Patent ID: 7880974
Filing Date: 2011-02-01
Classification: G02B

Abstract:
1. A zoom lens comprising: a first lens group having negative refractive power; a second lens group having positive refractive power; and a third lens group having positive refractive power; wherein said first, second, and third lens groups are arranged in that order from the object side; and wherein, at the time of changing power from a wide-angle end state to a tele end state, said first lens group moves such that air space between said first lens group and said second lens group decreases, and air space between said second lens group and said third lens group increases, and said second lens group moves toward the object side; and wherein said first lens group includes two lenses, which are, in order from the object side toward the image side, satisfying the following Conditional Expression (1) where f 1 represents the focal length of said first lens group, and fw represents the focal length of the entirety in the wide-angle end state.