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:
Mar. 01, 1977
Filed:
Aug. 20, 1975
Mitsuaki Horimoto, Osaka, JA;
Minolta Camera Kabushiki Kaisha, Osaka, JA;
Abstract
An extremely wide angle or fish eye lens system is provided capable of compensating for lateral chromatic aberration, field curvature and astigmatism while providing an aperture ratio of F/4 for use with a compact single lens reflex camera. The fish eye lens system includes a first lens group of four lenses on the object side of a diaphragm and a second lens group of at least three lenses on the image side of the diaphragm. From the object to image side, the first lens group includes a pair of negative lenses, a cemented doublet and a positive fourth lens having a convex surface on the image side adjacent a concave surface of the cemented doublet. The second lens group includes a pair of cemented doublets as two of the three lenses.