Patent ID: 7889436

Claim:
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; a reflection unit including a reflection surface for bending an optical path, a third lens unit having a negative refractive power; a fourth lens unit having a positive refractive power; and a fifth lens unit having one of a positive refractive power and a negative refractive power, wherein during zooming from a wide-angle end to a telephoto end, at least the second lens unit and the fourth lens unit move while the reflection unit remains stationary, and wherein a focal length of the first lens unit (f 1 ) and focal lengths of the zoom lens at the wide-angle end and at the telephoto end (fw, ft) satisfy the following condition: 0.7 <f 1 /√{square root over (fw·ft)}≦ 1.7.