Optical switch devices
A security device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. At least one first or second segment can include one or more microstructures or one or more nanostructures configured to produce one or more colors for the first or second image.
1. An optical device comprising:
an array of lenses;
a plurality of first and second segments disposed under the array of lenses, the first segments corresponding to portions of an icon and a background;
a metal layer; and
a transparent coating,
wherein at a first viewing angle, the array of lenses presents the icon for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses does not present the icon for viewing,
wherein individual ones of the first segments comprise specular reflecting features, transmissive features, and diffusing features, the specular reflecting features defining one of the icon and the background, the diffusing features defining the background when the specular reflecting features define the icon, and the diffusing features defining the icon when the specular reflecting features define the background,
wherein the metal layer is disposed on a side of the specular reflecting and diffusing features opposite the array of lenses, and
wherein the transparent coating is disposed on a side of the transmissive features opposite the array of lenses.
2. The optical device of claim 1 ,
wherein individual ones of the second segments comprise diffusing features when the diffusing features of the first segments define the background, and comprise specular reflecting features when the specular reflecting features of the first segments define the background.
3. The optical device of claim 1 , wherein upon viewing at an angle in the specular direction,
the icon appears bright or shiny and the background appears matte white, grey, or dark when the specular reflecting features define the icon and the diffusing features define the background, or
the icon appears matte white, grey, or dark and the background appears bright or shiny when the specular reflecting features define the background and the diffusing features define the icon.
4. The optical device of claim 1 , wherein for the first segments, the specular reflecting features define the icon and the diffusing features define the background.
5. The optical device of claim 1 ,
wherein the icon and background are a first icon and a first background respectively,
wherein the second segments correspond to portions of a second icon and a second background, and
wherein at the second viewing angle, the array of lenses presents the second icon for viewing.
6. The optical device of claim 5 ,
wherein individual ones of the second segments comprise specular reflecting features and diffusing features, and
wherein for the second segments, the specular reflecting features define one of the second icon and the second background, the diffusing features define the second background when the specular reflecting features define the second icon, and the diffusing features define the second icon when the specular reflecting features define the second background.
7. The optical device of claim 6 , wherein individual ones of the second segments further comprise transmissive features, wherein the metal layer is disposed on a side of the specular reflecting and diffusing features of the second segments opposite the array of lenses, and wherein the transparent coating is disposed on a side of the transmissive features of the second segments opposite the array of lenses.
8. The optical device of claim 6 , wherein upon viewing at an angle in the specular direction,
the second icon appears bright or shiny and the second background appears matte white, grey, or dark when the specular reflecting features define the second icon and the diffusing features define the second background, or
the second icon appears matte white, grey, or dark and the second background appears bright or shiny when the specular reflecting features define the second background and the diffusing features define the second icon.
9. The optical device of claim 6 , wherein for the second segments, the specular reflecting features define the second icon and the diffusing features define the second background.
10. The optical device of claim 1 , wherein the metal layer comprises aluminum.
11. The optical device of claim 1 , wherein the metal layer is patterned by selective metallization.
12. The optical device of claim 1 , wherein the metal layer is patterned by demetallization.
13. The optical device of claim 1 , wherein metal layer forms at least one of an alphanumerical character, a symbol, an image, or an object.
14. The optical device of claim 1 , wherein the transparent coating comprises a dielectric material.
15. The optical device of claim 1 , wherein the transparent coating has an index of refraction from 1.8 to 3.0.
16. The optical device of claim 15 , wherein the transparent coating comprises zinc sulfide, titanium oxide, indium tin oxide, or a combination thereof.
17. The optical device of claim 1 , wherein the transparent coating is disposed on a side of the metal layer opposite the array of lenses.
18. The optical device of claim 1 , wherein the optical device is configured to provide authenticity verification on an item for security.
19. The optical device of claim 18 , wherein the item is a credit card, a debit card, currency, a passport, a driver's license, an identification card, a document, a container or packaging, or a bottle of pharmaceuticals.
20. The optical device of claim 18 , wherein the optical device is a security thread, a hot stamp feature, an embedded feature, a windowed feature, or a laminated feature.