ALEXANDRIA, Va., Sept. 30 -- United States Patent no. 12,428,335, issued on Sept. 30, was assigned to ROLEX SA (Geneva).
"Colored watch glass" was invented by Maria-Isabel Borges-Machado (Thonex, Switzerland) and Alexandra Roulet (Geneva).
According to the abstract* released by the U.S. Patent & Trademark Office: "A transparent timepiece component, in particular a watch glass, has a substantially planar or curved interior surface, and has mainly a transparent material colored by a zone of modified chemical composition within the component through an introduction of at least one coloring chemical element of the transparent material, this zone of modified chemical composition extending in one part only of the total thickness of the timepiec...