exhibits a non-luminescent visible colour that is substantially the same as the non-luminescent visible colour exhibited by the first region in the absence of the at least one excitation wavelength.

7 . A security device comprising:
a decorative layer comprising a luminescent material arranged in a first region, wherein the luminescent material luminesces in response to irradiation at at least one excitation wavelength such that the first region exhibits a luminescent visible colour when illuminated by said at least one excitation wavelength; an array of viewing elements; and, a masking layer comprising masking material positioned between the decorative layer and the array of viewing elements, the masking layer arranged as an array of pattern elements at least partially overlapping with said first region, and comprising first pattern elements defined by the presence of the masking material, and second pattern elements defined by the absence of the masking material such that the decorative layer is visible through the second pattern elements, wherein; the masking material exhibits a non-luminescent visible colour when illuminated in the absence of said at least one excitation wavelength, and is non-luminescing in response to the at least one excitation wavelength, and wherein, when the security device is illuminated in the absence of the at least one excitation wavelength, in at least one part of the security device, the first pattern elements exhibit a visual appearance that is different to a visual appearance exhibited by the second pattern elements, whereby the array of pattern elements cooperates with the array of viewing elements such that the security device exhibits a first optically variable effect, and, when the security device is illuminated by said at least one excitation wavelength, where the array of pattern elements overlaps with the first region, the second pattern elements exhibit the luminescent visible colour, and the first pattern elements exhibit a visual appearance that is different to the luminescent visible colour, whereby the array of pattern elements cooperates with the array of viewing elements such that the security device exhibits a second optically variable effect; and wherein, the arrangement of the first region and the array of pattern elements is such that the first optically variable effect conveys first information, and the second optically variable effect conveys second information that is different to the first information.

8 . The security device of claim 7 , wherein the array of pattern elements defines a second region, wherein the pattern elements within the second region cooperate with the array of viewing elements to exhibit an optically variable effect, and wherein either: (i) the second region is laterally completely contained within the first region, and further wherein the first region exhibits a non-luminescent visible colour that is different to the non-luminescent visible colour exhibited by the masking material; or (ii) the second region laterally extends beyond the first region in at least a part of the device.

9 .- 13 . (canceled)

14 . The security device of claim 7 , wherein the masking layer comprises at least first and second masking materials such that some first pattern elements comprise the first masking material and some first pattern elements comprise the second masking material, the first and second masking materials having different optical properties when illuminated in the absence of the at least one excitation wavelength.

15 . The security device of claim 1 , wherein the decorative layer comprises an ink arranged in said first region, the ink comprising said luminescent material.

16 . The security device of claim 15 , wherein the ink further comprises an optically detectable material that exhibits a non-luminescent visible colour when illuminated in the absence of the at least one excitation wavelength.

17 . The security device of claim 8 , wherein the first region is in the form of indicia or an indicium; wherein the second region is in the form of indicia or an indicium, and wherein the first and second regions complement each other.

18 .- 24 . (canceled)

25 . The security device of claim 1 , wherein the masking material substantially absorbs radiation of the at least one excitation wavelength.

26 . (canceled)

27 . The security device of claim 1 , wherein the masking material is an ink.

28 . The security device of claim 1 , wherein the at least one excitation wavelength is at least one UV wavelength in the range of 200

Assignees

• De La Rue Int Ltd

Inventors

• Godfrey John

Classifications

• B42D25/387 Primary

  absorbing or reflecting ultraviolet light · CPC title

• B41M3/144

  using fluorescent, luminescent or iridescent effects · CPC title

• B42D25/373

  Metallic materials · CPC title

• B42D25/342 Primary

  Moiré effects · CPC title

• B42D25/29

  Securities; Bank notes · CPC title