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:
Aug. 05, 2003
Filed:
Jul. 20, 2001
Masayuki Murata, Saitama, JP;
Takayuki Ito, Saitama, JP;
Pentax Corporation, Tokyo, JP;
Abstract
A wide-angle lens system includes a negative first lens group, and a positive second lens group. The first lens group includes a positive lens element, and a negative lens element. The wide-angle lens system satisfies the following conditions: 0<(&phgr; +&phgr; )/&phgr;<0.3 . . . (1); 0.5<HF/HL<0.9 . . . (2); &phgr; =(1−n )/r ;&phgr; =(n −1)/r ; &phgr;=1/f; n : the refractive index of the positive lens element of the first lens group; n : the refractive index of the most object-side negative lens element of the first lens group;r : the radius of curvature of the image-side surface of the positive lens element of the first lens group; r : the radius of curvature of the object-side surface of the most object-side negative lens element of the first lens group; f: the focal length of the entire lens system; HF: the radius of a bundle of axial light rays with respect to the most object-side surface of the first lens group; and HL: the radius of a bundle of axial light rays with respect to the most object-side surface of the second lens group.