公开(公告)号：US20230301775A1

公开(公告)日：2023-09-28

申请号：US18023704

申请日：2021-10-07

Applicant: KOWA COMPANY, LTD.

Inventor： Shuji ABE ,  Yasuhiro HISHINUMA ,  Kotaro MITSUMOTO ,  Haruo ISHIKAWA ,  Norio SHIMIZU

IPC: A61F2/16

CPC classification number: A61F2/1618 ,  A61F2/1654 ,  G02B27/4205

Abstract: 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 points is two or more. The focal position fc for far vision in polychromatic performance evaluation is located nearer to the multifocal diffractive lens than the focal position fs for far vision in monochromatic performance evaluation.