ALEXANDRIA, Va., Nov. 25 -- United States Patent no. 12,481,220, issued on Nov. 25, was assigned to USHIO DENKI K.K. (Japan).
"Lighting optical system and exposure apparatus" was invented by Osamu Osawa (Tokyo) and Koichi Ito (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "Disclosed herein is a lighting optical system comprising: a light source having a plurality of light-emitting elements configured to emit light from light-emitting surfaces, respectively; a relay optical system configured to convert a luminous intensity distribution of light emitted from each of the light-emitting elements into an irradiance distribution and to superimpose a plurality of the irradiance distributions corresponding to ...