Patent ID: 7646548
Filing Date: 2010-01-12
Classification: G02B

Abstract:
1. A zoom lens comprising: at least three lens groups including a negative lens group having a negative refractive power, a shift lens group, and a positive lens group having a positive refractive power arranged in this order from an object side, at least the negative lens group and the positive lens group moving so that, when the lens position is moved from a wide-angle setting to a telephoto setting, a distance between the negative lens group and the shift lens group is decreased and a distance between the shift lens group and the positive lens group is changed; wherein the shift lens group comprises at least two subgroups, an aperture stop is disposed between the two subgroups, and an image is capable of being shifted by shifting one of the subgroups in a direction substantially perpendicular to an optical axis, and wherein the following conditional expression (1) is satisfied: where Ds denotes a distance along the optical axis extending from the lens surface that is the closest to the image among the lens surfaces of the subgroup located on the object side to the lens surface that is the closest to the object among the lens surfaces of the subgroup located on the image side, and ft denotes the focal length of the entire lens system in the telephoto setting, and wherein the following conditional expression (2) is satisfied: where D R