The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 15, 2022
Filed:
Nov. 25, 2020
Stanley Electric Co., Ltd., Tokyo, JP;
Nalux Co., Ltd., Osaka, JP;
Sadayuki Konishi, Tokyo, JP;
Kayuri Kinoshita, Tokyo, JP;
Kenta Ishii, Osaka, JP;
Norihisa Sakagami, Osaka, JP;
Daisuke Seki, Osaka, JP;
Stanley Electric Co., Ltd., Tokyo, JP;
Nalux Co., Ltd., Osaka, JP;
Abstract
An illumination optical system having a light source and a single convex lens with a diffractive structure, wherein the phase function of the diffractive structure is represented by where r represents distance from the central axis of the lens, the relationship|β|·(0.3)<|β|·(0.3)is satisfied where R represents effective radius of the lens, the second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, and the area of a surface of the light source is equal to or greater than 3% of the area of the entrance pupil when the light source side of the lens is defined as the image side.