US 4,397,544 AGranted

Optical apparatus for changing magnification or reduction rates

AssigneeFuji Photo Optical Co., Ltd.

InventorsToshiyuki Yajima, Syuzo Kimura

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Abstract

A main lens carriage holding a main lens assembly is moved along the optical path by a cam cylinder. A supplemental lens element is operatively coupled with the main lens assembly at the proper position to attain the desired optical reduction ratio. When the main lens assembly deviates from the proper position, a main lens support frame is shifted along the optical path in and relative to the main lens carriage by a correcting mechanism so as to correct the deviation. A further supplemental lens element is provided, but does not move with the main lens assembly. Both supplemental lens elements swing into and out of the optical path under cam action; and further cam action is provided to ensure that the two swinging lens elements do not collide with each other. The main lens support frame is rapidly moved along the optical path by the cam action of a rotating cylinder having a cam groove having part-circular portions that define the desired dwell positions and having open ends.

Claims11

Dependent claims

In an optical apparatus for changing magnification and/or reduction ratios at which copies of originals are produced, comprising a main lens assembly movable along an optical path and first and second supplemental correcting lens elements adapted alternatively to move into the optical path and to cooperate with said main lens assembly at fixed positions;

the improvement comprising:
a main lens support frame holding said main lens assembly;
a main lens carriage in which said main lens support frame is slidably mounted;
supporting means for supporting said main lens carriage for movement along the optical path;
a driving motor for moving said main lens carriage along the optical path;
motor control means for deenergizing said driving motor when said main lens carriage reaches a predetermined position;
a first support frame for holding said first supplemental correcting lens element;
a second support frame for holding said second supplemental correcting lens element and attached to said main lens carriage;
a first cam plate fixedly attached to said main lens carriage so as to move therewith and having a camming groove which causes said first support frame to move into and out of the optical path;
and
a second cam plate extending along the moving direction of said main lens carriage and having a camming groove which causes said second support frame to move into and out of the optical path.

8 more elements

Dependencies are inferred from the claim text.