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:
Jun. 24, 1997
Filed:
Jul. 19, 1993
Noriyuki Iwata, Fujisawa, JP;
Yoshiko Shimada, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A zoom finder has first to third lens groups sequentially arranged from an object side to an eye pupil side and performs a zooming operation by fixing the first and third lens groups and moving the second lens group. The first lens group is constructed by a positive single lens. The second lens group is constructed by a negative single lens. The third lens group has a positive combinational focal length and is constructed by a negative single lens arranged on the object side and a positive single lens arranged on the eye pupil side. A frame system of the zoom finder is formed by an eye pupil side lens face of the negative single lens of the third lens group and the positive single lens of the third lens group. Radii R.sub.1 and R.sub.2 of curvature of lens faces of the first lens group on the object and eye pupil sides satisfy the following condition.