Abstract: An imaging lens includes a first lens having negative refractive power; a second lens; a third lens; a fourth lens having positive refractive power; and a fifth lens. The second lens has a surface on the object side formed in an aspheric shape. The first to fifth lenses are formed of materials having specific Abbe's numbers to satisfy specific conditions.

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 imaging lens includes a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having negative refractive power, arranged in this order from an object side to an image plane side. The first lens group includes a first lens having positive refractive power, a second lens having negative refractive power, and a third lens having positive refractive power. The second lens group includes a fourth lens and a fifth lens. The third lens group includes a sixth lens and a seventh lens. The fourth lens is formed in a shape so that a surface on the object side thereof has a negative curvature radius. The fifth lens is formed in a shape so that a surface on the image plane side thereof has a positive curvature radius. The first to third lenses have specific Abbe's numbers.

Abstract: An imaging lens includes a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having negative refractive power, arranged in this order from an object side to an image plane side. The first lens group includes a first lens having positive refractive power, a second lens having negative refractive power, and a third lens having positive refractive power. The second lens group includes a fourth lens and a fifth lens. The third lens group includes a sixth lens having positive refractive power and a seventh lens having negative refractive power. The first to third lenses and the sixth to seventh lenses have specific Abbe's numbers.

Abstract: An imaging lens includes a first lens having negative refractive power; a second lens having positive refractive power; a third lens; and a fourth lens arranged in the order from an object side to an image plane side. The first lens has an image plane-side surface having a positive curvature radius. The first lens has a specific focal length to satisfy a specific conditional expression.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having negative refractive power; and a fifth lens having object-side and image plane-side surfaces thereof being aspheric, arranged in this order from an object side to an image plane side. The first lens has a shape so that a curvature radius of a surface thereof on the object side is positive. The fifth lens has a shape so that a curvature radius of the surface thereof on the object side and a curvature radius of the surface thereof on the image plane side are positive. The second lens, the third lens, and the fourth lens are arranged so that a specific conditional expression is satisfied.

Abstract: A compact low-cost imaging lens which provides brightness with an F-value of 2.5 or less and a wide field of view and corrects aberrations properly, meeting the demand for low-profileness. The imaging lens elements are arranged in order from an object side, an aperture stop, positive first lens having convex object-side and image-side surfaces, negative meniscus second lens having a concave image-side surface, positive third lens having at least one aspheric surface, positive double-sided aspheric fourth lens, and negative double-sided aspheric fifth lens having concave object-side and image-side surfaces with its image-side surface having a pole-change point off the axis. It satisfies conditional expressions below: 0.5<f1/f<1.0??(1) 10.0<f3/f??(2) 0.8<(r3+r4)/(r3?r4)<2.

Abstract: A compact low-cost imaging lens which provides high brightness with an F-value of 2.5 or less and a wide field of view and corrects aberrations properly, meeting the demand for low-profile design. The imaging lens elements are arranged in the following order from an object side to an image side: an aperture stop; a first lens with positive refractive power having a convex surface on each of the object and image sides; a second lens with negative refractive power; a third lens with positive refractive power having a convex surface on each of the object and image sides; a fourth lens with negative refractive power; and a fifth lens with negative refractive power as a double-sided aspheric lens. The imaging lens satisfies a conditional expression (1) below: 1.5<f3/f<5.0??(1) where f: focal length of the overall optical system of the imaging lens f3: focal length of the third lens.

Abstract: An imaging lens includes a first lens having negative refractive power; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having positive refractive power; and a fifth lens having negative refractive power. The first lens has object-side and image plane-side surfaces with positive curvature radii. The second lens has object-side and image plane-side surfaces with positive curvature radii. The third lens has an object-side surface with a positive curvature radius and an image plane-side surface with a negative curvature radius. The fourth lens has an object-side surface with a positive curvature radius and an image plane-side surface with a negative curvature radius. The fifth lens has object-side and image plane-side surfaces with negative curvature radii. The first to fifth lenses have specific Abbe's numbers to satisfy specific conditions. The fifth lens has a specific focal length to satisfy specific conditions.

Abstract: An imaging lens includes a first lens having negative refractive power; a second lens having positive refractive power; a third lens having positive refractive power; a stop; and a fourth lens having positive refractive power arranged in the order from an object side to an image plane side. The first lens has an image plane-side surface having a positive curvature radius. The second lens has an image plane-side surface having negative curvature radius. The third lens has an image plane-side surface having a negative curvature radius. The fourth lens has an object-side surface having a positive curvature radius and an image plane-side surface having a negative curvature radius. The first lens has a specific focal length and a specific Abbe's number to satisfy specific conditional expressions.

Abstract: An imaging lens includes a positive first lens; a negative second lens with a meniscus lens shape directing a convex surface thereof to an object side near an optical axis; a positive third lens; a negative fourth lens with a meniscus lens shape directing a concave surface thereof to the object side near the optical axis; a negative fifth lens with a meniscus lens shape directing a convex surface thereof to the object side near the optical axis, arranged in this order from the object side. The imaging lens satisfies the following conditional expressions when the first lens has a focal length f1, the second lens has a focal length f2, the third lens has a focal length f3, the fourth lens has a focal length f4, and the fifth lens has a focal length f5: f1<f3 and |f2|<f3 f3<|f4| and |f2|<|f5|.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having positive refractive power; and a third lens having positive refractive power, arranged in the order from an object side to an image plane side. The first lens and the third lens have object-side surfaces and image plane-side surfaces, curvature radii of which are both positive. When the first lens has refractive power P1, the second lens has refractive power P2, the third lens has refractive power P3, the first lens has a focal length f1, and the third lens has a focal length f3, the imaging lens satisfies the following conditional expressions: 5.0<(P1+P3)/P2<8.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having positive refractive power; and a third lens having negative refractive power, arranged in the order from an object side to an image plane side. The first lens and the third lens respectively have an object-side surface and an image plane-side surface whose curvature radii are both positive. The second lens has an image plane-side surface whose a curvature radius is negative. In addition, when the first lens has refractive power P1, the second lens has refractive power P2, the third lens has refractive power P3, the curvature radius of the image plane-side surface of the second lens is R2r, and the curvature radius of the object-side surface of the third lens is R3f, the imaging lens satisfies specific conditional expressions.

Abstract: An image pickup lens includes an aperture stop, a first lens with positive refractive power having a convex object-side surface, a second meniscus lens having a concave image-side surface, a third meniscus lens having a convex image-side surface, a fourth meniscus lens having a concave object-side surface near an optical axis, and a fifth meniscus lens having a concave image-side surface near the optical axis, wherein the image-side surface of the fourth lens has an aspherical shape in which a positive refractive power weakens toward the periphery, and wherein the following conditional expressions (1) and (7) are satisfied: 0.55<f1/f<1.0??(1) ?1.6<f2/f<?0.7??(7) where f represents a focal length of an overall image pickup lens, f1 represents a first lens focal length, and f2 represents a second lens focal length.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; and a fourth and a fifth lens having negative refractive power. The first lens is formed so that a curvature radius of an object-side surface is positive and the second lens is formed so that a curvature radius of an object-side surface and a curvature radius of an image plane-side surface are positive. The third lens is formed so that a curvature radius of an object-side surface is positive, and the fifth lens is formed so that a curvature radius of an object-side surface and a curvature radius of an image plane-side surface are both positive. An Abbe's number from the first and the third to the fifth lens is greater than 45, and an Abbe's number of the second lens is less than 35.

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<?0.1.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having negative refractive power; a fourth lens having positive refractive power; and a fifth lens having negative refractive power, arranged in this order from an object side to an image plane side. The first lens has an Abbe's number ?d1, the second lens has an Abbe's number ?d2, and the fourth lens and the fifth lens have a composite focal length f45 so that the following conditional expressions are satisfied: 45<?d1<75, 20<?d2<35, ?10.0<f45/f<?1.0, where f is a focal length of a whole lens system.

Abstract: An imaging lens includes an object-side lens group having positive refractive power; an aperture stop; and an image plane-side lens group having positive refractive power, arranged in this order from an object side to an image plane side. The object-side lens group includes a first lens having positive refractive power; a second lens having negative refractive power; and a third lens having positive refractive power. The image plane-side lens group includes a fourth lens having positive refractive power; and a fifth lens having negative refractive power. The first lens has an aspheric shape to have negative refractive power increasing toward a lens periphery from an optical axis, and has a surface on the object side having a positive curvature radius. The first to third lenses have specific focal lengths to satisfy specific conditions. The first to fifth lenses have specific Abbe's numbers to satisfy specific conditions.

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 negative refractive power; a second lens having positive refractive power; a third lens having positive refractive power; a stop; and a fourth lens having positive refractive power arranged in the order from an object side to an image plane side. The first lens has an image plane-side surface having a positive curvature radius. The second lens has an image plane-side surface having negative curvature radius. The third lens has an image plane-side surface having a negative curvature radius. The fourth lens has an object-side surface having a positive curvature radius and an image plane-side surface having a negative curvature radius. The first lens has a specific focal length and a specific Abbe's number to satisfy specific conditional expressions.