Patent ID: 8456746
Filing Date: 2013-06-04
Classification: G02B

Abstract:
1. A zoom lens comprising, in order from an object side to an image side: a first lens unit having a positive refractive power, which does not move for zooming; a second lens unit having a negative refractive power, which moves during zooming; a third lens unit having a negative refractive power, which moves during zooming; an aperture stop; and a fourth lens unit having a positive refractive power, which does not move for zooming, wherein the fourth lens unit includes a first lens sub-unit, a focal length conversion optical system configured to be inserted into or removed from an optical path, and a second lens sub-unit, and wherein the following conditions are satisfied: where f42 is a focal length of the second lens sub-unit, D is a distance from the aperture stop to a lens surface at the most object side of the second lens sub-unit, and Fno is an F-number of the entire zoom lens at a wide-angle end when the focal length conversion optical system is removed from the optical path.