Patent ID: 6101042
Filing Date: 2000-08-08
Classification: G02B

Abstract:
A zoom lens having in order from the object side thereof,a first lens group G1 having positive refractive power;a second lens group G2 having negative refractive power;and, at the image side thereof, one or more lens groups comprising a third lens group G3;wherein an airspace between the aforesaid first lens group G1 and the aforesaid second lens group G2 changes during a change in magnification;wherein the aforesaid second lens group G2 has five lens components, separated by air spaces, said five lens components being in order from the object side thereof: a negative lens component L1 comprising a negative lens presenting a concave surface toward the image side, a negative lens component L2 presenting a concave surface toward the object side, a positive lens component L3, a negative lens component L4, and a positive lens component L5;and wherein the following conditional expression (1) is satisfied:0<n4-n5<0.4, (1)where:n4=Refractive index at the d line of a negative lens within the aforesaid negative lens component L4, andn5=Refractive index at the d line of a positive lens within the aforesaid positive lens component L5.