Patent ID: 7948686
Filing Date: 2011-05-24
Classification: G02B

Abstract:
1. A zoom lens comprising, in order from the object side to the image side: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; and a fourth lens unit having positive refractive power; wherein the third lens unit includes, in order from the object side to the image side and wherein the second lens unit and the fourth lens unit move on the optical axis during zooming; and wherein the 3b′th lens sub-unit moves in a direction perpendicular to the optical axis, thereby displacing an image in the direction perpendicular to the optical axis; and wherein the 3a′th lens sub-unit includes, in order from the object side to the image side and wherein the 3b′th lens sub-unit includes, in order from the object side to the image side wherein, when assuming that the indices of the materials of the negative lens element G is satisfied, and wherein when assuming that the index of the material of the positive lens element having the highest index of a material which is part of the fourth lens unit is NG 4 p , a condition of is satisfied.