US Patent Issued to Hitachi on Aug. 26 for "Field emission electron source, electron optical device, and manufacturing method" (Japanese Inventors)

ALEXANDRIA, Va., Aug. 26 -- United States Patent no. 12,400,820, issued on Aug. 26, was assigned to Hitachi Ltd. (Tokyo).

"Field emission electron source, electron optical device, and manufacturing method" was invented by Takeshi Kawasaki (Tokyo) and Tetsuya Akashi (Tokyo).

According to the abstract* released by the U.S. Patent & Trademark Office: "In a field emission electron source used in an electron optical device, a tip distal end portion of the field emission electron source includes a needle-shaped shunt having a diameter that is reduced toward a distal end, a substantially spherical protrusion formed at the distal end of the shunt, a coating that covers the shunt and the substantially spherical protrusion, and an opening through w...