Abstract: A lens component of the present invention is made by cementing a lens LA and a lens LB having a refracting power smaller than a refracting power of the lens LA, and satisfies predetermined conditional expressions. Moreover, in an image forming optical system of the present invention which includes a lens group B having a negative refracting power, a lens group C having a positive refracting power and which moves only toward an object side at the time of zooming from a wide angle end to a telephoto end, and one or two more lens groups additionally, one of the lens components of the present invention is used in the lens group B.

Abstract: An objective lens OL comprises: a first lens group G1 disposed on an object side, having positive refractive power as a whole and having a positive lens (plano-convex lens L1) which is disposed closest to the object and of which lens surface closest to the object is a plane or a surface having a low curvature, and at least one cemented lens (cemented lens CL12 or the like); a second lens group G2 disposed on an image side, having negative refractive power as a whole, and having a concave surface facing the image and a concave surface facing the object, which face each other; and a diffractive optical element GD in which two diffractive element constituents made from different optical materials are cemented, which has a diffractive optical surface D formed with diffraction grating grooves on the cemented surface, and which is disposed closer to the object than a position where a principal ray crosses the optical axis.

Abstract: An imaging lens includes, in order from an object side, a first lens group having a positive power, an aperture diaphragm, and a second lens group having a positive or negative power. The first lens group includes, in order from the object side, a first lens which is a biconcave lens, a second lens that has a positive power and includes a convex image-side surface, and a third lens that has a positive power and includes a convex object-side surface. The second lens group includes, in order from the object side, a fourth lens that has a negative power and includes a concave image-side surface, and a fifth lens which is a biconvex lens. Each of the first to fifth lenses is a single spherical glass lens.

Abstract: An optical system includes a first optical element and a second optical element on at least one of an enlargement side and a reduction side relative to a point P at which a light axis and a paraxial chief ray intersect. Each of the first optical element and second optical element is composed of a solid material having a refractive light incident surface and a refractive light emergent surface. The optical system satisfies the following conditional expressions: ??gF1>0.0272, ??gF2<?0.0278, and f1×f2<0 where ??gF1 and ??gF2 denote anomalous partial dispersion values of the first and second optical elements for the g-line and F-line, respectively, and f1 and f2 denote focal lengths of the first and second optical elements, respectively, when the light incident surfaces and the light emergent surfaces of the first and second optical elements are in contact with air.

Abstract: Disclosed is an imaging lens capable of improving weatherability, reducing performance degradation, and obtaining an optical performance excellent across a wide wavelength region from the visible wavelength region to the near-infrared wavelength region. An imaging lens for forming an image of visible and near-infrared light includes, in order from the object side: a front group that has a positive power; an aperture stop; and a rear group that has a negative power. In the imaging lens, the rear group includes a negative meniscus lens that is disposed closer to the object side and has a surface convex toward the object side, and a biconvex lens that is disposed closer to the image side. In addition, all the lenses constituting the imaging lens are single lenses.

Abstract: The present invention provides a photographing optical lens assembly comprising, in order from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface, the object-side and image-side surfaces thereof being aspheric; a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, the object-side and image-side surfaces thereof being aspheric; and an aperture stop located in front of the first lens element; wherein an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, and they satisfy the relation: |V1?V2|<15; and wherein the number of the lens elements of the photographing optical lens assembly is limited to two. Such an arrangement of optical elements can effectively reduce the volume of the lens assembly and the sensitivity of the optical system and enable the lens assembly to obtain a higher resolution.

Abstract: The invention relates to an eyepiece-connected taking optical system well fit for TV camera heads using a small-format imaging device. The taking optical system comprises a field direction turning member 1P, 2P, a positive first group and a negative second group. The first group comprises a positive cemented lens convex on its object side, a positive single lens convex on its object side and a positive cemented lens convex on its object side, and the second group comprises a negative single lens. Focus adjustment is implemented by changing a spacing t2 between the first group and the second group. The taking optical system satisfies condition (1) for defining the position of the front focus with respect to the taking lens, condition (2) for defining the refracting power of each lens group, condition (3) for defining the imaging magnification of the second group, and condition (4) for defining the profile of refracting power in the first group.

Abstract: An image capture lens includes: when changed from infinity to close focusing, a first lens group moving from an image to an object with positive refractive power; and a second lens group fixed relatively to the image with negative refractive power, wherein the first lens group includes a negative first lens having a strong concave surface facing the image, the second lens group includes one negative lens having a strong concave surface facing the image or a negative cemented lens including positive and negative lenses, and conditional expressions; 0.7<f1/fi<0.9, 1.0<bf/fi<1.4, 0.5<Rf2/Rr2<1 are satisfied where fi: overall focal length, f1: first-lens-group focal length, bf: overall back focus, Rf2: radius of curvature of the image-side surface of the lens nearest to the object, and Rr2: radius of curvature of the surface nearest to the image of the second lens group.

Abstract: A miniature image capture lens is disclosed, comprising an aperture diaphragm having an aperture through which an image is captured and a wafer-level lens system, comprising a first lens group including a first substrate, a first lens disposed on a first side of the first substrate and a second lens disposed on a second side of the first substrate, and a second lens group including a second substrate, a third lens disposed on a first side of the second substrate and a fourth lens disposed on a second side of the second substrate. The first lens, the second lens, the third lens and the fourth lens are aspherical and the miniature image capture lens meets the following condition: L/fe<1.6; f1/fe=0.5˜1.5; f2/fe=?1˜?3; Tgroup2/TBFL=0.8˜1.2; Tair/Tgroup2=0.4˜0.

Abstract: An image forming optical system characterized by comprising a positive first lens group, a negative second lens group, and third and subsequent lens groups having a positive composite refracting power, wherein the first lens group is composed of a cemented lens made up of one positive lens and one negative lens arranged in order from the object side, and the image forming optical system satisfies the following conditional expressions (1-1) and (2-1): 0.05<T1g/Flt<0.10??(1-1) 0.50<?gF<0.75??(2-1) where T1g is the thickness of the first lens group on the optical axis, Flt is the focal length of the entire image forming optical system at the telephoto end, and ?gF is the partial dispersion ratio (ng1?nF1)/(nF1?nC1) of the negative lens, where nd1, nC1, nF1, and ng1 are refractive indices of the negative lens respectively for the d-line, C-line, F-line, and g-line.

Abstract: A wide-angle projection lens module is provided, including a reflective convex aspheric mirror and a refractive lens group of positive refractive power. The following Conditions (1) to (2) are satisfied: 15<|Freflective/F|<25 ??Condition (1), and 1.5<|Frefractive/f|<2.0 ??(Condition (2), wherein, F is a focal length of the wide-angle projection lens module, Freflective is a focal length of the reflective convex mirror, and Frefractive is a focal length of the refractive lens group.

Abstract: It is to provide an imaging lens that can improve optical performance while reducing size and weight. An imaging lens includes, in order from an object side to an image surface side: a diaphragm 2, a first lens 3 having a positive power whose convex surface faces the object side, and a second lens 4 that is a meniscus lens having a negative power whose convex surface faces the object side, wherein a condition expressed by the following expression is to be satisfied: 0.4?r1/FL?0.55 (where, r1: center radius curvature of the object side face 3a of the first lens, and FL: focal distance of the entire lens system).

Abstract: An imaging lens includes, in order from an object side, a first lens group having a positive power, an aperture diaphragm, and a second lens group having a positive or negative power. The first lens group includes, in order from the object side, a first lens which is a biconcave lens, a second lens that has a positive power and includes a convex image-side surface, and a third lens that has a positive power and includes a convex object-side surface. The second lens group includes, in order from the object side, a fourth lens that has a negative power and includes a concave image-side surface, and a fifth lens which is a biconvex lens. Each of the first to fifth lenses is a single spherical glass lens.

Abstract: It is to provide an imaging lens that can improve optical performance while reducing size and weight. An imaging lens includes, in order from an object side to an image surface side, a diaphragm, a first lens 3 that is a meniscus lens having a positive power whose convex surface faces the object side, and a second lens 4 that is a lens having a negative power whose concave surface faces the object side, wherein conditions expressed by the following expressions are to be satisfied: 0.25<r1/r2?0.45, 0.35?r1/FL?0.42, and 0.85?f1/FL?1 (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, FL: focal distance of the entire lens system, and f1: focal distance of the first lens).

Abstract: An article includes an optical device. The optical device includes a first lens and a second lens. The first lens includes an optically active material that responds to an external stimulus that affects a refractive index of at least a portion of the first lens. A method for making a method of use of the article is also provided.

Abstract: It is to provide an imaging lens that can improve optical performance while reducing size and weight. An imaging lens comprises, in order from an object side to an image surface side, a diaphragm 2, a first lens 3 that is a meniscus lens having a positive power whose convex surface faces the object side, and a second lens 4 that is a lens having a negative power whose concave surface faces the object side, wherein a condition expressed by the following expression is to be satisfied: 0.05?r1/r2?0.29 (where, r1: center radius curvature of the object side surface of the first lens 3, and r2: center radius curvature of the image surface side face of the first lens).

Abstract: It is to provide an imaging lens that can improve optical performance while reducing size and weight. An imaging lens comprises, from an object side, a diaphragm 2, a first lens 3 that is a lens having a positive power whose convex surface faces the object side, and a second lens 4 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: Provided is an imaging lens using a wafer scale lens which can easily be produced in a mass production. The entire optical length can be reduced without increasing a lens substrate or a lens formed on the substrate or without using a diffracting plane. The aberration can be preferably corrected. The imaging lens forms a first lens having a positive refractive power and Abbe number v1 on the object side and a second lens having a negative refractive power and Abbe number v2 on the image side of the first lens substrate. The difference between the Abbe number v1 and the Abbe number (v1?v2) is set to be a value greater than 10.

Abstract: An optical system includes a first optical element and a second optical element on at least one of an enlargement side and a reduction side relative to a point P at which a light axis and a paraxial chief ray intersect. Each of the first optical element and second optical element is composed of a solid material having a refractive light incident surface and a refractive light emergent surface. The optical system satisfies the following conditional expressions: ??gF1>0.0272, ??gF2<?0.0278, and f1×f2<0 where ??gF1 and ??gF2 denote anomalous partial dispersion values of the first and second optical elements for the g-line and F-line, respectively, and f1 and f2 denote focal lengths of the first and second optical elements, respectively, when the light incident surfaces and the light emergent surfaces of the first and second optical elements are in contact with air.

Abstract: A two-piece optical lens system for taking image comprises, from the object side: a first lens element and a second lens element. The first lens element is a positive meniscus lens element has a convex object-side surface. The second lens element is a negative meniscus lens element has a convex image-side surface. Both the object-side surface and the image-side surface of the first and second lens elements are aspheric, the first and second lens elements are made of plastic material, and they satisfy the relations: 0.55<f1/f<0.95, ?2.0<f2/f<?1.0, 27.0<?1??2. The focal length of the optical lens system is f, the focal length of the first lens element is f1, the focal length of the second lens element is f2, the Abbe number of the first lens element is ?1, and the Abbe number of the second lens element is ?2.

Abstract: An optical lens assembly comprises two plastic lenses with refractive power: from the object side to the image side: a first lens with positive refractive power, and a second lens with negative refractive power. A front surface and a rear surface of the first lens is convex and aspherical, a refractive index N1 of the first lens satisfies the relation: 1.6>N1>1.5, a focal length of the first lens is f1, and a focal length of optical system is f, and they satisfy the relation: f/f1>2.0. A front surface of the second lens is concave, a rear surface of the second lens is convex, and both the front and rear surfaces is aspherical, a refractive index N2 of the second lens satisfies the relation: N2>1.55. An aperture is located in front of the first lens for controlling the brightness of the optical system.

Abstract: An optical lens system for taking image comprises two lens elements with refractive power, from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface, the object-side surface and the image-side surface of the first lens element being aspheric; a second lens element with negative refractive power having a concave object-side surface and a concave image-side surface, the object-side surface and the image-side surface of the second lens element being aspheric, the image-side surface of the second lens element being formed with an inflection point; and an aperture stop located in front of the first lens element. A focal length of the second lens element is f2, a focal length of the optical lens system is f, and they satisfy the relation: ?0.55<f/f2<?0.05 and f/EPD<3.6.

Abstract: An image pickup lens system includes, successively in order from an object side, an aperture stop, a first lens as a double-convex positive lens, and a second lens as a negative meniscus lens having a convex surface on an image side. Each of the first and second lenses has at least one aspherical surface. The image pickup lens system satisfies the following conditional formulas (1), (2), and (3): 0.24<|f1/f2|<0.68??(1) 0.83<R1/f<3.68??(2) 0.13<D3/f<0.31, where??(3) f1: the focal length of the first lens; f2: the focal length of the second lens; R1: the paraxial radius of curvature of the surface on the object side of the first lens; f: the focal length of the entire system; and D3: the axial surface-to-surface distance between the first lens and the second lens.

Abstract: An imaging lens includes: in order from an object side, an aperture diaphragm; a first lens of a positive lens having a convex surface on the object side; a second lens of a meniscus lens having a concave surface on the object side; and a third lens. The imaging lens satisfies: f/f3<0.95 and BR2<0. BR2 satisfies BR2=A/D4, A represents a distance from a vertex position on a object-side surface of the second lens and on an optical axis to a position on a image-side surface of the second lens through which a light ray passes toward a corner of an image height, provided that a traveling direction of the light ray is taken as appositive direction, and D4 represents a center thickness of the second lens. f represents a focal length of the imaging lens. f3 represents a focal length of the third lens.

Abstract: A first lens group having a negative refractive power, an aperture diaphragm, and a second lens group having a positive refractive power are arranged in order from an enlargement side. A reduction side of a projection lens is made essentially telecentric. Further, cemented triplet lenses, each of which includes cemented three lenses, are provided in the first lens group and the second lens group, respectively. Further, air spacing which enables placement of a mirror is ensured between the first lens group and the second lens group. Moreover, specific conditional expressions for the lens are satisfied.

Abstract: A photographing optical system includes at least one of a positive lens and diffractive optical element being provided closer to an object side of the system than an intersection P of a light axis and paraxial chief ray, and a negative lens, provided closer to an image side than the intersection. The positive lens and the negative lens are formed of materials satisfying the following conditions when the maximum height of a paraxial marginal ray, passing through a lens surface, from the light axis at a location closer to the object side than the intersection is greater than a maximum height of the paraxial marginal ray, passing through a lens surface, from the light axis at a location closer to the image than the intersection: ?0.0015×?d+0.6425<?gF 60<?d where ?d is an Abbe number and ?gF is a partial dispersion ratio.

Abstract: A compact imaging lens system consists of a first positive aspheric lens element (1) on the object side and a second negative aspheric lens element (2) on the image side. The first lens element is a meniscus lens convex toward the image side, whereby the incident light beam can be diverged by the first concave surface (11) of the first lens element, and thus a wide area of the second convex surface (12) of the first lens element can be illuminated by the divergent light beam. The second negative aspheric lens element is provided mainly for correcting chromatic aberration and off-axis aberration.

Abstract: An optical lens assembly comprises two plastic lenses with refractive power: from the object side to the image side: a first lens with positive refractive power, and a second lens with negative refractive power. A front surface and a rear surface of the first lens is convex and aspherical, a refractive index N1 of the first lens satisfies the relation: 1.6>N1>1.5, a focal length of the first lens is f1, and a focal length of optical system is f, and they satisfy the relation: f/f1>2.0. A front surface of the second lens is concave, a rear surface of the second lens is convex, and both the front and rear surfaces is aspherical, a refractive index N2 of the second lens satisfies the relation: N2>1.55. An aperture is located in front of the first lens for controlling the brightness of the optical system.

Abstract: A compact lens system includes a first positive lens element (1) on the object side and a second negative lens element (2) on the image side. The first positive lens element is a meniscus lens having a convex surface (11) facing the object side. The second negative lens element is also a meniscus lens having a convex surface (12) facing the image side. Both of the first and second lens elements are aspheric lenses each having at least one aspheric surface. The first and second lens elements are made of different plastic materials and are symmetrically arranged with respect to each other along the optical axis.

Abstract: An image pick-up lens system includes an aperture stop (10), a biconvex first lens (20), and a meniscus-shaped second lens (30) having a concave surface on a side of an object. The aperture stop, the first lens and the second lens are aligned in that order from the object side to an image side. Each of the lenses has at least one aspheric surface, and at least one of the lenses is made from an optical glass. The system satisfies the following condition: (1) 1<T/f<1.6, wherein f is a focal length of the system, and T is a length from the aperture stop to an image pick-up surface of the image side. The first condition (1) limits the total length of the system in order to provide compactness. The system also satisfies other conditions (2)–(6) as disclosed, in order to provide compactness, improved optical performance, and cost-effectiveness.

Abstract: A converter lens includes a front unit and a rear unit disposed on an image side with respect to the front unit. The front unit has positive optical power and includes two positive lens elements. The two positive lens elements are spaced apart. The rear unit has negative optical power and includes a positive lens element and a negative lens element.

Abstract: At least one exemplary embodiment is directed to a telephoto type optical system capable of reliably correcting and/or reducing aberrations such as chromatic aberration. The optical system includes a refractive optical element which includes a solid-state material, a negative lens component and a positive lens component, respectively disposed on a front side relative to a pupil, the solid-state material meeting conditions of an Abbe number ?d(GNL) and of a partial dispersion ratio ?gF(GNL) as follows: ?2.100×10?3·?d(GNL)+0.693<?gF(GNL) 0.555<?gF(GNL)<0.9 Then, a refractive power of the refractive optical element, a mean partial dispersion ratio of a material of the negative lens component, and a mean Abbe number of a material of the positive lens component are properly set.

Abstract: It is to provide an imaging lens system which, while reduced in size and weight, can fully meet the demand for more improvement in the optical performance and also improvement in the productivity. The imaging lens system comprises, in order from an object side towards an image surface side, a diaphragm, a first lens which is a meniscus lens having a positive power whose concave surface facing the object side, and a second lens which is a meniscus lens having a negative power whose convex surface facing the image surface side, wherein the Abbe number of the second lens is set smaller than the Abbe number of the first lens.

Abstract: Provided is an optical system, in which various aberrations including chromatic aberrations are preferably corrected and which is easily manufactured and has a superior environmental resistance, comprising a solid material (GIT1) having two surfaces both on a light incident side on a light exit side being refractive surfaces, in which following conditional expressions are satisfied: ?d<30, ?gd<?3.333×10?3·?d+1.40, ?gF<?2.615×10?3·?d+0.67, where ?d represents an Abbe number of the solid material and ?gd and ?gF represent partial dispersion ratios thereof.

Abstract: A front teleconverter lens system having superb optical performance with less production of aberration in spite of its compactness. The front teleconverter lens system includes, in order from an object, a first lens group having positive refractive power, and a second lens group having negative refractive power, and forming an afocal optical system. A diffractive optical surface is arranged in at least one of the first lens group and the second lens group. The conditional expression 1.2<?F/?R<10 is satisfied, where ?F denotes the effective diameter of the most object side lens surface of the first lens group, and ?R denotes the effective diameter of the most image side lens surface of the second lens group.

Abstract: An optical system of a telephoto type is disclosed, in which a refractive optical element made of a solid material that satisfies?d<30, ?gd<?3.333×10?3·?d+1.40 and ?gF<?2.615×10?3·?d+0.67 is installed, ?d representing an Abbe's number, and ?gd and ?gF representing partial dispersion ratios. A refractive power with adequate sign is given to the refractive optical element in accordance with its location. Thereby, an optical system, which can excellently correct various aberrations such as chromatic aberration, and can be manufactured easily, and has an excellent environment resistance, is realized.

Abstract: The invention provides a liquid-immersion objective optical system including a first lens group and a second lens group. The first lens group includes a first lens component having positive refractive power, an object side thereof being a flat surface and a convex surface thereof facing an image-plane side; a second lens component having positive refractive power, a convex surface thereof facing the image-plane side; a third lens component having positive refractive power as a whole, formed by cementing a biconvex positive lens and a negative lens; and a fourth lens component formed by cementing a negative lens and a biconvex positive lens. The second lens group includes a fifth lens component formed by cementing a lens having a concave surface facing the object side and a lens having a convex surface facing the image-plane side; a sixth lens component having positive refractive power; and a seventh lens component having negative refractive power.

Abstract: A variable magnification lens includes, in order from the object side, a front lens unit with positive refracting power and a rear lens unit with negative refracting power so that spacing between the front lens unit and the rear lens unit is changed to thereby vary the magnification of the variable magnification lens. In this case, the front lens unit has a negative single lens element with a concave surface facing the object side at the most object-side position and a positive single lens element at the most image-side position. In the front lens unit, only the second lens element from the image side is provided with at least one aspherical surface, and all lens elements included in the front lens unit are constructed as single lens elements arranged through air spacing. An aperture stop is interposed between the front lens unit and the rear lens unit, and the rear lens unit is composed of a negative single lens element. The variable magnification lens satisfies the following condition: 1.8<flt/flw<3.

Abstract: An optical lens is described. The optical lens comprises a barrel, a first lens and a second lens. The barrel has a light incident opening, and a receiving space, wherein the receiving space is successive to the light incident opening. Additionally, the first lens is disposed in the receiving space, and the first lens is partially exposed by the light incident opening, wherein the first lens has a first annular conical surface at the outer rim of the first lens. Further, the second lens is disposed in the receiving space, and embedded with the first lens. The second lens has a second annular conical surface on outer rim of the second lens, and the first annular conical surface is embedded with the second annular conical surface. Accordingly, the optical lens has better alignment accuracy and assembly performance.

Abstract: This application discloses a lens system comprising in order from an object side to an image side: an aperture stop; a first lens element, having a positive optical power; and a second lens element, having a negative optical power. By setting the shapes of the respective lens elements and the materials making up the respective lens elements so as to meet predetermined conditions in such a lens system, a lens system of a compact size which provides good optical performance is realized while securing telecentric characteristics.

Abstract: An imaging lens system includes, in the named order from the side of an object toward an image surface, a light amount diaphragm, a first lens having a positive power with a main power on the side closer to the image surface, a meniscus-shaped second lens having a negative power with a strong concave surface turned toward the image surface. Thus, it is possible to provide the imaging lens system in which a sufficiently high resolution can be obtained, while meeting the demand for a reduction in entire length of an optical system to provide the compactness.

Abstract: A imaging module has an electronic imager and an objective lens system. The electronic imager has an active area that is typically rectangular is shape. An image is formed on the active area with a maximum effective image dimension DI. An objective lens system forms an image of a distant object on the image plane. The objective lens system has a focal length f0 and a height TT. A first lens element has a convex first surface that faces the object and a second surface. The first lens element has a positive power. A second lens element has a concave first surface facing the first lens second surface and an aspherical second surface facing the image plane. The first and second lens elements are shaped and spaced to obtain a ratio of f1/f0 from 0.5 to 2.0, and ratio of TT/DI<1.5.

Abstract: The present invention is directed to an image-forming optical system. The image-forming optical system according to the present invention contains, in order from an object side: an iris diaphragm; a first lens having a positive refractive power and at least one aspheric surface; and a second lens having a negative refractive power and at least one aspheric surface. In accordance with the present invention, there is provided an image-forming optical system for cameras using an image pickup device that has a small number of lenses to easily realize the compactness and satisfies a requirement for a high optical performance.

Abstract: An image pickup lens is provided in which various aberrations are satisfactorily corrected, and the optical length is not more than 6 mm, and moreover a sufficient back focus is secured. This image pickup lens is configured by arranging, in order from the object side, an aperture diaphragm S1; a first lens L1 having a meniscus shape with concave surface facing the object side, and having positive refractive power; a second diaphragm S2; and a second lens L2 having a meniscus shape with concave surface facing the image side, and having negative refractive power. The aperture diaphragm S1 forms an incidence plane. The second diaphragm S2 provided between the first lens L1 and the second lens L2 is inserted in order to cut out so-called flare, which is light which strikes the peripheral edge of a lens or similar and is irregularly reflected.

Abstract: A miniature image capturing lens includes an aperture diaphragm; and a lens system consisting of a first lens having a positive refracting power in which a convex surface of the first lens is directed toward an image; and a meniscus-shaped second lens in which a concave surface of the meniscus is directed toward an object. The aperture diaphragm, the first lens and the second lens are aligned in this order from the object side, the fist and second lenses have at least one aspherical surface. The following conditional formulas are satisfied: 0.50<f1/f<0.80 0.30<(R2+R1)/(R1−R2)<1.20 where f1 is a focal length of the first lens, f is a focal length of the entire image capturing lens, R1 is a radius of curvature of the object side surface of the first lens, and R2 is a radius of curvature of the image side surface of the second lens.

Abstract: An imaging lens comprising, in sequence from the object side to the image side: an aperture diaphragm, a first lens, a second diaphragm, and a second lens; the first lens consisting of a meniscus-shaped lens having positive power with a concave face oriented towards the object side; the second lens consisting of a meniscus-shaped lens with a concave face oriented towards the image side; wherein at least one face of the first lens is an aspherical face, and one or more faces of the second lens is an aspherical face, in such a manner that the imaging lens as a whole is a lens system comprising at least two aspherical faces, and satisfying each of the following condition equations (1), (2), (3). 0.01<|f1|/|f2|<0.6  (1) 0.3f<|R2|<0.6f  (2) 0.5f<D0<1.

Abstract: A corrector optic is provided, for use in a camera system that includes a thick prism in front of the focal plane. The corrector optic includes preferably two lenses to be aligned on the optical axis of the camera system. When coupled within the camera system, the corrector optic is disposed between the objective lens and the prism. A preferred corrector optic includes a positive lens having a convex surface facing the objective lens and a negative lens having a concave surface facing the prism, such that the lenses together reduce spherical and coma aberrations caused by imaging through the prism. Chromatic aberration is also reduced by choosing the negative lens material to have a higher index of refraction and higher dispersion than those of the positive lens material.

Abstract: An optical instrument for observation includes, in order from the object side, an objective lens system having positive refractive power, an erecting optical system, and an ocular lens system having positive refractive power. When an anti-vibration mechanism is used to maintain the erecting prism at an orientation in space that is stabilized so as to prevent image degradation due to vibrations of the optical instrument for observation, the erecting prism is constructed to satisfy specified conditions so that ghost light is not generated and so that the optical instrument for observation may be compact.

Abstract: A compact yet low-cost zoom lens system being particularly suited for use with small portable information terminal equipment is provided. The zoom lens system includes, in order from an object side thereof, a first, third and fourth lens groups G1, G3 and G4 that have positive refracting powers and a second lens group G2 that has negative refracting power. Lens group G1 remains fixed during zooming and lens groups G2 and G3 move during zooming and lens group G4 is movable during zooming. In one embodiment, the zoom lens system includes a negative lens located nearest to the imaging side of the second lens group G2 that satisfies condition (7).

Abstract: In an objective, in particular a microscope objective, wherein the objective has a first optics group on the object side with positive refractive power and a second optics group with negative refractive power following the first optics group, and wherein the first optics group contains a plurality of refractive elements, the first optics group contains at least one diffractive element with a refraction-increasing and achromatizing effect.