Abstract: This invention discloses a thin optical lens assembly, comprising two lens elements with refractive power arranged from an object side to an image side along an optical axis, a bi-convex first lens element with a positive refractive power, a second lens element with a negative refractive power having a concave object-side surface and a convex image-side surface, and an image sensor on an image plane. Each of the two lens elements has two aspheric optical surfaces, and preferably is made of plastic. Additionally, the thin optical lens assembly satisfies the conditions of the present invention in order to reduce the total length and the sensitivity for its use in compact cameras and mobile phones with photographing functions.

Abstract: An imaging lens system with two lenses is provided. The imaging lens system with two lenses, along an optical axis from an object side to an image side, comprises an aperture stop; a first lens having positive refractive power and being a biconvex lens; and a second lens having negative refractive power and being a meniscus lens with a concave surface on the object side and a convex surface on the image side.

Abstract: A wide angle lens includes sequentially from the object side, a first lens group having a negative refractive power; an aperture stop; and a second lens group having a positive refractive power, where the first lens group includes sequentially from the object side, a negative first lens having on the object side, a convex surface; a negative second lens having on the image side, a concave surface; a negative third lens; and a positive fourth lens. The second lens group includes sequentially from the object side a cemented lens having a positive refractive power and formed by a fifth lens and a sixth lens; a positive seventh lens; and a negative eighth lens having on the image side, a concave surface.

Abstract: A lens system includes a main lens and a transfer lens aligned with the main lens. The optical axis of the main lens is superposed on that of the transfer lens. The transfer lens includes, in order from the object side to the image side thereof, a first lens having negative refraction power, and a second lens having positive refraction power. The lens system satisfies the following conditions: 0.4<|f1/f2|<0.8; 2<v1/v2<3.8; 0.86<N1/N2<1.12; wherein, f1 is a focal length of the first lens, f2 is a focal length of the second lens, v1 is an Abbe constant of the first lens, v2 is an Abbe constant of the second lens, N1 is a refractive index of the first lens, N2 is a refractive index of the second lens.

Abstract: A lens assembly comprises a first lens and a second lens. The first lens includes a first central round portion and a first peripheral stepped portion surrounding the first central round portion. The first peripheral stepped portion comprises a downward-facing surface, a first supporting surface, and a first inclined surface interconnected. The second lens includes a second central round portion and a second peripheral stepped portion surrounding the second central round portion. The second peripheral stepped portion includes an upward-facing surface, a second inclined surface, a third surface, and a second supporting surface. The second lens is engaged on the first lens in a manner that the first supporting surface contacts the second supporting surface, the downward-facing surface is facing toward the upward-facing surface, the first inclined surface contacts the second inclined surface but a gap is defined between the first inclined surface and the third surface.

Abstract: Including: a front group Gf disposed to an object side of an aperture; and a rear group Gr disposed to an image side of the aperture; the front group including a sub group Ga having negative power, the sub group including, from the object side, at least three negative lenses, at least one of the three negative lens being an aspherical negative meniscus lens having a shape that negative power is getting smaller from the center to the periphery, a cemented lens constructed by a positive lens, a negative lens and a positive lens disposed to the image side of the sub group, an antireflection coating being applied on at least one surface of the front group, the antireflection coating including at least one layer formed by a wet process, and given conditions being satisfied, thereby providing a wide-angle lens having high optical performance with a large angle of view.

Abstract: A micro-lens module including a first lens, a second lens, and an aperture stop is provided. The first lens is disposed between an object side and an image side, wherein a first surface of the first lens facing the object side is an aspheric surface, and the curvature radius of the aspheric surface is R1. The second lens is disposed between the first lens and the image side, wherein a second surface of the second lens facing the image side is an aspheric surface, and the curvature radius of the aspheric surface is R2. The aperture stop is disposed between the first lens and the second lens, wherein the distance from the first surface to the aperture stop is d1, and the distance from the second surface to the aperture stop is d2. The micro-lens module satisfies 6>d2/d1>2.5 and ?2.5<R1/R2<1.5.

Abstract: A unit magnification projection optical system includes, listed in order along a system axis, a mirror, a lens group having negative power and a lens group having positive power. The optical system is a symmetric system, with an object plane on one side of the system axis and an object plane on an opposite side of the system axis. The object and image planes are spaced apart from the positive lens group by a working distance greater than 100 millimeters.

Abstract: A wide angle lens whose field angle exceeds 160 degrees, includes a front group, an aperture stop, and a rear group arranged in this order from an object-side toward an image-side. The front group includes a first lens (negative meniscus) whose convex surface faces the object, a second lens (negative), a third lens (negative), and a fourth lens (positive), arranged in this order from the object-side toward the image-side. The rear group includes a fifth lens (positive), a sixth lens (negative), and a seventh lens (positive), arranged in this order from an aperture-side toward the image-side. The fifth and sixth lenses are combined, forming a cemented lens having positive refractive power. The fifth and sixth lenses are made of materials having Abbe numbers of greater than or equal to 50 and less than or equal to 30, respectively. A surface of the seventh lens facing the image is aspheric.

Abstract: In constructing a lens for projection substantially consisting of seven lenses, and the reduction side of which is telecentric, a first-lens-group is composed of two lenses including at least one negative lens. A second-lens-group is composed of a positive second-group first-lens having a convex surface facing the magnification side, a negative second-group second-lens having a concave surface facing the magnification side, a positive second-group third-lens having a convex surface facing the reduction side, a positive second-group fourth-lens, and a positive second-group fifth-lens in this order from the magnification side. The formulas (A) and (B) are satisfied: 1.2?Bf/f?2.5??(A); and f23/f?1.5??(B), where Bf is a back focus in air of an entire lens system, f is the focal length of the entire lens system, and f23 is the focal length of an air lens between a reduction-side surface of the second-group second-lens and a magnification-side surface of the second-group third-lens.

Abstract: A wide angle lens whose field angle exceeds 180 degrees includes a front group, a diaphragm, and a rear group arranged in this order from an object side toward an image side. The front group includes a first lens (negative meniscus lens) whose convex surface faces the object side, a second lens (negative lens), and a third lens (positive lens) that are arranged in this order from the object side toward the image side. The rear group includes a fourth lens (positive lens), a fifth lens (negative lens), and a sixth lens (positive lens) that are arranged in this order from a diaphragm side toward the image side. Accordingly, an imaging system including six separate lenses is formed. The third lens is made of a material having an Abbe number ?dL3 satisfying ?dL3<21. The fifth lens is made of a material having an Abbe number ?dL5 satisfying ?dL5<21.

Abstract: An imaging lens consisting of in order from an object side to an image surface side, a diaphragm, a first lens that is a meniscus lens having a positive power whose convex surface faces the object side and a second lens that is a lens having a negative power whose concave surface faces the object side, wherein a condition expressed by the following expression is satisfied: 0.05?r1/r2?0.29, where r1 is a center radius curvature of the object side surface of the first lens and r2 is the center radius curvature of the image surface side of the first lens.

Abstract: An image pickup lens includes: a first lens group including a single negative lens and a single positive lens disposed in order from the object side to the image side and having a positive refracting power; and a second lens group having a positive refracting power. The first and second lens groups are disposed in order from the object side to the image side. The first lens group is fixed, when the image pickup object distance varies from the infinity to the proximity, with respect to an image surface while the second lens group is moved from the image side to the object side to carry out focusing.

Abstract: This invention provides a photographing optical lens assembly comprising, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a second lens element with positive refractive power having a concave object-side surface and a convex image-side surface, both of the two surfaces being aspheric; a third lens element with negative refractive power having a concave image-side surface on which at least one inflection point is formed, both of the two surfaces being aspheric; and a stop disposed between an imaged object and the second lens element; wherein there are only three lens elements with refractive power. Such an arrangement of optical elements can effectively reduce the size of the lens assembly, mitigate the sensitivity of the optical system and enable the lens assembly to obtain a higher resolution.

Abstract: This invention provides a compact imaging lens assembly in order from an object side toward an image side including a first lens with positive refractive power having at least one of the object-side and image-side surfaces thereof being aspheric, a second lens with negative refractive power having a concave object-side surface and a concave image-side surface with at least one of both surfaces thereof being aspheric, and an aperture stop positioned between the first lens element and the second lens element. There are two lens elements with refractive power in the compact imaging lens assembly.

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: An imaging lens system with two lenses is provided. The imaging lens system with two lenses, along an optical axis from an object side to an image side, includes an aperture stop; a first lens having positive refractive power and being a plano-convex lens with a convex surface on the image side; and a second lens having negative refractive power and being a meniscus lens with a concave surface on the object side and a convex surface on the image side.

Abstract: An imaging lens (LN) includes one or two lens blocks (BK), and an aperture stop (ape). The lens block (BK) includes a plane-parallel lens substrate (LS) and a lens (L) formed of different materials. In the imaging lens (LN), a first lens block (BK1) disposed at the most object-side exerts a positive optical power, and a conditional formula defined by the absolute difference between the index of refraction of a first lens substrate (LS1) and the index of refraction of a lens (L[LS1o]) contiguous with an object-side substrate surface of the first lens substrate (LS) is fulfilled.

Abstract: A compact wide-angle zoom lens and an image pickup device having the same. The zoom lens includes a first lens group having a negative refractive power and a second lens group having a positive refractive power in an order from an object side to an image side, performs zooming by varying a distance between the first and second lens groups, and performs focusing by using a first lens closest to the object side in the second lens group.

Abstract: Providing for a wafer level optical system employing composite lenses is disclosed herein. Conventional focus lens assemblies require three or more lenses. By way of example, two composite lenses can be used to reduce the cost of a wafer-level camera. In some aspects, the composite lenses can be aspheric and can employ a broader variety of wafer materials than earlier designs that only operated in narrow ranges of refractive indices and Abbe numbers.

Abstract: This invention provides a compact imaging lens assembly from an object side toward an image side in order including a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface with at least one of surfaces thereof being aspheric, a second lens element with negative refractive power having a concave object-side surface and a concave image-side surface with at least one of surfaces thereof being aspheric. An aperture stop is positioned between the imaged object and the second lens element. There are two lens elements with refractive power in the compact imaging lens assembly.

Abstract: An imaging lens (LN) includes one or two lens blocks (BK), and an aperture stop (ape). The lens block (BK) includes a plane-parallel lens substrate (LS) and a lens (L) formed of different materials. In the imaging lens (LN), a first lens block (BK1) disposed at the most object-side exerts a positive optical power, and a conditional formula defined by the absolute difference between the index of refraction of a first lens substrate (LS1) and the index of refraction of a lens (L[LS1o]) contiguous with an object-side substrate surface of the first lens substrate (LS) is fulfilled.

Abstract: An imaging optical system has, in order from the object side to the image side thereof, a front lens group, an aperture stop, and a rear lens group. A lens located closest to object side in said front lens group always remains fixed in position, with satisfaction of the following conditions (1) and (2): 1.15?fb/IH??1.7 ??(1) ?4.0?fn/f??1.3 ??(2) where f is a focal length of the whole imaging optical system, fn is a focal length of a first negative lens in said front lens group, fb is a back focus of the imaging optical system upon focusing on an object point at infinity, and IH? is a distance from an optical axis of a position where a chief ray from a maximum incident half angle of view (?) upon focusing on an object point at infinity is imaged at the imaging plane.

Abstract: A lens system includes, in order from an object: a first lens group having negative refractive power; and a second lens group having positive refractive power, the first lens group including, in order from the object, a lens having a negative refractive power, a plastic aspherical lens, and a lens having a positive refractive power, and the following conditional expression |fp/f1|>4.0 being satisfied, where fp denotes a focal length of the plastic aspherical lens, and f1 denotes a focal length of the first lens group.

Abstract: A compact short back focus imaging lens system with two lenses is revealed and includes along the optical axis from an object side to an image side: an aperture stop, a first lens with positive refractive power that is a meniscus aspherical lens with convex surface facing the object side, a second lens with negative refractive power that is a meniscus aspherical lens with convex surface facing the image side, an IR cut-off filter and an image sensor. Moreover, the following conditions are satisfied by the imaging lens system: - 0.3 ? f 1 f 2 ? - 0.01 0.25 ? bf TL ? 0.4 wherein f1 is focal length of the first lens, f2 is focal length of the second lens, bf is back focal length of the imaging lens system, and TL (overall length) is the distance from the aperture stop to the image plane.

Abstract: The spherical aberration of an imaging lens changes from an object side of image-plane base position Zo toward the other side thereof as a distance from optical axis Z1 increases, and formulas 0.02<a/f<0.10 and 0.02<b/f are satisfied. In an imaging apparatus to which the imaging lens is applied, a blur is corrected by performing contrast recovery processing on original image data obtained by imaging. In the formulas, a is the magnitude of spherical aberration from the image-plane base position Zo toward the object side thereof affecting a ray passing through a central part of the pupil of the imaging lens, and b is a sum of a maximum spherical aberration from the image plane base position Zo toward the object side thereof and a maximum spherical aberration from the image plane base position Zo toward the other side thereof, and f is the focal length of the imaging lens.

Abstract: A wide-angle imaging lens system with two positive lenses is revealed. The imaging lens system includes a first lens with positive refractive power that is a biconvex aspherical lens and a second lens having positive refractive power that is a meniscus lens with concave surface facing the image side. In the concave surface of the second lens, the effective diameter range from the lens center to the edge includes at least one inflection point that changes the refractive power of the second lens from positive to negative. Moreover, the following conditions are satisfied by the imaging lens system: 2 ? ? ? 70 ° ; 0.3 ? bf TL ? 0.6 wherein bf is back focal length, TL is distance from an aperture stop to an image plane, and 2? is maximum field angle. Thus, the imaging lens system of the present invention has wide angle effects, short back focal length, and reduced overall length.

Abstract: An imaging lens including, from an object side, a diaphragm, a first lens that is a lens having a positive power whose convex surface faces the object side, and a second lens having a negative power whose concave surface faces the object side, wherein a condition expressed by the following expressions is to be satisfied: ?0.1.?r1/r2<0.1, 0.85?f1/FL?1, and 0.1?d3/FL?0.3 (where, r1: center radius curvature of the object side face of the first lens, r2: center radius curvature of the image surface side face of the first lens, f1: focal distance of the first lens, d3: center thickness of the second lens and FL: focal distance of the entire lens system).

Abstract: An image pickup lens, comprises sequentially from an object side: an aperture stop, a first lens being a positive meniscus lens which has a convex surface at the object side and a concave surface at an image side opposite to the object side, and a second lens having a concave surface at the object side and an image side surface whose radius of curvature on an paraxial region is infinite or a negative value, wherein the first lens is the second lens and the image side surface of the second lens includes an aspheric surface to make a positive power strong toward a lens peripheral region, and wherein the image pickup lens is made to satisfy the following conditional formulas. 1.55<n1<1.80??(1) 0.4<D3/f<0.6??(2) 40.0<?2<90.

Abstract: An image pickup lens includes: a first lens block with a positive power and a second lens block. The first lens block includes a first lens substrate, a lens portion 1a with a positive power, formed on an object-side surface of the first lens substrate, and a lens portion 1b with a negative power, formed on an image-side surface of the first lens substrate. The object-side surface of the lens portion 1a is a convex surface, and an image-side surface of the lens portion 1b is a concave surface. The second lens block includes a second lens substrate, and a lens portion 2a with a negative power, formed on an object-side surface of the second lens substrate. The object-side surface of the lens portion 2a is a concave surface. The image pickup lens satisfies the predetermined conditional expressions.

Abstract: This invention provides a compact imaging lens assembly in order from an object side toward an image side including a first lens with positive refractive power having at least one of the object-side and image-side surfaces thereof being aspheric, a second lens with negative refractive power having a concave object-side surface and a concave image-side surface with at least one of both surfaces thereof being aspheric, and an aperture stop positioned between the first lens element and the second lens element. There are two lens elements with refractive power in the compact imaging lens assembly.

Abstract: An image system adapted to a projection display apparatus includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, an aspheric reflector, and a curved reflector. The second lens group includes an aspheric lens which is the nearest to the light valve in the second lens group. A material of the aspheric lens includes glass, the thermal-optical coefficient of the glass is between 1.0×10?6/K and 12.5×10?6/K, and the refractive index of the glass is between 1.482 and 1.847. The aspheric reflector is disposed front of the first lens group for reflecting the image beam passing through the first lens group and second lens group. The curved reflector is disposed above the first lens group for reflecting the image beam reflected by the aspheric reflector onto the screen. The image system has a good imaging quality.

Abstract: A single focus wide-angle lens module includes a fixed aperture diaphragm, a first lens and a second lens arranged from an object side to an image side in a sequence of: the diaphragm, the first lens and the second lens. The first lens has a positive refractive power, a concave surface on the object side and at least one aspheric surface. The second lens has a negative refractive power, a convex surface on the object side and at least one aspheric surface.

Abstract: A wide-angle lens comprising: an imaging lens system, including: a front lens group, an aperture, and a rear lens group, arranged in that order from an object side to an image side; wherein said front lens group comprises first and second lens elements, having negative power respectively, and a third lens that is a positive lens, arranged in that order from the object side to an aperture side; wherein said rear lens group comprises fourth and fifth lens elements, having positive power respectively, arranged in order from the aperture side to the image side; where an incident angle to an optical axis of the imaging lens system of a chief ray of a maximum angle of view passing through the aperture is ?I, the following Expression 1 is satisfied.

Abstract: An optical system includes, in order from an object side to an image side, a first lens unit, a stop, and a second lens unit. The first lens unit includes a first negative lens having a meniscus shape and a negative refractive power at a position closest to the object side and a negative lens Gn having a negative refractive power at a position closer to the image side than the first negative lens. The second lens unit includes a positive lens Gp having a positive refractive power. A material of each of the negative lens Gn and the positive lens Gp satisfies the following condition: ?gF?(?0.001682·?d+0.6438)?0.01 where “?d” denotes an Abbe number of a lens material and “?gF” denotes a relative partial dispersion with respect to g-line light and F-line light.

Abstract: A manufacture method of a non-spherical lens module includes: firstly, forming a housing having a row of through holes running through a first surface and a second surface thereof; secondly, providing and filling liquid waveguide with the through holes and forming two convex portions at jointing positions of the through holes and said two surfaces respectively; lastly, cooling the liquid waveguide to form the waveguide in the through hole, cooling the two convex portions to form first and second lens portions.

Abstract: The invention relates to an eyepiece optical system that, albeit being of small size, works in favor of gaining an angle of field and optical performance, and an electronic view finder incorporating such an eyepiece optical system. Specifically, the invention is characterized by comprising, in order from an object side to an exit side thereof, a first lens group that is a single lens that has positive refracting power and is in a meniscus configuration concave on its object side, a second lens group that is a single lens that has negative refracting power and is in a meniscus configuration concave on its object side, and a third lens group that is a single lens that has positive refracting power, wherein an object-side concave lens surface in the first lens group is an aspheric surface, an object-side concave lens surface in the second lens group is an aspheric surface, and an exit-side lens surface in the third lens group is an aspheric surface.

Abstract: An imaging lens includes an aperture stop, and plastic-made meniscus first and second lens elements arranged in the given order from an object side to an image side. Each of the first and second lens elements has an object-side surface and an imaging-side surface facing toward the object side and the image side, respectively. Each of the object-side surface of the first lens element and the imaging-side surface of the second lens element is a convex surface. At least one of the object-side and imaging-side surfaces of each of the first and second lens elements is an aspherical surface. The imaging lens satisfies the optical conditions of: 0.1<f1/EFL<2, and 0.1<R1/R2<2, wherein f1 is a focal length of the first lens element, EFL is an effective focal length of the imaging lens, and R1 and R2 are radii of curvature of the object-side and imaging-side surfaces of the first lens element, respectively.

Abstract: This invention provides a compact imaging lens assembly, in order from an object side to an image side, including a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface with at least one of the two surfaces thereof being aspheric, a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface with at least one of the two surfaces thereof being aspheric, and an aperture stop disposed between the first and second lens elements. There are only two lens elements with refractive power in the compact imaging lens assembly. By such an arrangement, total track length and optical sensitivity of the compact imaging lens assembly can be reduced while a high image quality can also be obtained.

Abstract: A projection optical system comprises a plurality of lenses disposed along an optical axis of the projection optical system; wherein the plurality of lenses is dividable into four non-overlapping groups of lenses, such that a total refractive power of each group of lenses is one of a negative refractive power and a positive refractive power; and wherein a refractive power of each lens of the fourth group of lenses is equal to or greater than 0. A lens of the third group of lenses which is disposed directly adjacent to a lens of the fourth group of lenses may have a concave surface facing towards the second object.

Abstract: An optical lens system for taking image comprises, in order from an object side to an image side: a first lens element with positive refractive power having an aspheric convex object-side surface and an aspheric concave image-side surface; a second lens element with positive refractive power having an aspheric convex object-side surface and an aspheric concave image-side surface. Radii of curvature of the object-side surface of the first lens element, the object-side and image-side surfaces of the second lens element are R1, R3 and R4 respectively, focal lengths of the optical lens system for taking image, the first and second lens elements are f, f1, f2 respectively, an on-axis distance between the first and second lens elements is T12, a center thickness of the second lens element is CT2, they satisfy the relations: 0.76 mm?1<1/R1<2.0 mm?1; 0.4<R3/R4<1.15; 0.35<(f/f1)?(f/f2)<0.72; T12/CT2>1.0.

Abstract: An image pickup lens, comprises sequentially from an object side: an aperture stop, a first lens being a positive meniscus lens which has a convex surface at the object side and a concave surface at an image side opposite to the object side, and a second lens having a concave surface at the object side and an image side surface whose radius of curvature on an paraxial region is infinite or a negative value, wherein the first lens is the second lens and the image side surface of the second lens includes an aspheric surface to make a positive power strong toward a lens peripheral region, and wherein the image pickup lens is made to satisfy the following conditional formulas: 1.55<n1<1.80??(1) 0.4<D3/f<0.6??(2) 40.0<?2<90.0??(3).

Abstract: A high performance fixed focal length optical imaging system for example for a cine camera is operable to receive radiation from an object space and deliver the received radiation through the optical system so as to form an image at an image surface in an image space. The imaging system has the advantage of providing high relative illumination and high contrast at elevated spatial frequencies even when using a fast aperture.

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: A five-lens image lens system is revealed. The five-lens image lens system includes a first lens group with a negative power and a second lens group with a positive power. Along an optical axis in order from an object plane to an image plane, the first lens group includes a negative first lens and a negative second lens while at least one of optical surfaces of the first lens and the second lens is an aspherical optical surface. The second lens group includes a positive third lens, a positive fourth lens, and a negative fifth lens from the object plane to the image plane while an image-side lens surface of the positive fourth lens is glued with an object-side lens surface of the negative fifth lens.

Abstract: A wide-angle lens LN consists of, in order from an object side: a first lens group Gr1 having positive refractive power; and a second lens group Gr2 having positive refractive power; the second lens group Gr2 is movable toward the object side with fixing the first lens group Gr1, thereby carrying out focusing on a close object, and a given conditional expression is satisfied. Therefore, a wide-angle lens having high optical performance with suppressing variation in aberrations upon focusing in spite of being a large aperture, an imaging optical apparatus equipped therewith, and a digital equipment are provided.

Abstract: Disclosed is an imaging lens having a small F-number, high resolution, a sufficiently wide angle of view, and a small size. An imaging lens includes: a first lens with a meniscus shape having a concave surface facing an object side; a second positive lens; a third negative lens with a meniscus shape having a convex surface facing an image side; and a fourth negative lens. The first to fourth lenses are arranged in this order from the object side. The imaging lens is configured such that a normal line of an object-side surface of the fourth lens at a point where the outermost light beam of an on-axis light flux passes intersects the optical axis on the image side of the object-side surface.

Abstract: An optical system (10), in particular a projection objective (12), for microlithography, has an optical axis and at least one optical correction arrangement (44), which has a first optical correction element (48) and at least one second optical correction element, wherein the first correction element is provided with a first aspherical surface contour, and wherein the second correction element is provided with a second aspherical surface contour, wherein the first surface contour and the second surface contour add up at least approximately to zero, wherein the correction arrangement (44) has at least one drive for movement of at least one of the two correction elements. In this case, at least one of the two correction elements can rotate about a rotation axis which is at least approximately parallel to the optical axis, and the at least one drive is a rotary drive for rotation of one or both of the correction elements about the rotation axis.

Abstract: In order that an image pickup lens etc. may be realized which make it possible to easily realize an arrangement which reduces a possibility of deterioration of an optical characteristic, and which is suitable for a reduction in manufacturing costs and for mass-production, an image pickup lens of the present invention satisfies the following formulas (1) and (2); 1.0<d1/d12<1.8 ??(1); and 0.

Abstract: A two-lens type optical lens system for taking image consists two lens elements with refractive power, from the object side: a positive first lens element with a convex object-side surface and a concave image-side surface, both the object-side surface and the image-side surface of the first lens element being aspheric; a positive second lens element with a concave object-side surface and a convex image-side surface, both the object-side surface and the image-side surface of the second lens element being aspheric, and an aperture stop located in front of the first lens element. A focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the optical lens system is f, a radius of curvature of the object-side surface of the second lens element is R3, and they satisfy the relations: f/f1>0.9; (f/f1)>(f/f2)>0.35; and 1/R3<?0.01 mm?1.