Patent ID: 7336429

Claim:
The 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; and a third 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, at least the first lens group and the third lens group are moved such that a distance between the first lens group and the second lens group increases, and a distance between the second lens group and the third lens group decreases. the first lens group comprises, in order from the object, a front lens group having positive refractive power and a rear lens group having positive refractive power, the front lens group comprises, in order from the object, at least one negative lens and at least one positive lens, the rear lens group consists of a single positive lens, and focusing from infinity to a close object is carried out by moving the rear lens group toward the object.