Abstract: Disclosed is a small lens system including a first lens, a second lens, and a third lens sequentially arranged from an object along an optical axis, wherein the thickness (ct1) of the first lens, the thickness (ct3) of the second lens, and the thickness (ct5) of the third lens satisfy ct1/ct3>1.5 and ct1/(ct3+ct5)>0.8, the refractive power (P2) of the second lens satisfies ?0.01<P2<0.01, the lens thickness (et) at a predetermined height and the center thickness (ct) of the second lens thereof satisfy |et?ct|<5 ?m up to 30% of the height of the rear effective diameter thereof and satisfy et?ct<?20 ?m at 70% of the height of the rear effective diameter thereof, and the f-number of the lens system is less than 1.7.

Abstract: Disclosed is a small lens system including a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from an object along an optical axis, wherein the thickness (ct1) of the first lens, the thickness (ct3) of the second lens, the thickness (ct5) of the third lens, and the thickness (ct7) of the fourth lens satisfy ct1+ct3>ct5+ct7, ct1>ct3, ct1>ct5, and ct1>ct7, the front surface of the first lens is convex toward the object while the SAG amount of the first lens is increased depending on the height thereof, the refractive power (P2) of the second lens satisfies ?0.01<P2<0.01, the front curvature (C3) and the rear curvature (C4) of the second lens satisfy |C3|<0.1 and |C4|<0.1, and the f-number of the lens system is less than 1.4.

Abstract: The present invention relates to a high-resolution wide angle lens system consisting of a total of six lens, wherein the first lens has a negative refractive power, the second lens has a positive refractive power, the third lens has a positive or negative refractive power, the fourth lens has a positive or negative refractive power, the fifth lens has a positive or negative refractive power with a concave shape on an object side and a convex shape on an image side, and the sixth lens has a positive or negative refractive power, and the system is satisfied with 0<|f/f5|<1 (herein, f represents an effective focal length of the entire lens system, and f5 represents an effective focal length of the fifth lens).

Abstract: A small wide-angle lens system having six lenses is proposed. In the lens systems, a first lens is biconvex toward a focal object, with center thickness (Tc) and thickness (Te) of the outermost effective diameter satisfying 1.1<Tc/Te<1.5, and a refractive power (P1) satisfying ?0.06<P1<0.06. A second lens has a positive refractive power, a front surface convex toward the focal object, and a radius of curvature (R4) of the rear surface satisfying 10<|R4|. A third lens has a negative refractive power, a rear surface concave toward an image and a radius of curvature (R5) of the front surface satisfying 10<|R5|. A distance interval (T12) in an effective diameter of the first and second lenses satisfies T12<0.2 mm, and a distance interval (T23) within an effective diameter of the second and third lenses satisfies T23<0.1 mm.

Abstract: A small lens system having five lenses arranged along an optical axis from a focal object side in order of a first, a second, a third, a fourth, and a fifth lens is proposed. A center interval (T12c) of the first and the second lens is T12c<0.2 mm, and an effective outermost interval (T12e) satisfies T12e<0.2 mm. The fifth lens has a positive refractive power, a front surface convex toward the focal object, a rear curvature (C10) satisfying ?0.01<C10<0.01, and the periphery of a rear surface convex upwards. A center interval (T45c) of the fourth and the fifth lens is T45c<0.1 mm and an effective outermost distance (T45e) thereof satisfies T45e>0.35 mm. Thicknesses of each lens from the first to the fifth lens and a distance (TL) from the front to the rear surface of the lens system satisfy (ct1+ct2+ct3+ct4+ct5)/TL<0.47.

Abstract: A telephoto lens system having a plurality of lenses toward a focal object is proposed. The system includes a first lens with a positive refractive power, a second lens with a negative refractive power, a third lens with a negative refractive power, a fourth lens with a negative refractive power, and a fifth lens with a positive refractive power. A refractor bending an optical axis is provided between the second lens and the third lens. The angle (A) between the optical axes of the second lens and the third lens satisfies 80°?A?86°. A barrel surrounding the first lens is provided by protruding more toward the focal object than the first lens. The inner diameter of the barrel is smaller than or equal to the effective diameter of the first lens, and a stop is arranged toward the focal object of the first lens.

Abstract: A small lens system having five lenses arranged along an optical axis from a focal object side in order of a first, a second, a third, a fourth, and a fifth lens is proposed. A center interval (T12c) of the first and the second lens is T12c<0.2 mm, and an effective outermost interval (T12e) satisfies T12e<0.2 mm. The fifth lens has a positive refractive power, a front surface convex toward the focal object, a rear curvature (C10) satisfying ?0.01<C10<0.01, and the periphery of a rear surface convex upwards. A center interval (T45c) of the fourth and the fifth lens is T45c<0.1 mm and an effective outermost distance (T45e) thereof satisfies T45e>0.35 mm. Thicknesses of each lens from the first to the fifth lens and a distance (TL) from the front to the rear surface of the lens system satisfy (ct1+ct2+ct3+ct4+ct5)/TL<0.47.

Abstract: A small wide-angle lens system having six lenses is proposed. In the lens systems, a first lens is biconvex toward a focal object, with center thickness (Tc) and thickness (Te) of the outermost effective diameter satisfying 1.1<Tc/Te<1.5, and a refractive power (P1) satisfying—0.06<P1<0.06. A second lens has a positive refractive power, a front surface convex toward the focal object, and a radius of curvature (R4) of the rear surface satisfying 10<|R4|. A third lens has a negative refractive power, a rear surface concave toward an image and a radius of curvature (R5) of the front surface satisfying 10<|R5|. A distance interval (T12) in an effective diameter of the first and second lenses satisfies T12<0.2 mm, and a distance interval (T23) within an effective diameter of the second and third lenses satisfies T23<0.1 mm.

Abstract: A telephoto lens system having a plurality of lenses toward a focal object is proposed. The system includes a first lens with a positive refractive power, a second lens with a negative refractive power, a third lens with a negative refractive power, a fourth lens with a negative refractive power, and a fifth lens with a positive refractive power. A refractor bending an optical axis is provided between the second lens and the third lens. The angle (A) between the optical axes of the second lens and the third lens satisfies 80°?A?86°. A barrel surrounding the first lens is provided by protruding more toward the focal object than the first lens. The inner diameter of the barrel is smaller than or equal to the effective diameter of the first lens, and a stop is arranged toward the focal object of the first lens.

Abstract: The present invention relates to a high-resolution wide angle lens system consisting of a total of six lens, wherein the first lens has a negative refractive power, the second lens has a positive refractive power, the third lens has a positive or negative refractive power, the fourth lens has a positive or negative refractive power, the fifth lens has a positive or negative refractive power with a concave shape on an object side and a convex shape on an image side, and the sixth lens has a positive or negative refractive power, and the system is satisfied with 0<|f/f5|<1 (herein, f represents an effective focal length of the entire lens system, and f5 represents an effective focal length of the fifth lens).

Abstract: A photographic lens system includes first to sixth lenses arranged sequentially from an object along the optical axis. The first lens has positive refractive power, the second lens is meniscus shaped and has negative refractive power, the third lens has an upwardly-convex shape and positive refractive power, the fourth lens has an upwardly-convex shape and negative refractive power, the fifth lens has positive refractive power, and the sixth lens has negative refractive power. The photographic lens system satisfies ?10<f2/f1<0 and L2te/L2tc<L16tc. The radius of curvature of an object-side lens surface of the third lens has a negative value, and the radius of curvature of an image-side surface of the third lens has a negative value. This reduces the tightness of manufacturing tolerance while reducing the size and weight of the lens system, thereby improving the reproducibility of performance of the lens system.

Abstract: A wide-angle photographic lens system enabling correction of distortion composed of three lenses, in which a first lens, an iris, a second lens and a third lens sequentially arranged along an optical axis from an object, wherein the first lens has weak refractivity, the second lens has strong positive refractivity, and the third lens has negative refractivity, wherein the lens system satisfies relations, |f1/f|>2.8, f2/f<1, and te/tc<0.4, wherein f1 is a focal length of the first lens, f is a total focal length of all the lenses, f2 is a focal length of the second lens, te is a lens thickness on an effective diameter of a rear surface of the second lens, and tc is a center thickness of the second lens.