Abstract: A system and method for collimating light emitted from a light source, such as a light-emitting diode (LED), is provided. The system and method includes two lenses, both lenses having a positive power for converging the light rays. In one example, the first lens is a hemispherical ball lens and the second lens is configured such that one surface conforms to the exiting surface of the first lens. The exiting surface of the second lens may be, for example, a Fresnel lens or an aspherical lens. In another example, the first lens may be a hemispherical or a hyperhemispherical ball lens. The second lens has an outer circumference having two aspherical surfaces. The inner portion of the second lens is in direct contact with the first lens. This configuration creates a dual-channel collimator.

Abstract: An image forming lens including an aperture stop, a first lens group arranged on the object side relative to the aperture stop, and a second lens group having a positive power arranged on an image side relative to the aperture stop, the first lens group including a first F lens group having a negative power and a first R lens group having a positive power arranged in this sequence from the object side with the widest air space between the first F lens group and the first R lens group, the first F lens group including at least two negative lenses, the first R lens group including at least one positive lens, the second lens group including a second F lens group having a positive power and a second R lens group arranged in this sequence from the object side, the second F lens group including a first positive lens, a first negative lens, a second negative lens, and a second positive lens arranged in this sequence from the object side, and the second R lens group including at least one lens.

Abstract: An optical viewer is disclosed which incorporates plastic lenses which reduce the weight and cost of the optical viewer. In accordance with an important aspect of the invention, the optical design of the viewer is configured to compensate for the inferior optical characteristics of the plastic lenses to provide an optical viewer with comparable performance relative to optical viewers with glass lenses.

Abstract: This invention provides a compact imaging lens assembly comprising, in order from an object side to an image side: a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a second lens element with positive refractive power, at least one of the object-side and image-side surfaces thereof being aspheric; and an aperture stop disposed between the second lens element and an image plane; wherein there are two lens elements with refractive power in the compact imaging lens assembly; and wherein the compact imaging lens assembly satisfies the relations: 0.40<f/f2<1.20, |R3/R4|>1.5. Such an arrangement of optical elements can effectively improve the image quality of the system, reduce the total track length of the lens assembly while maintaining a sufficient back focal length, and achieve a wide field of view.

Abstract: An image pickup lens includes a first lens block with a positive power and a second lens block with a positive or negative power. The first lens block includes a first lens substrate, and lens portions 1a and 1b arranged on opposing surfaces of the first lens substrate. The lens portions 1a and 1b are different from the first lens substrate in at least one of a refractive index and an Abbe number. The second lens block includes a second lens substrate, and lens portions 2a and 2b arranged on opposing surfaces of the second lens substrate. The lens portions 2a and 2b are different from the second lens substrate in at least one of a refractive index and an Abbe number. The image pickup lens satisfies a condition relating to focal lengths of the lens portions 1a and 2b.

Abstract: An exemplary optical lens group includes a first lens and a second lens. The first lens comprises a first central portion and an annular stepped portion. The annular stepped portion has a first outer step and a second outer step. The first outer step has a first outer side surface and a first downward-facing step surface. The second outer step has a second outer side surface and a second downward-facing step surface. The second lens comprises a second central portion and a peripheral portion. The peripheral portion has an inner side surface. The first lens is engaged in the second lens in a manner that the first outer side surface of the first lens is in contact with the inner side surface of the second lens. The second outer side surface of the first lens is spaced apart from the inner side surface of the second lens.

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 zoom lens includes, sequentially from an object side, a first lens group that is negative; and a second lens group that is positive, where focal length is varied by varying a distance between the first lens group and the second lens group. The first lens group includes, from the object side, a first lens that is a negative biconcave lens having at least one aspherical surface, and a second lens that is a positive meniscus lens having a convex surface facing toward the object side and at least one aspherical surface, and a first condition 0.8<|f1/f2|<1.0 and a second condition 0.5<|r2/f1|<0.8 are satisfied, where f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, r2 is radius of curvature of a surface of the first lens in the first lens group, the surface facing toward an image.

Abstract: An optical system has a positive lens group, a negative lens group, and an aperture stop. The negative lens group is disposed at an object side of the aperture stop and has a cemented lens, and in a rectangular coordinate system in which a horizontal axis is Nd and a vertical axis is ?d, when a straight line indicated by Nd=?×?d+? where ?=?0.017 is set, Nd and ?d of at least one lens forming the cemented lens are included in both an area determined by a line when a lower limit value is in a range of expression (1a) and a line when an upper limit value is in a range of the expression (1a), and an area determined by expressions (2a) and (3a): 1.45<?<2.15 (1a); 1.30<Nd<2.20 (2a); and 3<?d<12 (3a); where Nd denotes a refractive index, and ?d denotes an Abbe's number.

Abstract: A lens system includes a first lens which is formed of a medium exhibiting negative refraction and a second lens which is formed of a medium having a positive refractive index. Abbe's number for a material which forms the first lens differs from Abbe's number for a material which forms the second lens. Moreover, a lens system includes a first lens which is formed of a medium exhibiting negative refraction and a second lens which is formed of a medium exhibiting negative refraction. Abbe's number for a material which forms the first lens differs from Abbe's number for a material which forms the second lens.

Abstract: A photographic lens of a photographic apparatus which includes a plurality of lens groups may be manufactured using a method which includes correcting a focus deviation from a designed value generated in one lens group by adjusting a distance between lenses of another lens group. The distance between lenses may be adjusted using a washer. The lenses between which the distance is adjusted may include a positive lens and a negative lens, and the lens group having the lenses between which the distance is adjusted may have a negative refractive power.

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: The present invention provides an optical analyzer having illumination optics that include a light source, such as a laser or other source, adapted to emit a collimated, or approximately collimated, light beam, a focusing lens that focuses the beam onto a focus spot within a detection region, and beam-adjusting optics positioned in the light path between the light beam source and the focusing lens, which allow for precise positioning of the focus spot within the detection region. The beam-adjusting optics of the present invention comprise at least one movable focusing lens, mounted in a positioning device that allows repositioning of the lens in a plane perpendicular to the light path.

Abstract: Disclosed is an optical head apparatus comprising: a light source; a collimating means of converting a beam of light emitted from the light source into a substantially parallel beam of light; a focusing means of focusing the light onto an information medium surface; a beam splitting means of splitting the beam of light modulated by the information medium; and a light receiving means of receiving the light modulated by the information medium, wherein a lens having a negative power and a lens having a positive power are arranged in this order as viewed from the collimating means side between the collimating means and the focusing means, and at least either one of the lenses is moved along an optical axis to correct spherical aberration occurring on the information medium surface, and wherein the distance from the lens having the positive power to the focusing means is set substantially equal to the focal length of the lens having the positive power.

Abstract: A zoom lens assembly and zoom lens module are provided, including a first lens, a second lens, a plurality of guiding blocks, a sheathing tube, a plurality of linking members and an adjusting tube. The first lens includes a plurality of curved surfaces disposed on a second lens surface toward a first lens surface. The second lens includes a plurality of driving rods disposed on a third lens surface and abutting the curved surfaces. The guiding blocks are respectively fixed on the first lens. The sheathing tube sheathes the first lens and the second lens and comprises a plurality of guiding notches to receive the guiding blocks, and a plurality of slits. The linking members pass through the slits and are fixed on the second lens. The adjusting tube sheathes the sheathing tube and comprises a plurality of driving notches to receive the linking members.

Abstract: A lens system comprising an inner lens structure and an outer lens structure. The inner lens structure comprises an inner positive lens, a first transparent substrate and an inner negative lens. The outer lens structure comprises an outer positive lens, a second transparent substrate and an outer negative lens.

Abstract: An imaging lens of which optical performance does not deteriorate even in a high temperature environment, various aberrations are well corrected, optical length is short, and back focus is sufficiently secured. This imaging lens comprises a first diaphragm S1, a first junction type compound lens 14, a second diaphragm S2 and a second junction type compound lens 16, wherein the first diaphragm, the first junction type compound lens, the second diaphragm, and the second junction type compound lens are arranged in this sequence from an object side to an image side. The first junction type compound lens comprises a first lens L1, a second lens L2 and a third lens L3 arranged in this sequence from the object side to the image side, and the second junction type compound lens comprises a fourth lens L4, a fifth lens L5 and a sixth lens L6 in this sequence from the object side to the image side. The first lens, the third lens, the fourth lens and the sixth lens are formed of a curable resin material.

Abstract: An image pickup lens includes a first lens block with a positive refractive power, a second lens block with a negative refractive power, and an aperture stop. The first lens block includes a first lens substrate, and lens portions 1a and 1b arranged on the first lens substrate. The lens portions 1a and 1b are different from the first lens substrate in at least one of a refractive index and an Abbe number. The second lens block includes a second lens substrate, and lens portions 2a and 2b arranged on the second lens substrate. The lens portions 2a and 2b are different from the second lens substrate in at least one of a refractive index and an Abbe number. The image pickup lens satisfies predetermined conditions relating to a refractive index of the lens portion 2b, and composite thicknesses of the first lens block and the second lens block.

Abstract: A cemented lens is produced by cementing a first lens having a concave surface with a second lens having a convex surface. The second lens is placed on the concave surface of the first lens to align the concave surface with the convex surface. Adhesive is dropped in each predetermined place around the second lens by a predetermined quantity to abut against an outer circumferential end of the second lens. The position of the second lens is adjusted. The adhesive is irradiated with ultraviolet light. Thus, the outer circumferential end of the second lens is bonded with the concave surface of the first lens. There is no bonding layer between the cementing surfaces as in the related art. There is no fear that light passes through the bonding layer. It is therefore unnecessary to consider deterioration of optical performance caused by deformation of the adhesive exposed to intensive light.

Abstract: A lens system includes a first lens and a second lens in order from the object side thereof. The first lens includes a first optical portion and a first mounting portion surrounding the first optical portion. The second lens includes a second optical portion with a convex object side surface, and a second mounting portion surrounding the second optical portion. The convex object side surface includes an optical surface at the center thereof and a first connecting surface surrounding the optical surface. The second mounting portion includes a second connecting surface surrounding the first connecting surface. Wherein the angle measured anti-clockwise from the first connecting surface to the axis of the lens system satisfies a certain condition.

Abstract: An optical fiber micro array lens is provided along with an associated fabrication method. The micro array lens is fabricated from a mesh of optical fibers. The mesh includes a first plurality of cylindrical optical fibers. Each fiber from the first plurality has a flat bottom surface and a hemicylindrical top surface. The top and bottom surfaces are aligned in parallel with a central fiber axis. The mesh also includes a second plurality of cylindrical optical fibers. Each fiber from the second plurality has a hemicylindrical bottom surface overlying and in contact with the top surfaces of the first plurality of optical fibers, and a flat top surface. The top and bottom surfaces are aligned in parallel with a central fiber axis. Each contact of the first and second plurality of optical fibers forms a lens assembly in a micro array of lenses.

Abstract: An exemplary lens includes an optical axis, an optically active part, and an optically inactive part surrounding the optically active part. The optically inactive part includes a base and a peripheral sidewall extending in a direction parallel to the optical axis. The base is connected with the active part. The side wall is a hollow cylinder. The sidewall has an internal thread formed on an internal surface thereof.

Abstract: An exemplary projection lens includes, in this order from the magnification side to the minification side thereof, a negative lens group of negative fraction power, and a positive lens group of positive fraction power. The projection lens satisfies the formulas of: ?2.5<F1/F<?1.5; and 1.3<F2/F<1.5, where F1, F2, and F respectively represent the effective focal lengths of the negative lens group, the positive lens group, and the projection lens.

Abstract: A large caliber standard lens having a first lens of a positive refractive power; a second lens of a negative refractive power; a diaphragm; a third lens of a negative refractive power; a fourth lens of a positive refractive power; and a fifth lens of a positive refractive power, wherein the lenses are arranged sequentially from an object side to an image side, and the first lens, the second lens, the third lens, and the fourth lens are meniscus lenses having concave surfaces facing the diaphragm and satisfy the following inequality, 0.6 ? ? R 6 R 4 ? ? 1.0 where R4 represents the radius of curvature of the surface of the second lens facing the image, and R6 represents the radius of curvature of the surface of the third lens facing the object.

Abstract: An image pickup optical system includes a first-lens unit having negative refractive power; a second-lens unit having positive refractive power and being disposed closer to an image side than the first-lens unit; an aperture; and a diffraction optical part provided on the joint surface of a first-cemented lens closer to the image side than the aperture. The focal length of the whole system, the Abbe number of the negative lens of a second-cemented lens closer to the image side than the aperture, the focal length within the air, the Abbe number of a negative lens closer to an object side than the aperture, the average value between the curvature radius closest to the object side and the curvature radius closest to the image side of the first-cemented lens including the diffraction optical part, the curvature radius of the diffraction optical part, and so forth, are set appropriately.

Abstract: Micro lens manufacturing apparatus, a micro lens manufacturing method, a micro lens, and a camera module employing the micro lens are provided. First mold is manufactured in correspondence with a first lens profile of a lens element. Second mold is manufactured in correspondence with a second lens profile of the lens element. Second mold is aligned on a surface of a lens substrate having a hollow hole formed thereon. Material for the lens element is supplied into the hollow hole of the lens substrate. First mold is aligned on the other surface of the lens substrate having the hollow hole and compressed to form the first and second profiles of the lens element. Formed lens element hardened. First and second molds are separated from each other. Therefore, time and cost for manufacturing the micro lens are reduced, and the accurate alignment between the first and second lens profiles is achieved.

Abstract: An imaging lens is provided and includes, in order from the object side, a front group having a negative power, a stop, and a rear group having a positive power. The front group includes, in order from the object side, a first negative lens having a meniscus shape with a concave surface on an image side, a second negative lens, and a third positive lens. The rear group includes, in order from the object side, a fourth positive lens, a fifth negative lens having a meniscus shape with a concave surface on the object side, and a sixth positive lens. An Abbe number of each of the first lens, the second lens, the fourth lens, and the sixth lens at the d-line is equal to or larger than 40, and an Abbe number of each of the third lens and the fifth lens at the d-line is equal to or smaller than 40. Each lens constituting the front group and the rear group is a single lens.

Abstract: An optical device includes an elongated tube configured for insertion into a body and optical members located in the tube. The optical members are configured to have an optical invariant-to-clear aperture semidiameter ratio greater than about 0.05 and an optical path difference less than about a value of the optical invariant divided by at least 250 times a midrange wavelength in a spectral range from about 435.8 nm to about 656.3 nm, and are preferably formed of an extraordinary dispersion optical material. A method includes conducting polychromatic light through at least one optical member located in an elongated tube configured for insertion into a body, where the optical members have an optical invariant-to-clear aperture semidiameter ratio greater than about 0.05 and an optical path difference less than about a value of an optical invariant divided by at least 250 times the midrange wavelength from about 435.8 to about 656.3 nm.

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

Abstract: A wide angle lens especially suitable for digital single lens reflex cameras is described. The lens offers the advantages of superior performance while using fewer lens elements thus reducing size and cost to manufacture. The lens consists of two lens groups separated by an aperture stop. The first lens group consists of a meniscus lens and the novel use of a bi-concave lens element. The first group may also include a cemented doublet with novel ratios of refractive index and Abbe numbers. Embodiments of the wide angle lens satisfy conditional equations of 6?BFL/f?7.5 and 10<?d/f?21, where BFL is the distance from the most image side lens element surface to the image plane with the lens focused at infinity, f is the effective focal length of the wide angle lens and ?d is the distance from the most object side lens element surface to the most image side lens element surface.

Abstract: A heat-resistant lens kit configured within the pogo tower of the wafer tester is disclosed. The heat-resistant lens kit has two parallel lenses and a main body with a through hole. The main body and two parallel lenses enclose a vacuum room within the through hole.

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 that is a biconvex lens, and a second lens 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: ?0.3?r1/r2<?0.1 and 0.8?f1/FL?0.98 (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, and FL: focal distance of the entire lens system).

Abstract: A wide-angle lens module includes a first lens and a second lens with negative refracting power, a third lens with positive refracting power, a fourth lens with negative refracting power, a fifth lens with positive refracting power, a sixth lens with positive refracting power, and a seventh lens with negative refracting power. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are disposed in order from an object side to an image side.

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

Abstract: 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: A lens array unit includes first lens array plates, second lens array plates and a support member. Each of the first lens array plate has multiple first lenses thereon. Each of the first lenses has a first optical axis that extends in a first direction and the first lenses are arranged in a second direction perpendicular to the first. Each of the second lens array plates has multiple second lenses thereon. Each of the second lenses has a second optical axis that extends in the first direction and the second lenses are arranged in the second. The support member has opposite first and second sides. The support member extends in the second direction to support the first lens array plates on the first side and support the second lens array plates on a second side so that each of the first lens array plates opposes a different corresponding one of the second lens array plates.

Abstract: An optical accessory having a high optical performance arranged to change an optical characteristic of a shooting lens and to be attached on the object side of a shooting lens is provided. The optical accessory FE is to be detachably attached to the object side of a master lens M and has at least one lens FE having a negative refractive power. The image-side surface r2 of the lens FE is designed to have an aspherical shape having a negative refractive power that decreases toward its periphery.

Abstract: There is provided a wide-angle lens system having a wide angle of view and less distortion. The wide-angle lens system including: an object-side lens group disposed at an object side with respect to an aperture stop and having overall positive refractive power; and an image-side lens group disposed at an image side with respect to the aperture stop and having overall positive refractive power, wherein a focal length ratio between the object-side lens group and the image-side lens group satisfies following condition 1, 2<FO/FI<10??condition 1, where FO is a focal length of the object-side lens group (FO>0) and FI is a focal length of the image-side lens group (FI>0). This wide-angle lens system sufficiently corrects distortion even in a wide angle of view, thereby ensuring an image with superior quality.

Abstract: Disclosed are a projection lens that has a simple inner focus structure, an appropriate back focal length, telecentricity, a high optical performance, and a small size and can effectively correct, particularly, lateral chromatic aberration, and a projection display device. A projection lens includes a first lens group having a negative refractive power and a second lens group having a positive refractive power arranged in this order from a magnification side. A fifth lens arranged closest to a reduction side in the first lens group is moved along an optical axis to adjust focus, and at least two lenses are made of a material satisfying the following conditional expression: 0.018<??(?0.00164·?d+0.6427)<0.06 (where ?=(ng?nF)/(nF?nC), ?d=(nd?1)/(nF?nC), and ng, nF, nd, and nC indicate refractive indexes with respect to the g-line, the F-line, the d-line, and the C-line, respectively).

Abstract: There are provided an imaging lens, which is capable of promoting high definition and miniaturization of a small-size image pickup apparatus, and the small-size image pickup apparatus using the same. A aperture diaphragm S is arranged between a first lens L1 and a second lens L2 so that the first lens L1 is configured to be displaced into the orthogonal direction to the optical axis. Even when an error sensitivity of a lens is large, a stable high resolution can be secured by performing a lens alignment by displacing the first lens L1 into the orthogonal direction to the optical axis at the time of assembling, and thereby a high definition image can be obtained.

Abstract: Providing a zoom lens system excellently correcting various aberrations with accomplishing to be compact, lightweight, and slim upon being accommodated, and to provide an optical apparatus using the zoom lens system. The system consists of, in order from an object, a first group G1 having negative power, a second group G2 having positive power. Upon zooming from a wide-angle end W to a telephoto end T, a distance between the first group G1 and the second group G2 decreases. The first group G1 consists of, in order from the object, a first lens L1 having negative power and a second lens L2 having positive power. The second group G2 consists of, in order from the object, a third lens L3 having positive power, a fourth lens L4 having negative power, and a fifth lens L5 having positive power. Given conditions are satisfied.

Abstract: A lens arrangement for an LED display device includes a lens. The lens has a first lens surface and an optical axis. The optical axis penetrates the first lens surface of the lens. Furthermore, the lens arrangement includes a transparent transition body, which is firmly coupled with the lens on the first lens surface, which is more temperature-resistant than the lens and which has an optical axis that is parallel to the optical axis of the lens.

Abstract: Providing a large aperture wide-angle lens having high optical performance with sufficiently suppressed spherical aberration and sagittal coma flare, and an imaging apparatus using the lens. The lens including, in order from an object, a first lens group having positive refractive power, and a second lens group having positive refractive power, the second lens group being movable for focusing and including a 21 lens component having positive refractive power, a 22 lens component having negative refractive power, a 23 lens component having positive refractive power, and a 24 lens component having positive refractive power, and given conditions being satisfied.

Abstract: A lens module comprises a first lens, a second lens, a spacer, an adhesive and a lens barrel. The spacer is sandwiched between the first lens and the second lens, and includes a first surface, an opposite second surface, a lateral surface, a through hole and a plurality of cutouts. The lateral surface interconnects the first surface and the second surface. The through hole is defined in a central portion of the spacer. The cutouts are defined in the lateral surface. The adhesive is applied in the cutouts and interconnects the first lens with the second lens. The lens barrel receives the first lens, the second lens, the adhesive and the spacer therein.

Abstract: A cemented lens comprises first, second and third optical elements respectively formed by different solid materials, the third and first optical elements being cemented to each other, and the first and the second optical elements being cemented to each other, wherein both an incident surface and an exit surface of the first and second optical elements are refracting surfaces, and the following conditional expressions are satisfied: |??gF1|>0.0272 |??gF2|>0.0272 ??gF1×??gF2<0 ?1×?<0 where ??gF1 and ??gF2 are respectively anomalous dispersion characteristics of the materials for the first and the second optical elements with respect to a g line and an F line, and ?1 and ?2 are respectively refracting powers of the first and second optical elements when both the incident surface and the exit surface of the first and the second optical element are surfaces in contact with air.

Abstract: A lens system includes a first lens which is formed of a medium exhibiting negative refraction, and a second lens having a positive refractive index. Accordingly, it is possible to provide a lens system in which a negative refractive index medium for which a curvature of field is reduced. Moreover, it is also possible to have a lens system in which a lens having a positive focal length and a lens having a positive focal length, which is made of a positive refractive index medium, are combined.

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 a solar multistage concentrator in which at least one imaging lens system (1) is mounted in front of a non-imaging lens system (3, 4) in such a way that both systems are an integral part of a specifically formed, light-transparent dielectric (2).

Abstract: A camera lens unit includes a first lens including a first lens section having a first optical axis along which light runs, and a second lens. The second lens includes a second lens section having a second optical axis along which the light runs, a flange provided on an outer circumference of the second lens and having a surface facing the first lens, and a cylindrical section having an inner circumference extending from the flange along the second optical axis. The inner circumference of the cylindrical section faces the second lens section. The first lens contacts the inner circumference of the cylindrical section of the second lens and is engaged into the cylindrical section. The cylindrical section of the second lens includes plural protrusions protruding along the second optical axis, such that plural crenels are provided between the protrusions and have heights along the second optical axis lower than the protrusions. The camera lens unit prevents diffuse reflection caused by unnecessary incident light.

Abstract: An optical system includes a first lens with a functional film having film hardness of equal to or less than H formed on at least on one surface thereof, and a second lens located opposite the surface with the functional film of the first lens and having a diameter larger than that of the surface with the functional film, wherein the first lens and the second lens are in marginal contact with each other.