Optical: systems and elements – Lens – With variable magnification
Patent
1991-02-21
1993-03-02
Fields, Carolyn E.
Optical: systems and elements
Lens
With variable magnification
35419512, G02B 1302
Patent
active
051914778
ABSTRACT:
A zoom finder is provided which includes an objective optical system of a positive power having a first lens group of negative power, a second lens group of positive power, a third lens group of positive power, and an eye piece optical system of a positive power through which an image formed by the objective optical system is observed. The first lens group, the second lens group, the third lens group and the eye piece object system are arranged in this order from an object side. The second lens group of the objective optical system is movable in an optical axis direction to vary the power, and the first and second lens groups are movable in association with each other to keep a constant diopter.
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Abe Tetsuya
Morisawa Tahei
Asahi Kogaku Kogyo Kabushiki Kaisha
Dunn Drew A.
Fields Carolyn E.
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