An object of the present invention is to provide a low-cost, miniature, wide-angle high-zoom-ratio zoom lens that has high imaging performance, and an imaging apparatus equipped with the zoom lens. To achieve the object, a zoom lens including a first lens group having positive refracting power, a second lens group having negative refracting power and a third lens group having positive refracting power in order from an object side in which a lens group P having positive refracting power is arranged closer to an image plane side than the third lens group.

Zoom lens and imaging apparatus

A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit decreases while an interval between the second lens unit and the third lens unit changes so that variable magnification is achieved, the first lens unit comprises one object side negative lens element and one image side positive lens element with a convex surface facing the object side, which have an aspheric surface, and the conditions: n12>1.88 and ν12<26 (n12 and ν12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Zoom lens system, imaging device and camera

Provided are a zoom lens where the imaging angle of field at a wide angle end used for a video camera and a digital still camera includes a wide angle of field of 60 - 100 degrees, that has a magnification ratio of 3 to 6 times, that has a front lens element with a small diameter which makes the zoom lens more compact, and that has high image forming performance, and an imaging device with the zoom lens. A zoom lens (20) whose magnification is varied by varying the distance between lens groups, where the lens groups are composed of a first lens group (GR1) having positive refractive power, a second lens group (GR2) having negative refractive power, a 3rd lens group (GR3) having positive refractive power, and a final group (GRR) provided at a position nearest to an image surface and having negative refractive power, arranged in that order from the object side, the first lens group (GR1) is constructed from a single positive powered lens (G1), and the zoom lens satisfies (1) 0.5 40, where Ymax is the maximum image height on an image surface, FW, the focal length at a wide angle end of the entire lens system, and VdG1, the Abbe number at the d line of the first lens group (GR1).

Zoom lens and imaging device

A zoom lens system is provided that includes a compactly constructed focusing lens unit and that has a suppressed change in the image magnification at the time of movement of a focusing lens unit. The zoom lens system according to the present invention, in order from an object side to an image side, comprises: a first lens unit having positive optical power; a second lens unit having negative optical power; and at least two subsequent lens units, wherein the two lens units includes a lens unit A having positive optical power and a lens unit B arranged on the image side relative to the lens unit A, at the time of zooming, all lens units move in a direction along the optical axis so that intervals between the lens units vary, at the time of focusing, the lens unit B moves in a direction along the optical axis, and at the time of compensating image blur caused by vibration in the zoom lens system, either the entirety of a lens unit arranged on the object side relative to the lens unit A or a sub lens unit which is a part of a lens unit arranged on the object side relative to the lens unit A and is arranged on the image side therein moves in a direction perpendicular to the optical axis.

Zoom lens system, interchangeable lens apparatus and camera system

This zoom lens system is provided with: a first lens group that has negative power; a second lens group that has positive power; a third lens group that has negative power; and a fourth lens group that has positive power. During zooming, the first lens group, second lens group, and third lens group move along the optical axis. During focusing, the third lens group moves along the optical axis. The zoom lens system satisfies the conditions: 2.5 ≤ | (1 - (β 3T ) 2 ) × (β 4T ) 2 | ≤ 7.0 and 0.5 ≤ Bf W /f W ≤ 4.0 (β 3T being the lateral magnification of the third lens group at an infinite object distance at the telephoto end; β 4T the lateral magnification of the fourth lens group at an infinite object distance of the telephoto end; Bf W the back focus of the entire system at the wide angle end; and f W the focal length of the entire system at the wide angle end).

Zoom lens system, interchangeable lens device, and camera system

A zoom lens is disclosed which has a macro mode wherein the magnifying power is higher than 0.5. The zoom lens includes a first positive lens group, a second negative lens group movable upon power variation, and a plurality of movable lens groups cooperable with the second group to form a macro lens group, disposed in order from an object side. The movable lens groups include a single focusing group, and an additional negative lens group disposed further on the image side. The zoom lens has a macro mode in which it can be focused at a shorter distance than an ordinary region by moving the macro lens group integrally from a telephoto end position toward the object side while the first lens group is fixed at the telephotograph end.

Zoom lens and image pickup apparatus

The zoom of this invention comprises a first lens group having a positive refracting power, a second lens group having an negative refracting power, a third lens group having a positive refracting power, a fourth lens group having a positive refracting power, and a fifth lens group having a negative refracting power from an object side in this order, wherein a zooming is carried out by moving the second and the fourth lens groups, wherein the first lens group comprises, a foreside lens group having an negative refracting power, an optical element for folding an optical path, and a backside lens group having a positive refracting power from the object side, and a condition of 1.0<β 5 <1.9 is satisfied, provided that an imaging power of the fifth lens group where an object distance is at infinity is β 5.

Zoom lens, and an imaging apparatus using such zoom lens

A zoom lens system used for an imaging device for a fixed-lens camera etc. The zoom lens system includes at least the following lens groups sequentially arranged from the object side: a 1st lens group (GR1) with positive refractive power, a 2nd lens group (GR2) with negative refractive power, a 3rd lens group (GR3) with positive refractive power, a 4th lens group (GR4) with negative refractive power, a 5th lens group (GR5) with positive refractive power, and a 6th lens group (GR6) with negative refractive power. Magnification is varied by varying the intervals between the lens groups. The zoom lens system satisfies the following expressions of (1), (2), (3), (4), and (5): (1) DW(1 - 2) DT(2 - 3) (3) DW(3 - 4) > DT(3 - 4) (4) DW(4 - 5) < DT(4 - 5) (5) DW(5 - 6) < DT(5 - 6) Where, in the above, DW(i - j) is the distance between an i-th lens group and a j-th lens group at the wide angle end in infinity shooting and DT(i - j) is the distance between the i-th lens group and the j-th lens group at the tele end in infinity shooting, and focusing is made when the 4th lens group (GR4) is moved in the optical axis direction.

Zoom lens system and imaging device

A zoom lens is proposed, which includes a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, which are arranged in order from an object side, performing zooming by moving the second lens group and the fourth lens group, wherein the first lens group includes a front lens group having negative refractive power, an optical member refracting a light path, and a rear lens group having positive refractive power, which are arranged in order from the object side, wherein the fourth lens group includes one single lens, and if an image forming power of the fifth lens group at an object distance of infinity is β5, a conditional formula (1) 1.0<β5<1.8 is satisfied.

Masafumi Sueyoshi

Papers

Zoom lens and imaging device

Zoom lens and image pickup apparatus

Zoom lens, and an imaging apparatus using such zoom lens

Zoom lens system and imaging device

Zoom Lens and Image Pick-Up Apparatus