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:
Oct. 11, 2016
Filed:
Dec. 23, 2013
Applicant:
Takahiro Nakayama, Yokohama, JP;
Inventor:
Takahiro Nakayama, Yokohama, JP;
Assignee:
RICOH COMPANY, LTD., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G02B 9/60 (2006.01); G02B 13/04 (2006.01);
U.S. Cl.
CPC ...
G02B 9/60 (2013.01); G02B 13/04 (2013.01);
Abstract
An imaging optical system, includes: in the order from an object side to an image plane side, a first lens group having a first lens which is formed as a negative lens; a second lens group having a second lens which is formed as a plano-concave lens, a third lens which is formed as a negative meniscus lens, and a fourth lens which is formed as a biconvex lens; an aperture stop; a third lens group having a fifth lens which is formed as a biconvex lens, and a sixth lens which is formed as a biconcave lens; and a fourth lens group having a seventh lens which is formed as a negative meniscus lens.