Zoom lens
First Claim
1. A zoom lens comprising at least, in order from the object side, a first lens group of a negative refractive power that is closer to the object side than any other lens group of the zoom lens, a second lens group of a positive refractive power, a third lens group of a positive refractive power, and a fourth lens group of a negative refractive power, wherein, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases, the distance between the second and third lens groups varies, the distance between the third and fourth lens groups increases, and the following condition is satisfied:
- 0.3<
f2/f3<
3whereinf2;
focal length of the second lens group; and
f3;
focal length of the third lens group.
0 Assignments
0 Petitions
Accused Products
Abstract
A zoom lens is composed of a first lens group of a negative refractive power, a second lens group of a positive refractive power and a third lens group of a positive refractive power, in which, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases and the distance between the second and third lens groups varies.
43 Citations
7 Claims
-
1. A zoom lens comprising at least, in order from the object side, a first lens group of a negative refractive power that is closer to the object side than any other lens group of the zoom lens, a second lens group of a positive refractive power, a third lens group of a positive refractive power, and a fourth lens group of a negative refractive power, wherein, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases, the distance between the second and third lens groups varies, the distance between the third and fourth lens groups increases, and the following condition is satisfied:
-
0.3<
f2/f3<
3wherein f2;
focal length of the second lens group; andf3;
focal length of the third lens group. - View Dependent Claims (2)
-
- 3. A zoom lens comprising, in order from the object side, a first lens group of a negative refractive power, a second lens group of a positive refractive power, a third lens group of a positive refractive power and a fourth lens group of a negative refractive power, wherein, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases, the distance between said second and third lens groups increases, and the distance between said third and fourth lens groups increases.
- 6. A zoom lens comprising, in order from the object side, a first lens group of a negative refractive power that is closer to the object side than any other lens group of the zoom lens, a second lens group of a positive refractive power, a third lens group of a positive refractive power, and a fourth lens group of a negative refractive power, wherein, in the zooming operation from the wide angle end to the telephoto end, the distance between said first and second lens groups decreases, the distance between said second and third lens groups varies, the distance between said third and fourth lens groups varies, and the focusing operation from a long object distance to a short object distance is executed by a movement of said second lens group toward the image plane.
Specification