Patent ID: 8760769
Filing Date: 2014-06-24
Classification: G02B

Abstract:
1. A zoom lens comprising: a first lens group having negative refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power, arranged in this order from an object side to an image plane side, wherein said first lens group includes a first lens having negative refractive power so that a curvature radius of a surface thereof on the image plane side is positive, and a light path changing member for changing a traveling direction of an incident light, said second lens group includes a second lens having positive refractive power so that a curvature radius of a surface thereof on the object side is positive, and a third lens having negative refractive power so that a curvature radius of a surface thereof on the object side is negative, said second lens and said third lens are arranged adjacently from the object side to the image plane side, said third lens group is formed of only two lenses including a fourth lens having positive refractive power and a fifth lens having negative refractive power so that a curvature radius of a surface thereof on the object side is positive, and said first lens group is secured, said second lens group first moves to the image plane side and then moves to the object side, and said third lens group linearly moves to the object side when a magnification of the zoom lens is changed from an wide-angle end to a telephoto end.