Abstract: An eyepiece lens is constructed with, in order from an entrance side for light to an exit side for light, first, second, third, fourth and fifth lens units of negative, positive, positive, positive and positive refractive powers, respectively. Each of the first, second, third, fourth and fifth lens units of the eyepiece lens is composed only of one lens or a cemented lens, and an intermediate image by an objective lens is formed between the second lens unit and the third lens unit. An objective lens is constructed with, in order from an object side to an image side, first and second lens units of positive and negative refractive powers, respectively. The first and second lens units of the objective lens are composed of one positive lens and of one positive lens and one negative lens, respectively, and the various conditions are appropriately set. An optical apparatus includes the eyepiece lens, the objective lens and an erecting prism.

Abstract: A dioptric projection optical system for imaging a reduced image of a pattern on a first surface onto a second surface using radiation-transmitting refractors. The projection optical system has a front lens unit of a positive refracting power and a rear lens unit of a positive refracting power. An aperture stop is located in the vicinity of a rear focal point of the front lens unit.

Abstract: A dioptric projection optical system projects an image of a first surface onto a second surface and includes a first lens group having a negative refractive power and arranged in an optical path between the first surface and the second surface, a second lens group having a positive refractive power and arranged in an optical path between the first lens group and the second surface, a third lens group having a negative refractive power and arranged in an optical path between the second lens group and the second surface, a fourth lens group having an aperture stop and arranged in an optical path between the third lens group and the second surface, and a fifth lens group having a positive refractive power and arranged in an optical path between the fourth lens group and the second surface, wherein lens components belonging to the dioptric projection optical system are formed of at least two types of fluorides, and wherein a clear aperture of a light beam in the projection optical system is at a relative maximum

Abstract: A projection exposure system, intended in particular for microlithography, is used for generating, in an image plane, an image of a mask arranged in an object plane. The projection exposure system has a light source emitting projection light and projection optics arranged between the mask and the image. Starting from the mask, the following are arranged in the beam path of the projection optics: a first group of optical components with an overall positive refractive power; a second group of optical components with an overall negative refractive power; a third group of optical components with an overall positive refractive power; a fourth group of optical components with an overall negative refractive power, and, a fifth group of optical components with an overall positive refractive power. At least three optical subgroups having at least one optical component can be displaced along the optical axis of the projection optics.

Abstract: An object of the present invention is to provide a projection optical system having a large numerical aperture in which the maximum effective diameter of lens of the optical system is satisfactorily small.

Abstract: A Gaussian lens having no more than six lens elements of refractive power is formed of, in order from the object side: a first lens element which is biconvex, a second lens element which is a positive meniscus lens with its convex surface on the object side, a third lens element which is biconcave, a stop, a joined lens formed of a fourth lens element which is biconcave that is joined to a fifth lens element which is biconvex; and a sixth lens element having positive refractive power. Specified conditions are satisfied in order to provide a compact lens having an f-number FNO of 1.44 or less, an image angle 2&ohgr; of 23.8 degrees or more, and wherein the various aberrations are favorably corrected. The Gaussian lens of the invention is intended for mounting in monitor cameras.

Abstract: Provided is a single-focus lens in which cost reduction and a simple configuration with a shorter overall length are realized as well as preferable optical performance is achieved. In the single-focus lens, consecutively arranged form the object side are a first lens which is a meniscus lens and its concave surface faces the object side, a second lens which is a meniscus lens and has at least one aspheric surface, a third lens, both of whose surfaces are concave surfaces, a fourth lens, both of whose surfaces are convex surfaces and a fifth lens which is a meniscus lens and its concave surface faces the image surface, the fifth lens having at least one aspheric surface. Preferably, the second lens and the fifth lens are made of optical plastics.

Abstract: A zoom lens includes a first lens band having a positive focal length, a second lens band having a negative focal length, and at least third to fifth lens bands having positive focal lengths. An aperture diaphragm is located in the vicinity of the third lens band. When magnification i.e., zooming is performed from short to long focal point ends, the second lens band smoothly moves toward the third lens band and the fourth lens band simultaneously moves from the fifth lens band side toward a long focal point end so as to share a magnification function together with the second lens band.

Abstract: An optical projection lens system comprising one lens with an aspherical surface and comprising a first bulge followed by a first waist followed by a second bulge, wherein the diameter of the second bulge is smaller than the diameter of the first bulge.

Abstract: An imaging lens comprises, successively from an object side, a positive first lens L1 having a convex surface directed onto the object side, a negative second lens L2 having a concave surface directed onto an image side, a third lens L3 of a positive meniscus form having a convex surface directed onto the object side, a fourth lens L4 of a positive meniscus form having a convex surface directed onto the image side, a negative fifth lens L5 having a concave surface directed onto the object side, and a positive sixth lens L6 having a convex surface directed onto the image side, the first lens L1 and the second lens L2 being cemented to each other, the fifth lens L5 and the sixth lens L6 being cemented to each other, the imaging lens satisfying the following conditional expressions: 0.01<d6/f<0.17 0.9<f3/f<1.8 −0.4<f/f12<0.4 0.51<f34/f<0.72 1.15<v1/v2<1.

Abstract: A color image readout lens usable within a magnification range from −0.6X to −1.7X comprises, successively from the object side, a first lens group G1 comprising by a lens having a positive refracting power with a convex surface directed onto the object side, a second lens group G2, comprising by a cemented lens, composed of a biconvex lens and a biconcave lens, having a negative refracting power as a whole with a convex surface directed onto the object side, a third lens group G3, comprising a cemented lens, composed of a biconcave lens and a biconvex lens, having a negative refracting power as a whole with a convex surface directed onto an image side, a fourth lens group G4 comprising a positive lens with a convex surface directed onto the image side, and a fifth lens group G5 comprising a negative meniscus lens with a stronger concave surface directed onto the object side. The color image readout lens further satisfies predetermined conditional expressions.

Abstract: Provided is a single-focus lens in which cost reduction and a simple configuration with a shorter overall length are realized as well as preferable optical performance is achieved. In the single-focus lens, consecutively arranged form the object side are a first lens which is a meniscus lens and its concave surface faces the object side, a second lens which is a meniscus lens and has at least one aspheric surface, a third lens, both of whose surfaces are concave surfaces, a fourth lens, both of whose surfaces are convex surfaces and a fifth lens which is a meniscus lens and its concave surface faces the image surface, the fifth lens having at least one aspheric surface. Preferably, the second lens and the fifth lens are made of optical plastics.

Abstract: An attachment lens optical system for extending a focal length of a camera lens and balancing axial chromatic aberrations of the camera lens comprises, in order from the object side, a first lens group having a negative power single lens element, a second lens group including a cemented doublet of a biconcave lens element and a biconvex lens element, a positive power third lens group including three lens elements, and a negative power fourth lens group including a cemented doublet of two lens elements.

Abstract: A photographic lens for an electronic still camera having five lens components, with refractive powers in sequential order from the most object side, as follows: negative, positive, positive, negative and positive. A stop is positioned between the second lens component and the third lens component. The photographic lens has a short overall length, a wide angle of view, a large numerical aperture, and high resolution as a result of the lens being favorably corrected for aberrations. The first lens component includes at least one ashperical surface, the second lens component has a convex surface on the image side, the third lens component has at least one aspherical surface, and has a convex surface on the image side. The fourth lens component has a concave surface on the object side, and the fifth lens component has a convex surface on the image side.

Abstract: An eyepiece lens is constructed with, in order from an entrance side for light to an exit side for light, first, second, third, fourth and fifth lens units of negative, positive, positive, positive and positive refractive powers, respectively. Each of the first, second, third, fourth and fifth lens units of the eyepiece lens is composed only of one lens or a cemented lens, and an intermediate image by an objective lens is formed between the second lens unit and the third lens unit. An objective lens is constructed with, in order from an object side to an image side, first and second lens units of positive and negative refractive powers, respectively. The first and second lens units of the objective lens are composed of one positive lens and of one positive lens and one negative lens, respectively, and the various conditions are appropriately set. An optical apparatus includes the eyepiece lens, the objective lens and an erecting prism.

Abstract: An imaging lens comprises a front group constituted by a first lens L1 made of a negative meniscus lens having a convex surface directed onto the object side, the object-side surface thereof being made aspheric, and a second lens L2 made of a biconvex lens having a surface with a larger curvature directed onto the object side; and a rear group constituted by a third lens L3 made of a biconcave lens and two biconvex lenses L4, L5. Letting d be the distance from the object-side surface of the first lens L1 to the image-side surface of the second lens L2, f be the focal length of the whole lens system, and nA and &ngr;A be average values of refractive index and Abbe number, respectively, in the two biconvex lenses L4, L5, the imaging lens satisfies 1.0<d/f<2.0, nA>1.76, and &ngr;A>45.0.

Abstract: A compact, bright wide-angle lens including at least five lens elements, as follows, in order from the object side: a negative lens element, a positive lens element, a negative lens element, a positive lens element and a negative lens element. The large aperture, wide-angle lens is provided with favorable image formation capability throughout the entire field of view by arranging, as the negative lens element on the extreme object side, a meniscus lens with its concave surface on the object side, the meniscus lens having at least one aspherical surface and satisfying the following condition:-0.9<(R.sub.1 -R.sub.2)/(R.sub.1 +R.sub.2)whereR.sub.1 is the radius of curvature of the surface on the object side of the meniscus lens, andR.sub.2 is the radius of curvature of the surface of the image side of the meniscus lens.

Abstract: A super wide angle lens, having a viewing angle greater than 120 degrees, and an F-number of about 1.2 is disclosed. The lens is formed of a first lens group G.sub.1 of negative refractive power, a second lens group G.sub.2 of positive refractive power, and a third lens group G.sub.3 of positive refractive power. The lens is designed so that the lens elements used in the lens groups may be easily and economically manufactured. The first lens group has a first lens element L.sub.1 composed of a negative meniscus lens with its convex surface on the object side, and a second lens element L.sub.2 composed of a negative meniscus lens with its convex surface on the object side. The second lens group includes a third lens element L.sub.3, that is biconcave, cemented to a fourth lens element L.sub.4 that is biconvex. The third lens group has four lens elements: a fifth lens element L.sub.5 composed of a negative meniscus lens, with its convex surface on the object side; a sixth lens element L.sub.

Abstract: A collimator lens having five lens elements of negative, negative, positive, positive, and negative refractive power, in order from a collimated luminous flux side of the collimator lens, and designed to have a large back focus, to thereby prevent heat from the light source from causing aberrations in the collimator lens. The collimator lens includes a negative first lens element L.sub.1 of a meniscus shape with its concave surface on the collimated luminous flux side, a positive fourth lens element L.sub.4 with a convex surface on the collimated luminous flux side, and a negative fifth lens element L.sub.5 with a concave surface on the collimated luminous flux side. In addition, a diaphragm stop is arranged on the collimated luminous flux side of the first lens element, and certain conditions are satisfied to reduce aberrations and provide a large back focus.

Abstract: A projection lens system that is used to transfer a pattern from a reticle onto a wafer, incorporates a projection optical system that is capable of maintaining the same, or increased performance, as the current projection lens systems, and that achieves excellent aberration correction, has a numerical aperture of at least 0.6, an exposure field area of at least 18.7.times.18.7 mm or at least 26.45 mm diameter at the wafer plane, and has a total lens thickness to length ratio less than 0.64 and uses 5 or less aspherical lens surfaces.

Abstract: Successively from an object side, a negative lens having a concave surface directed onto an image surface side, a positive meniscus lens having a convex surface directed onto the image surface side, a positive lens having a convex surface directed onto the image surface side, a negative lens having a concave surface directed onto the image surface side, and a biconvex lens are disposed, thereby yielding a photographic lens for electronic still camera which can favorably correct distortion while attaining a compact size and a wide angle of view. Successively disposed from the object side are a negative first lens L.sub.1 having a concave surface directed onto the image surface side, a second lens L.sub.2 made of a positive meniscus lens having a convex surface directed onto the image surface side, a third lens L.sub.3 made of a biconvex lens whose surface with a stronger curvature is directed onto the image surface side, a negative fourth lens L.sub.

Abstract: A compact variable focal length optical system is suitable for high zoom ratio. At least a first lens group having a positive refractive power, a second lens group, and a third lens group having a negative refractive power are provided. At least the first lens group is moved toward an object side of the system to satisfy a particular conditional equation so that a distance between the first and second lens groups is increased and a distance between the second and third lens groups is changed. In certain constructions, a first lens group having a positive refractive power, a second lens group having a negative refractive power positioned adjacent to and on an object side of the first lens group, and a third lens group positioned adjacent to and on an image side of the first lens group are provided. The first lens group includes at least two sub-lens groups.

Abstract: An image-forming lens made of five lens elements having refractive power, from the object side, of negative, negative, positive, positive, and negative. The distance between the image side of the surfaces of second and third lens elements is made greater than or equal to 3.4 f, and less than or equal to 7.5 f, where f is the focal length of the image-forming lens, so as to minimize spherical aberration, coma, and astigmatism. The image-forming lens thus formed is a retro-focus lens having a half-picture angle of about 80.degree. and an F# of about 1.8.

Abstract: This invention relates to a compact wide-angle lens which consists of five members. The first member and the last member are each divergent lenses of low deviation, which consist of low refractivity crown glass. The second member and the third member are convergent lenses made of high refractivity crown glass. The fourth member, which is the final member of the lens according to the invention, consists of a convergent lens and a divergent lens which are cemented to each other. Type of glass are used for this cemented member which have a very low difference in refractive index but a very high difference in dispersion. The convergent lens has a low dispersion and the divergent lens has a high dispersion. One of the two glass/air surfaces of the cemented member is aspherical. A lens such as this according to the invention has a maximum aperture ratio of at least 1:5.6 and an image angle of 105.degree.. The chromatic correction is well defined and is very substantially independent of the distance of the object.

Abstract: An aberration-controllable optical system has a large angle of view and is capable of continuously varying spherical aberrations from negative values to positive values, including a point at which a sharp image can be produced. A master lens group includes a first sub lens group having a positive refractive power, a second sub lens group having a negative refractive power, and a third sub lens group having a positive refractive power in this order from the object side of the system. The converter lens group includes a positive lens element and a negative lens element in this order from the object side. The on-axis distance of the air gap which is formed between the positive lens element and the negative lens element can be controlled to mainly change the spherical aberrations in this system. When f.sub.m is a master lens group focal length and f.sub.C is a converter lens group focal length, the aberration-controllable optical system satisfies a condition:-1<f.sub.M /f.sub.C <0.

Abstract: A zoom lens system with vibration-reduction function, comprising, in order from an object side:a first lens group having a positive refractive power;a second lens group having a negative refractive power;a third lens group having a negative refractive power;a fourth lens group having a positive refractive power; anda fifth lens group having a negative refractive power;wherein, when zooming, each of the distances between the first and second lens groups, the second and third lens groups, the third and fourth lens groups, and the fourth and fifth lens groups, respectively, changes. The fourth lens group has a shift lens unit movable in a direction across an optical axis, has positive refractive power, and a fixed lens unit fixed in the direction across the optical axis.

Abstract: A short wavelength reduction projection optical system used for transferring integrated circuit patterns from a reticle to a wafer in a semiconductor manufacturing system. The optical system has object side and image side virtually telecentric, high resolution over a wide exposure area, and adequately compensates for optical aberrations without increasing the length of the optical system. The optical system has a first group of lenses with weak refractive power, a second group of lenses with a positive refractive power, a third group of lenses with a negative refractive power, a fourth group of lenses with a positive refractive power, and an aperture stop located between the third and fourth groups of lenses.

Abstract: A zoom lens includes a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, a fourth lens group having a negative refracting power, and a fifth lens group having a positive refracting power in this order from the object side in order to perform zooming by varying the distance between the lens groups, the fifth lens having at least one positive lens and a cemented lens which has a negative refractive index as a whole, its positive lens being cemented to its negative lens, and the cemented surface being convex on the image side.

Abstract: A telephoto zoom lens, sequentially from an object, comprising: a first lens group having positive refracting power; a second lens group having negative refracting power; a third lens group having negative refracting power; a fourth lens group having positive refracting power; and a fifth lens group having negative refracting power. During variable power from a wide-angle end to a telephoto end, the lens groups move so that a space dimension between the first and second lens groups increases, a space dimension between the second and third lens groups changes linearly or nonlinearly, and a space dimension between the fourth and fifth lens groups decreases. The zoom lens satisfies various conditions.

Abstract: An objective of some 10 magnifications usable with microscopes, etc. which has an increased numerical aperture and working distance, including a first lens component that is a cemented lens consisting of negative and positive lens elements, a second lens component a third lens component, a fourth lens component consisting of a cemented lens and a fifth lens component having a positive refractive power, characterized by satisfying the following conditions:.nu..sub.I2 -.nu..sub.I1 >20 (1)n.sub.I1 -n.sub.I2 >0.2 (2)wherein:n.sub.I1 is the refractive index of d-line of the negative lens element of the first component,.nu..sub.I1 is the Abbe's number of said negative lens element of the first lens component,n.sub.I2 is the refractive index for d-line of the positive lens element of the first lens component, and.nu..sub.I2 is the Abbe's number of said positive lens element of the first lens component.

Abstract: A lens for reading an original has first to fifth lens groups sequentially arranged from an object side of a lens system to an image side thereof. The first lens group is constructed by a first lens composed of a negative meniscus lens having a convex face directed on the object side. The second lens group is constructed by a second lens composed of a positive lens. The third lens group is constructed by a third lens composed of a biconcave lens. The fourth lens group is constructed by a fourth lens composed of a positive lens. The fifth lens group is constructed by a fifth lens composed of a positive meniscus lens having a convex face directed on the object side. A combined focal length f of the entire lens system, a focal length f.sub.1 of the first lens group, and a combined focal length f.sub.24 of the second to fourth lens groups satisfy the following conditions.-2.4<(f.sub.1 /f)<-1.2 (I)0.85<(f.sub.24 /f)<1.5 (II).

Abstract: An objective lens system for use with wavelengths in the visible spectrum, has first and second lens groups. The first lens group has one aplanat lens. The second lens group is a doublet. The second lens group is designed to correct for chromatic aberrations introduced by the first lens group. The power of the second lens group is inversely related to the index of refraction of the first lens group and the optical glasses of the lenses of the second lens group are selected to satisfy a novel color correction equation.

Abstract: Relay lenses for endoscopy include an axially symmetrical three-part optical component having a thin symmetrical negative element interposed between identical, substantially spherical outside elements; and an axially symmetrical five-part optical component in which the three-part component described above is disposed between two additional outer components.