Abstract: A miniature zoom lens includes a first, a second and a third lens groups arranged along an optical axis and from an object side to an image side in sequence. The refractive powers of the three lens groups are negative, positive and positive, respectively. The first lens group is fixed at a predetermined position. The second lens group is movable along the optical axis in accordance with a change of magnification. The third lens group is movable along the optical axis for keeping an image plane fixed at an image sensor. The first lens group is in resting state and the second and the third lens groups are movable during zoom-in or zoom-out operation of the miniature zoom lens. In addition, the miniature zoom lens can be composed of at least seven pieces of lens, thus the cost is reduced, the manufacture is easy and the assembly is simple.

Abstract: A zoom lens includes a first, a second, a third and a fourth lens groups that are arranged along an optical axis and from an object side to an image side in sequence. The refractive powers of the four lens groups are positive, negative, positive and positive, respectively. The first and the third lens groups are fixed at a fixed position. The second lens group is movable along the optical axis in accordance with the change of magnification. The fourth lens group is movable along the optical axis in accordance with keeping an image plane fixed at an image sensor. The present invention has at least four pieces of lens that are made of plastic material in order to decrease camera lens weight and move easily the lens groups. In addition, the present invention has small variation of aperture value, moderate zoom ratio and compact size at the same time.