Zoom lens utilizing inner focus system
AssigneeNikon Corporation
InventorsMasahiro Nakatsuji, Kenzaburo Suzuki
Life of this patent
Estimating the term…
Abstract
A zoom lens of five group construction utilizing an inner focus system. The zoom lens includes a first lens group G1 having a positive refracting power, a second lens group G2 having a negative refracting power, a third lens group G3 having a negative refracting power, a fourth lens group G4 having a positive refracting power and a fifth lens group G5 having a negative refracting power, which are arranged in this order from an object side, and the distances among the respective lens groups are selectively varied to effect the desired zooming operation. During close-up photographing, the second lens group G2 is moved along an optical axis to effect the desired focusing.
Claims16
A zoom lens utilizing an inner focus system comprising:
- a first lens group having a positive refracting power;
- a second lens group having a negative refracting power;
- a third lens group having a negative refracting power;
- a fourth lens group having a positive refracting power;
- and
- a fifth lens group having a negative refracting power;
- said first to fifth lens groups being arranged in said order from an object side, whereby during the period of zooming, with said second lens group being held stationary, said first, third, fourth and fifth lens groups are moved relative to one another to mutually vary a lens group spacing therebetween, whereas during the period of focusing only said second lens group is moved along an optical axis to vary a lens group spacing between said second lens group and said first and third lens groups, respectively.
Dependencies are inferred from the claim text.