| 摘要 |
PURPOSE: A compact zoom lens is provided to obtain a visual field at a wide angle position of over 62 degrees and has a zooming ratio of at least 2 times and a telescopic ratio of at most 1. CONSTITUTION: The zoom lens includes a first lens group(I) which has an overall positive refractive power and a second lens group(II) which has an overall negative refractive power. The first lens group further includes a first lens unit(1) which is a meniscus lens that is convex toward an object, and which has a positive refractive power with respect to the object. Also included in the first lens group(I) is a second lens unit(2) which has a negative refractive power with respect to the object. Further, the first lens group(I) includes a third lens unit(3) which is a biconvex lens having a positive refractive power with respect to the object, and which is fixed to the second lens unit. Finally, the first lens group(I) includes a fourth lens unit(4) which is a biconvex lens having a positive refractive power with respect to the object.
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