Patent ID: 7940470
Filing Date: 2011-05-10
Classification: G02B

Abstract:
1. A zoom lens comprising, sequentially from an object side: a positive first lens group; a negative second lens group; a diaphragm; a positive third lens group; a positive fourth lens group; and a positive fifth lens group, wherein a first condition 0.8≦(SLM−(SLW+SLT)/2)/FW≦2.0 and a second condition F14t≦0 are satisfied, SLW being a distance from the diaphragm at a wide angle edge to an imaging plane, SLM being a distance from the diaphragm at an intermediate zoom position to the imaging plane, SLT being a distance from the diaphragm at a telephoto edge to the imaging plane, FW being optical system focal length for infinity at the wide angle edge, and F14t being a combined focal length for the first to the fourth lens groups at the telephoto edge.