| 摘要 |
The present invention relates to an imaging lens, which can be suitably mounted in small-sized information terminals, such as mobile phones equipped with cameras or Personal Digital Assistants (PDAs). The imaging lens includes an iris, a first lens, a second lens, a third lens, and a fourth lens sequentially arranged in a direction from an object side. The first lens is a positive lens having positive reflective power, the second lens is a negative lens having negative reflective power, the third lens is a positive lens, which has at least one surface formed in an aspherical shape and has positive reflective power, and the fourth lens is a negative lens, which has an image side surface formed in an aspherical shape and an object side surface formed in a spherical shape, and has negative reflective power. The imaging lens is configured to satisfy the following conditional expressions ( r 3+ r 4)/( r 3- r 4)>-0.7, v 1- v 2>15.0, and v 3- v 2>15.0, where r3 is a radius of curvature of an object side surface of the second lens, r4 is a radius of curvature of an image side surface of the second lens, and v1, v2 and v3 are Abbe constants of the first, second and third lenses, respectively.
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