ALEXANDRIA, Va., Sept. 24 -- United States Patent no. 12,741,478, issued on Sept. 22, was assigned to DE LA RUE INTERNATIONAL Ltd. (Basingstoke, Great Britain).
"Optical device and method of manufacture thereof" was invented by Brian Holmes (Fleet, Great Britain) and Frederic Fournier (Thatcham, Great Britain).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method for forming an optical device and an optical device, wherein upon illumination, exhibits diffractive images dependent upon viewing angle, the device having a diffractive structure including grating regions, each region corresponding to a component of a respective diffractive image, wherein: each region of the diffractive structure includes grating ...