Patent ID: 7636201

Claim:
A zoom lens comprising: a first lens group having a positive focal length; a second lens group having a negative focal length; a third lens group having a positive focal length; a fourth lens group having a negative focal length, the first to fourth lens groups arranged in order from an object side to an image side; and a diaphragm disposed between the second and third lens groups, wherein: during a change of zoom ratio from a short focus end to a long focus end, the first to fourth lens groups are configured to move so that an interval between the first and second lens groups increases, an interval between the second and third lens groups decreases, and an interval between the third and fourth lens groups increases; and the first lens group comprises a first negative lens, a second negative lens, a reflective optical element, and at least one positive lens arranged in order from the object side to the image side; the reflective optical element is configured to bend an optical path of an incident light beam in the first lens group.