Patent ID: 7583449
Filing Date: 2009-09-01
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; a second lens unit having a negative refractive power configured to move during zooming; a third lens unit having a positive refractive power configured to move during zooming; and a fourth lens unit having a positive refractive power, characterized in that the third lens unit includes a positive lens, a negative lens, and a diffractive optical element, and that a focal length (fc) of the third lens unit, a focal length (fdoe) of a diffraction portion of the diffractive optical element, a focal length (fW) at a wide angle end of the zoom lens, and a focal length (fT) at a telephoto end of the zoom lens satisfy the following conditions: