Optical security device comprising a layer having a microstructured surface and a dielectric layer filling in or complementary to the microstructured surface
AssigneeViavi Solutions Inc.
InventorsPaul T. Kohlmann, Alberto Argoitia, Cornelis Jan Delst
Life of this patent
Estimating the term…
Abstract
A color shifting security device has a Fabry-Perot type structure wherein a dielectric layer is disposed between a reflector and an absorbing layer. The absorber and reflector layers may be conforming and the dielectric layer therebetween is non-conforming, filling the regions in the micro structured adjacent absorbing or reflecting layer, at least one of which has a microstructure therein or thereon. By having the dielectric layer not conform to the microstructure it is next to, its thickness varies in cross section, which allows for different colors to be seen where the thickness varies.
Claims20
An optical device comprising:
- a first absorbing or reflecting layer having a microstructured surface;
- a second absorbing or reflecting layer having a lower surface;
- and
- a first dielectric layer disposed between the first absorbing or reflecting layer and the second absorbing or reflecting layer,
- wherein the first dielectric layer has a first surface complementary with the microstructured surface and a second surface complementary with the lower surface,
- wherein the first dielectric layer at least partially fills in valleys within the microstructured surface,
- wherein a first region of the first dielectric layer has a first thickness, and
- wherein a second region of the first dielectric layer has a second thickness different than the first thickness.
An optical device comprising:
- a Fabry-Perot cavity comprising:
- a first layer having a microstructured upper surface, wherein the first layer is one of an absorbing layer or a reflecting layer;
- a second layer, wherein the second layer is one of an absorbing layer or a reflecting layer;
- and
- a dielectric layer having an upper surface and a lower surface disposed between the microstructured upper surface of the first layer and the second layer,
- wherein the lower surface of the dielectric layer conforms to the microstructured upper surface of the first layer,
- wherein the dielectric layer at least partially fills in valleys within the microstructured upper surface, and
- wherein a first region of the dielectric layer has a first thickness that is different from a second thickness of a second region of the dielectric layer.
An optical device comprising:
- one or more deposited layers forming a microstructure, wherein at least one of the deposited layers is a reflecting or absorbing layer;
- a dielectric material filling in grooves within the microstructure to form a planar surface over a continuous region of the microstructure;
- and
- an absorbing or reflective cover layer covering at least a part of the continuous region.
Dependencies are inferred from the claim text.