Abstract: A projection lens is disclosed. The projection lens includes, in sequence from an object side to an image side: an object surface, a first lens having positive refractive power, a second lens having negative refractive power, and a third lens having positive refractive power, where a focal length of the entire projection lens is f, a total optical length of the projection lens is TTL, a refractive index of the second lens is n2, a refractive index of the third lens is n3, and the following conditions are satisfied: 1.7?n2?2.2; 1.7?n3?2.2; and 1.25?f/TTL?2.20. The projection lens can effectively reduce the system length, and has good performance stability at different temperatures.

Abstract: This invention provides an image capturing lens system comprising three non-cemented lens elements with refractive power: a first lens element with positive refractive power having a convex object-side surface, and both the object-side and image-side surfaces being aspheric; a plastic second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, and both the object-side and image-side surfaces being aspheric; and a plastic third lens element having a convex object-side surface and a concave image-side surface, and both the object-side and image-side surfaces being aspheric. By such arrangement, the space of the image capturing lens system can be allocated much more properly and thereby an image capturing lens system with shorter total track length can be obtained while retaining superior image quality.

Abstract: A fixed focal length optical lens system includes a lens group and a diaphragm. The diaphragm is located in front of the lens group. The lens group includes three lenses, respectively the first, the second and the third lens, which are sequentially arranged as a “negative-positive-positive” separated focal power system. The first lens is a plano-concave negative lens, the second lens is a positive meniscus lens, and the third lens is a double convex positive lens. All of the curved surfaces of the second lens are bent in the direction towards the diaphragm, wherein, the focal length of the entire optical system is f, the focal lengths of the first, the second and the third lens are respectively f1, f2, and f3, and which satisfies the following requirement: ?0.6<f1/f<?0.4; 1.0<f2/f<1.2; 0.6<f3/f<0.8.

Abstract: An optical lens assembly for image capture, in order from an object side to an image side, comprising: a first lens element with positive refractive power having a concave object-side surface and a convex image-side surface, a second lens element with negative refractive power having a concave object-side surfaces and a convex image-side surface, a third lens element with positive refractive power having bi-convex surface. Additionally, the optical lens assembly for image capture satisfies several desirable conditions. By such arrangements, the optical assembly for image capture can effectively correct the aberration and be used as a compact image pickup device for image taking.

Abstract: An optical lens assembly includes, 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 having a concave object-side surface and a convex image-side surface, a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface. By adjusting the conditions among the above-mentioned lens elements, the optical lens assembly can favorably reduce its size and correct the aberration while obtaining superior imaging quality.

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: An optical lens system for taking image consisting of from the object side to the image side: an aperture stop; a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, at least one of the object-side and the image-side surfaces of the second lens element being aspheric; and a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface, at least one of the object-side and the image-side surfaces of the third lens element being aspheric.

Abstract: A circuit for implementing a registration-free, contiguous conductive plane. A circuit may include a plurality of conductive structures in a first plane. The circuit may further include a contiguous conductive equipotential surface in a second plane parallel to the first plane. The circuit may further include activation means configured to adjust an electric field between the first and second planes thereby activating one or more structures in the first plane by increasing a potential difference between the first and second planes to a threshold level deemed to constitute an active state. The circuit may further include deactivation means configured to adjust the electric field between the first and second planes thereby deactivating one or more structures in the first plane by decreasing the potential difference between the first and second planes below a threshold level deemed to constitute a deactivated state.

Abstract: To provide a high-brightness, small, low-cost optical apparatus which covers a wide-angle to super-wide-angle region and which reliably corrects various aberrations with a small number of lenses. At least one negative lens unit 1, a meniscus lens 2 that is convex on an object side, an aperture stop S, and a double-convex positive lens 3 are arranged in order from the object side. At least one of the lenses positioned on the object side of the aperture stop S and the positive lens 3 include respective aspherical surfaces.

Abstract: A compact lens system includes, in succession from an object side to an image side, an aspheric first lens element (1) having a positive power, an aperture stop (4), an aspheric second lens element (2) having a negative power, and a third lens element (3) having a positive power. Both the first and second lens elements are meniscus lenses made of plastic, and the third lens element is a biconvex lens or a plano-convex lens made of glass. The first lens element has a convex surface (10) facing the object side and an opposite concave surface (11) facing the aperture stop. The second lens element has a concave surface (21) facing the aperture stop and an opposite convex surface (20) curved toward the image side. The surface (30) of the third lens element facing toward the image side has a radius of curvature larger than that of the other surface (31) facing the second lens element.

Abstract: An image forming optical system comprises, in order from an object side, a first positive meniscus lens having a convex surface directed toward an object side, an aperture stop, a second positive meniscus lens having a convex surface directed toward the object side and a negative lens. At least one of surfaces of the negative lens is a spherical and the following condition is satisfied: ?2.0<?m/?p<0 ?2.0<(r1r+r2f)/(r1r?r2f)<1.0 where ?m represents the power of the negative lens at the position of the maximum light height and ?p represents the power of the negative lens at the position of the near axis, r1r represents the radius of curvature of the first lens at the image side and r2f is the radius of curvature of the second lens at the object side.

Abstract: A single focus lens is disclosed that is formed of only three lens components. In order from the object side, these are: a first lens component that has positive refractive power and includes a first lens element; an aperture diaphragm; a second lens component that has positive refractive power, at least one aspheric lens surface, and includes a second lens element made of plastic; and a third lens component that has positive refractive power, at least one aspheric lens surface, and includes a third lens element made of plastic. The following condition is satisfied: 1.0<f1/f<5.0 where f1 is the focal length of the first lens component, and f is the focal length of the single focus lens.

Abstract: A lens system includes a plastic positive lens, a plastic negative lens and a glass positive lens. The plastic lenses are made to be meniscus lenses and an aspheric surface and a diffractive surface are respectively mounted onto the plastic lenses so as to have better image with low manufacturing cost.

Abstract: The object of the present invention is to provide a wide converter lens capable of obtaining an angle of view of about 80° or over and having small appearance of distortion. According to one aspect, a wide converter lens for using by attaching to an object side of a photographic lens includes, in order from the object side, a first positive lens having double convex surfaces, a negative lens unit including at least one negative lens, and a second positive lens having double convex surfaces. The following conditional expression is satisfied: −0.8<(r2+r1)/(r2−r1)<0.8 where r1 denotes the radius of curvature of the object side surface of the first positive lens and r2 denotes the radius of curvature of the image side surface of the first positive lens.

Abstract: An image pickup lens system according to the present invention includes a diaphragm, a first lens which has a convex fact formed on the side of an image surface in the vicinity of an optical axis and which has a positive power and radii of curvature at a center, whose signs are not opposite from each other, a second lens which has a convex face formed on the side of an object in the vicinity of the optical axis and which has a negative power and radii of curvature at a center, whose signs are not opposite from each other, and a third lens which has a convex face formed on the side of the image surface in the vicinity of the optical axis and which has a positive power. The diaphragm and the first, second and third lenses are disposed sequentially from the side of the object, and the first face of at least the second lens being formed into an aspherical shape.

Abstract: An image readout lens comprises, successively from the object side, a first lens L1 made of a positive meniscus lens having a convex surface directed onto the object side, a second lens L2 made of a biconcave lens having a surface with a greater curvature directed onto the object side, and a third lens L3 made of a biconvex lens having a surface with a greater curvature directed onto the image side, the first lens L1 and second lens L2 each being a plastic lens with aspheric surfaces on both sides. The image readout lens satisfies the following conditional expressions (1) and (3) to (5): 0.08<D6/F<0.2  (1) 1.5<|R6|/F<2.2  (3) 0.5<R2/F<1.55   (4) 0.5<R4/F<1.2  (5) where D6 is the center thickness of the third lens, Rj (j=1 to 7) is the radius of curvature of the j-th surface from the object side, and F is the focal length of the whole lens system.

Abstract: An image-reading lens is formed of a two lens elements of meniscus shape, one with its convex surface on the most object-side of the image-reading lens and one with its convex surface on the most image-side of the image-reading lens. An intermediate lens element of negative refractive power may be optionally provided. A zone plate diffractive optical surface having different depth zones surrounding a vertex is formed on at least one aspherical surface of the two lens elements of meniscus shape so as to correct simltaneously for both lateral color and curvature of field. Another surface, preferably of the same lens element having the zone plate diffractive/aspherical surface, is made aspherical. Of the two lens elements of meniscus shape, one is made of plastic material and the other is made of non-plastic material. The image reading lens provides a high image quality having a small temperature dependence, despite one lens element thereof being made of plastic material.

Abstract: In a three-sheet image readout lens, predetermined expressions are satisfied, so as to yield a bright lens system which can favorably correct each kind of aberration, while attaining a smaller size and a lighter weight. The lens system is constituted by, successively from the object side, three positive, negative, and positive lenses L.sub.1 to L.sub.3, while a stop i is disposed downstream the third lens L.sub.3, satisfying the following conditional expressions (1) to (6):(1) 0.85<f.sub.1 /f<0.93(2) -0.90<f.sub.2 /f.sub.3 <-0.84(3) 0.025<d.sub.2 /f<0.043(4) 0.09<d.sub.5 /f<0.16(5) -2.5<r.sub.3 /r.sub.4 <-2.1(6) .vertline.d.sub.6 .vertline./f.ltoreq.0.03.

Abstract: A photographic lens system for compact cameras comprising in order from the object side: a first positive meniscus lens element having a convex surface on the object side; a second biconcave lens element; a third biconvex lens element; and a stop, wherein at least two lens element including the first lens element have refractive indices not exceeding 1.6. This photographic lens system is configured so as to be manufactured at a low cost and exhibit high optical performance by selecting an adequate focal length for the third lens element.

Abstract: Disclosed is a telephoto-type lens system of a head separated charge coupled device (CCD) camera, which includes a first lens group having a positive focal length, a second lens group having a negative focal length, and a third lens group. The first lens group has a first convex lens surface facing an object and an upper convex surface. The third lens group has a second lens with a negative focal length joined to a first lens with a positive focal length. An image angle greater than 29.degree. and high definition images can be achieved with the present invention.

Abstract: The invention provides a high-performance, bright and compact triplet that has a zoom ratio of about 1.05 with an wide field angle, said triplet comprising, in order from the object side, a first lens L1 consisting of a positive single lens of glass in a meniscus form convex on the object side, a second lens L2 located with an air separation between it and said first lens L1 and consisting of a negative single lens of glass, a third lens L3 located with an air separation between it and said second lens L2 and consisting of a positive single lens of glass in a double-convex form, and an aperture stop S located on the image side of said third lens, at least two of said first to third lenses having aspherical surfaces, and conforming to the following conditions n.sub.1 >1.6, n.sub.3 >1.6 wherein n.sub.1 and n.sub.3 are the refractive indices of said first and third lenses, respectively.

Abstract: A triplet lens using plastic lens elements is disclosed. The triplet lens includes, in order from the object side, a glass lens element that is positively meniscus having the convex surface on the object side, a plastic lens element formed of polycarbonate, polystyrene, or a copolymer of polystyrene and methacrylate which is biconcave in shape with a more pronounced concave surface on the image side, a plastic lens having a copolymer of polystyrene and methacrylate that is biconvex in shape, and a diaphragm. Lens characteristics are chosen to satisfy various conditions for optimum imaging.

Abstract: A compact objective lens with a diaphragm arranged behind the lens system suitable for use in very compact photographic cameras. The objective lens comprises a plurality of components arranged in a triplet or a triplet type configuration and is capable of covering at least a 55 degree field of view.

Abstract: A compact objective lens system with a diaphragm arranged in front of or preferably behind the lens system and suitable for use in compact photographic cameras. The objective lens comprises a plurality of components arranged in a triplet-type configuration that are capable of covering at least a 55 degree field of view and utilizes the locations of aperture stop, the lens bendings, and the size of lens elements, clear apertures of the lens element surfaces to enhance the lens system performance and to eliminate stray light problems.

Abstract: A real image mode finder optical system includes an objective system having a positive refracting power as a whole, an image erecting system for erecting an image, and an eyepiece system having a positive refracting power. The objective system has a meniscus lens with a negative refracting power, whose convex surface is directed toward the eye, and an objective lens with a positive refracting power. Thus, even when finder magnification is high, a wide field angle can be derived and the distance between the last surface of the eyepiece system and the eyepoint can be ensured in a long range, with a resultant easy observation.

Abstract: A copying lens system of a three-unit/three-element composition that can be made from relatively inexpensive optical materials and which exhibits satisfactory performance at copying ratios ranging from about 0.5 to 2.0. The lens system includes, in order from the object side, a first lens of positive meniscus having a convex surface directed to the object, a negative second lens having a concave surface on both sides, and a positive third lens having a convex surface on both sides. The lens system satisfies the following conditions:(1) 1.70<n.sub.1 +.nu..sub.1 /200.ltoreq.1.93(2) 0.10<n.sub.3 -n.sub.1(3) 0.06<d.sub.t /f.sub.t 0.11(4) 0.60<-r.sub.3 /r.sub.4 <1.05(5) 1.40<-r.sub.5 /r.sub.6 <2.70wheref.sub.t : the focal length of the overall system;n.sub.i : the refractive index of the ith lens at the d-line;.nu..sub.i : the Abbe number of the i.sup.th lens;r.sub.j : the radio of the curvature of the j.sup.th lens; andd.sub.t : the overall length of the system.