Patent ID: 8432623
Filing Date: 2013-04-30
Classification: G02B

Abstract:
1. A zoom lens comprising in order from an object side: a first lens group with a negative refracting power; a second lens group with a positive refracting power; a third lens group with a positive refracting power; and a fourth lens group with a refracting curved surface, wherein upon zooming from a wide-angle end to telephoto end, at least the first lens group, second lens group, and third lens group move, and a spacing between the respective lens groups are changed, the first lens group comprises, in order from the object side to an image side, a negative lens component with a negative refracting power and a positive lens component with a positive refracting power, the total number of the lens components in the first lens group is two, the second lens group comprises at least three lenses including at least one negative lens and at least one positive lens, the second lens group comprises a plurality of cemented surfaces, at least two of which are obtained by cementing two face-to-face refracting surfaces of two lenses each having different curvature on the object side surface and image side surface, the positive lens component in the first lens group and the negative lens component in the first lens group are separated by a thickness of an air gap on an optical axis, and a total number of the lenses in the zoom lens is at least eight.