| 摘要 |
PURPOSE: A zoom lens is provided to improve an aberration property like distortion aberration and astigmatism by using an aspherical lens in a first negative lens group. CONSTITUTION: A zoom lens comprises a first negative lens group(I) having a negative refractive power, an aperture(S), a second positive lens group(II) having a positive refractive power, and a third positive lens group(III) having a positive refractive power. The first negative lens group includes a meniscus lens(1) having a negative refractive power, a concave lens(2) having a negative refractive power, and a convex lens(3) having a positive refractive power. The aperture is positioned between the first lens group and the second lens group. The second positive lens group includes a first convex lens(4) having a positive refractive power, a second convex lens(5) having a positive refractive power, and a concave lens(6) having a negative refractive power. The third positive lens group includes a convex lens(7).
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