Patent ID: 7372636

Claim:
A zoom lens, comprising: a first lens group having a positive focal length; a second lens group having a negative focal length; a third lens group having a positive focal length; a fourth lens group having a positive focal length, the first to fourth lens groups being disposed in sequence from an object side of the zoom lens; and an aperture stop being disposed in a side facing an object of the third lens group, wherein when zooming from a short focal end to a long focal end, an interval between the first and second lens groups increases, an interval between the second and third lens groups decreases, and an interval between the third and fourth lens groups increases, wherein the first lens group comprises a negative meniscus lens L 1 having a convex surface facing the object and a positive lens L 2 , which are disposed in sequence from the object side, wherein a conditional expression: Nd 11 >1.96 is satisfied where Nd 11 is a refractive index of the negative meniscus lens.