Zoom eyepiece lens system
AssigneeNikon Vision Co., Ltd.
InventorKenji YAMADA
Life of this patent
Estimating the term…
Abstract
A zoom eyepiece lens system EL includes, in order from an eyepoint EP side: a first lens group G1 having positive refractive power; a second lens group G2 having positive refractive power; and a third lens group G3 having negative refractive power. Upon zooming from a low magnification end state to a high magnification end state, the second lens group G2 and the third lens group G3 move along an optical axis in opposite directions with each other. The second lens group G2 includes, in order from the eyepoint EP side, a first lens L3 having negative refractive power, a second lens L4 having positive refractive power, and a third lens L5 having positive refractive power. At least one aspherical surface is formed on the third lens L5.
Claims4
A zoom eyepiece lens system comprising, in order from an observation eye side:
- a first lens group having positive refractive power;
- a second lens group having positive refractive power;
- and
- a third lens group having negative refractive power;
- upon zooming from a low magnification end state to a high magnification end state, the second lens group and the third lens group moving along an optical axis in opposite directions with each other,
- the second lens group including, in order from the observation eye side, a first lens having negative refractive power, a second lens having positive refractive power, and a third lens having positive refractive power, and
- at least one aspherical surface being formed on the third lens.
Dependencies are inferred from the claim text.