US Patent 7589908 Zoom lens and image pickup apparatus having the same

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a rear lens unit including one or more lens units and having an overall positive refractive power. In the zoom lens, the third lens unit includes a first subunit having a positive refractive power and including one lens component having a positive refractive power, an aperture stop, and a second subunit including a negative lens. In the third lens unit of the zoom lens, a focal length of each of the first subunit and the second subunit is appropriately set.