Patent ID: 7777966

Claim:
A zoom lens comprising: a first lens group with a positive refractive power; a second lens group with a negative refractive power; a third lens group with a positive refractive power; a fourth lens group with a negative refractive power; and a fifth lens group with a positive refractive power, wherein the first through the fifth lens groups are sequentially arranged from an object side toward an image side, wherein the second, the fourth, and the fifth lens groups move along an optical axis during zooming, and wherein the fifth lens group moves in a back and forth motion along the optical axis during zooming from a wide-angle end to a telephoto end, and wherein the first lens group comprises two meniscus lenses, each of the two meniscus lens having a convex surface toward the object side, and a doublet lens formed by attaching together two lenses and interposed between the two meniscus lenses.