TOKYO VISIONARY OPTICS Co., Ltd.

There is provided an imaging lens with small telephoto ratio and excellent optical characteristics which satisfies demand of the downsizing, the low-profileness and the low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive refractive power, a second lens, a third lens, a fourth lens being a double-sided aspheric lens, a fifth lens being a double-sided aspheric lens, and a sixth lens having a convex surface facing the image side, and a below conditional expression is satisfied: 0.60<TTL/ f <1.00 where TTL: a total track length, and f: a focal length of the overall optical system of the imaging lens.

An imaging lens includes: arranged in order from an object side to an image side IM, a first lens L 1 having positive refractive power; a second lens L 2 having negative refractive power; a third lens L 3 having positive refractive power; a fourth lens L 4 having negative refractive power; a fifth lens L 5 ; a sixth lens L 6 having negative refractive power; a seventh lens L 7 having negative refractive power; and an eighth lens L 8 having negative refractive power. The second lens L 2 has a convex object-side surface in a paraxial region, and the sixth lens L 6 has a concave object-side surface in a paraxial region.

There is provided an imaging lens with excellent optical characteristics while satisfying demand of wide field of view. An imaging lens comprises, in order from an object side to an image side, a first lens with negative refractive power in a paraxial region, a second lens with positive or negative refractive power having an object-side surface being concave in a paraxial region, a third lens with positive refractive power having a biconvex shape with convex surfaces on the object side and the image side in a paraxial region, and a fourth lens with positive refractive power having an image-side surface being convex in a paraxial region, and predetermined conditional expressions are satisfied.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with positive refractive power, a second lens, a third lens, a fourth lens, a fifth lens with positive refractive power, a sixth lens, and a seventh lens with negative refractive power, wherein said first lens has an object-side surface being convex in a paraxial region, and said fifth lens has an image-side surface being convex in a paraxial region, and predetermined conditional expressions are satisfied.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with negative refractive power, a second lens with positive refractive power, a third lens with positive refractive power, a fourth lens with negative refractive power, a fifth lens with positive refractive power, and a sixth lens with negative refractive power, wherein said first lens has an object-side surface being concave in a paraxial region, said fourth lens has an image-side surface being concave in a paraxial region, and said sixth lens has an image-side surface being concave in a paraxial region, and predetermined conditional expressions are satisfied.

There is provided an imaging lens with small telephoto ratio and excellent optical characteristics which satisfies demand of the downsizing, the low-profileness and the low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive refractive power, a second lens, a third lens, a fourth lens being a double-sided aspheric lens, a fifth lens being a double-sided aspheric lens, and a sixth lens having a convex surface facing the image side, and a below conditional expression is satisfied: 0.60<TTL/ f <1.00 where TTL: a total track length, and f: a focal length of the overall optical system of the imaging lens.

There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with positive refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens, a fifth lens with positive refractive power, a sixth lens with positive or negative refractive power, and a seventh lens with negative refractive power, wherein said first lens is formed in a meniscus shape having an object-side surface being convex in a paraxial region, said second lens has an image-side surface being concave in a paraxial region, said sixth lens has an image-side surface being concave in a paraxial region, and said seventh lens has an image-side surface being concave in a paraxial region, and predetermined conditional expressions are satisfied.

There is provided an imaging lens having a low profile and a low F-number and allowing satisfactory correction of aberrations. An imaging lens comprises in order from an object side, a first lens L 1 with positive refractive power, a second lens L 2 with negative refractive power, a third lens L 3 , a fourth lens L 4 with positive refractive power, and a fifth lens L 5 with negative refractive power, wherein an image-side surface of said fourth lens L 4 is convex in a paraxial region, an object-side surface of said fifth lens L 5 is an aspheric surface having at least one inflection point, and the following conditional expressions are satisfied: f /Dep<2.0  (1) 1.2< T 3/ T 2<1.8  (2) 15< vd 3<35  (3) −1.0< R 5 f/R 5 r <−0.3  (4) where f: a focal length of the overall optical system of the imaging lens, Dep: an entrance pupil diameter of the imaging lens, T2: a thickness along the optical axis X of the second lens L 2, T3: a thickness along the optical axis X of the third lens L 3, vd3: an abbe number at d-ray of the third lens L 3, R5f: a curvature radius of an object-side surface of the fifth lens L 5 , and R5r: a curvature radius of an image-side surface of the fifth lens L 5.

Provided is an imaging lens unit that is able to suppress a reduction in optical performance even if plastic lenses absorb water. The imaging lens unit includes a lens barrel formed of a resin material and first to seventh plastic lenses housed in the lens barrel. Among the first to seventh plastic lenses, at least two adjacent plastic lenses have different water absorption rates and have conical fitting slopes that are centered on an optical axis, are formed outside optical effective portions of the adjacent plastic lenses, and are fittable to each other. The fitting slope of a high-water-absorption plastic lens that has a high water absorption rate is formed outside the fitting slope of a low-water-absorption plastic lens that has a low water absorption rate.

There is provided an imaging lens with high-resolution which satisfies demand of the wide field of view, the low-profileness and the low F-number, and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having a convex surface facing the object side near an optical axis, a second lens, a third lens having negative refractive power near the optical axis, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens having a concave surface facing the image side and the negative refractive power near the optical axis, wherein an image-side surface of said eighth lens is formed as an aspheric surface having at least one pole point in a position off the optical axis, said sixth lens has positive refractive power near the optical axis, an object-side surface of said seventh lens is a convex surface facing the object side near the optical axis, and a below conditional expression (1) is satisfied: 0.15<ν d 7/ν d 8<0.55 where νd7: an abbe number at d-ray of the seventh lens, νd8: an abbe number at d-ray of the eighth lens.