| 摘要 |
An image pickup lens that includes the following disposed from an object side in the order listed below: a first lens having a positive refractive power; a second lens having a negative refractive power; a third lens having a positive refractive power; and a fourth lens having an object side surface which is concave or flat adjacent to an optical axis of the lens and a negative refractive power adjacent to the optical axis, and satisfies Conditional Expression (1) given below in order to realize total length reduction and high image forming performance. 0.3<|(R4+R3)/(R4−R3)|<1.5 (1) where, R3 is a paraxial radius of curvature of an object side surface of the second lens, and R4 is a paraxial radius of curvature of an image side surface of the second lens.
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