This variable-magnification optical system (ZL) comprises, in order along an optical axis from the object side, a first lens group (G1) that has a positive refractive power, a second lens group (G2) that has a negative refractive power, a third lens group (G3) that has a positive refractive power, a fourth lens group (G4) that has a negative refractive power, and a fifth lens group (G5) that has a negative refractive power. The distances between adjacent lens groups change during magnification. The fourth lens group (G4) is a focusing lens group that moves along the optical axis during focusing. The following conditional expression is satisfied: 0.11<f4/f5<0.70, where f4 is the focal length of the fourth lens group (G4) and f5 is the focal length of the fifth lens group (G5).

A variable magnification optical system comprising a plurality of lens groups which includes a first positive lens group disposed at a most object side and having positive refractive power, a first negative lens group disposed at an image side of the first positive lens group and having negative refractive power, and a second negative lens group disposed at a more image side than the first negative lens group and having negative refractive power; upon varying a magnification, distances between adjacent lens groups being varied; the first negative lens group being movable to include a component in a direction perpendicular to the optical axis as a vibration reduction lens group; the second negative lens group being moved along the optical axis upon carrying out focusing; and the first negative lens group further including a lens that satisfies predetermined conditional expression(s), thereby various aberrations being corrected superbly, and vibration reduction lens group being made small in size.

A variable magnification optical system comprising a plurality of lens groups which includes a first positive lens group disposed at a most object side and having positive refractive power, a first negative lens group disposed at an image side of the first positive lens group and having negative refractive power, and a second negative lens group disposed at a more image side than the first negative lens group and having negative refractive power; upon varying a magnification, distances between adjacent lens groups being varied; the first negative lens group being movable to include a component in a direction perpendicular to the optical axis as a vibration reduction lens group; the second negative lens group being moved along the optical axis upon carrying out focusing; and the first negative lens group further including a lens that satisfies predetermined conditional expression(s), thereby various aberrations being corrected superbly, and vibration reduction lens group being made small in size.

The technology of this application relates to a zoom lens, a camera module, and a mobile terminal. The zoom lens includes a plurality of lens groups, for example, a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group that are arranged from an object side to an image side. The first lens group is a lens group with a positive focal power, the second lens group is a lens group with a negative focal power, and the third lens group is a lens group with a positive focal power. The fourth lens group is a lens group with a positive focal power or a negative focal power, and the fifth lens group is a lens group with a positive focal power or a negative focal power.

A zoom lens ZL includes: a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power, an N1th lens unit, and an Nth lens unit, the lens units being arranged in order from an object side to an image side. The N1th lens unit and the Nth lens unit are located on the image side with respect to an aperture stop SP.

In an optical system according to each exemplary embodiment, an interval between adjacent lens units changes in focusing from an infinite-distance object to a close-distance object, and a first in-focus state in which =1.2 is obtained can be caused, where is a lateral magnification of an entire system. The optical system according to each exemplary embodiment includes a plurality of focus lens units, and out of a focus lens unit having a largest absolute value of a focus sensitivity and a focus lens unit having a second largest absolute value of a focus sensitivity in a state in which focus is put on an infinite-distance object, a focus lens unit disposed on an object side is a lens unit LA, and a focus lens unit disposed on an image side is a lens unit LB. A partial optical system LC including all lenses disposed on the image side of the lens unit LB has negative refractive power. The partial optical system LC satisfies a predetermined conditional expression.

The zoom lens consists of, in order from an object side, a first lens group that has a positive refractive power, a second lens group that has a negative refractive power, a middle group that includes one or more lens groups, and a final lens group. The middle group has a positive refractive power as a whole throughout an entire zoom range. During zooming, a spacing between the first lens group and the second lens group changes, a spacing between the second lens group and the middle group changes, and a spacing between the middle group and the final lens group changes. The zoom lens satisfies predetermined conditional expressions.

The zoom lens consists of, in order from an object side, a first lens group that has a positive refractive power, a second lens group that has a negative refractive power, a middle group that includes one or more lens groups, and a final lens group. The middle group has a positive refractive power as a whole throughout an entire zoom range. During zooming, a spacing between the first lens group and the second lens group changes, a spacing between the second lens group and the middle group changes, and a spacing between the middle group and the final lens group changes. The zoom lens satisfies predetermined conditional expressions.