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. 19, 1999
Filed:
Aug. 21, 1997
Applicant:
Inventor:
Eijiroh Tada, Tokyo, JP;
Assignee:
Asahi Seimitsu Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
359752 ; 359713 ; 359753 ;
Abstract
A retrofocus type super wide angle lens system includes a front lens group of negative power and a rear lens group of positive power, arranged in this order from the object side. The front lens group consists of a negative meniscus first lens element with a convex surface facing the object side and a second lens element having at least one aspherical surface, arranged in this order from the object side. The aspherical second lens element is shaped such that it forms a biconcave lens in the vicinity of the optical axis and forms a negative meniscus lens with a convex surface located on the object side at a peripheral portion thereof.