| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a three-group zoom lens or the like where respective lens groups have lens components two by two, and which is advantageous in terms of securement of a variable power ratio, brightness and optical performance. Ž<P>SOLUTION: The three-group zoom lens comprises the lens groups having negative, positive and positive power in order from an object side to an image side. When varying power from a wide angle end to a telephoto end, the second lens group moves to narrow a space between the first lens group and the second lens group and to widen a space between the second lens group and the third lens group. The first lens group comprises two lens components, that is, a negative front side lens component and a positive rear side lens component in order from the object side. The second lens group comprises two lens components, that is, a positive front side lens component and a negative rear side lens component in order from the object side. The third lens group comprises two lens components, that is, a front side lens component and a positive rear side lens component in order from the object side. A brightness diaphragm is arranged nearer to an image side than the first lens group and nearer to the object side than the rear side lens component in the second lens group, and moves in an optical axis direction integrally with the second lens group when varying power from the wide angle end to the telephoto end. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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