Patent ID: 8498059
Filing Date: 2013-07-30
Classification: G02B

Abstract:
1. A variable power zoom lens that has the foremost or first lens group of positive refractivity, the second lens group of negative refractivity, the third lens group of positive refractivity, and the fourth lens group of positive refractivity disposed in sequence from a position closer to an object to photograph toward an image plane; the third lens group having a front lens subset of positive refractivity and a back lens subset; the back lens subset alone being moved orthogonal to the optical axis to correct a blur of an image on the image plane caused by a shake of a photographer's hands; and the zoom lens being adapted to meet requirements as defined in conditional formulae (1) as follows: where Lt is the entire length of the lens optics from the front surface of the foremost lens piece to the image plane at the telephoto end, Ft is a focal length of the lens optics in whole at the telephoto end, and Fw is the focal length of the lens optics in whole at the wide-angle end.