A zoom optical system includes, in order from an object, 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. The first lens group moves toward an object and air distances between the first to the third lens groups are varied upon zooming from a wide-angle end state to a tele-photo end state. The first lens group comprises a cemented lens consisting of a negative lens and a positive lens in order from the object. The following conditional expressions are satisfied:

4.40<f1/(−f2)<8.00

0.60<f3/fw<3.50

0.60<(−f2)/f3<1.05

30.00°<ωw<80.00°

where f1 denotes a focal length of the first lens group, f2 denotes a focal length of the second lens group, f3 denotes a focal length of the third lens group, fw denotes a focal length of the zoom optical system in the wide-angle end state, and ωw denotes a half angle of view in the wide-angle end state

A zoom lens, a camera module, and a mobile terminal. The zoom lens includes a first lens group, a second lens group, and a third lens group arranged along an axis extending from an object side to an image side, where the first lens group is a fixed lens group with positive focal power nearest an object side, where the second lens group is a zoom lens group with negative focal power, where the third lens group is a compensative lens group with positive focal power nearest an image side to an image side, and where the second lens group is configured to move, in a zooming process of the zoom lens from a short-focal end to a long-focal end, toward the image side along an optical axis, and the where third lens group is configured to move toward the object side along the optical axis.

An endoscope magnification optical system including: a first lens group that has positive power and includes at least a negative lens with a concave surface facing an object side, a positive lens with a convex surface facing an image side, and a doublet obtained by bonding a negative lens and a positive lens; a second lens group that has negative power and includes at least a doublet obtained by bonding a negative lens and a positive lens; and a third lens group that has positive power and includes at least a positive lens and a doublet obtained by bonding a negative lens and a positive lens, is configured such that predetermined conditions are satisfied.

A zoom optical system includes, disposed in order from an object, 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. At least a part of the third lens group is arranged to be movable along an optical axis as a focusing lens group, and the focusing lens group is moved toward an image when a focusing state on a long-distance object is changed to a focusing state on a short-distance object. The following conditional expression is satisfied: 0.90<f3/fw<1.50, where f3 denotes a focal length of the third lens group and fw denotes a focal length of the zoom optical system in a wide-angle end state.

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative power, and a rear unit having a positive refractive power as a whole and including one or more lens units. A distance between adjacent lens units changes during zooming. The first lens unit includes a first subunit having a positive refractive power and a second subunit disposed on the image side of the first subunit. The first subunit includes a first positive lens having the smallest absolute value of a focal length among lenses included in the first subunit. The second subunit includes a second positive lens and a first negative lens having the smallest absolute value of a focal length among negative lenses included in the second subunit. A predetermined condition is satisfied.

The invention relates to personal display devices and in particular an eyepiece therefor. The eyepiece is adapted for projecting an image from an image plane on one side of the eyepiece through an exit pupil on the opposite side of the eyepiece and comprises at least one stationary lens group and at least two movable lens groups being movable with respect to the stationary lens group along an optical axis between the image plane and the exit pupil. According to the invention, the lens groups are arranged in positive-negative-positive configuration and the movable lens groups are arranged to move along the optical axis between a first state providing a first field-of-view and a second state providing a second field-of-view smaller than the first field-of-view to the image plane. The invention allows for improving optical performance and user experience of personal display devices.

Provided is a zoom lens, including: a front lens group only including one or more positive lens unit; a magnification-varying lens unit consisting of a negative lens unit which moves during zooming; and a positive rear lens group including a plurality of lens units, in which an interval between adjacent lens units is changed during zooming, in which front lens group includes a positive focusing unit La, in which rear lens group includes a focusing unit Lb, in which focusing unit La moves toward object side and focusing unit Lb moves toward one of object side and image side, during focusing from infinity to close distance, and a movement amount of focusing unit La at a wide angle end during focusing from infinity to closest distance, and a movement amount of focusing unit La at a telephoto end during focusing from infinity to closest distance are each appropriately set.

The disclosure provides a zoom lens group, sequentially including, from an object side to an image side along an optical axis: a first lens group with positive refractive power, including a first lens with refractive power and a second lens with refractive power, which are sequentially arranged along the optical axis; a second lens group with negative refractive power, including a third lens with negative refractive power and a fourth lens with refractive power, which are sequentially arranged along the optical axis; and a third lens group with positive refractive power, including a fifth lens with positive refractive power, a sixth lens with refractive power, a seventh lens with negative refractive power and an eighth lens with refractive power, which are sequentially arranged along the optical axis, Positions of the second lens group and the third lens group on the optical axis are adjustable.

A zoom lens system includes a first lens group; a second lens group; and a subsequent lens group arranged in that order from the object side. The second lens group consists of a second lens group-a, a second lens group-b, and a second lens group-c arranged in that order from the object side. A distance between the first lens group and the second lens group increases and a distance between the second lens group and the subsequent lens group decreases during a change in magnification from a short focal length end to a long focal length end. During a change in focus from infinity to a short distance, the second lens group-b is movable to the image side, and a distance between the second lens group-a and the second lens group-b and a distance between the second lens group-b and the second lens group-c are changeable.

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a subsequent unit having a positive refractive power as a whole. A distance between adjacent lens units changes during zooming. The first lens unit includes a single lens, and the subsequent unit includes a third lens unit having a positive refractive power closest to the object side in the subsequent unit and a lens unit LP having a positive refractive power closest to the image side among the zoom lenses. During zooming from a wide-angle end to a telephoto end, the second lens unit moves toward the object side. A predetermined condition is satisfied.