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:
Jan. 14, 2020
Filed:
Jun. 10, 2016
Applicant:
Seiko Epson Corporation, Tokyo, JP;
Inventor:
Nobutaka Minefuji, Azumino, JP;
Assignee:
SEIKO EPSON CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B 21/53 (2006.01); G02B 13/18 (2006.01); G02B 13/16 (2006.01); G03B 21/28 (2006.01);
U.S. Cl.
CPC ...
G03B 21/53 (2013.01); G02B 13/16 (2013.01); G02B 13/18 (2013.01); G03B 21/28 (2013.01);
Abstract
A projection optical system and that includes a relatively small number of lenses and are able to cover a wide zooming range and a projector. A 1-2 lens group which is a focus lens group is constituted with a lens which includes a single positive lens having a convex surface to the reduction side, a lens which includes a single negative meniscus lens having a convex surface to an enlargement side, and a lens which includes a single negative lens, and the 1-2 lens group is moved at the time of focusing accompanying magnification change.