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.

A zoom lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; and a subsequent group that has a plurality of lens groups, wherein: the zoom lens includes an aperture stop at a position closer to the image side than a lens surface closest to the image side in the second lens group, a lens group closest to the image side in the subsequent group includes at least one negative lens of which an object side lens surface is a concave surface being in contact with air, during zooming, a spacing between the first lens group and the second lens group changes, a spacing between the second lens group and the subsequent group changes, and spacings between all adjacent lens groups in the subsequent group change.

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.

An optical system includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a first focus lens unit having a negative refractive power, and a second focus lens unit having a positive refractive power. The first lens unit is fixed during focusing. The first focus lens unit and the second focus lens unit move so that a distance between the first focus lens unit and the second focus lens unit changes during focusing. The first lens unit includes a single lens which is disposed closest to an object and has a negative refractive power. A predetermined condition is satisfied.

A zoom optical system comprises, in order from an object side: a first lens group having positive refractive power; a front-side lens group; an intermediate lens group having positive refractive power; and a rear-side lens group. The front-side lens group is composed of one or more lens groups and has a negative lens group. At least part of the intermediate lens group is a focusing lens group. The rear-side lens group is composed of one or more lens groups. Upon zooming, distances between the first lens group and the front-side lens group, between the front-side lens group and the intermediate lens group, and between the intermediate lens group and the rear-side lens group change. The following conditional expressions are satisfied:

−10.000<fF/fRF<10.000

0.010<|fF/fXR|<10.000

where fF denotes a focal length of the focusing lens group, fRF denotes a focal length of a lens group closest to the object side in the rear-side lens group, and fXR denotes a focal length of a lens group closet to an image surface in the front-side lens group.

A zoom lens includes, in order from an object side, a first lens group that is positive, a second lens group that is negative, a third lens group that is positive, and a fourth lens group that is positive. During zooming from a wide angle end to a telephoto end, at least the first lens group and the third lens group are fixed and an interval on an optical axis of an adjacent lens group relative thereto is changed. In the zoom lens, the fourth lens group includes at least one positive lens and satisfies a predetermined conditional expression. In addition, an imaging device includes the zoom lens and an image sensor.

An optical system includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a first focus lens unit having a negative refractive power, and a second focus lens unit having a positive refractive power. The first lens unit is fixed during focusing. The first focus lens unit and the second focus lens unit move so that a distance between the first focus lens unit and the second focus lens unit changes during focusing. The first lens unit includes a single lens which is disposed closest to an object and has a negative refractive power. A predetermined condition is satisfied.

An attachment optical system attachable to and detachable from an imaging optical system includes a first converter optical system attachable to an object side of the imaging optical system, and a second converter optical system attachable to an image side of the imaging optical system. The first converter optical system includes a first unit consisting of a dome-shaped cover. A predetermined condition is satisfied.

The zoom lens consists of a first lens group, a front group, a middle group, and a rear group, in order from an object side. The first lens group has a positive refractive power and includes a negative lens and a positive lens, successively in order from a position closest to the object side to an image side. The front group consists of one or more lens groups that move during zooming and has a negative refractive power as a whole throughout an entire zoom range. The middle group includes only one lens group as a lens group. The rear group consists of a plurality of lens groups. An aperture stop is disposed between a lens surface closest to the image side in the front group and a lens surface closest to the object side in the rear group. The zoom lens satisfies predetermined conditional expressions.

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 β=−1.2 is obtained can be caused, where β 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.