VARIABLE MAGNIFICATION OPTICAL SYSTEM, OPTICAL DEVICE, AND PRODUCTION METHOD FOR VARIABLE MAGNIFICATION OPTICAL SYSTEM

摘要

Composing, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power;;upon zooming from a wide-angle end state to a telephoto end state, 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 an image plane being varied; on the most image side, a fixed lens group being fixed in a position upon zooming from the wide-angle end state to the telephoto end state; and the third lens group being moved in the direction of the optical axis upon focusing from an infinite distance object to a near distance object, thereby providing a small-size variable magnification optical system having a high zoom ratio and an excellent optical performance upon focusing from an infinite distance object to a near distance object, an optical apparatus, and a method for manufacturing the variable magnification optical system.

主权项

1. A variable magnification optical system comprising, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power;
upon zooming from a wide-angle end state to a telephoto end state, 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 an image plane being varied; on a most image side, a fixed lens group being fixed in a position upon zooming from the wide-angle end state to the telephoto end state; and the third lens group being moved along the optical axis upon focusing from an infinite distance object to a near distance object.