Patent ID: 7502171

Claim:
A zoom lens system comprising, in order from an object 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, the zoom lens system having five lens units in total, during zooming from a wide-angle end toward a telephoto end, the first lens unit being fixed, at least the second lens unit and the third lens unit being moved, and a space between the lens units being changed, the second lens unit being positioned closer to an image-surface side in the telephoto end than in the wide-angle end, the third lens unit being positioned closer to the object side in the telephoto end than in the wide-angle end, the first lens unit comprising a reflective optical element which reflects an optical path, the zoom lens system satisfying the following condition: 0.5 <f 1G /f w <3.5 (1B), wherein f 1G denotes a focal length of the first lens unit, and f w denotes a focal length of the zoom lens system in the wide-angle end.