Abstract: An imaging lens includes a first lens group and a second lens group, arranged in this order from an object side to an image plane side. The first lens group includes a first lens, a second lens having positive refractive power, and a third lens. The second lens group includes a fourth lens, a fifth lens, and a sixth lens. The third lens and the fourth lens are arranged in a specific configuration.

Abstract: An imaging lens includes a first lens group having positive refractive power; a second lens group having positive 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 negative 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 first to third lenses have specific Abbe's numbers.

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 at least one aspheric surface; a fifth lens having at least one aspheric surface; a sixth lens having two aspheric surfaces; and a seventh lens having two aspheric surfaces, arranged in this order from an object side to an image plane side. The first lens is formed in a shape so that both surfaces are convex near an optical axis thereof. The fourth lens is formed in a meniscus shape so that a surface thereof on the object side is concave near the optical axis. The seventh lens is formed in a shape so that a surface thereof on the image plane side is concave near the optical axis.

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; a third lens; a fourth lens; a fifth lens having negative refractive power; and a sixth lens. The first lens is formed in a shape so that a surface thereof on the object side and a surface thereof on the image plane side have positive curvature radii. The fifth lens is formed in a shape so that a surface thereof on the image plane side has a negative curvature radius. The sixth lens is formed in a shape so that a surface thereof on the image plane side has a positive curvature radius.

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 group having positive refractive power and a second 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 positive refractive power, and a third lens having negative refractive power. The second lens group includes a fourth lens having positive refractive power, a fifth lens, and a sixth lens having negative refractive power. The first lens and second lens have specific focal lengths. The first to third lenses have specific Abbe's numbers.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; and a sixth lens, arranged in this order from an object side to an image plane side. The first lens has a surface thereof on the object side having a positive curvature radius. The second lens has surfaces on the object side and the image plane side having positive curvature radii. The third lens has a surface on the object side having a positive curvature radius and a surface on the image plane side having a negative curvature radius. The fifth lens is formed has an aspheric shape surface on the object side. The sixth lens has an aspheric shape surface on the image plane side. The first to fourth lenses have refractive power weaker than that of the fifth and sixth lenses.

Abstract: An imaging lens includes a first lens group having positive refractive power and a second 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 positive refractive power, and a third lens having negative refractive power. The second lens group includes a fourth lens having positive refractive power, a fifth lens, and a sixth lens having negative refractive power. The first lens has a specific focal length. The first to third lenses have specific Abbe's numbers.

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: 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 positive refractive power; a fifth lens having negative refractive power; and a sixth lens having negative refractive power. The first to sixth lenses have specific Abbe's numbers to satisfy specific conditions.

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: An imaging lens includes a first lens group having positive refractive power; a second lens group having positive 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 having positive refractive power and a fifth lens having positive refractive power. The third lens group includes a sixth lens and a seventh lens. The first to fifth lenses have specific Abbe's numbers.

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<8.5 6<f3/f1<30.

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

Abstract: An imaging lens includes an aperture stop, a positive first lens with a biconvex shape, a negative second lens; a negative third lens, a positive fourth lens, and a negative fifth lens arranged in this order from an object side. When the whole lens system has a focal length f, focal lengths and Abbe's numbers of the first and the second lenses are f1, ?d1, f2, and ?d2, focal lengths of the fourth and fifth lenses are f4 and f5, a composite focal length of the first lens L1 and the second lens L2 is f12, and a distance from a surface of the first lens L1 on the object side to a surface of the fifth lens L5 on the image side is ?d, the imaging lens satisfies the following conditional expressions: 0.7<f12/f<1.4 0.2<|f1/f2|<0.6 15<?d1??d2 0.4<f4/f<1.0 ?d/f<1.2 |f5/f|<1.0.

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, in this order from an object side, an aperture stop ST, a positive first lens L1, a negative second lens L2 having a meniscus shape that directs a convex surface on the object side near an optical axis, a positive third lens L3, a positive fourth lens L4 having a meniscus shape that directs a concave surface on the object side near an optical axis, and a negative fifth lens L5 having a meniscus shape that directs a convex surface on the object side near an optical axis.