Abstract: Various embodiments disclosed herein include zoom lens assemblies, as well as cameras and devices that incorporate these zoom lens assemblies. The zoom lens assemblies described herein include three lens groups, the first of which includes a light-folding element such as a prism. The second and third lens groups are moveable relative to the first lens group and relative to each other to change the focal length of the camera.

Abstract: A lens system provides a zoom function (variable magnification) in a low profile camera (lens system height less than or equal to 6 mm), which may be in a cellular phone. The lens system includes at least three movable lens groups that are movable along a common optical axis. Each of the three movable lens groups is coupled to a corresponding actuator. Responsive to a request for a change in focal length or magnification, a controller sends a corresponding signal to each of the actuators that move the corresponding lens group by a corresponding distance in a corresponding direction. The various movable lens groups may be moved by different distances and in different directions of movement. An f-number of the lens system is less than f/3.0. Focusing of an image cast onto an image sensor is accomplished by adjusting the position along the optical axis of one of the movable lens groups.

Abstract: An imaging lens of the disclosure includes, in order from an object side toward an image plane side, a first lens group having positive refractive power and including a plurality of optical elements, a second lens group having positive refractive power, and a third lens group having negative refractive power. The second lens group travels in an optical axis direction upon focusing. The plurality of optical elements include, in order from the object side toward the image plane side, at least a first lens having positive refractive power and a second lens, and predetermined conditional expressions are satisfied.

Abstract: An imaging lens of the present disclosure includes: 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, the second lens group, and the third lens group being provided in order from an object side to an image plane side, in which only the second lens group travels in an optical axis direction upon focusing, and the second lens group includes a negative lens and a positive lens in order from the object side to the image plane side with an air spacing in between, and satisfies the following conditional expression, 1.75<nn<2.20??(1) where nn is a refractive index, at d-line, of the negative lens in the second lens group.

Abstract: A zoom lens includes, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, the fourth lens group having at least two positive lenses, the zoom lens satisfying a conditional expression (a) of ?2.0<f3/f4<?0.35 where f3 indicates a focal length of the third lens group and f4 indicates a focal length of the fourth lens group.

Abstract: There is provided a zoom lens including a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power, the lens groups being arranged in order from an object side to an image side. The second lens group includes a front group having positive refractive power, and a rear group having positive refractive power, the front and rear groups being arranged in order from the object side to the image side. The front group includes a positive lens, a positive lens, a negative lens, and a positive lens, the lenses being arranged in order from the object side to the image side. The rear group includes at least one positive lens.

Abstract: There is provided a zoom lens including a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power, the lens groups being arranged in order from an object side to an image side. The second lens group includes a front group having positive refractive power, and a rear group having positive refractive power, the front and rear groups being arranged in order from the object side to the image side. The front group includes a positive lens, a positive lens, a negative lens, and a positive lens, the lenses being arranged in order from the object side to the image side. The rear group includes at least one positive lens.

Abstract: A zoom lens includes, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, the fourth lens group having at least two positive lenses, the zoom lens satisfying a conditional expression (a) of ?2.0<f3/f4<?0.35 where f3 indicates a focal length of the third lens group and f4 indicates a focal length of the fourth lens group.

Abstract: A zoom lens includes: first to fourth lens groups having positive, negative, positive, and negative refractive power, respectively. The first to fourth lens groups are arranged in order from the object plane. The fourth lens group is configured of one negative lens or a cemented lens including positive and negative lenses that are arranged in order from object plane and are attached to each other. A magnification-varying operation from wide end to telephoto end causes the first and third lens groups to travel toward the object plane and causes the second and fourth lens groups to travel along an optical axis. A focusing operation causes the fourth lens group to travel along the optical axis. The following conditional expression is satisfied: 0.7<(R4f+R4r)/(R4f?R4r)<5??(1) where R4f and R4r are radiuses of curvature of a most-object-sided and a most-image-sided optical surfaces, respectively, in the fourth lens group.

Abstract: A zoom lens includes, in order from an object side to an image side: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a negative refractive power. During zooming from a wide-angle end state to a telephoto end state, air spacing between the first and second lens groups increases, air spacing between the second and third lens groups decreases, spacing between the third and fourth lens groups changes, and spacing between the fourth and fifth lens groups changes. Thus, all the lens groups are moved in an optical axis direction. The zoom lens satisfies the following Conditional Expression (1). 1.0<?5w?4.0??(1) Here, ?5w is a lateral magnification of the fifth lens group at a wide-angle end.

Abstract: A zoom lens includes, in order from an object side to an image side: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a negative refractive power. During zooming from a wide-angle end state to a telephoto end state, air spacing between the first and second lens groups increases, air spacing between the second and third lens groups decreases, spacing between the third and fourth lens groups changes, and spacing between the fourth and fifth lens groups changes. Thus, all the lens groups are moved in an optical axis direction. The zoom lens satisfies the following Conditional Expression (1). 1.0<?5w?4.0??(1) Here, ?5w is a lateral magnification of the fifth lens group at a wide-angle end.

Abstract: A zoom lens includes: first, second, third and fourth lens groups having negative power, positive power, negative power and positive power, respectively, and sequentially arranged from an object side toward an image side. When the magnification at a wide angle side is changed to the magnification at a telescopic side, the first lens group is so moved along an optical axis that the distance between the first lens group and the second lens group decreases, and the second third and fourth lens groups are moved from the image side toward the object side, the third lens group is moved along the optical axis for focusing, and the zoom lens satisfies the following conditional expression (1) ?2.0<f3/?(fw×ft)<?0.3??(1) where f3, fw and ft represent the focal lengths of the third lens group, the entire lens system at the wide angle end, and the entire lens system at the telescopic end, respectively.

Abstract: Provided is an imaging lens including a fixed first lens group having a positive refractive power and including a plurality of lenses, a second lens group serving as a focus group and including a negative lens, and a third lens group having a positive refractive power that are arranged sequentially from an object side to an image side. A stop is disposed between predetermined lenses of the first lens group, and, on an assumption that a lens group located closer to the object side than the stop of the first lens group is a 1ath lens group and a lens group located closer to the image side than the stop is a 1bth lens group, Condition Equation (1) below is satisfied: 0.7<f/f1b<2.0,??(1) where f is a focal distance of an entire system and f1b is a focal distance of the 1bth lens group.

Abstract: A zoom lens includes: a first lens group having negative refractive power; a diaphragm; a second lens group having positive refractive power; a third lens group having negative refractive power; and a fourth lens group having positive refractive power, arranged in order from an object side. The first lens group is configured by at least one negative lens and one positive lens. The third lens group is configured by one negative lens. Then power is changed from a wide angle end state to a telephoto end state, the first, second, and third lens groups are moved in the direction of an optical axis, and the fourth lens group is fixed. When focusing, the third lens group is moved in the direction of the optical axis so as to satisfy the following Conditional Equations, ?2.8<f3/fw<?0.5??(1) 2.0<f4/fw<15.0??(2).

Abstract: There is provided a zoom lens including a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power, the lens groups being arranged in order from an object side to an image side. The second lens group includes a front group having positive refractive power, and a rear group having positive refractive power, the front and rear groups being arranged in order from the object side to the image side. The front group includes a positive lens, a positive lens, a negative lens, and a positive lens, the lenses being arranged in order from the object side to the image side. The rear group includes at least one positive lens.

Abstract: An internal focusing lens includes sequentially from an object side, a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a third lens group having a positive refractive power. During focusing, the second lens group is moved along the optical axis and, the first lens group and the third lens group are fixed. The internal focusing lens satisfies a conditional expression (1) 0.31<f1/f<0.58, where f1 is the focal length of the first lens group and f is the focal length of the entire optical system, at infinity focus.

Abstract: The present invention is directed to provide an enhanced variable power zoom lens that has focusing lens optics reduced in weight so as to relieve of a load on a focusing drive system, and that has its anti-vibration lens optics reduced in both diameter and weight so as to relieve of a load on an anti-vibration drive system and downsize the same. The enhanced variable power zoom lens is adapted to have the foremost or first lens group G1 of positive refractivity, the second lens group G2 of negative refractivity, the third lens group G3 of positive refractivity, the fourth lens group G4 of negative refractivity, and the fifth lens group G5 of positive or negative refractivity arranged in sequence from a position closer to the object where the fourth lens group G4 serves as a focusing lens, and the third lens group G3 and the fifth lens group G5 together move on and along the same cam structure during zooming.

Abstract: An enhanced variable power zoom lens is lightweight in whole and in part, especially, having its focusing lens optics reduced in weight so as to relieve of a load on a focusing drive system, and having its anti-vibration lens optics reduced in both diameter and weight so as to relieve of a load on an anti-vibration drive system and downsize the same. The zoom lens has the foremost or first lens group of positive refractivity, the second lens group of negative refractivity, the third lens group of positive refractivity, the fourth lens group of negative refractivity, and the fifth lens group arranged in sequence from a position closer to the object. The fourth lens group moves toward the image plane for focusing on from the infinity to a proximity object while part of the third lens group moves orthogonal to the optical axis for shifting an image.

Abstract: A zoom lens includes: first to fourth lens groups having positive, negative, positive, and negative refractive power, respectively. The first to fourth lens groups are arranged in order from the object plane. The fourth lens group is configured of one negative lens or a cemented lens including positive and negative lenses that are arranged in order from object plane and are attached to each other. A magnification-varying operation from wide end to telephoto end causes the first and third lens groups to travel toward the object plane and causes the second and fourth lens groups to travel along an optical axis. A focusing operation causes the fourth lens group to travel along the optical axis. The following conditional expression is satisfied: 0.7<(R4f+R4r)/(R4f?R4r)<5??(1) where R4f and R4r are radiuses of curvature of a most-object-sided and a most-image-sided optical surfaces, respectively, in the fourth lens group.

Abstract: A zoom lens includes: first, second, third and fourth lens groups having negative power, positive power, negative power and positive power, respectively, and sequentially arranged from an object side toward an image side. When the magnification at a wide angle side is changed to the magnification at a telescopic side, the first lens group is so moved along an optical axis that the distance between the first lens group and the second lens group decreases, and the second third and fourth lens groups are moved from the image side toward the object side, the third lens group is moved along the optical axis for focusing, and the zoom lens satisfies the following conditional expression (1) ?2.0<f3/?(fw×ft)??0.3 ??(1) where f3, fw and ft represent the focal lengths of the third lens group, the entire lens system at the wide angle end, and the entire lens system at the telescopic end, respectively.