Patent ID: 7336425
Filing Date: 2008-02-26
Classification: G02B

Abstract:
1. A zoom lens system comprising, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having positive refractive power; and a fifth lens group having positive refractive power, wherein when a state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group moves with respect to an image plane, the fifth lens group is fixed with respect to the image plane, a distance between the first lens group and the second lens group varies, a distance between the second lens group and the third lens group decreases, a distance between the third lens group and the fourth lens group decreases, and a distance between the fourth lens group and the fifth lens group increases, and the following conditional expression being satisfied: where fW denotes the focal length of the zoom lens system in the wide-angle end state and f