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:
Nov. 25, 2025
Filed:
May. 17, 2021
Sony Group Corporation, Tokyo, JP;
Mariko Nishiyama, Kanagawa, JP;
Jun Nishikawa, Kanagawa, JP;
Sony Group Corporation, Tokyo, JP;
Abstract
A projection optical system of an image display apparatus that includes a lens system and a concave reflection surface. The lens system is has a positive refractive power as a whole. The concave reflection surface reflects the image light emitted from the lens system toward an object. The projection optical system is configured such that a relationship 0<|Δθ(hmax) Δθ(0.9·hmax)|/θ(hmax)<0.056 is satisfied, where a light beam height from the reference axis is h, an angle with respect to an optical axis height direction of a tangent line of a function Z(h) representing a shape of the concave reflection surface corresponding to the light beam height h is θ(h), an amount of change in the angle θ(h) is Δθ(h), and the light beam height h of a reflection point farthest from the reference axis of the concave reflection surface for reflecting the image light is hmax.