| 摘要 |
PROBLEM TO BE SOLVED: To achieve the miniaturization and the reduction of cost of a zoom lens. SOLUTION: The zoom lens includes: a first lens group (I) having negative refractive power and fixed when varying power and when focusing; a second lens group (II) having negative refractive power and moving when varying power and when focusing; a third lens group (III) having positive refractive power and moving when varying power; and a fourth lens group (IV) having positive refractive power and fixed when varying power and when focusing, which are arrayed in order from an object side to an image surface side. By such constitution, since the first lens group (I) and the fourth lens group (IV) positioned at both ends are fixed when performing operation for varying power and operation for focusing, the zoom lens is strong structurally and mechanical strength is secured. Then, a mechanism for moving the first lens group (I) and the fourth lens group (IV) is not required, so that the reduction of cost is achieved. COPYRIGHT: (C)2007,JPO&INPIT
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