ALEXANDRIA, Va., March 26 -- United States Patent no. 12,258,658, issued on March 25, was assigned to OPTICS BALZERS AG (Balzers, Liechtenstein).
"Method of manufacturing a linearly variable optical filter" was invented by Tobias Geldhauser (Wangs, Switzerland) and Petra Greussing (Meiningen, Switzerland).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method for producing a spectral gradient filter on a substrate including: providing the substrate with a first surface to be coated; providing a shadow mask that includes a bordered coating area with an edge, wherein the geometry of the shadow mask is adjusted to the desired gradient profile of the gradient filter; creating a masked substrate by fixing the sha...