Patent ID: 6094312
Filing Date: 2000-07-25
Classification: G02B

Abstract:
A zoom lens consisting of in the following order from the object side:a first lens unit which is fixed in position during zooming and has a positive refractive power;a second lens unit which is movable upon zooming and has a negative refractive power;a third lens unit which is fixed in position during zooming and has a positive refractive power;a fourth lens unit which is movable upon zooming and has a negative refractive power; anda fifth lens unit which is fixed in position during zooming and has a positive refractive power,wherein, upon zooming from the wide-angle end to the telephoto end, said second lens unit is unidirectionally moved from the object side to the image side along an optical axis, and said fourth lens unit is moved along the optical axis from the object side to the image side within a range from the wide-angle end to a middle position between the wide-angle and telephoto ends, and is moved along the optical axis from the image side to the object side within a range from the middle position to the telephoto end.