ALEXANDRIA, Va., Aug. 20 -- United States Patent no. 12,392,659, issued on Aug. 19, was assigned to KONICA MINOLTA INC. (Tokyo).
"Photometric device" was invented by Tsugumi Umanodan (Osaka, Japan), Toru Nakatani (Osaka, Japan) and Yusuke Hirao (Takatsuki, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "The photometric device includes a variable light attenuator. The variable light attenuator includes a plurality of light attenuation filters and a driving device. Each of the plurality of light attenuation filters includes an interference multilayer film and a transparent substrate. A combination of any two of the plurality of light attenuation filters is set as a first light attenuation filter and a sec...