Patent ID: 6967783

Claim:
A zoom lens formed of only two lens groups, in order from the object side, as follows: a first lens group; and a second lens group; wherein the first lens group includes, in order from the object side: a first lens component of negative refractive power that is made of plastic and has at least one aspheric lens surface; and a second lens component of positive refractive power; the second lens group includes, in order from the object side: a stop; a first lens component consisting of a first lens element having a biconvex shape and made of plastic with at least one lens surface aspheric; and a second lens component that includes, in order from the object side, a lens element having negative refractive power with the absolute value of the curvature of its object-side lens surface being smaller than the absolute value of the curvature of its image-side lens surface, said lens element being joined at said image-side lens surface to a lens element having a biconvex shape; and the following conditions are satisfied: B 1/2 <f G2 /f w <0.9 ·B −2.0 <f G1-1 /f W <−1.5 R G2-1 /f W >0.8 | f G1 /f W |<3 ·B where B is the zoom ratio of the zoom lens, namely, the ratio of the focal length at the telephoto end divided by the focal length at the wide-angle end, f G2 is the focal length of the second lens group, f w is the focal length of the zoom lens at the wide-angle end, f G1-1 is the focal length of the first lens component of the first lens group, R G2-1 is the radius of curvature of the object-side lens surface of the first lens element of the second lens group, and f G1 is the focal length of the first lens group.