Sony Corporation

Tamron Company, Ltd.

Masaharu Hosoi

Makoto Kanai

Masafumi Sueyoshi

Toshihiro Sunaga

Hisayuki Yamanaka

Motoyuki Otake

Masaki Maruyama

Hiroshi Koizumi

Hiroyuki Matsumoto

Naoki Miyagawa

Takahiko Sakai

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 &#x2212;2.0&#x3c;f3/f4&#x3c;&#x2212;0.35 where f3 indicates a focal length of the third lens group and f4 indicates a focal length of the fourth lens group.

Zoom lens and imaging apparatus

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.

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&#x3c;(44)/(44)&#x3c;5&#x2003;&#x2003;(1)

Zoom lens and image pickup unit

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&#x3c;&#x3b2;5&#x2266;4.0&#x2003;&#x2003;(1) Here, &#x3b2;5w is a lateral magnification of the fifth lens group at a wide-angle end.

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)&#x2212;2.0&#x3c;3/&#x221a;()&#x3c;&#x2212;0.3&#x2003;&#x2003;(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.

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 1alens group and a lens group located closer to the image side than the stop is a 1blens group, Condition Equation (1) below is satisfied:0.7&#x3c;1&#x3c;2.0,&#x2003;&#x2003;(1)where f is a focal distance of an entire system and f1b is a focal distance of the 1blens group.

Imaging lens and imaging apparatus

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,&#x2212;2.8&#x3c;3/&#x3c;&#x2212;0.5&#x2003;&#x2003;(1)2.0&#x3c;4/&#x3c;15.0&#x2003;&#x2003;(2).

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&#x3c;f1/f&#x3c;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.

Internal focusing lens

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 Gof positive refractivity, the second lens group Gof negative refractivity, the third lens group Gof positive refractivity, the fourth lens group Gof negative refractivity, and the fifth lens group Gof positive or negative refractivity arranged in sequence from a position closer to the object where the fourth lens group Gserves as a focusing lens, and the third lens group Gand the fifth lens group Gtogether move on and along the same cam structure during zooming.

Enhanced variable power zoom lens

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.

A zoom lens including first, second, and third lens groups having positive, negative, and positive refractive powers, respectively, which are arranged in that order from the object side to the image side such that, when zooming from wide-angle to telephoto, the first lens group moves to the object side, and spacings between the lens groups change. The third lens group has at least two lenses including a first lens, which is a positive lens arranged closer to the object side than the other lenses of the third lens group. Blur correction is performed by moving the first lens perpendicularly to the optical axis. The third lens group is configured such that the following conditional expression is satisfied: 0.3&#x3c;(1&#x2212;&#x3b2;kFW)&#xb7;&#x3b2;kRW&#x3c;1.9, where &#x3b2;kFW and &#x3b2;kRW are the lateral magnifications at wide-angle of, respectively, the first lens and the remaining lenses of the third lens group.

The present invention is directed to provide an enhanced variable power zoom lens that is lightweight as a whole, and especially, has its 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 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 this sequence from a position closer to the object where a distance between each pair of the adjacent lens groups is varied during zooming from the wide-angle end to the telephoto end, each lens group comes closer to the object at the telephoto end than at the wide-angle end, the third lens group and the fourth lens group separating the farthest apart from each other at the intermediate zooming range, and the fourth lens group is moved closer to the image plane for shifting from infinity focusing to proximity focusing.

Disclosed herein is a zoom lens formed by arranging a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power in order from an object side to an image side, wherein at a time of varying power from a wide-angle end to a telephoto end, the first lens group is moved, the second lens group is moved to the object side, and the third lens group is moved to the image side such that an air interval between the first lens group and the second lens group is decreased and such that an air interval between the second lens group and the third lens group is increased.

Zoom lens and image pickup device

A zoom lens includes first to third negative, positive, positive lens groups. The second lens group includes first to fourth positive, negative, negative, positive lenses. The third and fourth lenses of the second lens group are bonded to each other to serve as a cemented lens. The zoom lens is configured to satisfy Conditional Expressions (1) and (2) as follows:&#x2212;0.5&#x3c;2/2&#x3c;0, and&#x2003;&#x2003;(1)0.09&#x3c;2/&#x3c;0.19,&#x2003;&#x2003;(2)where f2 is a focal length of the second lens group, f2R is a combined focal length of the cemented lens including the third and fourth lenses of the second lens group, L2 is an overall length on an optical axis of the second lens group, and LT is an optical overall length at the telephoto end.

Growing community of inventors

Kanagawa, Japan

Masaharu Hosoi