Patent ID: 11906716
Assignee: NIKON CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A zoom optical system comprising a plurality of lens groups, wherein
upon zooming, distances between adjacent lens groups change,
the zoom optical system comprises: a focusing lens group that moves upon focusing and an image-side lens group disposed adjacent to an image side of the focusing lens group,
the focusing lens group comprises a first focusing lens group that moves upon focusing and a second focusing lens group that is disposed closer to an image than the first focusing lens group and moves upon focusing,
the first focusing lends group and the second focusing lens group have positive refractive powers,
the second focusing lens group consists of a single lens, and
the zoom optical system satisfies the following conditional expressions:

0.000<dL0t/dL1t<1.000

0.20<fF1/fF2<3.00

where dL0t: a distance on an optical axis between the focusing lens group and the image-side lens group upon focusing on an infinity object in a telephoto end state,
dL1t: a distance on the optical axis between the focusing lens group and the image-side lens group upon focusing on a short-distance object in the telephoto end state,
fF 1: a focal length of the first focusing lens group, and
fF2: a focal length of the second focusing lens group.