Abstract: An optical lens, in order from an object side to an image-forming side, includes: a first lens having negative refractive power, a second lens having positive refractive power, a third lens having positive refractive power, a fourth lens having refractive power, and a fifth lens having refractive power. The fourth lens may be positive refractive power, or the fourth lens may have a fourth object-side surface which curves toward the image-forming side. The fifth lens may be negative refractive power, and a spacing may be between the fourth lens and the fifth lens.

Abstract: A wide-angle lens assembly includes a first lens group with negative refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, a fourth lens group with positive refractive power and a fifth lens group with positive refractive power. The first lens group includes a first lens, the second lens group includes a second lens, and the third lens group includes a third lens. The wide-angle lens assembly satisfies: 0.5<|fLG4/fLG5|<1.8, where fLG4 is an effective focal length of the fourth lens group, and fLG5 is an effective focal length of the fifth lens group.

Abstract: An objective optical system includes, in order from an object side to an image side, a front group having a negative refractive power, an aperture stop, and a rear group having a positive refractive power. The front group includes a negative single lens, the rear group includes, in order from the object side, a positive single lens and one or more cemented lenses, and following conditional expressions (1), (2), (3), and (5) are satisfied. 1.95<ndCLn (1), 35<??dCL (2), 1.1<fL2/ft<1.6 (3), ?7<R1/ft<?3.6 (5).

Abstract: A five-piece optical lens system with a wide field of view includes, in order from the object side to the image side: a first lens element with a negative refractive power, a stop, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power, a fifth lens element with a negative refractive power, a radius of curvature of an object-side surface of the second lens element is R3, a radius of curvature of an image-side surface of the second lens element is R4, focal lengths of the system, first, second and fourth lens elements are f, f1, f2, f4, respectively, satisfying the relations: 1.9 mm<f+(R3+R4)/(R3?R4)<2.9 mm, ?2.0 mm<f1/(f2*f4)<?1.2 mm. Such arrangements can provide a five-piece optical lens system which has a wide field of view, high resolution, short length and less distortion.

Abstract: An endoscope objective optical system consists of a front group having a negative refractive power, an aperture stop, and a rear group having a positive refractive power. The front group consists of a first lens having a negative refractive power, and a second lens having a positive refractive power, and the rear group consists of a third lens having a positive refractive power, a cemented lens of a fourth lens having a positive refractive power and a fifth lens having a negative refractive power, and a sixth lens having a positive refractive power. An object-side surface of the first lens is a flat surface, and the second lens has a meniscus shape with a convex surface directed toward an image side, and the sixth lens is cemented to an image pickup element, and the following conditional expression (1) is satisfied: ?1.2?D6/F12??0.47??(1).

Abstract: An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. At least one lens among the first to the fifth lenses has positive refractive force. The fifth lens can have negative refractive force, wherein both surfaces thereof are aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the fifth lenses. The optical image capturing system can increase aperture value and improve the imagining quality for use in compact cameras.

Abstract: Present invention provides an electronic device and an optical imaging lens thereof. The optical imaging lens comprises a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element positioned in an order from an object side to an image side along an optical axis. The first lens element has negative refractive power, the second lens element has a convex portion formed on the object side surface and a concave portion formed on the image side surface, the third lens element has a convex portion formed on the object side surface and the fifth lens element has a convex portion formed on the image side surface. Through controlling the convex or concave shape of the surfaces, designing parameters satisfying an inequality and/or the refracting power of the lens elements, the field of view is broadened, and the better image performance is maintained.

Abstract: A photographing optical lens assembly includes five lens elements with refractive power, in order from an object side to an image side. The first lens element with refractive power has a convex object-side surface. The second lens element with positive refractive power has an object-side surface and an image-side surface both being aspheric. The third lens element has positive refractive power. The fourth lens element with refractive power has a concave object-side surface. The fifth lens element with refractive power has an object-side surface and a concave image-side surface with at least one inflection point, both the object-side surface and the image-side surface being aspheric.

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 substantially consists of a first lens-group, a stop and a second lens-group in this order from an object-side. The first lens-group substantially consists of three or less lenses including at least one negative lens and a positive lens. The second lens-group substantially consists of a 21st lens-group and a 22nd lens-group in this order from the object-side. The 21st lens-group substantially consists of three or less lenses and has positive refractive-power. The 22nd lens-group substantially consists of two lenses of a negative lens and a positive lens in this order from the object-side. Predetermined conditional formulas about distance on an optical-axis from a most-object-side lens surface in an entire system to an image-plane, maximum image height, distance on the optical-axis from a most-object-side lens surface in the first lens-group to a most-image-side lens surface in the second lens-group, and focal-length of the entire system are satisfied.

Abstract: An imaging lens includes first to fifth lens elements arranged from an object side to an image side in the given order. Through designs of surfaces of the lens elements and relevant optical parameters, a short system length of the imaging lens may be achieved while maintaining good optical performance.

Abstract: An imaging lens includes a first lens having negative refractive power; a stop; a second lens having positive refractive power; a third lens having negative refractive power; 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 object-side surface and an image plane-side surface, curvature radii of which are both negative. The second lens has an object-side surface and an image plane-side surface, curvature radii of which are both positive. The third lens has an object-side surface and an image plane-side surface, curvature radii of which are both negative. The fourth lens has an object-side surface, a curvature of which is positive.

Abstract: An optical imaging lens set includes a first lens with positive refractive power and a convex object-side surface, a second lens element with negative refractive power and an image-side surface with a concave portion in a vicinity of its periphery, a third lens element has an object-side surface with a concave portion in a vicinity of its periphery, a fourth lens element with positive refractive power, a concave object-side surface and a convex image-side surface, a fifth lens element with an object-side with a convex portion in a vicinity of the optical axis, an image-side surface with a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of its periphery.

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 substantially consists of six lenses of a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens and a positive sixth lens in this order from an object side. When a curvature radius of an object-side surface of the fourth lens is R8, and a curvature radius of an image-side surface of the fourth lens is R9, and an Abbe number of the material of the third lens for d-line is ?d3, and an Abbe number of the material of the fifth lens for d-line is ?d5, the following conditional formulas (1) and (6) are satisfied: ?0.61<(R8+R9)/(R8?R9)<0.44??(1); and 38.1<?d3+?d5<45.1??(6).

Abstract: An imaging lens includes a first lens group having negative refractive power; a stop; and a second lens group having positive refractive power, arranged in the order from the object side to the image plane side. The first lens group includes a first lens having a strong concave surface facing the image plane side and negative refractive power; and a second lens having negative refractive power and a biconcave lens shape near the optical axis. The first lens group has a focal length F1, the second lens group has a focal length F2, the first lens has a focal length f1, and the second lens has a focal length f2 so that the following conditional expressions are satisfied: ?1.0<F1/F2<?0.5 0.2<f1/f2<1.5.

Abstract: A variable-magnification projection optical system substantially consists of a negative first lens group that is disposed at the most enlargement-side position and is fixed during magnification change, a positive last lens group that is disposed at the most reduction-side position and is fixed during magnification change, and a plurality of lens groups that are disposed between the first lens group and last lens group and are moved during magnification change. The lens groups that are moved during magnification change substantially consist of three lens groups, wherein the most enlargement-side lens group is a negative lens group. Predetermined conditional expressions relating to a back focus of the entire system on the reduction side at the wide-angle end, a focal length of the entire system at the wide-angle end, a focal length of the last lens group, and a focal length of the first lens group are satisfied.

Abstract: A variable-magnification projection optical system substantially consists of a negative first lens group that is disposed at the most enlargement-side position and is fixed during magnification change, a positive last lens group that is disposed at the most reduction-side position and is fixed during magnification change, and a plurality of lens groups that are disposed between the first lens group and last lens group and are moved during magnification change. The most enlargement-side lens group (the second lens group) of the lens groups that are moved during magnification change has a negative refractive power. Predetermined conditional expressions relating to a back focus of the entire system on the reduction side at the wide-angle end, a focal length of the entire system at the wide-angle end, a focal length of the second lens group and a focal length of the last lens group are satisfied.

Abstract: A lens for projection substantially consists of a negative first lens with its concave surface facing a reduction side, a positive second lens with its concave surface facing the reduction side, a negative third lens with its concave surface facing a magnification side, a positive fourth lens with its convex surface facing the reduction side, a positive fifth lens and a positive sixth lens in this order from the magnification side. The reduction side is telecentric. The following conditional formulas (1) and (2) about refractive power P4 of a reduction-side surface of the second lens, refractive power P5 of a magnification-side surface of the third lens, and focal length f of an entire system are satisfied: ?3.0?1/(P4×f)??0.4 ??(1); and ?2.0?1/(P5×f)??0.2 ??(2).

Abstract: A projection lens unit for a pico-projector includes a plurality of plastic lenses and a single glass lens to minimize a change in focal length due to the heat generated inside the pico-projector. The lens array includes: a 1st lens with negative (?) refractive power, a 2nd lens with positive (+) refractive power, a 3rd lens with negative (?) refractive power, a 4th lens with negative (?) refractive power, and a 5th lens with positive (+) refractive power, wherein the 1st to 5th lenses are arranged in order from a screen upon which an image is projected, the 1st to 4th lenses are plastic lenses and the 5th lens is a glass lens.

Abstract: An imaging lens assembly comprises a fixing diaphragm and an optical set including five lenses. An arranging order from an object side to an image side is: a first lens; a second lens; a third lens having a lens with a positive refractive power defined near the optical axis and a convex surface directed toward the image side; a fourth lens having a lens with a positive refractive power defined near the optical axis and a convex surface directed toward the image side; and a fifth lens having a concave surface with a corrugated contour directed toward the image side and disposed near the optical axis. At least one surface of the five lenses is aspheric. By the concatenation between the lenses and the adapted curvature radius, thickness, interval, refractivity, and Abbe numbers, the assembly attains a big diaphragm with ultra-wide-angle, a shorter height, and a better optical aberration.

Abstract: An imaging lens consists of a first-lens having a meniscus-shape with its convex-surface facing an object-side and negative-refractive-power and second through fifth lenses, at least one of the surfaces of each of which is aspherical. An image-side surface of the second-lens has a concave-shape facing an image-side. The second-lens has negative-refractive-power. An object-side surface of the third-lens has a convex-shape facing the object-side. The third-lens has positive-refractive-power. An image-side surface of the fourth-lens has a convex-shape facing the image-side. The fourth-lens has positive-refractive-power. The fifth-lens has a meniscus-shape with its convex-surface facing the image-side and negative-refractive-power.

Abstract: Arranging a negative first lens, a positive second lens, a negative third lens, a positive fourth lens, and a negative fifth lens from the object side, in which the image side surface of the fifth lens has an aspherical shape with one or more inflection points and a concave shape toward the image side in a paraxial region, and, when the focal length of the entire lens system, radius of curvature of the image side surface of the first lens, radius of curvature of the image side surface of the second lens, overall optical length, focal length of jth lens, and Abbe number of jth lens are taken as f, R2, R4, TL, fj, and ?j respectively, the image capturing lens is configured to simultaneously satisfy conditional expressions (1a): ?1.5<f/R2<1.6, (2a): ?1.6<f/R4<0.05, (3a): 0.95?f4/f?4.3, (5a): 1.0?TL/f?2.2, and (12b): ?2.0<?(fj/?j)/f<0.5.

Abstract: Arranging a negative first lens, a positive second lens, a negative third lens, a positive fourth lens, and a positive fifth lens from the object side, in which the image side surface of the fifth lens has an aspherical shape with one or more inflection points and a concave shape toward the image side in a paraxial region, and, when the overall optical length, focal length of the entire lens system, focal length of the first lens, distance between image side surface of the second lens and object side surface of the third lens, refractive index of the second lens, and refractive index of the third lens are taken as TL, f, f1, Dg2-3, N2, and N3 respectively, the image capturing lens is configured to simultaneously satisfy conditional expressions (1a): 1.0?TL/f?1.8, (2a): 0.09<Dg2-3/f, (3a): 0.07<|N2?N3|, and (4a): ?35?f1/f??2.3.

Abstract: An imaging lens assembly comprises a fixing diaphragm and an optical set including five lenses. An arranging order from an object side to an image side is: a first lens; the fixing diaphragm; a second lens; a third lens; a fourth lens; and a fifth lens. At least one surface of the five lenses is aspheric. By the concatenation between the lenses and the adapted curvature radius, thickness/interval, refractivity, and Abbe numbers, the assembly attains a big diaphragm with wide-angle, a shorter height, and a better optical aberration.

Abstract: An imaging lens substantially consists of a first-lens-group, a stop and a second-lens-group in this order from object-side. The first-lens-group substantially consists of a 1-1st-lens having negative-refractive-power and a meniscus-shape with its convex-surface facing object-side and a 1-2nd-lens having positive-refractive-power, and an object-side-lens-surface of which has a convex-shape facing object-side, in this order from object-side.

Abstract: A wide field optically athermalized orthoscopic lens system includes, in order from object to image, a first lens having a negative power, a second lens having a positive power, a third lens group having a positive power, a fourth lens having a positive power and a fifth lens having a negative power. The third lens group includes two lenses having, in order, a first lens with positive power and a second lens with negative power. The powers, shapes, Abbe dispersion values and temperature coefficients of refractive indices of the lenses are selected such that the lens system is athermalized, orthoscopic and achromatized over a wide (e.g. >140° C.) temperature range.

Abstract: According to exemplary embodiments of the present invention, an imaging lens includes, in an ordered way from an object side, 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, a fifth lens having negative (?) refractive power, and a sixth lens having negative (?) refractive power, wherein, a conditional expression of 0.5<Y6/Y10<0.55 is satisfied, where a height of a point 60% of a highest height of an image-forming surface is Y6, a full size of an opposite angle within an active area of an image sensor is Y10.

Abstract: The present invention provides a wide-viewing-angle imaging lens assembly comprising, in order from an object side to an image side: a front lens group, a stop, and a rear lens group. The front lens group comprises, in order from the object side to the image side: a first lens element with negative refractive power having a concave image-side surface and a second lens element. The rear lens group comprises, in order from the object side to the image side: a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface, a fourth lens element with positive refractive power having a convex object-side surface and a convex image-side surface, and a fifth lens element with negative refractive power having a concave object-side surface. Such an arrangement of optical elements can effectively enlarge the field of view of the wide-viewing-angle imaging lens assembly, reduce the sensitivity of the optical system, and obtain good image quality.

Abstract: A miniature image pickup lens includes a first lens, a second lens, a third lens, an aperture, a fourth lens, and a fifth lens in sequence along an optical axis from an object side to an image side. The first lens is a meniscus lens with negative refractive power and has a convex side facing the object side. The first lens has at least an aspheric side. The second lens is a biconvex lens with positive refractive power. The third lens is a biconcave lens with negative refractive power. The fourth lens is a biconvex lens with positive refractive power and has at least an aspheric side. The fifth lens has a negative refractive power.

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: A wide-angle image capturing lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element and each of the first through fifth lens elements is single and non-cemented. The first lens element with negative refractive power has a concave image-side surface. The second lens element with refractive power has a concave object-side surface and a convex image-side surface. The third lens element has positive refractive power. The fourth lens element has negative refractive power, wherein at least one of an object-side surface and an image-side surface of the fourth lens element is aspheric. The fifth lens element with positive refractive power has a convex image-side surface, wherein at least one of an object-side surface and the image-side surface of the fifth lens element is aspheric.

Abstract: A slim lens assembly includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is a convex-concave lens with negative refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The second lens is with positive refractive power. The third lens is a biconcave lens with negative refractive power. The fourth lens is a biconvex lens with positive refractive power. The fifth lens is a convex-concave lens with negative refractive power and includes a convex surface facing the object side and a concave surface facing the image side.

Abstract: An optical system includes a negative lens unit including one or more negative lenses located closest to an object side, and a positive lens unit having positive refractive power including a plurality of lenses on an image side of the negative lens unit. When the one or more negative lenses are denoted by negative lenses LNi (i=1, 2, . . . ) in order from the object side, and a portion of lenses among the plurality of the lenses constituting the positive lens unit is denoted by lenses LAj (j=1, 2, . . . ) in order from the object side, a focal length fni of the negative lens LNi, a refractive index Nni of a material thereof, a focal length fAj of the lens LAj, a refractive index NAj, and partial dispersion ratio ?gFAj of a material of the lens LAj are set to satisfy respective predetermined conditions.

Abstract: An imaging lens consists of a negative first lens having a concave object-side surface, a positive second lens, a negative third lens, a positive fourth lens having a convex object-side surface, and a positive fifth lens, which are in this order from an object side. A stop is arranged between an image-side surface of the first lens and an object-side surface of the third lens. When the focal length of an entire system is f, and the focal length of the first lens is f1, and the focal length of the second lens is f2, the following formula is satisfied: ?1.30<f1/f2>?0.65??(7).

Abstract: The present invention provides a wide-angle imaging lens assembly comprising, in order from an object side to an image side: a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a second lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a third lens element with positive refractive power; a fourth lens element with negative refractive power having a concave image-side surface; and a fifth lens element with positive refractive power; wherein the two lens elements with refractive power closest to the object side are the first lens element and the second lens element; and wherein the number of lens elements with refractive power does not exceed six.

Abstract: The present invention provides a wide-angle optical system constituted of, in order from the object side to the image side, front group 11, stop 12, and rear group 13. The front group 11 is constituted, in order from the object side to the image side, of first lens 111 having negative optical power, second lens 112 having negative optical power, and third lens 113 having positive optical power. The rear group 13 is constituted, in order from the object side to the image side, of fourth lens 131 having positive optical power, and fifth lens 132 having negative optical power. The opposite surface from the stop of each of the paired lenses 113 and 131 arranged at the both sides of the stop 12 is a convex surface.

Abstract: This invention provides an optical image capturing lens system comprising: a negative first lens element having a convex object-side surface and a concave image-side surface at the paraxial region; a positive second lens element; a negative third lens element; a positive fourth lens element having a convex image-side surface at the paraxial region; and a negative plastic fifth lens element having a convex object-side surface at the paraxial region as well as a concave at the paraxial region and convex at the peripheral region image-side surface, at least one of the object-side and image-side surfaces being aspheric. The optical image capturing lens system of the present invention effectively increases the angle of view to a proper range and suppresses the distortion. In addition, the present invention has a tighter arrangement of the lens elements and a smaller back focal length, and therefore is more appropriate for the compact device.

Abstract: An imaging lens, an optical apparatus equipped therewith, and a method for manufacturing the imaging lens are disclosed. An imaging lens consists of, in order from an object, a front group having negative power, and a rear group including a sub-lens group having negative power. At least a portion of the sub-lens group is movable in a direction including a component substantially perpendicular to an optical axis. The sub-lens group includes, in order from the object, a first negative component having negative power, a second negative component having negative power and a positive component having positive power. The shape of an air lens formed by the first negative component and the second negative component is a double convex shape. An antireflection coating is applied on at least one optical surface of the front group, and the antireflection coating including at least one layer formed by use of a wet process.

Abstract: An photographing optical lens assembly includes, in order from an object side to an image side, a first lens element with negative refractive power including a convex object-side surface, a second lens element with positive refractive power, a third lens element with positive refractive power including a concave object-side surface and a convex image-side surface, a fourth lens element with negative refractive power includes a concave object-side surface and a convex image-side surface, and a fifth lens element with positive refractive power including an image-side surface, an object-side surface and at least one inflection point. At least one of the object-side surface and the image-side surface of the fifth lens element is aspheric. By adjusting the photographing optical lens assembly, the total length of the photographing optical lens assembly is reduced, the aberration is corrected, and the image quality is improved.

Abstract: This invention provides an image capturing lens assembly in order from an object side to an image side comprising five lens elements with refractive power: a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface, a second lens element with positive refractive power having a convex image-side surface, a third lens element with positive refractive power having a convex object-side surface, a fourth lens element with negative refractive power having a convex object-side surface and a concave image-side surface; and a fifth lens element with positive refractive power. By such arrangement, sufficient field of view is provided, and the aberration of the lens assembly is corrected for obtaining higher image resolution.

Abstract: A miniaturized lens assembly includes a first lens, a stop, a second lens, a third lens, a fourth lens and a fifth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is made of plastic material, is a meniscus lens with negative refractive power, and includes a convex surface facing the object side. The second lens is made of plastic material and is a biconvex lens with positive refractive power. The third lens is made of glass material and is a biconvex lens with positive refractive power. The fourth lens is made of glass material, is a biconcave lens with negative refractive power, and is adhered to the third lens to form a compound lens. The fifth lens is made of plastic material, is provided with positive refractive power, and includes an aspheric surface.

Abstract: An imaging lens includes a first lens having negative refractive power; a second lens having negative refractive power; a third lens; a fourth lens; and a fifth lens. The first lens has a positive curvature radius on an image plane side. The second lens has a sharp convex surface, and a positive curvature radius on the image plane side. The third lens has a positive curvature radius on the object side and a negative curvature radius on the image plane side. The fourth lens has a negative curvature radius on the object side and a positive curvature radius on the image plane side. The fifth lens has a positive curvature radius on the object side and a negative curvature radius on the image plane side, and an aspheric surface.

Abstract: An image-forming lens includes, in order from an object side to an image side, a first group having a negative power as a whole, the first group consisting of a positive meniscus lens having a convex surface on the object side and a negative meniscus lens having a convex surface on the object side, the positive meniscus lens and the negative meniscus lens being cemented, an aperture stop, a second group consisting of a positive meniscus lens having a convex surface on the image side, a third group consisting of a positive meniscus lens having a convex surface on the image side, a fourth group consisting of a lens having a negative power, and a fifth group consisting of a biconcave lens.

Abstract: A projection lens consists of first and second les groups and a stop. The first lens group is formed of a negative lens. The second lens group is formed of three positive lenses and a negative lens. The stop is disposed between the first and second lens groups or in the second lens group. The first and second lens groups are arranged in order from a magnification side. The projection lens is telecentric on a reduction side. The projection lens is configured to satisfy the following conditional expressions (1) and (2): 1.0?f2h/f?5.0??(1) ?2.5?f1/f??0.8??(2) where f2h is a focal length of an aspheric lens of at least one of the first and second positive lenses of the second lens group, f is a focal length of the whole system, and f1 is a focal length of the first lens group.

Abstract: This present disclosure provides an image lens assembly in order from an object side to an image side comprising five lens elements with refractive power: a first lens element with negative refractive power having a concave image-side surface; a second lens element with positive refractive power having a convex image-side surface; a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a fourth lens element with negative refractive power; and a fifth lens element with positive refractive power. By such arrangement, sufficient field of view is provided, and the aberration of the lens assembly is corrected for obtaining higher image resolution.

Abstract: A lens system includes a first to fifth lenses. The second and fifth lenses have negative refractive power and the others have positive refractive power. The lens system satisfies: D/TTL>1.05; Z/Y>0; G3R1/F3>G1R1/F1>0; G1R2/F1<G3R2/F3<0; and G5R1/F5<G5R2/F5<0, where D is the diameter of the optical images of the lens system, TTL is the total length of the lens system, Z is the distance between the outer periphery of an image-side surface of the fourth lens to the center of an object-side surface of the fourth lens, Y is the distance between the outer periphery of the fourth lens to the center of the fourth lens, G1R1, G2R2, G3R1, G3R2, G5R1 G5R2 are the radii of curvature of the object-side and image-side surfaces of the first, third, fifth lenses, respectively, and F1, F3, F5 are focal lengths of the first, third, fifth lenses, respectively.

Abstract: This invention provides an imaging optical lens assembly, in order from an object side to an image side comprising: a front lens group, an aperture stop and a rear lens group; wherein the front lens group comprises, in order from the object side to the image side: a first lens element with negative refractive power having a concave image-side surface; a second lens element with negative refractive power; a third lens element with positive refractive power and a fourth lens element with positive refractive power; wherein the rear lens group comprises, in order from the object side to the image side: a fifth lens element with positive refractive power; and a sixth lens element with negative refractive power; wherein the fifth lens element and the sixth lens element are connected to form a doublet. By such arrangement, sufficient field of view is provided, and the aberration of the lens assembly is corrected for obtaining high image resolution.

Abstract: A wide-conversion lens, in order from the object-side to the image-side, includes a first lens with negative refraction power, a second lens with negative refraction power, a third lens with positive refraction power, a fourth lens with positive refraction power, and a fifth lens with negative refraction power. The first lens includes a surface facing the object side. The wide-conversion lens satisfies the following conditions: R1<0; Vd2?Vd1?19; Vd2?Vd3?35. Wherein, R1 is the curvature radius of the surface of the first lens; Vd1 is the Abbe number of the first lens; Vd2 is the Abbe number of the second lens; Vd3 is the Abbe number of the third lens.

Abstract: The projection lens comprises: the first of the components of negative power, facing with its concave surface to the object and cemented of negative and positive menisci, the second component comprising a positive meniscus, having the concave surface facing an object side, the third one being a biconvex lens, the forth one being a positive meniscus, having the concave surfaces facing an image side, the fifth one being negative, faced with its concave surface to the image and being cemented of biconvex and biconcave lenses. The technical objective is that relative aperture (1:1.8) is increased, brightness at the image edge field is enhanced against that in the centre (0.91), in the image, formed by the lens, the required value of negative distortion is provided (?3%), an image quality is enhanced, conditions of lens operating are provided for the object, located at the finite distance.