JP2009210691A5 - - Google Patents

Claims (13)

In order from the object side to the 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, and a fourth lens group having a positive refractive power. is more configuration, during zooming, at least the zoom lens where the first lens unit moves, an aperture stop, the third lens group has a positive lens closest to the image side and at least one negative lens, the second the most distance in the direction of the optical axis from the image side apex of the deployed negative lens on the image side to throttle said third lens group Ds, respectively the focal length of the zoom lens at the wide-angle end and the telephoto end fw, ft, the third When the focal length of the lens group is f3,
−0.3 <Ds / √ (fw · ft) <0.3
1.0 <f3 / fw <3.0
A zoom lens that satisfies the following conditions: In order from the object side to the image side, the lens unit includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens group having a positive refractive power. The zoom lens in which the lens group moves has a stop, and the third lens group has at least one negative lens and a positive lens closest to the image side, and is disposed closest to the image side of the third lens group. When the distance in the optical axis direction from the image side vertex of the negative lens to the stop is Ds, the focal lengths of the zoom lens at the wide-angle end and the telephoto end are fw and ft, respectively, and the focal length of the third lens group is f3.
−0.3 <Ds / √ (fw · ft) <0.3
1.0 <f3 / fw <3.0
A zoom lens characterized by satisfying the following conditions: Wherein said diaphragm, characterized in that it is placed between the image-side vertex of the third lens group on the most object side arranged lens arranged closest to the image side and object side apex of the lens Item 3. The zoom lens according to Item 1 or 2 . The stop is a vertex of the convex lens surface of the third lens group, any one of claims 1 to 3, characterized in that disposed between the intersection of the outer peripheral portion of the convex lens surface Zoom lens described in 1. The third lens group comprises, in order from the object side to the image side, a positive lens, a negative lens, a zoom lens according to any one of claims 1 to 4, characterized in that a positive lens. When the radius of curvature of the image side surface of the negative lens disposed on the most image side of the third lens group and R3n,
0.3 <R3n / fw <0.9
The zoom lens according to any one of claims 1 to 5, characterized by satisfying the following condition. When the focal length of the second lens group is f2,
1.2 <f3 / | f2 | <2.0
The zoom lens according to any one of claims 1 to 6, characterized by satisfying the following condition. When the Dg3 the distance in the optical axis direction between the image-side vertex of the third lens group on the most object side arranged lens arranged closest to the image side and object side apex of the lens,
0.4 <Dg3 / fw <0.85
The zoom lens according to any one of claims 1 to 7, characterized by satisfying the following condition. The zoom lens according to any one of claims 1 to 8 , wherein the first lens group includes one negative lens and one positive lens. The zoom lens according to any one of claims 1 to 9 , wherein the second lens group includes two negative lenses and one positive lens. The zoom lens according to any one of claims 1 to 3, wherein the fourth lens group includes one positive lens. The zoom lens according to any one of claims 1 to 11, characterized in that the solid-state imaging device is an optical system for forming an image. A zoom lens according to any one of claims 1 to 12, an imaging apparatus characterized by comprising a solid-state image sensor for receiving an image formed by the zoom lens.