Zoom lens and imaging apparatus

摘要

A zoom lens includes a positive first lens group, a negative second lens group, a positive third lens group, and a fourth lens group. The first through third lens groups move such that the distance between the first and second lens groups is greater while the distance between the second lens group and the third lens group is less at the telephoto end compared to the wide angle end, and the fourth lens moves with the third lens group. The third lens group includes a fixed positive subgroup, including at least one positive lens and one negative lens, and a movable subgroup provided toward an image side of the fixed lens group including one negative lens that moves perpendicular to an optical axis to correct an image plane when camera shake occurs. The fourth lens group includes a fixed subgroup and a movable subgroup that moves during focusing operations.

主权项

1. A zoom lens, comprising:
a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; and a fourth lens group having a positive or a negative refractive power; provided in this order from an object side; the first lens group, the second lens group, and the third lens group moving such that the distance between the first lens group and the second lens group is greater while the distance between the second lens group and the third lens group is less at the telephoto end compared to the wide angle end, and the fourth lens moving integrally with the third lens group; the third lens group substantially consisting of a fixed third lens group having a positive refractive power as a whole, constituted by at least one lens having a positive refractive power and at least one lens having a negative refractive power, and a movable third lens group provided more toward an image side than the fixed third lens group constituted by a single lens having a negative refractive power that moves in a direction perpendicular to an optical axis to correct an image plane when camera shake occurs; and the fourth lens group substantially consisting of a movable fourth lens group that moves along the optical axis during focusing operations and a fixed fourth lens group which is fixed with respect to the direction of the optical axis during focusing operations.