Patent ID: 7612949
Filing Date: 2009-11-03
Classification: G02B

Abstract:
1. A zoom lens comprising, in order from an object side; a first lens group having a negative refractive power; a second lens group having a positive refractive power; and a third lens group having a positive refractive power; wherein when a lens position state changes from a maximum wide-angle state to a maximum telephoto state, the second lens group moves in an optical axis toward the object side, and the first and the third lens groups move in an optical axis direction such that a gap between the first lens group and the second lens group decreases, while a gap between the second lens group and the third lens group is increased; when a change in subject position occurs, close-range focusing is performed by movement of the third lens group; conditional equations (1) and (2) shown below are satisfied where TLw is a total lens length in the maximum wide-angle state, TLt is a total lens length in the maximum telephoto state, fl is a focal length of the first lens group, and ft is a focal length of an overall lens system in the maximum telephoto end state.