Patent ID: 7436600
Filing Date: 2008-10-14
Classification: G02B

Abstract:
1. A zoom lens system comprising, from the object side: a first lens group with a negative refractive power, a second lens group with a negative refractive power, a third lens group with a positive refractive power and a fourth lens group with a positive refractive power, when zooming between wide mode and tele mode, the second, third, and fourth lens groups move along an optical axis; wherein: the first lens group is a lens element with a negative refractive power and a concave surface facing the image side; the second lens includes, from the object side: a negative meniscus lens element with a convex surface facing the object side, and a positive meniscus lens element with a convex surface facing the object side; the third lens group includes, from the object side: an aperture stop, a biconvex lens element, a biconvex lens element, a biconcave lens element; the fourth lens group includes a positive meniscus lens element with a convex surface facing the image side.