Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Sony Corporation

Isamu Izuhara

Kyoichi Miyazaki

Shunichiro Yoshinaga

Takuya Imaoka

Naoto Nishimura

Nobuyuki Adachi

Akihiro Ishida

Hiromichi Nose

A zoom lens system includes, in the following order from an object side toward an image side, a first lens group with negative power, a second lens group with positive power, a third lens group with negative power, and a fourth lens group with positive power. The first lens group includes, in the following order from the object side toward the image side, a first lens element having a negative meniscus shape with a concave surface facing the image side, a second lens element having a negative meniscus shape with a concave surface facing the image side, a third lens element with a concave surface facing the image side, a fourth lens element with a convex surface facing the object side, and a fifth lens element with a concave surface facing the object side. The third lens element and the fourth lens element compose a cemented lens.

Zoom lens system, image capturing device

A wide-angle lens system includes a first lens group, an aperture stop, and a second lens group having positive optical power. The first lens group includes, at least, a first lens element that has a meniscus shape convex on the object side, and has negative optical power, a second lens element that has a meniscus shape convex on the object side, and has negative optical power, a third lens element that is concave on the image side and has negative optical power, and a posterior lens element. The second lens element is an aspherical lens, and the second lens element satisfies a conditional expression:0.3&#x3c;(21&#x2212;22)/(21+22)&#x3c;0.8where

Wide-angle lens system and imaging apparatus

A zoom lens system, in order from an object side to an image side, comprising: a negative first lens unit; a positive second lens unit; a negative third lens unit; and a positive fourth lens unit, wherein the first, second and third lens units move along an optical axis in zooming, the third lens unit moves along the optical axis in focusing, and the conditions: 2.5&#x2266;|(1&#x2212;(&#x3b2;))&#xd7;(&#x3b2;)|&#x2266;7.0 and 0.5&#x2266;Bf/f&#x2266;4.0 (&#x3b2;: a lateral magnification of the third lens unit at an infinite object point distance at the telephoto limit, &#x3b2;: a lateral magnification of the fourth lens unit at an infinite object point distance at the telephoto limit, Bf: a back focal length of the zoom lens system at the wide-angle limit, f: a focal length of the zoom lens system at the wide-angle limit) are satisfied.

Zoom lens system, interchangeable lens apparatus and camera system

A zoom lens system comprising a plurality of lens units, wherein a lens unit located closest to an object side and a lens unit located closest to an image side are fixed with respect to an image surface in zooming from a wide-angle limit to a telephoto limit at a time of image taking, and at least three lens units among all the lens units are moving lens units that move along an optical axis in the zooming, at least one lens unit among the moving lens units is a focusing lens unit that moves along the optical axis in focusing from an infinity in-focus condition to a close-object in-focus condition, and the following condition: &#x3a3;(Tn)/H&#x2266;2.1 (&#x3a3;(Tn): the total of axial thicknesses of all the moving lens units, H: the maximum image height) is satisfied.

Compact and lightweight zoom lens systems having less aberration fluctuation in association with focusing, lens barrels, interchangeable lens apparatuses, and camera systems are provided. The zoom lens system comprises: a first lens unit having positive optical power; a first focusing lens unit which is located on an image side relative to the first lens unit, has negative optical power, and moves along an optical axis in zooming and focusing; and a second focusing lens unit which is located on the image side relative to the first focusing lens unit, has positive optical power, and moves along the optical axis in the zooming and the focusing, and satisfies the condition: |d/d|&#x3c;1.0 (d: an amount of movement of the first focusing lens unit in focusing at a telephoto limit, d: an amount of movement of the second focusing lens unit in focusing at a telephoto limit).

Zoom lens system, lens barrel, interchangeable lens apparatus and camera system

A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, in order from an object side to an image side, a first lens unit having positive optical power and composed of not more than two lens elements, a second lens unit having negative optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power. In zooming from a wide-angle limit to a telephoto limit, the fourth lens unit moves along an optical axis. Further, the following conditions are satisfied: 1.50&#x3c;nd&#x3c;1.72, 50&#x3c;vd&#x3c;75 (nd: a refractive index to the d line of a positive lens element constituting the first lens unit, vd: an Abbe number of a positive lens element constituting the first lens unit).

Zoom lens system, interchangeable lens apparatus, and camera system

A zoom lens includes a first lens group having negative refractive power and a second lens group having positive refractive power, each including at least one plastic aspherical lens. The zoom lens satisfies the following Conditional Expressions (1) and (2), (1) 0.40&#x3c;fw/bkw&#x3c;0.60; (2) 0.01&#x3c;|(X1&#x2212;X0)/h0|&#x3c;0.022, where fw: focal length of the entire zoom lens in focus at infinity in a wide-angle end state; bkw: back focus when the entire zoom lens is in focus at infinity in the wide-angle end state; X1: thickness at an image-side effective diameter position of the plastic aspherical lens of the first lens group; X0: thickness at the center of the plastic aspherical lens of the first lens group; and h0: image-side effective radius of the plastic aspherical lens of the first lens group.

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Osaka, Japan

Isamu Izuhara