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. 03, 2006
Filed:
May. 11, 2005
Shuji Yoneyama, Gyeongsangnam-do, KR;
Shuji Yoneyama, Gyeongsangnam-do, KR;
PENTAX Corporation, Tokyo, JP;
Abstract
A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group. Upon zooming, the second lens group moves from the object side to the image side, and the fourth lens group moves in order to compensate the move of the image plane. The fourth lens group includes sub-lens groups, wherein a first sub-lens group satisfies specific conditions. The first sub-lens group has an aspherical surface on at least the object-side surface thereof. The aspherical surface is formed so that the higher a height from the optical axis in a radial direction becomes the weaker the refractive power is, compared with a paraxial spherical surface.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile