A zoom lens includes in order from object side: a positive first unit not moving for zooming; a negative second unit moving in an optical axis direction for zooming; a positive M unit moving in the optical axis direction for zooming; and a positive R unit disposed closest to the image side, wherein the first unit includes a subunit moving for focusing, wherein the zoom lens includes an aperture stop closer to the image side than the second unit, wherein a length on the optical axis from a surface of the R unit closest to the object side to a surface of the R unit closest to an image side, a length on the optical axis from the surface of the R unit closest to an image side to a rear principal point of the R unit, and a back focus of the zoom lens are defined.

The present disclosure discloses a zoom lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens group having refractive power; a second lens group having negative refractive power; a third lens group having refractive power; and a fourth lens group having refractive power. The zoom lens assembly may be continuously zoomed by changing positions of the second lens group and the third lens group along the optical axis. A total effective focal length ft of the zoom lens assembly in a telephoto state, and a total effective focal length fw of the zoom lens assembly in a wide-angle state satisfy: 1.3<ft/fw<3.3.

Provided is a zoom lens including, in order from an object side to an image side, a positive first lens unit, a negative second lens unit, a positive third lens unit, a positive fourth lens unit and a rear lens group consisting of at least one lens unit. An interval between each pair of adjacent lens units is changed during zooming. The rear lens group includes a negative N-th lens unit configured to move during focusing. The second lens unit and the third lens unit are configured to move during zooming. A focal length of the second lens unit, a focal length of the third lens unit, a focal length of the fourth lens unit, a lateral magnification of the fourth lens unit at a wide angle end and a lateral magnification of the fourth lens unit at a telephoto end are appropriately set.

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, one or two intermediate lens units having positive refractive powers, and a final lens unit having a positive power. A distance between each pair of adjacent lens units changes in zooming from a wide-angle end to a telephoto end. The one or two intermediate lens units include three or four lenses. The one or two intermediate lens units include a single lens having a positive refractive power and being closest to the image side. The final lens unit includes three or four lenses. The zoom lens satisfies specified conditional expressions.

An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions,

νdLZ<35.0, and

0.702<θgFLZ+(0.00316×νdLZ), where νdLZ: Abbe number of the lens with reference to d-line, and θgFLZ: a partial dispersion ratio of the lens, wherein θgFLZ is defined by the following expression,

θgFLZ=(ngLZ−nFLZ)/(nFLZ−nCLZ). wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.

Provided is a variable magnification optical system comprising, in order from an object side along an optical axis, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4; upon zooming from a wide angle end state to a telephoto end state, a distance between the first lens group G1 and the second lens group G2 being varied, a distance between the second lens group G2 and the third lens group G3 being varied, and a distance between the third lens group and the fourth lens group being varied; the third lens group G3 comprising, in order from the object side along the optical axis, a 3a-th lens group G3a having positive refractive power, an aperture S, and a 3b-th lens group G3b having positive refractive power; a lens group having negative refractive power within the 3b-th lens group G3b being used as a vibration reduction lens group and moved so as to include a component in a direction orthogonal to the optical axis, whereby image plane correction is performed when image blurring occurs; and predetermined conditions being satisfied. Whereby, a small-size and high-performance variable magnification optical system, capable of realizing a small variation in aberration and attaining a sufficient brightness even in the telephoto state, an imaging apparatus, and a method for manufacturing the variable magnification optical system are provided.

The present invention relates to a reflective eyepiece optical system and a head-mounted near-to-eye display apparatus. The system includes: a first lens group, and a first optical element and a second lens group for transmitting and reflecting a light from a miniature image displayer. The second lens group includes an optical reflection surface, and the optical reflection surface is an optical surface farthest from a human eye viewing side in the second lens group. The optical reflection surface is concave to a human eye viewing direction. The first optical element reflects the light refracted by the first lens group to the second lens group, and then transmits the light refracted, reflected, and refracted by the second lens group to the human eye.

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a plurality of lens units which move in zooming, and a final lens unit having a positive refractive power, an interval between each pair of adjacent lens units changing in zooming, the plurality of lens units including a lens unit having a negative refractive power, the first lens unit including a negative lens and a positive lens, at least a part of the first lens unit moving for focusing, the first lens unit including a negative lens made of a material satisfying inequalities defined by a refractive index, an Abbe number, and a partial dispersion ratio, and the zoom lens satifying an inequality defined by a maximum value of an Abbe number of at least one positive lens of the first lens unit.

The present invention relates to a reflective eyepiece optical system and a head-mounted near-to-eye display device. The system includes: a first optical element and a second optical element arranged successively in an incident direction of an optical axis of human eyes, and a first lens group located on an optical axis of a miniature image displayer. The first optical element is used for transmitting and reflecting an image light from the miniature image displayer. The second optical element includes an optical reflection surface. The first optical element reflects the image light refracted by the first lens group to the second optical element, and then transmits the image light reflected by the second optical element to the human eyes.

The present disclosure discloses a zoom lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens group having refractive power; a second lens group having negative refractive power; a third lens group having refractive power; and a fourth lens group having refractive power. The zoom lens assembly may be continuously zoomed by changing positions of the second lens group and the third lens group along the optical axis. A total effective focal length ft of the zoom lens assembly in a telephoto state, and a total effective focal length fw of the zoom lens assembly in a wide-angle state satisfy: 1.3<ft/fw<3.3.