Optical Device Exhibiting Color Shift Upon Rotation
AssigneeJDS Uniphase Corporation
InventorsMatthew R. Witzman, Jason Satern, Roger W. Phillips, Oleg Bouevitch
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Abstract
An optical device exhibiting a color shift upon rotation is disclosed. The optical device has a textured surface having a relief structure finer than a human eye resolution but large enough not to exhibit diffraction effects. The textured surface is coated with an interference thin film that exhibits a color shift with tilt. A uniform color seen at one angle of rotation changes to another uniform color when the optical device is rotated in its own plane. A method of manufacturing of such an optical device, as well as the use of the optical device as an optical security and authentication element, is also disclosed.
Claims43
An optical device exhibiting a shift of color upon rotation, comprising:
- a substrate having an array of structures disposed thereon or therein, and
- a coating supported by the substrate and forming a color shifting reflector therewith;
- wherein each of the structures of the substrate has first and second surfaces having a line of mutual intersection forming a non-zero angle with a plane of the substrate, wherein the first and the second surfaces each have a width and a length larger than 2 microns;
- whereby the shift of color of the optical device is observable by rotating the optical device in the plane of the substrate.
An optical device exhibiting a shift of color upon rotation, comprising:
- a substrate having first and second areas each having grooves disposed on the substrate or in the substrate and running parallel to each other, the grooves having a polygonal cross-section;
- a coating supported by the substrate and forming a color shifting reflector therewith;
- whereby the shift of color of the first and the second areas of the optical device is visibly different, so as to form indicia discernible by color,
- wherein the shift of color of the first or the second areas is observable by rotating the optical device in a plane of the substrate.
Dependencies are inferred from the claim text.