Abstract: The present invention provides a mobile device and an optical imaging lens thereof. The optical imaging lens comprises an aperture stop, first, second, third and fourth lens elements positioned sequentially from an object side to an image side. The first lens element with positive refracting power has a surface facing toward the object side. The second lens element with negative refracting power has a convex surface facing toward the object. The third lens element has a positive refracting power. The fourth lens element has a surface facing toward the object side with a concave portion in the vicinity of the optical axis and a surface facing toward the image side with a convex portion in the peripheral vicinity. The optical imaging lens of the present invention is capable of shortening the total length of the optical imaging lens efficiently and has good optical characteristics.

Abstract: This invention provides an optical lens system comprising: a first lens element with negative refractive power having a convex object-side surface; a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface; a third lens element with positive refractive power; a plastic fourth lens element with negative refractive power having a concave object-side surface and a convex image-side surface, with both the object-side and image-side surfaces thereof being aspheric, and having at least one inflection point positioned on at least one of the object-side and image-side surfaces thereof; wherein the number of lens elements with refractive power is limited to four. By such arrangement, especially by the first and the second lens elements with negative refractive power, the system has sufficient back focal length for arranging required optical elements, and thereby is suitable for various applications.

Abstract: An image capturing lens system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element with refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The third lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof. The fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof, wherein an object-side surface and the image-side surface of the fourth lens element are aspheric. The image capturing lens system has a total of four lens elements with refractive power.

Abstract: An imaging 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 and a fourth lens element. The positive first lens element has a convex object-side surface at a paraxial region. The negative second lens element has a concave image-side surface at a paraxial region, wherein the image-side surface thereof has a convex shape at a peripheral region, and the surfaces thereof are aspheric. The positive third lens element has a convex object-side surface at a paraxial region and a convex image-side surface at a paraxial region. The negative fourth lens element has a concave image-side surface at a paraxial region, wherein the image-side surface thereof has a convex shape at a peripheral region, and the surfaces thereof are aspheric. The imaging lens assembly has a total of four lens elements with refractive power.

Abstract: An image 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 and a fourth lens element. The first lens element with positive refractive power has a convex object-side surface in a paraxial region thereof. The second lens element with negative refractive power has a concave object-side surface in a paraxial region thereof and a concave image-side surface in a paraxial region thereof. The third lens element with positive refractive power has a concave object-side surface in a paraxial region thereof and a convex image-side surface in a paraxial region thereof. The fourth lens element with negative refractive power has a concave image-side surface in a paraxial region thereof. The image lens assembly has a total of four lens elements with refractive power.

Abstract: An imaging lens module includes first, second, third and fourth optical lens elements that are arranged sequentially from an object side to an image side along an optical axis and that respectively have positive, positive, negative and negative refractive powers, and a fixed aperture stop that is disposed between the object side and the second optical lens element. The fourth optical lens element has an object-side surface and an image-side surface that has a concave surface segment near the optical axis. At least one of the object-side surface and the image-side surface of the fourth optical lens element has at least an inflection point.

Abstract: An optical module having an object side and an image side; the module comprising, from the object side to the image side: a first positive meniscus lens having a convergence C1, made of a material having a refractive index Nd1 and an Abbe number Vd1, a second negative meniscus lens having a convergence C2 made of a material having a refractive index Nd2 and an Abbe number Vd2, a third positive meniscus lens having a convergence C3, made of a material having a refractive index Nd3 and an Abbe number Vd3, a fourth negative lens having a convergence C4, made of a material having a refractive index Nd4 and an Abbe number Vd4, wherein: 1.1<C1/C<1.35 II C1/C2 II>2 0.5<C1/C3<1.1 C1/Vd1<<5.2 II C2/Vd2 II<7 IIå(Ci/Vdi)II<4 with i=1 to 4.

Abstract: Provided is a zoom lens, including, in order from an object: a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; a third lens group (G3) having positive refractive power; and a fourth lens group (G4) having positive refractive power. The first lens group (G1 includes only, in order from the object, a cemented lens of a negative lens (L11) and a positive lens (L12), and a positive meniscus lens (L13) having a convex surface facing the object, an aperture stop (S) for determining brightness is disposed to the object side of the third lens group (G3), and upon zooming, all of the four groups (G1 to G4) move and the aperture stop (S) moves together with the third lens group (G3), and the conditional expression ?dp1>85.0 is satisfied, where ?dp1 denotes an Abbe number of the positive lens (L12), which is disposed closest to the object in the first lens group (G1), at the d-line as a standard.

Abstract: An imaging lens assembly includes first, second, third and fourth optical lens elements that are arranged sequentially from an object side to an image side along an optical axis and that respectively have negative, positive, positive and negative refractive powers, and a fixed aperture stop that is disposed between the first and second optical lens elements. The fourth optical lens element has object-side surface and an image-side surface that has at least an inflection point. The imaging lens assembly satisfies the optical condition of 1.8<TL/f<2.4, in which, TL represents a distance from an object-side surface of the first optical lens element to an imaging plane, and f represents a focal length of the imaging lens assembly.

Abstract: A wide-angle image lens, in the order from the object side to the image side thereof, includes a first lens, a second lens, a third lens, a fourth lens and an image plane. The image lens satisfies the following formulas: D/TTL>0.45; CT4/ET4<2.11; Z/Y>0.06; wherein D is the maximum image diameter of the image plane; TTL is a total length of the wide-angle image lens; CT4 is a distance along an optical axis from the seventh surface to the eighth surface; ET4 is a distance along the optical axis from an outmost edge of the seventh surface to an outmost edge of the eighth surface; Z is a distance from a central point of the fifth surface to an outmost edge of the sixth surface along the optical axis; Y is a distance from the outmost edge of the sixth surface to the optical axis.

Abstract: An imaging lens formed of 4 lenses, in which a negative first lens having a meniscus shape with a convex surface on the object side, a biconvex positive second lens, a negative third lens having a concave surface on the image side, and a positive fourth lens having a convex surface on the object side, arranged in order from the object side, and the imaging lens satisfies conditional expressions (1): L12/f<0.82; (2): 2.3<L12×R2F2/f2<10.0; (5): ?1.3<f1/f<?0.9; and (6): 48<v1 simultaneously, where, L12 is the air equivalent distance between the first lens and the second lens, f is the focal length of the entire lens system, R2F is the radius of curvature of the object side lens surface of the second lens, f1 is the focal length of the first lens, and v1 is the Abbe number of the first lens with respect to the d-line.

Abstract: A thin-type wide-angle imaging lens assembly comprises a fixing diaphragm and an optical set including four lenses. An arranging order from an object side to an image side is: a first lens; a second lens; a third lens; a fourth lens; and the fixing diaphragm disposed between an object and the second lens. 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 optical system includes, in order from the object side to the image side, an aperture stop, a first lens element with a positive refractive power having a convex object-side surface, a second lens element with a negative refractive power having a convex image-side surface in the vicinity of an outer circumference, a third lens element with a positive refractive power having a concave object-side surface in a vicinity of an optical axis and a convex image-side surface in the vicinity of the optical axis, and a fourth lens element having a concave image-side surface in the vicinity of the optical axis and a convex image-side surface in the vicinity of the outer circumference. The sum of thicknesses of the first, second, third, and fourth lens elements and the sum of total air gaps therebetween 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 optical lens assembly for image taking includes a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power includes a convex object-side surface at a paraxial region. The second lens element with negative refractive power includes a concave object-side surface at a paraxial region. The third lens element with refractive power includes a concave object-side surface at a paraxial region and a convex image-side surface at a paraxial region. The fourth lens element made of plastic with negative refractive power includes a concave object-side surface at a paraxial region and an image-side surface. Both of the object-side surface and the image-side surface of the fourth lens element are aspheric, and the image-side surface of the fourth lens element is concave at a paraxial region and convex at a peripheral region.

Abstract: A wide-angle photographic lens system enabling correction of distortion composed of four lenses, in which a first lens, an iris, a second lens, a third lens and a fourth lens sequentially arranged along an optical axis from an object, wherein the first lens has weak refractivity, the second lens has positive refractivity, the third lens has strong positive refractivity, and the fourth lens has negative refractivity, wherein the lens system satisfies relations, |f1/f|>4, f3/f<1.5, and te/tc<0.5, wherein f1 is a focal length of the first lens, f is a total focal length of all the lenses, f3 is a focal length of the third lens, to is a lens thickness on an effective diameter of a rear surface of the third lens, and tc is a center thickness of the third lens.

Abstract: An image capturing lens system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element has refractive power. The second lens element with positive refractive power has a convex image-side surface in a paraxial region thereof. The third lens element with negative refractive power has a concave object-side surface in a paraxial region thereof and a convex image-side surface in a paraxial region thereof. The fourth lens element with refractive power has a concave image-side surface in a paraxial region thereof, wherein both of an object-side surface and the image-side surface thereof are aspheric, and the image-side surface thereof has at least one convex shape in an off-axis region thereof. The image capturing lens system has a total of four lens elements with refractive power.

Abstract: An image pickup optical system includes in order from an object side, a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, and a fourth lens having a negative refractive power. The first lens has a biconvex shape. An image-side surface of the second lens has a shape such that, a concave surface is directed toward an image side. At least an image-side surface of the third lens has a shape such that, a convex surface is directed toward the image side. An aperture is disposed nearest to the object side, and the following conditional expression (1) is satisfied: 0.9<f1/f??(1), where f1 denotes a focal length of the first lens and f denotes a focal length of the overall image pickup optical system.

Abstract: An imaging lens includes plastic-made first, second, third, and fourth lens elements arranged in the given order from an object side to an imaging side. The first lens element has a positive focusing power and is biconvex. The second lens element has a negative focusing power, is biconcave, and has an abbe number not greater than 30. The third lens element has a positive focusing power and has a convex imaging-side surface facing toward the imaging side. The fourth lens element has an imaging-side surface formed with a concave area in a vicinity of an optical axis of the fourth lens element. The imaging lens further includes an aperture stop disposed between the first and second lens elements.

Abstract: Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises four lens elements positioned in an order from the object side to the image side. Through controlling the convex or concave shape of the surfaces of the lens elements, the thickness of the at least one lens element, an air gap between two lens elements, and a sum of all air gaps between all four lens elements along the optical axis satisfying the relations: (T3/G34)>4 and (Gaa/T3)>1, wherein T3 is the thickness of the third lens element, G34 is the air gap between the third lens element and the fourth lens element, and Gaa is the sum of all air gaps between all four lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

Abstract: According to one embodiment, an imaging lens includes a first optical system and a microlens array. The first optical system includes an optical axis. The microlens array is provided between the first optical system and an imaging element. The microlens array includes microlens units provided in a first plane. The imaging element includes pixel groups. Each of the pixel groups includes pixels. The microlens units respectively overlap the pixel groups when projected onto the first plane. The first optical system includes an aperture stop, a first lens, a second lens, a third lens, and a fourth lens. The first lens is provided between the aperture stop and the microlens array. The second lens is provided between the first lens and the microlens array. The third lens is provided between the second lens and the microlens array. The fourth lens is provided between the third lens and the microlens array.

Abstract: A wide-angle image capturing lens assembly includes four lens elements with refractive power, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element and each of the first through fourth 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 with positive refractive power has a convex image-side surface. The fourth to lens element with negative refractive power has a concave object-side surface and a convex image-side surface, wherein both of the object-side surface and the image-side surface of the fourth lens element are aspheric.

Abstract: An optical image capturing lens assembly includes four non-cemented lens elements, in order from an object side to an image side: a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element with negative refractive power has a concave object-side surface and a convex image-side surface. The third lens element with positive refractive power has a convex object-side surface and a convex image-side surface, and is made of plastic material, wherein the surfaces of the third lens element are aspheric. The fourth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, and is made of plastic material, wherein the surfaces of the fourth lens element are aspheric.

Abstract: An imaging lens comprising, in order from the object side: an aperture stop; a positive first lens having convex object-side and image-side surfaces; a double-sided aspheric negative second lens having a concave object-side surface; a meniscus double-sided aspheric positive third lens having a convex image-side surface; and a meniscus double-sided aspheric negative fourth lens having a concave image-side surface. All of the lenses are made of a plastic material.

Abstract: Provided is an endoscope objective optical system 1 including, in order from an object side, a first lens 2 composed of a negative single lens, a second lens 3 composed of a positive single lens, an aperture stop 4, a third lens 5 composed of a positive single lens, and a fourth lens 6 composed of a positive combined lens, wherein the third lens 5 has a meniscus shape having a convex surface facing the image side. The endoscope objective optical system (1) satisfies the following conditions: 0.3<Df/f<1.15,??(1) n1<1.79,??(2) n2>n1,??(3) 0.6<IH/f<0.83,??(4) and |r1|?|r2|+d1>1.

Abstract: A lens assembly includes a lens set which includes a first lens, a second lens, a third lens and a fourth lens arranged in sequence along an optical axis. The first lens has a positive optical power. The second lens has a positive optical power. The third lens has a negative optical power. The fourth lens has a positive optical power, and has an image-side surface, an object-side surface, and a peripheral surface interconnecting the two. At least one of the object-side and image-side surfaces has an inflection point located between the optical axis and the peripheral surface. The lens assembly satisfies 15<HFOV/f<50, in which, HFOV represents one half of a maximum angle of view of the lens assembly, and f represents a focal length thereof.

Abstract: An imaging lens is formed from a first group lens having negative power, a second group lens having positive power, a third group lens having negative power, and a fourth group lens having positive power, disposed in order from the subject side to the image side. Letting f be the focal distance for the entire lens system and ff2 the focal distance for the second group lens, 1.0?ff2/f?2.0 is satisfied; therefore, the entire length of the lens system can be kept short and image curvature can be suppressed. In addition, each of the subject side lens surfaces and the image side lens surfaces for the second group lens, third group lens, and fourth group lens are provided with aspherical surface shapes; therefore, the imaging lens is constituted to be bright.

Abstract: A zoom lens system includes in order from an object side to an image side a first lens unit having a positive refracting power; a second lens unit having a negative refracting power; a third lens unit having a positive refracting power; and a fourth lens unit having a positive refracting power. At the time of zooming from a wide angle end to a telephoto end, each of distances between the first lens unit and the second lens unit, between the second lens unit and the third lens unit, and between the third lens unit and the fourth lens unit is changed, and the first lens unit is moved. The first lens unit includes a lens component having positive refracting power, a total number of lens components included in the first lens unit is one, and the third lens unit includes five lens elements.

Abstract: A projection lens, in order along an optical axis from an image formation side to an image source side, includes a first lens, an aperture, a second lens, a third lens, and a fourth lens. The first lens is a meniscus lens with positive refractive power and a convex surface thereof facing the image formation side, and has at least an aspheric surface. The second lens is a biconcave lens with negative refractive power, and has at least an aspheric surface. The third lens is a biconvex lens with positive refractive power, and the fourth lens is a biconvex lens with positive refractive power, and has at least an aspheric surface. Therefore, the projection lens has a small size and high zoom ratio.

Abstract: An optical unit and an image pickup unit are provided that allow a full angular field to be increased in spite of small size and low cost. An image pickup lens 100 has a first lens 111 with a positive power, a second lens 113 with a positive power, a third lens 114 with a positive power, and a fourth lens 115 with a negative power that are arranged in order from an object side OBJS toward an image surface side, that are arranged in order from the object side toward the image surface side.

Abstract: An inner focus lens system comprises, in order from an object side to an image side, a first lens unit, an aperture stop, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a positive refractive power. The first lens unit has at least one negative lens and at least one positive lens, the second lens unit has at least one negative lens and at least one positive lens, the third lens unit has at least one negative lens, and the fourth lens unit has at least one positive lens. When focusing on an object at a short distance from an object at infinity, the third lens unit moves to lengthen a distance to the second lens unit and to shorten a distance to the fourth lens unit.

Abstract: An imaging lens has a negative first-lens, a first-cemented-lens of a second-lens and a third-lens, a stop, a positive fourth-lens, and a second-cemented-lens of a fifth-lens and a sixth-lens in this order from an object-side. The first-lens has a plano-concave or meniscus shape with a concave image-side surface. One of the second-lens and the third-lens is a positive lens and the other one is a negative lens. An object-side surface of the fourth-lens is a flat surface or a surface with a curvature radius having an absolute value greater than that of its image-side surface. One of the fifth-lens and the sixth-lens is a positive lens and the other one is a negative lens.

Abstract: To provide a projection lens that is compact, lightweight, low-cost, and readily portable, a first lens having a positive power and at least one surface that is an aspheric surface; a second lens having a negative power and having a concave surface on the magnification side; a third lens having a positive power and having a convex surface on the reduction side; and a fourth lens having a positive power are arranged in order from the magnification side. In addition to arranging the lenses telecentrically on the reduction side, the following formulas are satisfied simultaneously, and images formed on the conjugation surface on the reduction side are enlarged and projected on the conjugation surface on the magnification side: formula (A) 0.8<Bf/f; formula (B) 1.1<f1/f<1.6; formula (C) Nd1<1.7, formula (D) vd1<35.

Abstract: An image capturing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has a convex object-side surface at a paraxial region. The second lens element with negative refractive power has a concave image-side surface. The third lens element with positive refractive power has a convex object-side surface at a paraxial region and a convex image-side surface at a paraxial region. The fourth lens element with negative refractive power has a concave image-side surface at a paraxial region, wherein the image-side surface of the fourth lens element has a convex shape at a peripheral region, and both of the surfaces of the fourth lens element are aspheric. The image capturing system has a total of four lens elements with refractive power.

Abstract: An imaging lens includes plastic-made first, second, third, and fourth lens elements arranged in the given order from an object side to an imaging side. The first lens element has a positive focusing power and is biconvex. The second lens element has a negative focusing power, is biconcave, and has an abbe number not greater than 30. The third lens element has a positive focusing power and has a convex imaging-side surface facing toward the imaging side. The fourth lens element has an imaging-side surface formed with a concave area in a vicinity of an optical axis of the fourth lens element. The imaging lens further includes an aperture stop disposed between the first and second lens elements.

Abstract: An imaging lens assembly comprises a fixing diaphragm and an optical set including four lenses. An arranging order from an object side to an image side is: a first lens; a second lens; a third lens; and a fourth lens. At least one surface of the first and the second lenses is aspheric. At least one surface of the third and the fourth lenses are aspheric. The fixing diaphragm is disposed between an object and the second lens. 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 includes plastic-made first, second, third, and fourth lens elements arranged in the given order from an object side to an imaging side. The first lens element has a positive focusing power and is biconvex. The second lens element has a negative focusing power, is biconcave, and has an abbe number not greater than 30. The third lens element has a positive focusing power and has a convex imaging-side surface facing toward the imaging side. The fourth lens element has an imaging-side surface formed with a concave area in a vicinity of an optical axis of the fourth lens element. The imaging lens further includes an aperture stop disposed between the first and second lens elements.

Abstract: An image capturing lens system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has a convex object-side surface in a paraxial region thereof and a convex image-side surface in a paraxial region thereof. The second lens element has positive refractive power. The third lens element has positive refractive power. The fourth lens element with negative refractive power has a concave image-side surface in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fourth lens element are aspheric. The image capturing lens system has a total of four lens elements with refractive power.

Abstract: Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises four lens elements positioned in an order from the object side to the image side. Through controlling the convex or concave shape of the surfaces of the lens elements, the thickness of the at least one lens element, an air gap between two lens elements, and a sum of all air gaps between all four lens elements along the optical axis satisfying the relations: (T3/G34)>4 and (Gaa/T3)>1, wherein T3 is the thickness of the third lens element, G34 is the air gap between the third lens element and the fourth lens element, and Gaa is the sum of all air gaps between all four lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

Abstract: In a zoom lens including a positive first lens unit, negative second lens unit, positive third lens unit, and positive fourth lens unit, the fourth lens unit includes a 41 lens group, a 42 lens group, and a 43 lens group. the lateral magnification of the third lens unit at a wide-angle end when an infinite object is focused, the focal length of the fourth lens unit, the lens configuration length of the fourth lens unit, the air interval between the 41 and 42 lens groups, the air interval between the 42 and 43 lens groups, the focal length of the 42 lens group, the average values of the Abbe constants and partial dispersion ratios of positive lens of the 42 lens group, the average values of the Abbe constants and partial dispersion ratios of negative lenses of the 42 lens group, and the like are appropriately set.

Abstract: A zoom lens includes a first lens unit, a second lens unit, a third lens unit and a fourth lens unit that includes a 41 lens group and a 42 lens group. The 41 lens group includes a 411 lens group and a 412 lens group. A lens surface on a most image side of the 411 lens unit has a shape convex to the image side and a lens surface on the most object side of the 412 lens unit has a shape concave to the object side. A curvature radius r411 of the lens surface on the most image side of the 411 lens unit, a curvature radius r412 of the lens surface on the most object side of the 412 lens unit, and lateral magnification ?3w of the third lens unit at a wide-angle end are respectively appropriately set.

Abstract: An image capturing lens system includes four lens elements with refractive power, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The positive first lens element has a convex object-side surface at a paraxial region. The negative second lens element has a concave object-side surface at a paraxial region and an image-side surface changing from concave at a paraxial region to convex at a peripheral region, wherein the surfaces of the second lens element are aspheric. The positive third lens element has a concave object-side surface at a paraxial region and a convex image-side surface at a paraxial region. The negative fourth lens element has an image-side surface changing from concave at a paraxial region to convex at a peripheral region, and the surfaces of the fourth lens element are aspheric.

Abstract: An imaging lens includes plastic-made first, second, third, and fourth lens elements arranged in the given order from an object side to an imaging side. The first lens element has a positive focusing power and is biconvex. The second lens element has a negative focusing power, is biconcave, and has an abbe number not greater than 30. The third lens element has a positive focusing power and has a convex imaging-side surface facing toward the imaging side. The fourth lens element has an imaging-side surface formed with a concave area in a vicinity of an optical axis of the fourth lens element. The imaging lens further includes an aperture stop disposed between the first and second lens elements.

Abstract: A zoom lens includes a positive first lens group fixed during zooming, a negative second lens moved to the image side upon zooming from the wide angle end to the telephoto end, a negative third lens group for image plane correction during zooming, and a positive fourth lens group fixed during zooming. The first lens group is composed of a negative first lens group front group, a positive first lens group middle group, and a positive first lens group rear group, disposed in order from the object side. The first lens group front group is composed of two negative lenses and one positive lens, disposed in order from the object side. Focusing is performed by moving only the first lens group middle group in an optical axis direction. The zoom lens satisfies a predetermined conditional expression.

Abstract: An optical imaging lens system 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, a fifth lens element, and a sixth lens element. The first lens element has refractive power. The second lens element has positive refractive power. The third lens element has positive refractive power. The fourth lens element has refractive power. The fifth lens element with positive refractive power has a convex object-side surface and a convex image-side surface, wherein both of the surfaces thereof are aspheric. The sixth lens element with refractive power has a concave image-side surface, wherein both of the surfaces thereof are aspheric, and at least one of the surfaces thereof has at least one inflection point. The optical imaging lens system has a total of six lens elements with refractive power.

Abstract: An optical lens system, sequentially arranged from an object side to an image side along an optical axis, includes: a stop, a first lens element with positive refractive power having a convex object-side surface, a second lens element with negative refractive power, a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface, and a fourth lens element with negative refractive power having a concave image-side surface with both being aspheric. Furthermore, the optical lens system satisfies conditions related to increase the field of view and reduce the total length as well as the sensitivity of assembly tolerance of the optical lens system.

Abstract: A four element lens system for use with an imaging sensor includes first, second, third, and fourth lens elements and an optical filter that are arranged sequentially in order from an object side to an imaging side. The lens elements are coated with an anti-reflective film. The lens system further includes an optical filter that is disposed at a distance from the imaging sensor. The lens elements are relatively positioned to each other to satisfy specific conditions. The lens elements further include thickness to diameters ratios that satisfy specific conditions.

Abstract: An imaging lens is provided with: a first lens with negative power; a second lens with negative power; a third lens with positive power; and a fourth lens with positive power. The cemented fourth lens is formed from an object side lens with negative power and an image side lens with positive power. The thickness of a resin adhesive layer that bonds the object side lens and the image side lens is 20 ?m or greater on the optical axis, and when Sg1H is the amount of sag in the image side lens surface of the object side lens and Sg2H is the amount of sag in the object side lens surface of the image side lens. The bonding operation is easy without damage occurring to the cemented surfaces, with a design that takes into account thickness of the resin adhesive layer; therefore various forms of aberration can be corrected.

Abstract: An imaging lens assembly captures return light from a target, and projects the captured light onto a solid-state imager during electro-optical reading of the target. One plastic lens and one glass lens, together having a relatively low negative optical power, are situated at one side of an aperture stop. Another plastic lens and another glass lens, together having a relatively high positive optical power, are situated at the opposite side of the aperture stop. An aperture extends along an optical axis through the opposite sides. Each plastic lens is configured with opposite aspheric nearly concentric surfaces to widen and flatten the field of view of the imager, and to reduce sensitivity to manufacturing and assembly tolerances. A holder holds the lenses and the aperture stop in spaced relation along the optical axis relative to the imager.

Abstract: An imaging lens includes, arranged in sequence from the object side to the imaging surface side, a first lens having a positive power and convex surfaces on both sides; an aperture diaphragm; a second lens being a meniscus lens having a negative power and a convex surface on the object side; a third lens being a meniscus lens having a positive power and a concave surface on the object side; and a fourth lens having a negative power and concave surfaces on both sides. With this structure, the imaging lens is well corrected for various aberrations in spite of being compact in the lens radial direction and thin in the optical axis direction.