Patent ID: 9110275
Filing Date: 2015-08-18
Classification: G02B

Abstract:
1. A zoom lens comprising in an 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 the first lens unit comprises a negative lens, a positive lens, and a positive lens in the order from the object side to the image side, wherein the second lens unit comprises a negative lens, a negative lens, and a positive lens in the order from the object side to the image side, wherein each lens unit moves during zooming so that a distance between the first lens unit and the second lens unit at a telephoto end is longer than the distance at a wide-angle end, a distance between the second lens unit and the third lens unit at the telephoto end is shorter than the distance at the wide-angle end, a distance between the third lens unit and the fourth lens unit at the telephoto end is longer than the distance at the wide-angle end, and a distance between the fourth lens unit and the fifth lens unit at the telephoto end is longer than the distance at the wide-angle end, and wherein the following conditions are satisfied: where M2 and M4 respectively represent movement amounts of the second lens unit and the fourth lens unit during the zooming from the wide-angle end to the telephoto end, β2w and β2t respectively represent lateral magnifications of the second lens unit at the wide-angle end and the telephoto end, and fw and ft respectively represent focal lengths of an entire system at the wide-angle end and the telephoto end.