| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-zoom-ratio, and high resolution zoom lens easily achieving high performance. SOLUTION: The zoom lens includes in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power, and varies the power by changing each distance between the respective lens groups. In the zoom lens, upon varying the power from a wide angle end to a telephoto end, the lenses are moved while increasing the distance between the first lens group and the second lens group, decreasing the distance between the second lens group and the third lens group, and decreasing the distance between the third lens group and the fourth lens group, and the zoom lens satisfies the following conditional inequalities (1) and (2): (1) 5.5<f1/fw<8.0, and (2) 0.5<Σd3/Σd4<0.9, wherein fw denotes a focal length at the wide angle end, f1 denotes the focal length of the first lens group,Σd3 denotes a real distance on an optical axis from the lens surface located closest to the object side to the lens surface located closest to the image side in the third lens group, andΣd4 denotes a real distance on an optical axis from the lens surface located closest to the object side to the lens surface located closest to the image side in the fourth lens group. COPYRIGHT: (C)2010,JPO&INPIT
|
