Patent ID: 8693113
Filing Date: 2014-04-08
Classification: G02B

Abstract:
1. A lens system having a plurality of lens groups each made up of at least one lens element, consisting of a first lens group, an aperture diaphragm, and a second lens group in order from an object side, wherein the first lens group has a configuration including a first lens element having positive power, a second lens element having positive power, and a third lens element having negative power in order from the object side, or a configuration including a first lens element having positive power, a second lens element having positive power, a third lens element having positive power, and a fourth lens element having negative power in order from the object side, one lens element as a focus lens in the second lens group is moved with respect to an image surface in focusing from an infinity focusing state to a close range focusing state, the second lens group has five or more lens elements, and the second lens group has a configuration including a negative lens element, a positive lens element, and a positive lens element in order from the object side.