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.

Date of Patent:
Jan. 12, 2021

Filed:

Mar. 17, 2019
Applicants:

Yohei Takano, Kanagawa, JP;

Hirotoshi Nakayama, Kanagawa, JP;

Inventors:

Yohei Takano, Kanagawa, JP;

Hirotoshi Nakayama, Kanagawa, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B 21/28 (2006.01); G03B 21/00 (2006.01); G02B 26/08 (2006.01); G03B 21/14 (2006.01); G02B 13/16 (2006.01);
U.S. Cl.
CPC ...
G03B 21/28 (2013.01); G02B 13/16 (2013.01); G02B 26/0833 (2013.01); G03B 21/008 (2013.01); G03B 21/142 (2013.01);
Abstract

A projection optical system satisfies θ1≥15 (deg) and 3<EP/Ym<7. θ1 is a maximum inclination angle of the reflective surface of each of the micromirrors with respect to the line normal to the image display surface; EP is an entrance pupil distance of the projection optical system; and Ym is a maximum distance in a plane from an optical axis to a point on the image display surface, the plane being a plane in which a light ray propagating from a center of the image display surface toward the projection surface through a center of an aperture stop of the projection optical system exists, the optical axis being an axis shared by a largest number of the plurality of lenses of the projection optical system, the point corresponding to an image on the projection surface.


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