| 摘要 |
PURPOSE: A zooming lens is provided to have a high scaling, to reduce a cost using a plastic aspheric lens, and to minimize the change amount of a focus location by a refraction change of the plastic lens due to a temperature variation. CONSTITUTION: In a zooming lens for a high scaling, the first lens group(I) has a positive refraction. The second lens group(II) having a positive refraction includes the first plastic aspheric lens having a positive refraction. The third lens group(III) having a negative refraction includes the second plastic aspheric lens having a negative refraction. Therefore, though a fraction of the plastic lens is changed due to a temperature change, a focus location change amount is reduced by an inter-refraction complement of the first plastic aspheric lens and the second plastic aspheric lens.
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