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:
Mar. 24, 2026
Filed:
May. 13, 2024
Nissei Technology Corporation, Hyogo, JP;
Takuya Otsu, Hyogo, JP;
NISSEI TECHNOLOGY CORPORATION, Hyogo, JP;
Abstract
A projection optical system includes, in sequence from a projection surface: an aperture stop; a first lens with a positive refractive power; a second lens with a positive refractive power; and a third lens with a positive refractive power. The third lens have a convex surface closer to the projection surface. The projection system satisfies: 1.0<f/EPD<1.35, 1.0<(r2+r1)/(r2−r1)<1.45, and 0.2<d2/f<0.45, where f is a focal length of the overall projection optical system, EPD is an entrance pupil diameter, r1 is a radius of curvature of a surface of the first lens closer to the projection surface, r2 is a radius of curvature of a surface of the first lens closer to the image display element, and d2 is an air spacing between the first lens and the second lens on an optical axis.