ALEXANDRIA, Va., March 19 -- United States Patent no. 12,253,687, issued on March 18, was assigned to DISPELIX OY (Espoo, Finland).
"Grating arrangements" was invented by Juuso Olkkonen (Espoo, Finland).
According to the abstract* released by the U.S. Patent & Trademark Office: "The invention concerns a diffractive waveguide element for a personal display device, the element comprising a waveguide body (21), and at least two grating regions (23, 24) arranged on the waveguide body (21), at least some of the grating regions adapted to expand the exit pupil of the element. According to the invention, the grating regions (23, 24) are positioned with respect to each other so that and are provided with gratings having different grating vectors ...