| 摘要 |
<p>An imaging lens having a smaller size than lenses of conventional type and having excellently corrected aberrations. The imaging lens comprises in order from the object side an aperture stop, a first lens provided with a positive refractive power and having a convex surface facing the object side, a second lens having a negative refractive power and having a concave surface facing the image side, a third lens provided with a positive refractive power and having a convex surface facing the image side, a fourth lens having a positive refractive power, having a convex surface facing the image side, and formed in a meniscus shape, and a fifth lens provided with a negative refractive power and having a concave surface facing the image side, and the imaging lens satisfies the following conditional expressions: 2.0 < (r7 + r8)/(r7 - r8) < 8.0 and 0.8 < SL/f < 1.5, where r7 is the curvature radius of the object-side surface of the fourth lens, r8 is the curvature radius of the image-side surface of the fourth lens, SL is the distance on the optical axis from the aperture stop to the image-side focal point, and f is the focal distance of the entire imaging lens system.</p> |
