Patent ID: 8395849
Filing Date: 2013-03-12
Classification: G02B,Y10T

Abstract:
1. An imaging lens comprising, in order from an object side: a first lens group having negative refractive power; a second lens group having positive refractive power; and a third lens group having negative refractive power, upon focusing on a close object from an infinitely distant object, at least one of the first lens group and the second lens group being moved to the object side so that a distance between the first lens group and the second lens group varies, and the following conditional expressions being satisfied: where β denotes a shooting magnification upon focusing on the closest object, X 1 is a moving amount of the first lens group, which comes to the maximum when focusing varies from an infinitely-distant-object focusing state to a life-size shooting magnification state, and f 2 is a focal length of the second lens group.