Abstract: An imaging lens includes a first lens; a second lens; and a third lens arranged from an object side to an image plane side. The first lens has an object-side surface with a positive curvature radius. The second lens has an object-side surface and an image plane-side surface with negative curvature radii. The third lens has an object-side surface and an image plane-side surface with positive curvature radii. The object-side surface and the image plane-side surface of the third lens are respectively formed as an aspheric shape having an inflexion point. When the whole lens system has a focal length f, the first lens has a focal length f1, the second lens has a focal length f2, and the third lens has a focal length f3, the imaging lens satisfies the following conditional expressions: f1<f2 1.0<f1/f<1.5 0.7<f2/f3<1.

Abstract: An imaging lens includes a first lens; a second lens; and a third lens arranged from an object side to an image plane side. The first lens has an object-side surface having a positive curvature radius R1f and an image plane-side surface having a negative curvature radius R1r. The second lens has an object-side surface and an image plane-side surface with negative curvature radii. The third lens has an object-side surface and an image plane-side surface with positive curvature radii and formed as aspheric surfaces having inflexion points. When the whole lens system has a focal length f, the first lens has a focal length f1, the second lens has a focal length f2, and the third lens has a focal length f3, the imaging lens satisfies the following conditional expressions: f1<f2<f3 1.0<f1/f<1.5 ?0.

Abstract: An image pickup lens having a relatively wide angle of field with various aberrations preferably corrected and having a small F-value is achieved. The image pickup lens is composed of, in order from an object side, an aperture stop, a first lens of a biconvex shape having a refractive power, a second lens of a meniscus shape having a negative refractive power with a concave surface facing the object side near the optical axis, a third lens of a meniscus shape having a positive refractive power with a concave surface facing the object side near the optical axis, and a fourth lens of a biconcave shape having a negative refractive power near the optical axis, wherein the image pickup lens satisfies a following conditional expression (1): 0.6<f1/f<0.8??(1) where f1 represents a focal length of the first lens, and f represents a focal length of the overall image pickup lens.

Abstract: A wide-angle image pickup lens having small F-value, high resolution, and small distortion is provided. The image pickup lens is configured from, in order from an object side to an image side, a first lens having a positive refractive power with a concave surface facing the object side, an aperture stop, a second lens having a negative refractive power with a concave surface facing the image side, a third lens having a positive refractive power, a fourth lens having a positive refractive power with a concave surface facing the object side, and a fifth lens having a negative refractive power with a concave surface facing the image side.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; and a third lens having positive refractive power, arranged in this order from an object side to an image plane side. Further, the first lens is formed in a shape so that a curvature radius of a surface thereof on the object side is positive. The second lens is formed in a shape so that a curvature radius of a surface thereof on the object side is negative and a curvature radius of a surface thereof on the image plane side is positive. The third lens is formed in a shape so that a curvature radius of a surface thereof on the object side and a curvature radius of a surface thereof on the image plane side are both positive.

Abstract: An image pickup lens includes a first lens having a positive refractive power with a convex surface facing the object side, a second lens having a negative refractive power with a concave surface facing an image side, a third lens of a meniscus shape having a convex surface facing the object side, a fourth lens of a meniscus shape having a positive refractive power with a convex surface facing the image side, and a fifth lens having a negative refractive power with a concave surface facing the image side, wherein the both surfaces of the fifth lens have an aspherical shape, and the curvature radius of the fourth lens satisfies conditional expression (13) below: 1.4<r7/r8<3.0??(13) where r7 is the curvature radius of the object-side surface of the fourth lens, and r8 is the curvature radius of the image-side surface of the fourth lens.

Abstract: An image pickup lens includes a first lens having a positive refractive power with a convex surface facing the object side, a second lens having a negative refractive power with a concave surface facing an image side, a third lens having a negative refractive power with both surfaces formed from aspheric surface, a fourth lens of a meniscus shape having a positive refractive power with a convex surface facing the image side, and a fifth lens of a meniscus shape having a negative refractive power with a concave surface facing the image side, wherein the curvature radius of the fourth lens satisfies conditional expression (13) below: 1.4<r7/r8<3.0??(13) where r7 is the curvature radius of the object-side surface of the fourth lens, and r8 is the curvature radius of the image-side surface of the fourth lens.

Abstract: Disclosed is a low-cost, compact image pickup lens for a solid-state image pickup element. The image pickup lens includes, in the order from an object side, a first lens L1, which has a convex surface facing the object side on an optical axis and has a positive refractive power; a second lens L2, which has a concave surface facing an image side on the optical axis and has a negative refractive power; a third lens L3, which has a positive refractive power and has aspheric surfaces on the object side and the image side; a fourth lens L4, which has a convex surface facing the image side on the optical axis, has a positive refractive power, and has a meniscus shape; and a fifth lens L5, which has a concave surface facing the image side on the optical axis, has a negative refractive power, and has a meniscus shape.

Abstract: An imaging lens includes a first lens and a third lens having negative refractive power, and a second lens and a fourth lens having positive refractive power. Curvature radiuses of surfaces of the first lens on an object side and an image plane side are positive. A curvature radius of a surface of the second lens on the object side is positive. Curvature radiuses of surfaces of the third lens on the object side and the image plane side are negative. Curvature radiuses of surfaces of the fourth lens on the object side and the image plane side are positive. The first lens has a focal length f1 and the second lens has a focal length f2, so that the following conditional expression is satisfied: ?0.6<f2/f1<?0.

Abstract: An image pickup lens for a solid-state image pickup element includes a first lens having a positive refractive power with a convex surface facing the object side, a second lens with concave surfaces facing the object side and an image side, a third lens of a meniscus shape having a positive refractive power with a convex surface facing the image side, and a fourth lens with concave surfaces facing the object side and the image side, wherein the image pickup lens satisfies the following conditional expressions (1),(2),(5), and (7); ?1.3<r1/r2<0.03 ??(1) 0.09<r6/r5<1.0 ??(2) ?0.16270?r8/r7??0.0049871 ??(5) 0.38659694?f3/f?0.565293 ??(7) where r1, r2: curvature radius of the first lens; r5, r6: curvature radius of the third lens; r7, r8: curvature radius of the fourth lens; f: composite focal length of an overall image pickup lens system; and f3: focal length of the third lens.