Patent ID: 7110187

Claim:
A zoom lens comprising, in order from an object side toward an image side: a first lens unit with negative refracting power as a whole, consisting of, in order from the object side toward the image side: a negative lens; and a positive lens; a second lens unit with positive refracting power as a whole, comprising, in order from the object side toward the image side: a positive lens; and a cemented lens component comprising, in order from the object side toward the image side: a positive lens; and a negative lens; and a third lens unit consisting of a single positive lens component, wherein an image-side surface of the negative lens of the first lens unit is configured as a concave surface so that an absolute value of power of the concave surface is larger than the absolute value of power of an object-side surface of the negative lens, the first lens unit has at least one aspherical surface, and the second lens unit is constructed so that at least two surfaces, excluding a cemented surface between the positive lens and the negative lens constituting the cemented lens 20 component, are aspherical, and wherein when a magnification of the zoom lens is changed in a range from a wide-angle position to a telephoto position in infinite object point focusing, spacing between the first lens unit and the second lens unit is narrowed and spacing between the second lens unit and the third lens unit is widened, and the zoom lens satisfies the following condition: 2.1<|β2 T |<2.8 where β2T is a magnification of the whole of the second lens unit at the telephoto position in the infinite object point focusing.