Patent ID: 8792181

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 third lens unit having a positive refractive power; a fourth lens unit having a negative refractive power; and a fifth lens unit having a positive refractive power, wherein each of the lens units moves in such a way that, during zooming from a wide-angle end to a telephoto end, a distance between the first lens unit and the second lens unit increases, a distance between the second lens unit and the third lens unit decreases, a distance between the third lens unit and the fourth lens unit increases, and a distance between the fourth lens unit and the fifth lens unit increases, and wherein following conditions are satisfied: 4.0<( D 34 t+D 45 t )/( D 34 w+D 45 w )<15.0 1.0<( D 34 t−D 34 w )/ fw< 6.0 −0.35 ≦f 4/ ft<− 0.1 −1.71 ≦f 1/ f 4<−0.5 where the distances between the third lens unit and the fourth lens unit at the wide-angle end and at the telephoto end are D 34 w and D 34 t , respectively, the distances between the fourth lens unit and the fifth lens unit at the wide-angle end and at the telephoto end are D 45 w and D 45 t , respectively, focal lengths of the entire zoom lens at the wide-angle end and at the telephoto end are fw and ft, respectively, and focal lengths of the first lens unit and the fourth lens unit are f 1 and f 4 , respectively.