Abstract: The zoom lens includes, as lens groups, in order from the object side, only a first lens group having a positive power, a second lens group having a negative power, a third lens group having a positive power, a fourth lens group having a negative power, and a fifth lens group having a positive power. An aperture stop is disposed between a lens surface closest to the image side in the second lens group and a lens surface closest to the object side in the fourth lens group. During zooming, at least the first lens group, the second lens group, the third lens group, and the fourth lens group move. The first lens group consists of a negative lens, a positive lens, and a positive lens in order from the object side. The zoom lens satisfies predetermined conditional expressions.

Abstract: The present disclosure discloses a camera lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens. The first lens has a positive refractive power; the second lens has a positive refractive power; the third lens has a refractive power; the fourth lens has a refractive power and an object-side surface thereof is a convex surface; the fifth lens has a positive refractive power; and the sixth lens has a negative refractive power. Half of a diagonal length ImgH of an effective pixel area on an imaging plane of the camera lens assembly and a total effective focal length f of the camera lens assembly satisfy 0.4<ImgH/f<0.6.

Abstract: An optical imaging lens includes a first lens element to a fifth lens element from an object side to an image side in order along an optical axis, and each lens element has an object-side surface and an image-side surface. An optical axis region of the image-side surface of the first lens element is concave, a periphery region of the image-side surface of the fourth lens element is concave, an optical axis region of the object-side surface of the fifth lens element is convex, and a periphery region of the image-side surface of the fifth lens element is convex. EFL is an effective focal length of the optical imaging lens and TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis to satisfy 1.1?EFL/TTL?1.6.

Abstract: An optical imaging lens including a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element having refracting power arranged in sequence from an object side to an image side is provided. Twice of an Abbe number of the fourth lens element is greater than a sum of an Abbe number of the second lens element, an Abbe number of the third lens element, and an Abbe number of the fifth lens element. Other optical imaging lenses are also provided.

Abstract: A converter optical system includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having negative refractive power; and a fifth lens having positive refractive power; wherein the first to fifth lenses are sequentially disposed in numerical order from the first lens to the fifth lens from an object side of the converter optical system to an image side of the converter optical system; and the fourth lens is bonded to either one or both of the third lens and the fifth lens.

Abstract: The present disclosure is directed to a converter lens device that includes a first mount to which a master lens device is capable of being attached, a second mount to which a camera body is capable of being attached and a converter lens having a negative refractive power, wherein, an optical system comprising the converter lens device and the master lens device has a focal length longer than a focal length of an optical system of the master lens device, the converter lens comprises sequentially from an object side, a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, and a third lens unit.

Abstract: There are provided a subminiature optical system having a miniature size and capable of obtaining a narrow view angle using only five sheets of lenses, and a portable device having the same. The subminiature optical system includes a first lens convex toward the object side and having positive refractive power. a second lens concave toward an image side and having negative refractive power, a third lens convex toward the object side and having positive refractive power, a fourth lens concave toward the image plane and having negative refractive power, and a fifth lens convex toward the image plane and having negative or positive refractive power, sequentially from an object side.

Abstract: An imaging lens substantially consisting of a first lens group, a stop, and a second lens group in this order from the object side, the first lens group includes at least a positive lens, a negative meniscus lens with a convex surface toward the object side, a biconcave negative lens, and a cemented lens substantially constituted by two lenses, which are a positive lens and a negative lens, in this order from the object side; the second lens group includes at least a first positive lens with a convex surface toward the image side, a cemented lens substantially constituted by two lenses, which are a positive lens and a negative lens, and a second positive lens with a convex surface toward the image side, in this order from the object side; and a predetermined conditional expression is satisfied.

Abstract: The present invention is directed to an imaging lens with an optical system that comprises the foremost lens group closest to an object and of positive refractivity, the succeeding middle lens group, and the rearmost lens group closest to an image plane and of negative refractivity where the middle lens group, having the first, second, and third lens subgroups disposed in series, is moved axially along the optical axis for focusing, and the foremost lens group includes at least three or more convex lens pieces and a single concave lens piece and meets predetermined requirements defined in formulae. The imaging lens has a quality image stabilizing system in which a light-weight lens piece(s) is moved in directions perpendicular to the optical axis.

Abstract: An optical imaging lens set includes: a first lens element with positive refractive power, a second lens element having an image-side surface with a concave portion in a vicinity of its periphery, a third lens element with positive refractive power, having a convex image-side surface, an object-side surface with a concave portion in a vicinity of its periphery, a fourth lens element having a concave object-side surface, and a plastic fifth lens element having an image-side surface with a concave portion in a vicinity of the optical axis. The total thickness Ta1 of the all lens elements along the optical axis, all four air gaps Gaa between each lens element along the optical axis, the thickness T3 of the third lens element along the optical axis and the thickness T5 of the fifth lens element along the optical axis satisfy the relation (Ta1+Gaa)/(T3+T5)?4.00.

Abstract: An imaging lens substantially includes five lenses, constituted by: 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 convex surface that faces an object side; a fourth lens having a negative refractive power and a meniscus shape with a concave surface that faces the object side; and a fifth lens having a positive refractive power, a meniscus shape with a convex surface that faces the object side, and at least one inflection point on the surface thereof toward an image side.

Abstract: An imaging 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. The first lens element with positive refractive power has a convex object-side surface and a convex image-side surface. The second lens element with negative refractive power has a concave image-side surface. The third lens element has positive refractive power. The plastic fourth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, wherein the surfaces are aspheric. The plastic fifth lens element has a concave image-side surface, wherein an object-side surface and the image-side surface are aspheric, and at least one surface has at least one inflection point.

Abstract: An image capturing lens system includes five non-cemented 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, a fourth lens element and a fifth 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 has negative refractive power. The third lens element has positive refractive power. The fourth lens element with negative refractive power has a concave object-side surface in a paraxial region thereof. The fifth lens element with refractive power has a concave image-side surface in a paraxial region thereof, wherein both of the surfaces thereof are aspheric, and at least one inflection point is formed on the image-side surface thereof. The image capturing lens system has a total of five lens elements with refractive power.

Abstract: A large aperture zoom optical system and an image pickup apparatus have a five-lens-group arrangement of positive-negative-positive-negative-positive refractive powers. At the time of zooming, the fifth lens group is fixed, and at least the second lens group, the third lens group and the fourth lens group are moved. The third lens group for use in focusing is composed of a single lens element.

Abstract: This disclosure provides an optical image capturing lens system comprising: a positive first lens element having a convex object-side surface, a negative second lens element, a positive third lens element having a convex image-side surface, a fourth lens element having a concave object-side surface and a convex image-side surface; and a positive fifth lens element having a convex object-side surface at a paraxial region thereof, both of the object-side and image-side surfaces being aspheric, and at least one inflection point is positioned on at least one of the object-side and image-side surfaces thereof. When particular relations are satisfied, the angle at which light projects onto the image plane can be efficiently controlled for increasing the relative illumination and preventing the occurrence of vignetting.

Abstract: The zoom lens includes a front unit including a first positive lens unit and a second positive or negative lens unit, a reflective mirror and a rear unit including two or more lens units. During zooming, the reflective mirror is not moved, and the first lens unit and at least two lens units of the rear unit are moved. When the zoom lens is retracted into a body of an image pickup apparatus, at least one of rotation of the reflective mirror such that a normal line thereto is brought closer to parallel to an optical axis of the rear unit and axial movement thereof in a direction of the optical axis of the rear unit is performed. The front unit is moved into a space formed by the at least one of the rotation and the axial movement. Conditions of 10.5<ft/|fn|<30.0 and 0.80<(Lf?L)/Lm<1.30 are satisfied.

Abstract: An 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. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element has refractive power. The fourth lens element has refractive power, wherein both of an object-side surface and an image-side surface thereof are aspheric. The fifth lens element with positive 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 thereof are aspheric. Each of the first through fifth lens elements with refractive power is single and non-cemented. The image capturing lens assembly has a total of five lens elements with refractive power.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power. In the zoom lens, during zooming from a wide-angle end to a telephoto end, the first lens unit is configured to remain stationary, the second lens unit, the third lens unit, and the fourth lens unit are configured to move separately from one another, and the aperture stop is configured to move along a locus convex towards the object side.

Abstract: A zoom lens includes first to fifth lens units arranged sequentially from object to image sides and having respective refractive powers. Compared to a wide-angle end, at a telephoto end, the distance between the first and second lens units, the distance between the third and fourth lens units, and the distance between the fourth and fifth lens units are increased, and the distance between the second and third lens units is decreased. Compared to the wide-angle end, at the telephoto end, the first lens unit is positioned closer to the object side. The first and second lens units each consist of a positive lens element and a negative lens element. The distances between the third and fourth lens units at the wide-angle and telephoto ends D34w and D34t and the focal length of the entire zoom lens at the wide-angle end fw are appropriately set.

Abstract: A zoom lens includes first to third lens units having positive, negative, and positive refractive power, respectively, and a rear lens group having positive refractive power. An aperture stop is arranged between a lens surface of the second lens unit closest to the image side and a lens surface of the third lens unit closest to the image side. The third lens unit includes first and second positive lenses each including an aspheric surface, and a negative lens. In the third lens unit, a refractive index of the first positive lens, and an Abbe number and relative partial dispersion of the second positive lens are appropriately set.

Abstract: A zoom lens includes, from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power. During zooming, the first lens unit and the aperture stop do not move and the second, third, and fourth lens units move along different loci. Lateral magnifications of the second lens unit at a wide angle end and at a telephoto end and lateral magnifications of the third lens unit at the wide angle end and at the telephoto end are each appropriately set based on predetermined mathematical conditions.

Abstract: A zoom lens includes, in order from an object side to an image side, first to fifth lens units respectively having positive, negative, positive, negative, and positive refractive powers. During zooming from a wide-angle end to a telephoto end, each of the lens units moves in such a way that a distance between the first and second lens units increases, a distance between the second and third lens units decreases, a distance between the third and fourth lens units increases, and a distance between the fourth and fifth lens units increases. The distances D34w and D34t between the third and fourth lens units, the distances D45w and D45t between the fourth and fifth lens units, focal lengths fw and ft of the entire zoom lens, and focal lengths f1 and f4 of the first and fourth lens units are appropriately set.

Abstract: A zoom lens including a first lens unit having a positive refractive power, a second lens unit having a negative reflective power, a third lens unit having a positive refractive power, and a rear lens group including one or more lens units in this order from an object side to an image side, wherein distances between the respective lens units vary during the zooming operation, wherein the first lens unit consists of three lenses including one negative lens, and a partial dispersion ratio of a material for the negative lens of the first lens unit, an Abbe number of the same, a focal length of the entire system at a wide angle end and a focal length of the first lens unit are set individually and adequately.

Abstract: A photographing 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 and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with positive refractive power is made of plastic material and has a convex object-side surface and a convex image-side surface. The fourth lens element with negative refractive power is made of plastic material and has a concave object-side surface and a convex image-side surface. The fifth lens element with refractive power is made of plastic material and has a concave image-side surface, wherein the fifth lens element has at least one inflection point. The object-side surfaces and the image-side surfaces of the third through fifth lens elements are aspheric.

Abstract: An optical 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, 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 positive refractive power has a convex object-side surface and a concave image-side surface. The second lens element has refractive power. The third lens element has positive refractive power. The fourth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, and the surfaces of the fourth lens element are aspheric. The fifth lens element with refractive power has a concave image-side surface, and the surfaces of the fifth lens element are aspheric. The fifth lens element has at least one inflection point formed on the image-side surface thereof.

Abstract: An imaging lens substantially consists of five lenses of an aspheric first lens having a convex surface facing an object side and positive refractive power, an aspheric second lens having a concave surface facing the object side and negative refractive power, an aspheric third lens having a meniscus shape in which its object-side surface is convex toward the object side, and positive refractive power, an aspheric fourth lens having negative refractive power and a fifth lens having a convex surface facing the object side and positive refractive power, which are in this order from the object side. Further, the imaging lens satisfies predetermined conditional formulas.

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, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with refractive power is made of plastic material, and has at least one surface being aspheric. The fourth lens element with refractive power is made of plastic material, and has a concave object-side surface and a convex image-side surface, wherein at least one surface of the fourth lens element is aspheric. The fifth lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface, wherein at least one surface of the fifth lens element is aspheric.

Abstract: An optical imaging lens assembly, sequentially arranged from an object side to an image side along an optical axis, comprising: the first lens element with positive refractive power having a convex object-side surface, the second lens element with negative refractive power having a convex object-side surface and a concave image-side surface, the third lens element with positive refractive power having a convex image-side surface, the fourth lens element with refractive power having both optical surfaces being aspheric, the fifth lens element with refractive power having a concave image-side surface and both optical surfaces being aspheric, wherein a stop and an image sensor disposed on an image plane are also provided. By such arrangements, the image pickup optical system satisfies conditions related to shorten the total length and to reduce the sensitivity for use in compact cameras and mobile phones with camera functionalities.

Abstract: The present invention provides an imaging lens assembly, comprising in order from an object side toward an image side, a first lens element with positive 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 having a concave object-side surface and a convex image-side surface, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and an aperture stop positioned between an imaged object and the first lens element. The above lens arrangement shortens the total track length effectively, enabling a high performance imaging lens assembly with a wide field of view.

Abstract: A zoom lens including first to fifth lens units in order from an object side toward an image. The refractive powers of the first to the fifth lens units are positive, negative, positive, negative and positive, respectively. The distance between the first and the second lens units is increased at the time of zooming from the wide angle end to the telephoto end, and the distance between the second and the third lens unit is decreased at the time of zooming from the wide angle end to the telephoto end. The first lens unit and the fourth lens unit are fixed for the zooming. When M2 and M3 are the amounts of movement of the second lens unit and the third lens unit at the time of zooming from the wide angle end to the telephoto end, respectively, the conditional expression; 0.2<|M2/M3|<5.0 is satisfied.

Abstract: This invention provides an image capturing lens system in order from an object side to an image side comprising five lens elements with refractive power: 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 both the object-side and image-side surfaces thereof being aspheric; a plastic fourth lens element with both the object-side and image-side surfaces thereof being aspheric; and a plastic fifth lens element having a concave image-side surface, both the object-side and image-side surfaces thereof being aspheric, and at least one inflection point is formed on at least one of the object-side and image-side surfaces thereof. By such arrangement, the lens system of the invention has larger chief ray angle, and thereby not only the total track length of the system can be reduced, but also better image quality can be obtained.

Abstract: An optical system including five lens units having, in order from the object side, positive, negative, positive, negative, positive refracting powers respectively. The distances between the lens units change during zooming. The first and third lens units are located closer to the object side at the telephoto end than at the wide angle end of the zoom range. The first lens unit includes a negative lens, a first positive lens, and a second positive lens. The second lens unit includes a plurality of negative lenses and at least one positive lens. The third lens unit includes a plurality of positive lenses and at least one negative lens. The fourth and fifth lens units each include two lenses or less. The refractive indices of the at least one negative lens in the first lens unit, the at least one positive lens in the second lens unit, and the at least one negative lens in the third lens unit are not lower than 1.9. The optical system satisfies a certain condition.

Abstract: An photographing optical lens assembly includes, in order from an object side to an image side, a first lens element with positive refractive power, a second lens element with negative refractive power having a concave object-side surface and a concave image-side surface, a plastic third lens element with positive refractive power having a concave aspheric object-side surface and a convex aspheric image-side surface, a plastic fourth lens element with negative refractive power having a concave aspheric object-side surface and a convex aspheric image-side surface and a plastic fifth lens element having an aspheric object-side surface and an aspheric image-side surface. By adjusting the focal lengths of the second and the fourth lens element and the photographing optical lens assembly, and the curvature radii of the object-side and the image-side surface of the second lens element, the photographing optical lens assembly is miniaturized, and the image quality is improved.

Abstract: A zoom lens comprising, in order from an object side thereof, a first lens group of positive refracting power, a second lens group of negative refracting power, an aperture stop, a third lens group of positive refracting power, a fourth lens group of negative refracting power, and a fifth lens group of positive refracting power. Upon zooming from the wide-angle end to the telephoto end, at least the first lens group and the aperture stop remain fixed in position, the second and third lens groups move in the optical axis direction, and the separation between each of the lens groups and the aperture stop changes. Upon focusing from a focusing-on-infinity state to a close-range-focusing state, the fourth lens group moves in the optical axis direction, with satisfaction of the following: ?0.36<f4/f1<?0.05??(1A), where fl and f4 are the focal lengths of the first and fourth lens groups, respectively.

Abstract: Disclosed herein is a variable focal length lens system including a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group. The first to the fifth lens groups are arranged in order from an object side. The variable focal length lens system satisfies following conditional expressions (1) to (3): 0.95<f13T/ft<1.4??(1) 0.08<f2/f4<0.3??(2) 0.06<?3/ft<0.22??(3) where f13T is combined focal length of the first to third lens groups in the telephoto end state, ft is focal length of the lens system as a whole in the telephoto end state, f2 is focal length of the second lens group, f4 is focal length of the fourth lens group, and ?3 is an amount of travel of the third lens group from the wide-angle end state to the telephoto end state.

Abstract: An projection optical system for an i-line projection exposure apparatus includes positive, negative, positive, negative and positive lens units which include a lens having an Abbe number equal to or smaller than 62. 0.125?NAO, ?0.251<?<?0.249, 80 mm?|OB1max|, 20 mm?|OB2max|, |Dt/(NAO·|OB1max|)|?62.0, Dt/Td?0.645, 0.072?|OB1max|/Td| are met, where NAO is a numerical aperture on the object plane, ? is an imaging magnification, Td is a distance on an optical axis from the object plane to the image plane, Dt is a sum of thicknesses of the glass materials on the optical axis in the projection optical system, OB1max is a maximum object height on the object plane, and OB2max is a maximum image height on the image plane.

Abstract: The present invention provides an imaging lens assembly, comprising in order from an object side toward an image side, a first lens element with positive 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 having a concave object-side surface and a convex image-side surface, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and an aperture stop positioned between an imaged object and the first lens element. The above lens arrangement shortens the total track length effectively, enabling a high performance imaging lens assembly with a wide field of view.

Abstract: An image pickup optical lens assembly, sequentially arranged from an object side to an image side along an optical axis, comprising: the first lens element with positive refractive power having a convex object-side surface, the second lens element with negative refractive power, the third lens element with refractive power, the fourth lens element with positive or negative refractive power having a concave object-side surface and a convex image-side surface with both being aspheric, and the fifth lens element with positive or negative refractive power having a convex object-side surface and a concave image-side surface with both being aspheric. Additionally, the image pickup optical lens assembly satisfies conditions related to the reduction of the total length and the sensitivity of the image pickup optical lens assembly for compact cameras and mobile phones with camera functionalities.

Abstract: A zoom lens comprises, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit, and a fourth lens unit having a positive refractive power. The fourth lens unit includes a forty-first lens unit having a negative refractive power and arranged at the object side with reference to the longest air gap and a forty-second lens unit having a positive refractive power and arranged at the image side with reference to the air gap. The forty-first lens unit includes a negative 411st lens, and the forty-second lens unit includes a positive 421st lens. Abbe numbers and partial dispersion ratios of materials of the 411st lens and the 421st lens ?d411, ?gF411, ?d421 and ?gF421 are appropriately set.

Abstract: An imaging lens includes at least a first positive lens group, a first negative lens group that moves during focusing, a second positive lens group that moves during focusing, a second negative lens group that can move in a direction substantially vertical to an optical axis, and a positive lens group, which are disposed in order from an object, wherein a condition of an expression, which is 2.0<(?f4)/d34<20.

Abstract: This invention provides an imaging optical lens assembly including: in order from an object side toward an image side: a first lens with positive refractive power and having a convex object-side surface, a second lens with negative refractive power and having a convex object-side surface and a concave image-side surface, a third lens with positive refractive power and having a concave object-side surface and a convex image-side surface, a fourth lens with negative refractive power and having a concave image-side surface, the object-side and image-side surfaces being aspheric, and a fifth lens having a concave image-side surface, the object-side and image-side surfaces being aspheric. The imaging optical lens assembly further comprises an aperture stop, disposed between an imaged object and the second lens, and an electronic sensor, disposed at the image plane for image formation.

Abstract: An image-capture apparatus includes a variable magnification lens, imaging means for converting an image taken by the variable magnification lens into an electrical image signal, and imaging control means. By referring to a conversion coordinate coefficient, the image control means moves a point on the image and outputs the new image signal. In the variable magnification lens, in order from the object side, a first lens group having positive refractive power, a second lens group that has negative refractive power and performs a variable magnification action by shifting on an optical axis, a third lens group having positive refractive power, a fourth lens group that has negative refractive power and a fifth lens group having positive refractive power are arrayed.

Abstract: The present invention provides an imaging lens system 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; a second lens element with negative refractive power; a third lens element with positive refractive power, at least one of the object-side and image-side surfaces thereof being aspheric; a fourth lens element, the image-side surface thereof being aspheric and provided with at least one inflection point; a fifth lens element having a concave object-side surface, at least one of the object-side and image-side surfaces thereof being aspheric; and an aperture stop disposed between an imaged object and the second lens element. Such an arrangement of optical elements can effectively reduce the total track length and sensitivity of the optical system, and image quality can also be improved.

Abstract: The present invention provides an imaging lens assembly, comprising in order from an object side toward an image side, a first lens element with positive 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 having a concave object-side surface and a convex image-side surface, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and an aperture stop positioned between an imaged object and the first lens element. The above lens arrangement shortens the total track length effectively, enabling a high performance imaging lens assembly with a wide field of view.

Abstract: A zoom lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power. The first to fifth lens units are arranged in order from the object side to the image side. All of the lens units are moved during zooming from the wide-angle end to the telephoto end such that the distance between the first lens unit and the second lens unit is increased and the distance between the third lens unit and the fifth lens unit is increased. The refractive power of the fourth lens unit and the refractive power of the fifth lens unit are adequately set with respect to the zoom ratio.

Abstract: An optical lens system for taking image comprises, in order from the object side to the image side: 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; a fourth lens element with positive refractive power; a fifth lens element with refractive power; and an aperture stop located between an object to be photographed and the second lens element. In the optical lens system for taking image, the number of the lens elements with refractive power being limited to five. Such lens arrangements can effectively reduce the volume of the optical lens system, reduce the sensitivity of the optical lens system and obtain higher resolution.

Abstract: The present invention discloses a large-field unit-magnification projection optical system. The optical system includes an optical axis, a spherical concave reflection mirror; a lens group with positive refracting power arranged adjacent the mirror with an air space therebetween. The lens group includes a first plano-convex lens, a negative meniscus lens adjacent the plano-convex lens, a positive lens adjacent the negative meniscus lens, a negative double-convex lens spaced apart far from the positive lens, and a second plano-convex lens. The optical system further includes a pair of prisms each having respective first and second surface. The second surfaces are arranged adjacent the flat surface of the plano-convex lens element on opposite sides of the optical axis and the first surfaces are arranged adjacent object planes and image planes, respectively.

Abstract: An projection optical system for an i-line projection exposure apparatus includes positive, negative, positive, negative and positive lens units which include a lens having an Abbe number equal to or smaller than 62. 0.125?NAO, ?0.251<?<?0.249, 80 mm?|OB1max|, 20 mm?|OB2max|, |Dt/(NAO·|OB1max|)|?62.0, Dt/Td?0.645, 0.072?|OB1max|/Td| are met, where NAO is a numerical aperture on the object plane, ? is an imaging magnification, Td is a distance on an optical axis from the object plane to the image plane, Dt is a sum of thicknesses of the glass materials on the optical axis in the projection optical system, OB1max is a maximum object height on the object plane, and OB2max is a maximum image height on the image plane.

Abstract: A zoom lens system has a front lens group and a rear lens group along the optical axis and in order from the object side. The rear lens group has a first lens unit having a positive refracting power, a second lens unit having a negative refracting power, and a third lens unit having a positive refracting power. Upon zooming from a wide-angle end state to a telephoto end state, a space between the front lens group and the first lens unit varies, a space between the first lens unit and the second lens unit increases, and a space between the second lens unit and the third lens unit decreases. At least a part of the second lens unit is movable so as to have a component in a direction perpendicular to the optical axis.

Abstract: A zoom lens includes first to fourth lens units which respectively have negative, positive, negative, and positive refractive powers in order from the object side to the image side. Distances between the first and second lens units, the second and third lens units, and the third and fourth lens units at the telephoto end are respectively smaller, larger, and smaller than those at the wide-angle end. An Abbe number ?1n and a partial dispersion ratio ?1n of a material of at least one negative lens included in the first lens unit, an Abbe number ?1p, a partial dispersion ratio ?1p, and a refractive index N1p, respectively, of a material of at least one positive lens included in the first lens unit, a focal length f1 of the first lens unit, and a focal length fw of the entire system at the wide-angle end are adequately set.