Nikon Corporation

Naoto Ohta

Hideo Kanno

Hiroshi Okano

Yoshiharu Shiokama

Hitoshi Imanari

Hideshi Naito

Kiyotaka Inadome

Yoshiro Kodaka

A zoom lens assembly comprises a photo-taking optical system having a focusing portion, a zooming portion, and an optic axis, a manual operator movable in the direction of the optic axis for zooming and rotatable about the optic axis for focusing, an electrically rotated drive shaft, a member for moving the zooming portion of the photo-taking optical system for zooming in response to the movement of the manual operator in the direction of the optic axis, an intermediate member rotatable in response to the rotation of the manual operator to move the focusing portion of the photo-taking optical system for focusing, and movable in the direction of the optic axis with the manual operator, a transmission system for coupling the intermediate member to the drive member for movement in the direction of the optic axis to thereby transmit the rotation of the drive member to the intermediate member irrespective of the movement of the intermediate member in the direction of the optic axis, and a change-over device operable to connect and disconnect the rotation of the manual operator and the intermediate member.

Zoom lens assembly

In a zoom lens a zoom operating ring is rotatable to vary the focal length of an optical system between a first focal length and a second focal length. A distance ring is rotatable to effect focusing of the optical system with respect to an object to be photographed which is positioned in a normal photographing distance range including infinity. A macro operating ring is rotatable to effect focusing of the optical system with respect to an object to be photographed which is positioned in a macro photographing distance range including an area of a shorter distance than a close distance in the normal photographing distance range. The optical system has a maximum magnification when the focal length is equal to the first focal length. In response to rotation of the macro operating ring, the zoom operating ring is rotated when the focal length of the optical system is equal to a given focal length different from the first focal length and the macro operating ring is in a position of rotation corresponding to a shortest distance within the macro photographing distance range conforming to the given focal length.

Zoom lens capable of macro photography

Growing community of inventors

Chigasaki, Japan

Naoto Ohta