ALEXANDRIA, Va., Nov. 11 -- United States Patent no. 12,468,081, issued on Nov. 11, was assigned to SEIKO EPSON Corp. (Tokyo).
"Optical element and virtual image display device" was invented by Osamu Yokoyama (Shiojiri, Japan), Atsushi Saito (Chino, Japan) and Toshiyuki Noguchi (Shiojiri, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "An optical element includes a substrate and a first hologram element provided on one side of the substrate, and a second hologram element provided on another side of the substrate. The first hologram element is provided to overlap with the second hologram element in a front view. The first hologram element includes a first hologram layer that diffracts part of incident li...