| 摘要 |
An imaging lens is provided and includes: a positive first lens with a convex surface directed to the object side; a second lens having a negative meniscus shape with a concave surface directed to the image side; a third lens having a positive meniscus shape with a convex surface directed to the image side; a negative fourth lens with both surfaces being an aspheric surface and the image-side surface being concave in the proximity of the optical axis; and a positive or negative fifth lens with both surfaces being an aspheric surface, in order from the object side. The following conditional expressions are satisfied as for Abbe numbers vd1 and vd2of the first lens and the second lens and Abbe number vd4 of the fourth lens. <?in-line-formulae description="In-line Formulae" end="lead"?>vd1>50 (1)<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>vd2<30 (2)<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>vd4<30 (3)<?in-line-formulae description="In-line Formulae" end="tail"?>
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