Patent ID: 8520317
Filing Date: 2013-08-27
Classification: G02B

Abstract:
1. A zoom lens comprising, in order from an object side to an image side: a first lens group having a positive refractive power and including lens components which are fixed to each other; a second lens group having a negative refractive power and being movable in an optical axis direction to perform at least a zooming; a third lens group having a positive refractive power and being fixed; a fourth lens group having a positive refractive power and being movable in the optical axis direction to perform focal position correction and focusing by performing a zooming; and a fifth lens group having a positive refractive power, wherein: an aperture stop is arranged at a position between the image side of the second lens group and the object side of the fifth lens group, at least one of the lens groups positioned at the image side of the aperture stop, includes a three-element cemented lens composed of three lenses cemented together, and the zoom lens is configured to satisfy the following conditional expressions (5) and (6): where fm is the focal length of a middle lens in the three-element cemented lens, and νm is the Abbe number of the middle lens of the three-element cemented lens.