Patent ID: 7277236

Claim:
A zoom lens having an effective focal length fw for the wide angle mode, wherein the zoom lens, from an image side, sequentially comprises: a first lens group having a negative effective power and an effective focal length f 1 , wherein 2.1<|f 1 /fw|<2.6, and the first lens group comprises: a first lens having a first negative power and at least a first concave aspheric lens surface; and a second lens having a first positive power; a second lens group having a first positive effective power and an effective focal length f 2 , wherein 1.5<|f 2 /fw|<1.8, and the second lens group comprises: a third lens having a second positive power and at least a second aspheric lens surface; and a fourth lens having a third positive power; and a third lens group having a second positive effective power.