ALEXANDRIA, Va., Sept. 3 -- United States Patent no. 12,404,448, issued on Sept. 2, was assigned to Transitions Optical Ltd. (Tuam, Ireland).
"Dihydroquinoline photochromic compounds" was invented by Robert W. Walters (Murrysville, Pa.), Jun Deng (Mars, Pa.) and Shengwen Yuan (Northbrook, Ill.).
According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention relates to a photochromic compound having a core fused ring structure represented by at least one of the following Formula (Ia) or Formula (IIa), (Ia) (IIa) Independently for each of Formula (Ia) and Formula (IIa): R1 is in each case independently selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, -SO2R5, or -C(O...