A security device and method of making thereof

Patent metadata

Field	Value
Publication number	US-2020130396-A1
Application number	US-201816627252-A
Country	US
Kind code	A1
Filing date	Jun 27, 2018
Priority date	Jun 30, 2017
Publication date	Apr 30, 2020
Grant date	—

Abstract

A security device is provided, comprising: a colour shifting element that exhibits different wavelengths of light at different viewing angles, and; an at least partially transparent light control layer covering at least a part of the colourshifting element and comprising a surface relief adapted to modify the angle of light from the colour shifting element, wherein; a first region of the light control layer comprises a first optical characteristic, whereby light at a first viewing angle from the first region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the first optical characteristic, and; a second region of the light control layer either: (i) is substantially colourless such that light at the first viewing angle from the second region is perceived to have a resultant optical effect exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, or; (ii) comprises a second optical characteristic different from the first optical characteristic, whereby light at the first viewing angle from the second region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the second optical characteristic. Methods of manufacture thereof are also disclosed.

First claim

1 . A security device comprising:
a colour shifting element that exhibits different wavelengths of light at different viewing angles, and; an at least partially transparent light control layer covering at least a part of the colourshifting element and comprising a surface relief adapted to modify the angle of light from the colour shifting element, wherein; a first region of the light control layer comprises a first optical characteristic, whereby light at a first viewing angle from the first region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the first optical characteristic, and; a second region of the light control layer either: (i) is substantially colourless such that light at the first viewing angle from the second region is perceived to have a resultant optical effect exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, or; (ii) comprises a second optical characteristic different from the first optical characteristic, whereby light at the first viewing angle from the second region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the second optical characteristic.

2 . The security device of claim 1 , wherein the resultant optical effect is a perceived colour.

3 . The security device of claim 1 , wherein the first and/or second optical characteristic is any of: a visible colour, fluorescence, luminescence and phosphorescence.

4 . The security device of claim 1 , wherein the first optical characteristic is such that the first region exhibits a first visible colour and the second optical characteristic is such that the second region exhibits a second, different visible colour.

5 . The security device of claim 1 , wherein the first and second optical characteristics are such that the first region and the second region exhibit substantially the same visible colour, wherein a level of transparency of the first region is different to a level of transparency of the second region such that the resultant perceived colours exhibited by the first and second regions are different.

6 . The security device of claim 1 , wherein the first and second optical characteristics are such that the first region and second region exhibit substantially the same wavelength of fluorescence, luminescence or phosphorescence emission, wherein a concentration of fluorescent, luminescent or phosphorescent material differs between the first and second regions.

7 . The security device of claim 1 , wherein at a first viewing angle, the light from the first region of the light control layer is perceived to have a first resultant colour and, at a second viewing angle, the light from said first region of the light control layer is perceived to have a second resultant colour different from the first resultant colour.

8 - 10 . (canceled)

11 . The security device of claim 1 , wherein the first and/or second regions of the light control layer define indicia.

12 . (canceled)

13 . A security device comprising:
a colour shifting element that exhibits different wavelengths of light at different viewing angles; an at least partially transparent light control layer covering at least a part of the colour shifting element and comprising a surface relief adapted to modify the angle of light from the colour shifting element, and; an optical characteristic layer positioned between the colour shifting element and the light control layer, or positioned on a distal side of the colour shifting element with respect to the light control layer, wherein at least a first region of the optical characteristic layer comprises a first optical characteristic such that it exhibits a first optical effect at substantially all viewing angles; whereby light at a first viewing angle from the first region is perceived to have a first optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the first optical characteristic.

14 . The security device of claim 13 , wherein the first optical characteristic is any of: a visible colour, fluorescence, luminescence and phosphorescence.

15 - 18 . (canceled)

19 . The security device of claim 13 , wherein the optical characteristic layer comprises a second region having a second optical characteristic such that the second region exhibits a second optical effect at substantially all viewing angles different to the first optical effect.

20 . The security device of claim 19 , wherein the first and second optical characteristics are such that the first region and the second region exhibit substantially the same visible colour, wherein a level of transparency of the first region is different to a level of transparency of the second region.

21 - 24 . (canceled)

25 . The security device of claim 13 , wherein the optical characteristic layer defines indicia.

26 . A security device comprising:
a colour shifting element that exhibits different wavelengths of light at different viewing angles; an at least partially transparent light control layer covering at least a part of the colour shifting element and comprising a surface relief adapted to modify the angle of light from the colour shifting element, and; a substantially opaque layer having a first optical characteristic positioned between the colour shifting element and the light control layer and covering a first region of the colour shifting element, wherein; a first region of the light control layer comprises a second optical characteristic, whereby light at a first viewing angle from the first region of the light control layer is perceived to either: (i) have a resultant optical effect that is the resultant of the first optical characteristic and the second optical characteristic, when the first region of the light control layer overlaps with the opaque layer, or; (ii) have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the second optical characteristic, when the first region of the light control layer does not overlap with the opaque layer.

27 . The security device of claim 26 , wherein the first and/or second optical characteristic is any one of: a visible colour, fluorescence, luminescence and phosphorescence.

28 . (canceled)

29 . The security device of claim 26 , wherein a second region of the light control layer is substantially colourless such that light at the first viewing angle from the second region is perceived to either:
(i) have a resultant optical effect that is the resultant of the first optical characteristic, when the second region of the light control layer overlaps with the opaque layer, or; (ii) have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer,

Assignees

• De La Rue Int Ltd

Inventors

• Godfrey John
• Locke Rebecca

Classifications

• B42D25/23 Primary

  Identity cards · CPC title

• B42D25/24

  Passports · CPC title

• B42D25/328

  Diffraction gratings; Holograms · CPC title

• B42D25/373

  Metallic materials · CPC title

• B42D25/29

  Securities; Bank notes · CPC title