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:
Sep. 08, 1992
Filed:
Jun. 05, 1991
Ikuya Tsurukawa, Yokohama, JP;
Kunihisa Yamaguchi, Ichikawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An apparatus for driving a photographic zoom lens in which at least a first and second lens group are disposed on the same optical axis and wherein the apparatus makes it possible to rapidly perform a zooming operation for changing a focal length of the photographic zoom lens. The apparatus comprises a fixed frame and a body tube frame supported within the fixed frame so as to be capable of moving along the optical axis. The apparatus further comprises a first group frame supporting a first lens group, a zooming cam, and a second group frame fixedly supporting a second lens group. Additionally, the apparatus includes a first group driving screw having a first multiple thread screw on a circumferential surface thereof, and adapted to be driven through a first group driving gear and a transmission gear; and a body tube frame driving screw having a second multiple thread screw, and adapted to be driven through a body tube frame driving gear and the transmission gear. The apparatus of the present invention makes it possible to rapidly perform a zooming operation and a housing operation when the power of a driving source and the radius of a driving screw are fixed.