Patent ID: 7729058
Filing Date: 2010-06-01
Classification: G02B

Abstract:
1. A three-unit zoom lens system comprising, in order from an object side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power, wherein during zooming from a wide-angle end to a telephoto end, a space between the first lens unit and the second lens unit narrows, at least the second lens unit and the third lens unit move only toward the object side; the second lens unit comprises a cemented lens component which comprises, in order from the object side, a positive lens element, a negative lens element and a positive lens element; the lens elements are cemented on an optical axis; the third lens unit comprises a positive lens element, and the total number of the lens elements in the third lens unit is one.