Abstract: A wide-angle lens whose angle of view is more than 90 degrees and less than 120 degrees includes, in order from an object side thereof: a first lens having a negative power and including a spherical glass body; a second lens having a positive power and including an aspheric surface; and a third lens having a positive power and including an aspheric surface.

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: Large aperture optical systems that are extremely well corrected over a large flat field and over a large spectral range are disclosed. Breathing and aberration variation during focusing are optionally controlled by moving at least two groups of lens elements independently. Aberration correction in general is aided by allowing the working distance to become short relative to the format diagonal. Field curvature is largely corrected by a steeply curved concave surface relatively close to the image plane. This allows the main collective elements to be made of low-index anomalous dispersion materials in order to correct secondary spectrum. In wide-angle example embodiments, distortion may be controlled with an aspheric surface near the front of the lens.

Abstract: An optical system includes a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. The second lens unit includes a front lens unit, a stop, and a rear lens unit. The front lens unit includes a biconvex positive lens located closest to the image side. A back focus during focusing on an infinitely-distant object point (BF), a focal length of the entire optical system (f), a focal length of the positive lens of the front lens unit located closest to the image side (fp), a focal length of the front lens unit (f2a), a refractive power of a surface of the rear lens unit located closest to the object side (?f), and a refractive power of the entire optical system (?) satisfy the following conditions: 1.0<BF/f<3.0 0.1<fp/f2a<0.5 0.7<|?f/?|<1.5.

Abstract: A vehicle camera and wide-angle objective lens system are disclosed wherein the wide-angle objective lens has image aberrations or errors that do not deteriorate the detection of obstructions or obstacles in its field of view.

Abstract: According to the present invention, an image projector includes a reflecting light valve, a group of refracting lenses forming a projecting optical system that enlarges and projects an optical image given from the light valve, a power mirror having a power and forming the projecting optical system together with the group of refracting lenses, and a transmissive screen for displaying the optical image that is given from the light valve and enlarged by the projecting optical system, wherein the exit pupil position is set such that the minimum angle of view ?min exceeds 40°, and the Petzval partial sum of lenses is set larger than a value determined by the minimum angle of view.

Abstract: A high-performance lens system includes lens elements of small diameters for projecting enlarged images from light valves (mainly Digital Micromirror Devices (DMDs))for forming images by changing reflecting directions of light. The lens system includes, sequentially in order from a magnifying side, a first lens group which makes up a substantially afocal optical system as a whole and a second lens group having a positive refractive power as a whole. Depending on the application a third lens group made up of a single positive lens element is provided in the vicinity of the light valve on a contracting side of the second lens group.

Abstract: A panoramic optical system includes optical means including one or more objective and relay optics to focus at least one image representing at least some portion of a substantially spherical field-of-view scene in focus to an imaging plane, housing means including support means to hold the optical means and mounting means that attaches the panoramic optical system to an adjacent camera.

Abstract: Providing a retrofocus lens system and an image-taking device having small variation in aberrations upon focusing on a close object with a high imaging magnification. The retrofocus lens system includes, in order from an object, a first lens group G1 having negative refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. Upon focusing from infinity to a close object, the first lens group G1, the second lens group G2, and the third lens group G3 are moved to the object such that a distance between the first lens group G1 and the second lens group G2 increases, and a distance between the second lens group G2 and the third lens group G3 decreases.

Abstract: The present invention discloses an aspherical LED angular optical lens for wide distribution patterns and an LED assembly using the same. The optical lens comprises a concave surface on a source side and a convex surface on a project side. The LED assembly comprising the optical lens can accumulate light emitted from the LED die and generate a peak intensity of the wide angular circle distribution pattern which is greater than 120° and smaller than 180°. The present invention only uses a single optical lens capable of accumulating light and forming a required distribution pattern to satisfy the requirement of a luminous flux ratio greater than 85% and the requirement of an illumination, a flash light of a cell phone or a flash light of a camera.

Abstract: An image forming optical system which comprises a negative lens unit and a positive lens unit arranged in order from an object side. The negative lens unit includes, in order from the object side, a first negative lens and a second negative lens, or a first negative lens, a second negative lens and a third negative lens. The positive lens unit includes, in order from the object side, a third positive lens, a fourth negative lens, a fifth positive lens and a sixth positive lens, or a fourth positive lens, a fifth negative lens, a sixth positive lens and a seventh positive lens.

Abstract: An image capturing lens including: in order from an object side, a first lens group having a negative refractive power; a stop; and a second lens group having a positive refractive power; the first lens group including, in order from the object side, a first lens in a meniscus shape having a convex surface which faces the object side and a negative refractive power, and a second lens in a meniscus shape having a convex surface which faces the object side and a positive refractive power, and the second lens group including, in order from the object side, a third lens in a double-convex shape having a positive refractive power, a fourth lens in a double-concave shape having a negative refractive power, and a fifth lens having a positive refractive power.

Abstract: A projection zoom lens is provided and includes: in order from the magnification side, a negative first lens group performing focusing with being fixed during power-varying; a positive second lens group, a positive third lens group, a positive fourth lens group, a positive fifth lens group, which are moved with correlation; and a positive sixth lens group fixed during the power-varying. An aperture diaphragm is moved between the fourth lens group and the fifth lens group during the power-varying to keep Fno constant in the whole power-varying region. In addition, the expression of 1.7<Bf/f<3.0 is satisfied, where f is a focal length of the whole system, and Bf is a back focal length (air conversion distance) of the whole system.

Abstract: A first lens group having a positive refractive power, an aperture stop, and a second lens group having a positive refractive power are provided in order from an object side. The first lens group includes, in order from the object side, a first lens that is a negative meniscus lens having a convex surface directed toward the object side, a negative second lens whose surface on an image side has a concave shape, and a positive third lens whose surface on the image side has a convex shape directed toward the image side. The second lens group includes, in order from the object side, a positive fourth lens whose surface on the image side has a convex shape directed toward the image side, a negative fifth lens having a biconcave shape, and a positive sixth lens having a biconvex shape. The fifth lens and the sixth lens are cemented together.

Abstract: An optical system used for an image pickup apparatus including an image pickup element is provided. The optical system includes a negative lens disposed furthest away on the enlargement conjugation side and satisfies the following condition: 80 degrees<2?, where 2? (degrees) denotes an angle of view of the optical system. In addition, the following parameters of the optical system are optimally determined: a lens open angle ? of a surface of the negative lens on the reduction conjugation side, an index of refraction Ndn and an Abbe number vdn of a material of the negative lens for a d-line, and a relative partial dispersion ?gFn of the material of the negative lens for a g-line and an F-line.

Abstract: A lens system comprises a first lens negative in power, a second lens positive in power, a third lens negative in power, a fourth lens positive in power, a fifth lens negative in power, and a sixth lens positive in power. The lens system meets a criteria of TT/f?1.68 and 0.3<f/f23<0.4, wherein TT denotes a distance between an object-side surface of the first lens and an image plane of the lens system; f23 denoting an effective focal length of a combination of the second lens and the third lens; f denoting an effective focal length of the entire lens system.

Abstract: The wide angle lens system described herein allows projection devices (e.g., rear projection display devices) to be more compact than would otherwise be possible. The lens system includes a wide angle lens stage and a relay lens stage. When operating as a projection device, the relay lens stage projects a distorted intermediate image to the wide angle lens stage, which projects the image for display. The distortion cause by the relay lens stage compensates (i.e., is approximately equal and opposite) for the distortion caused by the wide angle stage. The distortion can be the image shape and/or the focal plane. When operating as a taking device, the wide angle stage provides a distorted image to the relay lens stage, which compensates for the distortion and provide a less distorted, or even non-distorted image, for capture.

Abstract: An exemplary super-wide-angle lens includes a lens barrel, a set of imaging lenses, and a prism. The set of imaging lenses is received in the lens barrel. The prism has three light incident surfaces, each of which is coated with a unique color filter for exclusively transmitting a predetermined color light, and a light emissive surface. The prism is positioned such that each of the light incident surfaces is configured for receiving light from a unique field of view of the super-wide-angle lens and the light emissive surface faces the set of imaging lenses, and is structured so that light transmitting in the prism is directed from the light incident surfaces to the light emissive surface.

Abstract: A projection objective having a fixed focal length for digital projection includes the following arrangement of the lenses in the sequence from the image (enlargement side) to the object (reduction and illumination side): a first, negative lens, a second, negative lens, a third lens, a fourth, positive lens, a fifth lens, a sixth, positive lens, a seventh, negative lens, an eighth, positive lens, and a ninth, positive lens. By means of such an objective, the quality requirements in the field of digital projection can be met with a minimal number of lenses.

Abstract: A fixed-focus lens suitable for projecting an image beam from a light valve onto a screen is provided. The fixed-focus lens comprises a first lens group, a second lens group, and a third lens group arranged in sequence. The third lens group is disposed near the light valve. The first lens group having a negative refractive power comprises at least an aspheric lens. The second lens group having a positive refractive power comprises at least a lens. The third lens group having a positive refractive power comprises at least four lenses.

Abstract: A fixed-focus lens including a first lens group, a second lens group and a third lens group, which are arranged in sequence from an object side to an image side, is provided. The first lens group has a negative refractive power and includes three lenses arranged from the object side to the image side. The lens, closest to the object side, of the first lens group is an aspheric lens. The second lens group has a positive refractive power and includes two lens arranged from the object side to the image side. The third lens group has a positive refractive power and includes six lenses arranged from the object side to the image side. Refractive powers of the lenses of the third lens group in sequence from the object side to the image side are negative, positive, negative, positive, positive and positive.

Abstract: The invention relates to a compact image-formation optical system that is diminished in a diametrical direction with as few lenses as possible while well adapting to an wide-angle arrangement having a half angle of 90° or greater, and an imaging system incorporating the same. The image-formation optical system comprises, in order from its object side, a first lens L1 that is a negative lens, a second lens L2 that is a meniscus lens concave on its object side, an apertures stop S, and a lens group G having positive refracting power.

Abstract: A wide-angle imaging lens is provided and includes: a first lens, a second lens, and a third lens in this order from the object side. The first lens is a negative meniscus and has a convex surface on the object side; the second lens, at least one surface of which is an aspherical surface; and the third lens is a positive lens and has a convex surface on the image side and at least one surface of the third lens is an aspherical surface. The first len is made of a material having an Abbe number of 40 or more and the third lens is made of a material having an Abbe number of 50 or more. At least one surface of the second lens and the third lens has a diffracting function. An aperture stop is disposed between the second lens and the third lens.

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: An ultra wide angle imaging optical system includes, in order from an object side, a first lens group, an aperture stop, and a second lens group. The first lens group includes, in order from the position closest to the object side, a negative meniscus lens element convex to the object side, a negative lens element, and a negative lens element. The second lens group includes a plurality of positive lens elements. The first lens group and the second lens group each includes at least one anamorphic surface having different optical powers with respect to a first section extending in a first direction on a flat plane substantially orthogonal to an optical axis, and with respect to a second section extending in a second direction substantially orthogonal to the first direction. The first lens group includes the lens element satisfying the following conditional formula (1): ?0.6<(Ph?Pv)*(fh+fv)<?0.

Abstract: An endoscope objective lens system includes a negative front lens group, a diaphragm, and a positive rear lens group, in this order from the object. The negative front lens group includes one lens element, or a plurality of non-cemented lens elements; and the most object-side lens element is constituted by a negative lens element. The positive rear lens group includes a plurality of non-cemented lens elements; and at least one negative lens element is provided in the positive rear lens group.

Abstract: A wide-angle lens system has, from the object side thereof: a first lens element having a negative optical power and having a meniscus shape convex to the object side; a second lens element having a biconcave shape; a third lens element having a biconvex shape; and a fourth lens element having a negative optical power and having a meniscus shape convex to the image side. Alternatively, a wide-angle lens system has, from the object side thereof: a first lens element having a negative optical power; a second lens element having a negative optical power; a third lens element having a positive optical power; and a fourth lens element having a positive optical power.

Abstract: An object is to provide an aspherical lens having compactness in dimension, large degree of freedom in design, and good optical performance, with increasing in productivity, and lowering production cost. The aspherical lens constructed by a substrate member A and a member B having different composition formed on the substrate member A. A boundary between the substrate member A and the member B having different composition is formed by a first aspherical surface RAB, and a surface of the member B having different composition opposite to the boundary being formed by a second aspherical surface RB having higher fabrication accuracy than that of the first aspherical surface RAB, and given conditional expressions are satisfied.

Abstract: A zoom lens includes, in sequence from the object side: a first lens group with an overall negative refractive power; and a second lens group with an overall positive refractive power. A zoom factor changes by moving the second lens group. Focal adjustments are made by moving the first lens group accompanied by the change of the zoom factor made by the movement of the second lens group. The first lens group includes a first lens having a negative refractive power and a second lens having a positive refractive power. The second lens group includes a third lens having a positive refractive power, a fourth lens with a positive refractive power and a fifth lens with a negative refractive power bonded together, and a sixth lens with a positive refractive power. The bonded lenses form a meniscus shape with a convex surface facing the object side. The resulting lens is short in length, compact, thin, and suitable for digital still cameras.

Abstract: A compact wide converter lens having a small front-lens diameter. When attached to an object side of a main lens system, the wide converter lens provides reduced degradation of aberrations to achieve high optical performance. The wide converter lens includes a first negative lens element disposed most proximate to the object side and whose object-side surface is concave, a second positive lens element disposed at an image side of the first lens element, and a third negative lens element disposed at an image side of the second lens element. The following conditions are satisfied: 1.0<(r1?r2)/(r1+r2)<2.0 ?40<f1/D<?7, wherein r1 and r2 respectively represent curvature radii of the object-side and image-side surfaces of the first lens element, f1 represents a focal length of the first lens element, and D represents a spatial distance between the second and third lens elements.

Abstract: A wide-angle lens system includes a negative front lens group and a positive rear lens group, in this order from the object. The negative front lens group includes a negative first sub-lens group and a positive second sub-lens group, in this order from the object. The positive rear lens group includes cemented lens elements having a positive R1 lens element and a negative R2 lens element, a positive R3 lens element having a convex surface facing toward the image, and a positive R4 lens element, in this order from the object. The wide-angle lens system satisfies the following conditions: ?0.8<f1a/f1b<?0.1 ??(1) 0.6<f/fR<1.1 ??(2) wherein f1a designates the focal length of the negative first sub-lens group; f1b designates the focal length of the positive second sub-lens group; f designates the focal length of the entire wide-angle lens system; and fR designates the focal length of the positive rear lens group.

Abstract: A wide angle of view optical system, suitable for monitor cameras such as an in-vehicle camera and a security camera, having a reduced optical entire length and aberration correction for forming an optical image on light-receiving surfaces of an imaging element having a first lens having a negative optical power and a group of lenses each having a positive optical power, which are serially disposed from an object side. The first lens comprises at least one aspherical surface, and has a concave surface centered around an optical axis in vicinity of the optical axis on an image-side surface thereof. Further, an optical entire length T in millimeters (mm) of the entire system, a half angle of view ?, and a focal distance ftot of the entire system, also in millimeters, satisfy the conditional expressions.

Abstract: To provide a technique to constitute a fisheye lens unit with a small number of lenses. A fisheye lens unit uses a predetermined projection method, wherein a variation for the predetermined projection method is not less than the variation for an equidistant projection method, the variation being expressed by an increment of an image height in relation to an increment of an incident angle at a predetermined incident angle. The fisheye lens unit includes: a first lens group provided on an object side; a second lens group provided on an image side; and an aperture stop provided between the first lens group and the second lens group. The first lens group consists of three or four lenses, the second lens group consists of two or three lenses including a final lens provided on the furthest image side of the second lens group, and the final lens is an aspheric lens that has an aspheric shape on at least one of two surfaces of the aspheric lens.

Abstract: A projection lens includes three lens groups, arranged as follows from the magnification side: a first lens group of negative refractive power, a second lens group of positive refractive power, and a third lens group of positive refractive power. The first lens group includes three lens elements, each of negative refractive power, and two of these lens elements each have a meniscus shape with its convex surface on the magnification side. The second lens group includes a lens element having positive refractive power, a meniscus shape, and a convex surface on the magnification side. The third lens group includes: a lens element of positive refractive power and a meniscus shape with its convex surface on the reduction side; a cemented lens component; and at least one aspheric surface. The projection lens satisfies specified conditions regarding focal lengths and spacings of lens surfaces. A projection display device uses the projection lens.

Abstract: In order to provide a fast super wide-angle lens system having the f-number of f/2.8 and a wide angle of view of 2?=100° or more in an imaging area of a digital camera and an image-capturing device equipped with the super wide-angle lens system. The lens system includes, in order from an object, a first lens group G1 having negative refractive power, an aperture stop S, and a second lens group G2 having positive refractive power, and the lens system satisfies predetermined conditional expressions.

Abstract: A large aperture wide-angle lens includes first and second lens groups separated by a stop. The first lens group includes more than one lens element and the second lens group includes, in order from the object side, a first lens component having at least one aspheric surface, having negative refractive power, and having increasingly negative refractive power toward the periphery, a second lens component having a convex surface on the image side, and a third lens component having at least one aspheric surface and having decreasingly positive refractive power or increasingly negative refractive power toward the periphery. The large aperture wide-angle lens includes six or seven lens components and seven lens elements, and preferably satisfies specified conditions related to f-number and focal length of the wide-angle lens, the maximum image height at the image surface, and the index of refraction of the object-side lens element of the second lens group.

Abstract: A zoom lens having at least a first lens group including a reflection member for bending an optical axis fixedly during zooming and having a negative refractive power, a second lens group having a negative refractive power, and a third lens group arranged in the order from an object side is provided. In the zoom lens, an image can be shifted into a direction perpendicular to the optical axis by moving either of the second and the third lens groups (“shift lens group”) in a direction perpendicular to the optical axis, and a following conditional expression (1) is satisfied, 0.5<(1???)×?b<3.0,??(1) where: ??: a magnification of the shift lens group in a maximum telephoto state, and ?b: a magnification of a lens group arranged on an image surface side of the shift lens group in the maximum telephoto state.

Abstract: Provided is a projection lens, including: a plurality of moving lens units that move on an optical axis for zooming; and a plurality of plastic lenses containing plastic, in which when a focal distance of an i-th positive lens from a predetermined plane side of N positive lenses of the plurality of plastic lenses is given by fpi, a focal distance of a j-th negative lens from the predetermined plane side of M negative lenses of the plurality of plastic lenses is given by fnj, and fp and fn are defined by 1 fp = ? i = 1 N ? 1 fpi 1 fn = ? j = 1 M ? 1 fnj (N and M each are a natural number, that is, an integer equal to or larger than 1), ?0.56<fn/fp<?0.05 is satisfied.

Abstract: A wide-angle lens system includes a positive front lens group, a diaphragm, and a positive rear lens group. The front lens group includes a negative first-sub-lens group and a positive second-sub-lens group. The negative first-sub-lens group includes a negative lens element, a positive lens element, and a negative lens element. The front lens group satisfies the following conditions: 0.5<f/|f1a|<0.75??(1) 0.5<|f1a|/f1b<1.0??(2) 0.35<f/f1bi<0.6??(3) wherein f: the focal length of the entire lens system; f1a: the focal length of the negative first-sub-lens group; f1b: the focal length of the positive second-sub-lens group; f1bi: the focal length of the most image-side surface of the positive second-sub-lens group; r1bi: the radius of curvature of the most image-side surface of the positive second-sub-lens group; and N1bi: a refractive index of the most image-side lens element of the positive second-sub-lens group.

Abstract: An image pickup unit which consists of an objective optical system and a solid-state image pickup device: the objective optical system being composed of a first negative lens unit comprising a first meniscus lens element having a convex surface on the object side and negative power, a second positive lens unit comprising a convex lens element and an aperture stop disposed between the first lens unit and the second lens unit and this image pickup unit having a small outside diameter, allowing a field angle to be changed little due to variations of parts and an assembling variation, and having a maximum field angle of 150° or larger.

Abstract: A fisheye lens system with a half angle-of-view of 90° includes a negative front lens group, a diaphragm, and a positive rear lens group. The negative front lens group includes at least three negative meniscus lens elements each of which has the convex surface facing toward the object; and the three negative meniscus lens elements satisfy the following conditions: 0.2<SF(i=1)<0.6??(1) 0.8<SF(i=2)/SF(i=1)<1.5??(2) 0.8<SF(i=3)/SF(i=1)<2.0??(3) wherein SFi designates the shaping factor of the ith (1?i?3) negative meniscus lens element (SFi=(R1i?R2i)/(R1i+R2i)); R1i designates the radius of curvature of the object-side surface of the ith (1?i?3) negative meniscus lens element; and R2i designates the radius of curvature of the image-side surface of the ith (1?i?3) negative meniscus lens element.

Abstract: An object of the present invention is to provide a fisheye lens, in spite of its compactness, having an angle of view of 180 degrees and a fast f-number of 2.8 with securing sufficient back focal length and suitable for a digital camera. The fisheye lens consists of a front lens group G1 having negative refractive power and a rear lens group G2 having positive refractive power locating with a space along the optical axis apart from the front lens group G1. The front lens group G1 includes a plurality of negative lens components, L1 and L2. The rear lens group G2 includes at least one cemented lens L5, and given conditional expressions are satisfied.

Abstract: The invention relates to a superwide-angle lens optical system having a long back-focus lens arrangement and comprising a relay lens group. The optical system is constructed of, in order from an object side thereof, an objective lens group Ob having positive refracting power, a primary image-formation plane formed by the objective lens group Ob and a relay lens group R1 having positive refracting power. A field stop FS is positioned at or near the primary image-formation plane, and condition (1-1) is satisfied. h/fo>1.8??(1-1) Here fo is the focal length of the objective lens group Ob, and h is the diameter of an image circle on the primary image-formation plane.

Abstract: A projection optical system and an image projection apparatus that are small in size and can achieve projection with a wide angle while a good image forming performance is assured includes a first lens group having a negative refracting power and a second lens group also having a negative refracting power. The first and second lens groups are arranged in order from the projection side. The first lens group includes a negative meniscus lens that has a concave surface directed to the projection side and formed as an aspherical reflecting surface.

Abstract: A wide-angle lens system includes a negative first lens group, a negative second lens group, and a positive third lens group. The negative first lens group includes at least two negative meniscus lens elements each having the convex surface facing toward the object, and a positive lens element provided on the image-side of the two negative meniscus lens elements. The negative second lens group includes cemented lens elements and a negative meniscus lens element having the convex surface facing toward the object. The wide-angle lens system satisfies the following conditions: f2-3/f>1.6??(1) f3/f>1.5??(2) (f2-3/f)/(f3/f)>1.0??(3) wherein f2-3 designates the combined focal length of the negative second lens group and the positive third lens group; f designates the focal length of the entire wide-angle lens system; and f3 designates the focal length of the positive third lens group.

Abstract: Provided is a retrofocus type optical system including a lens or a layer made of a material satisfying the following conditions of the Abbe constant ?d and partial dispersion ratios ?gd and ?gF, ?d<30, ?gd<?3.333×10?3·?d+1.40, ?gF<?2.615?10?3·?d+0.67. In the case that this layer is disposed on the front side of the aperture stop, the layer is designed to have a positive refractive power, and in the case that the layer is disposed on the rear side of the aperture stop, the layer is designed to have a negative refractive index.

Abstract: A flat wide-angle lens system of the invention has a reduced axial length and is intended for creating images with extremely wide angle of observation. The system consists of the first component which is intended for reduction of the field angle of light incidence onto the objective and comprises an assembly of at least two microlens arrays with the same pitch between the adjacent microlenses and arranged with respect to each other so as to provide afocality, and a second component that comprises an assembly of conventional spherical or aspherical microlenses that create an image on an image receiver. Each two coaxial microlenses of the microlens arrays of the first component form an inverted microtelescope of Galileo. The outlet aperture of a single microtelescope is made so that spherical aberration can be minimized almost to 0, while field aberrations can be corrected by design parameters of the microlenses.

Abstract: A fisheye-corrected lens system includes a plurality of axially aligned lenses. At least one of the lenses includes an aspheric surface and an image distortion of the lens system is less than about five percent at a maximum field angle. A furthest point of the aspheric surface is positioned within a distance less than about fifty percent of a diagonal dimension of an associated imager.

Abstract: A zoom lens includes a plurality of lens groups including a first lens group arranged on the foremost side and having negative optical power. Zooming is performed by moving at least one of the plurality of lens groups along a direction parallel to an optical axis of the zoom lens. The first lens group is fixed during the zooming. A first lens arranged on the foremost side, of the first lens group has negative refractive power. When an Abbe constant and a partial dispersion of a material configuring the first lens are respectively represented by ?dn and ?g,Fn, a focal distance of the first lens group is represented by f1, and an air-equivalent back focus upon focusing on an infinity object is represented by bf, the following conditions are satisfied: ?dn<32, 0.008<?g,Fn?(0.644?0.00168×?dn)<0.040, and |f1/bf|<0.9.

Abstract: A lens (1), a lens (2) and a lens (3) constitute a first group of lenses, a lens (4), a lens (5), a lens (6) and a lens (7) constitute a second group of lenses, and a lens (8) constitutes a third group of lenses in a zoom lens of the present invention. The second group of lenses is constituted by a first positive lens (4), a negative lens (5) which is in a meniscus shape which faces its convex shape toward a side of an object (70), a second positive lens (6) in a meniscus shape which faces its convex shape toward the object (70) side, and the third positive lens (7), which are in order from the object (70) side.