Patent ID: 11953664
Assignee: NIKON CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 14:
15. A method for manufacturing a zoom optical system comprising:
arranging, in a lens barrel, a first lens group having positive refractive power, a second lens group disposed on an image side of the first lens group and having negative refractive power, a third lens group disposed on an image side of the second lens group and having positive refractive power, a fourth lens group disposed on an image side of the third lens group and having negative refractive power, and a final lens group disposed on an image side of the fourth lens group and also disposed closest to an image,
arranging the first to fourth lens groups such that a distance between the first lens group and the second lens group, a distance between the second lens group and the third lens group, and a distance between the third lens group and the fourth lens group change during zooming,
arranging the first lens group to be movable along an optical axis during zooming,
configuring the second lens group to comprise a vibration proof group capable of moving with a displacement component in a direction perpendicular to the optical axis and having negative refractive power, and
providing a focusing lens group having negative refractive power to be moved along the optical axis during focusing, with the final lens group being disposed on an image side of the focusing lens group,
the method further comprising at least one of the following features A and B,
the feature A including:
configuring the vibration proof group to comprise, in order from an object, a negative lens, an air gap and a cemented lens of a negative lens and a positive lends,
the feature B including:
configuring the final lens group so as to have a negative refractive power.