| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens that has a high zooming magnification and is remarkably reduced in the entire thickness in the direction of its optical axis. <P>SOLUTION: The zoom lens according to the present invention comprises, in order from the object side to the image side along its optical axis, a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power, and a fourth lens group of positive refractive power. The first, second, third, and fourth groups are able to move along the optical axis during the varying of power, and satisfy the following conditional expression: -0.15<L3/Lt<-0.35 in which L3 is a movement vector on the optical axis of the third lens group when the zoom lens varies power from a wide angle end to a telephoto end. The movement vector of the third lens group from the object side to the image side is a positive value and the movement vector of the third lens group from the image side to the object side is a negative value. Lt is the entire length of the zoom lens in the direction of the optical axis from the telephoto end. <P>COPYRIGHT: (C)2012,JPO&INPIT |
