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:
May. 05, 2020

Filed:

Jun. 24, 2019
Applicant:

Nittoh Inc., Suwa-shi, Nagano, JP;

Inventor:

Takahiko Matsuo, Suwa, JP;

Assignee:

NITTOH INC., Suwa-Shi, Nagano, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B 21/28 (2006.01); H04N 9/31 (2006.01); G02B 13/16 (2006.01); G02B 17/08 (2006.01); G03B 21/00 (2006.01); G03B 21/14 (2006.01); G02B 15/20 (2006.01);
U.S. Cl.
CPC ...
H04N 9/315 (2013.01); G02B 13/16 (2013.01); G02B 15/20 (2013.01); G02B 17/08 (2013.01); G02B 17/0852 (2013.01); G03B 21/00 (2013.01); G03B 21/14 (2013.01); G03B 21/147 (2013.01); G03B 21/28 (2013.01); H04N 9/3141 (2013.01);
Abstract

A projection optical system () projects from a first image plane () on a reducing side to a second image plane () on an enlargement side. The projection optical system () includes a first optical system () that includes a plurality of lenses and forms a first intermediate image () formed inside the first optical system () by light incident from the reducing side into a second intermediate image () on the enlargement side of the first optical system; a second optical system () that includes a first reflective surface (M) with positive refractive power which is positioned further to the enlargement side than the second intermediate image (); and a glass block () that is disposed between the first optical system () and the first reflective surface (M), the glass block () passing light rays from the first optical system to the second intermediate image.


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