Patent ID: 8730586
Filing Date: 2014-05-20
Classification: G02B,H04N

Abstract:
1. A zoom lens system comprising a negative first lens group, a positive second lens group, and a positive third lens group, in that order from the object side, wherein upon zooming from the short focal length extremity to the long focal length extremity, the distance between said first lens group and said second lens group decreases and the distance between said second lens group and said third lens group changes, in the optical axis direction, wherein said second lens group comprises a biconvex positive lens element provided with an aspherical surface on each side thereof, and a negative meniscus lens element provided with an aspherical surface on at least one surface thereof and having a concave surface on the image side, in that order from the object side, and wherein the following condition (1) is satisfied: wherein m2t designates the lateral magnification of said second lens group at the long focal length extremity when focused on an object at infinity, and m2w designates the lateral magnification of said second lens group at the short focal length extremity when focused on an object at infinity.