US Patent Issued to KOWA on Dec. 9 for "Multifocal diffractive lens" (Japanese Inventors)

ALEXANDRIA, Va., Dec. 9 -- United States Patent no. 12,491,067, issued on Dec. 9, was assigned to KOWA COMPANY LTD. (Nagoya, Japan).

"Multifocal diffractive lens" was invented by Shuji Abe (Hamamatsu, Japan), Yasuhiro Hishinuma (Hamamatsu, Japan), Kotaro Mitsumoto (Hamamatsu, Japan), Haruo Ishikawa (Hamamatsu, Japan) and Norio Shimizu (Hamamatsu, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A multifocal diffractive lens is provided which achieves efficient use of light. The multifocal diffractive lens 100 includes a diffraction grating 1c. Negative-order light L2 produces a focal point f2 for far vision and 0-order light L1 produces a focal point f1 nearer to that for far vision. The number of focal ...