Abstract: A bifocal double group lens assembly, sequentially from the object side, comprises: a stationary first lens group with a negative refractive power, a second lens group with a positive refractive power being moveable along optical axis. The second lens group, at two different positions, can focus appropriately on an infinitely distant object when moving along the optical axis. When the lens assembly is in the wide angle mode, and the object to be shot moves from an infinite distance to a near point, the second lens group will move toward the object side for focusing. When the lens assembly is in the Tele mode, and the object to be shot moves from an infinite distance to a near point, the second lens group will move toward the image side for focusing. A linear driver is employed to move the second lens group for executing the function of two-section zoom and continuous focus.

Abstract: Providing a wide zoom lens system having a wide angle of view in the wide-angle end state and a high speed aperture ratio suitable for a solid-state imaging device with securing high optical performance. The system includes, in order from an object, a first lens group having negative refractive power and a second lens group having positive refractive power. The first lens group includes, in order from the object, a negative meniscus lens having convex surface facing to the object, a negative lens, and a positive lens having convex surface facing to the object. The second lens group includes, in order from the object, a positive lens, and a negative lens. At least one surface of the negative meniscus lens of the first lens group is composed of an aspherical surface. Zooming is carried out by changing a distance between the first and second lens groups. Given conditions are satisfied.

Abstract: In one form, an imaging system comprises an imager that forms an image of an object in a field of view, a rotationally symmetric lens assembly disposed between the imager and the object, and an equalizer. The rotationally symmetric lens assembly provides increased collection efficiency for a given depth of field, whereby the rotationally symmetric lens assembly causes aberration, compared to a well-focused lens. The rotationally symmetric lens assembly comprises a front negative lens, a rear positive lens, and an aperture positioned between the front and rear lenses. The equalizer, which is connected to the imager, receives image data and at least partially compensates for the aberration caused by the rotationally symmetric lens assembly.

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: The invention makes a suitable selection from zoom modes and lens elements so thin that the thickness of each lens group can reduced, thereby slimming down a zoom lens with great thoroughness and, hence, an electronic image pickup system. The electronic image pickup system a zoom lens and an electronic image pickup device located on the image plane side of the zoom lens. The zoom lens comprises, in order from the object side, a first lens group G1 comprising two lens components and having generally negative power and a second lens group G2 comprising two lens components and having generally positive power. The focal length of the zoom lens can be varied by varying the air separation between the first lens group G1 and the second lens group G2. The zoom lens should satisfy at least one of conditions (a) to (n).

Abstract: A soft zoom lens system includes an axially expandable or shrinkable holding portion, a supporting portion, a first lens and a second lens. This holding portion has an inner space, a first end and a second end. The supporting portion is made by a soft material. The first lens is disposed between the first end and the supporting portion. The second lens is disposed between the second end and the supporting portion. When this holding portion is applied by predetermined electricity, it will expand or to shrink axially. So, the curvatures of the first lens and the second lens will be changed. The zooming is performed. The invention's structure is simple. The adjusting of focal length is easy. The production is easy with low cost.

Abstract: A zoom lens comprises a plurality of lens units including a first lens unit disposed most adjacent to an enlargement side and having negative refractive power, wherein one or more lens units of the plurality of lens units are moved in the direction of the optical axis thereof during magnification change, and wherein the first lens unit includes a 1-1st lens unit comprising at least one lens of negative refractive power and moved during focusing and a 1-2nd lens unit having positive refractive power, and fixed during focusing.

Abstract: A projection zoom lens that is suited to projector with a DMD is provided. The projection zoom lens projects, onto a screen, projection light from the DMD and comprises, in order from a screen side, a first lens group with negative refractive power and a second lens group with positive refractive power. The second lens group includes, from the DMD side, a final lens that is a positive lens, a pre-final lens that is a negative biconcave lens positioned next to the final lens, and a stop, and both surfaces of the pre-final lens are aspherical. Using the projection zoom lens, it is possible to realize the compact projector that can project bright images with high resolution that makes full use of the characteristics of the DMD.

Abstract: A projection lens system that is suited to a compact, wide-angle lens system. The projection lens system projects projection light from a light modulator onto a screen, wherein the projection lens system is constructed, in order from a screen side thereof, of a first lens group with negative refractive power and a second lens group with positive refractive power and is non-telecentric on an incident side thereof, and the second lens group includes a pair of cemented doublet lenses with positive refractive power whose cemented surfaces face in opposite directions and a cemented triplet lens with positive refractive power.

Abstract: A zoom lens system includes a negative first lens group and a positive second lens group. The negative first lens group includes a negative lens element and a positive lens element. The positive second lens group includes a positive lens element, a negative lens element, and a positive lens element. At least the object-side positive lens element and the negative lens element are cemented together. The zoom lens system of the present invention satisfies the following conditions: 1.5<f2G/(fT/fW)<3.0??(1) 1<f2G(mW?mT)/(fT/fW)<3??(2) wherein f2G: the focal length of the positive second lens group; mW: the lateral magnification of the positive second lens group at the short focal length extremity; and mT: the lateral magnification of the positive second lens group at the long focal length extremity; fT: the focal length of the entire zoom lens system at the long focal length extremity; and fW: the focal length of the entire zoom lens system at the short focal length extremity.

Abstract: The invention relates to a zoom lens that has high optical performance specifications such as high zoom ratios, wide angles of view, reduced F-numbers and limited aberrations, and enables an optical path to be easily bent. The zoom lens comprises a moving lens group B(G2) that has positive refracting power and moves only toward the object side upon zooming from the wide-angle end to the telephoto end, and a lens group A(G1) remaining fixed during zooming, which is located on the object side of the zoom lens with respect to the moving lens group B and has negative refracting power. The moving lens group B is composed of, in order from its object side, a positive lens element, a positive lens element and a negative lens element, three lens elements in all.

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: A simple two-group zoom optical system that favorably corrects aberrations includes, in order from the object side, a first lens group of negative refractive power, a stop, and a second lens group of positive refractive power. The first lens group includes, in order from the object side, a lens element having negative refractive power and a meniscus shape with its concave surface on the image side, a biconcave lens element, and a lens element having positive refractive power. The second lens group includes, in order from the object side, a lens element having positive refractive power and at least one aspheric surface, a lens element having negative refractive power, and a biconvex lens element. Certain conditions are satisfied that relate to the focal lengths of the zoom optical system, the focal lengths of the two lens groups, and to the Abbe numbers of lens elements.

Abstract: Disclosed is a zoom lens herein. The zoom lens has a first group G1 having a negative focal length, a second group G2 having a positive focal length and a third group G3 having a positive focal length in turn from an object side, and has an opening iris S for moving integrally with the second group G2 on the object side of the second group G2, wherein in variation of magnification from a short focus end to a long focus end, the second group G2 moves monotonously from image side to object side and the first group G1 moves to correct the variation in position of image surface accompanying the variation of magnification. The second group G2 consists of four elements of a positive lens L4, a negative lens L5, a positive lens L6 and a positive lens L7 in turn from the object side.

Abstract: A zoom lens system comprises, successively from the object side, a first negative lens group and a positive second lens group. The first lens group includes a negative meniscus lens and a positive meniscus lens, the negative meniscus lens and the positive meniscus lens each has at least one aspherical surface. The second lens group includes a first positive auxiliary group and a positive second auxiliary group. The refractive power of the first group is 1/f1, the refractive power of the second group is 1/f2, the focal length of the whole lens system fw when the distance between the lens groups is increased, fT is the focal length of the whole lens system when the distance between the lens groups is decreased, and they satisfy the following conditional expressions of: 0.9?|f1|/(fw·fT)1/2?1.1 and 1.15?|f1|/f2?1.35.

Abstract: A lens system disclosed in the present application comprises: in order from the front to the rear, a first lens element having a meniscus shape whose concave surface is directed rearward and having a negative optical power; an aperture stop; a second lens element whose both lens surfaces have a convex shape; a third lens element whose both lens surfaces have a concave, and a fourth lens element whose rear surface has a convex shape and having a positive optical power. Thus, a lens system which maintains telecentricity and high optical performance despite a simple and small-sized structure is disclosed.

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: A zoom lens system including, from the object side to the image side, a first lens unit and a second lens unit, where when zooming, the distance between the first lens unit and the second lens unit changes. In at least one exemplary embodiment, the first lens unit includes a first lens element having negative optical power, and a second lens element having positive optical power.

Abstract: The invention relates to an electronic image pickup system that enables a wide image-pickup, and ensures that even when an image is printed, sufficient image quality and clearness are obtained from the center to as far as the margin of the image and the image of a subject is depicted with a sense of extension. The electronic image pickup system comprises an image-formation optical system 10 for forming an image of a subject and an electronic image pickup device 20 located on an image side of the image-formation optical system for obtaining image information on the image.

Abstract: Disclosed is a compact zoom lens system having a image stabilizing function. This zoom lens system is provided with a plurality of lens units of which the interval between adjacent ones is changed during zooming. Shake correction is effected by a part of a lens unit of negative optical power of the plurality of lens units. Specifically, the lens unit of negative optical power is comprised of two lens components of negative optical power, and one of these two lens components is moved so as to have a component in a direction perpendicular to an optical axis to thereby change the imaging position of the zoom lens system.

Abstract: A compact high performance objective zoom lens system is disclosed that provides optimum optical performance over the entire zoom focal length range at focus distances from close to infinity. The system comprises, from object space to image space, one focusing objective lens group (comprising a focus lens group and a stationary lens group) and three zoom lens groups aligned on the optical axis. The focus lens group and the zoom lens groups are axially movable along the optical axis for focusing and zooming. In one embodiment, the system has a focal length zoom region from about 19 mm to 90 mm, an aperture of F/2.7 and substantially the same optical performance as high quality fixed objective lenses of the same range. The performance characteristics of this system makes it suitable for use with both film and electronic detector cameras.

Abstract: A zoom lens having a high zoom ratio and also a small size is proposed. The zoom lens has a front group of lenses and a rear group of lenses. The front group of lenses has a first lens, a second lens, and a third lens. The first lens is a meniscus negative lens. The second lens is a biconcave lens negative lens. The third lens is a positive lens. The rear group of lenses has a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The fourth lens is a positive lens. The fifth lens is a biconvex lens. The sixth lens is a meniscus negative lens. The seventh lens is a meniscus negative lens. The fourth and seventh lenses are aspheric lenses made of plastic material. The proposed zoom lens can meet the requirement of miniaturized size and also maintain the image quality.

Abstract: The invention relates to an electronic image pickup system that enables a wide image-pickup, and ensures that even when an image is printed, sufficient image quality and clearness are obtained from the center to as far as the margin of the image and the image of a subject is depicted with a sense of extension. The electronic image pickup system comprises an image-formation optical system 10 for forming an image of a subject and an electronic image pickup device 20 located on an image side of the image-formation optical system for obtaining image information on the image.

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: The object is to provide a zoom lens system having a zoom ratio of 2.5 or more, compactness and high optical performance, applicable to a plurality of imaging devices with different image heights. According to one aspect of the present invention, a zoom lens system applicable to a plurality of imaging devices having different image heights with each other by partially sharing zooming trajectories without changing an optical element of the zoom lens system.

Abstract: A two-group zoom lens includes, in order from the object side, a first lens group that includes a negative lens component formed of a negative plastic lens element having at least one aspheric lens surface and a positive lens component, and a second lens group that includes a diaphragm, a positive lens component that is formed of a positive plastic lens element having at least one aspheric lens surface, and a negative lens doublet component. The first lens group and at least a part of the second lens group is movable along the optical axis for zooming, and either the first lens group or a lens component of the second lens group moves independently of the other lens components of the second lens group for focusing. Except for the negative lens doublet component, each lens component may be a lens element. The lens components and lens elements satisfy certain conditions.

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 zoom lens system having an exit pupil far away from the image plane, zoom ratio of about three, and in particular having compactness and high optical performance includes, in order from an object, a first lens group having negative refractive power, an aperture stop, a second lens group having positive refractive power, and a third lens group having positive refractive power. When zooming from a wide-angle end state to a telephoto end state, the first and second lens groups are moved and the third lens group is fixed such that a distance between the first lens group and the second lens group varies, and a distance between the second lens group and the third lens group increases. The second lens group is composed of four lenses or less and includes a diffractive optical surface formed on a lens surface except the most object side lens surface.

Abstract: The invention relates to a zoom optical system wherein various aberrations are corrected while the total thickness of a lens arrangement upon received at a collapsible lens mount is reduced thereby ensuring compactness, high image-formation capabilities, and high zoom ratios at the wide-angle end, and an imaging system that incorporates the same. The zoom optical system comprises a first lens group G1 of negative refracting power and a second lens group G2 of positive refracting power. The first lens group G1 comprises a negative single lens comprising at least one aspheric surface and a positive single lens with an air separation interposed between the negative single lens and the positive single lens. The second lens group G2 comprises a positive lens, a cemented lens consisting of a positive lens and a negative lens and a positive lens, and comprises at least one aspheric surface. Zooming is carried out by varying a spacing between the respective lens groups.

Abstract: A zooming lens is suitable for projecting images produced by a display device onto a screen. The zooming lens includes a first set of lenses and a second set of lenses, wherein the second set of lenses is disposed in the optical path between the first set of lenses and the display device. The first set of lenses includes first lens, second lens, third lens, and fourth lens sequentially, and the fourth lens is adjacent to the second set of lenses. The second set of lenses includes fifth lens, sixth lens, seventh lens, and composite lens sequentially, and the composite lens is adjacent to a side of the display device. The optical focusing of the lenses, from the first one through the seventh and to the composite lens, are positive, negative, negative, positive, positive, negative, positive value and positive, respectively. The composite lens includes two optical lenses.

Abstract: A zoom lens with a zoom ratio of about three includes a first lens group of negative refractive power that moves along an optical axis during zooming relative to a second lens group of positive refractive power and having a vibration-proof function to correct for hand shaking that causes image blurring. The second lens group includes a first lens subgroup on its object side having positive refractive power and at least one aspheric surface, and a second lens subgroup having positive refractive power. The second lens subgroup is movable in a direction perpendicular to the optical axis of the zoom lens in order to correct for vibration of the zoom lens. The second lens group satisfies a condition regarding the ratio of focal lengths of the two lens subgroups, and the second lens subgroup satisfies a condition regarding its transverse magnification at the telephoto end.

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: A zoom lens includes (i) a negative first lens group having a negative meniscus first lens element and a positive meniscus second lens element; and (ii) a positive second lens group having a positive third lens element, a positive fourth lens element, a negative fifth lens element which is cemented to the positive fourth lens element, and a sixth lens element having a weaker refractive power. Zooming is performed by moving the first lens group and the second lens group along the optical axis. The zoom lens system satisfies TL/fW<1.9; and 0.6<fW/fII<0.77, wherein TL is the sum of the length of the first lens group and that of the second lens group; fW is the combined focal length of the zoom lens at the wide-angle extremity; and fII is the focal length of the second lens group.

Abstract: A comparatively low f-number, compact two-group zoom optical system that corrects aberrations in the visible and the near-infrared regions includes, in order from the object side, a first lens group of negative refractive power and a second lens group of positive refractive power. The first lens group includes three lens components that are lens elements of negative, negative, negative, and positive refractive power, respectively, in order from the object side. The second lens group includes four lens components that are lens elements of positive, positive, negative, and positive refractive power, respectively, in order from the object side. Aspheric surfaces are disclosed. Certain conditions relating to the focal lengths of the two lens groups, indexes of refraction and Abbe numbers of various lens elements, and radii of curvature of an interior lens element of the second lens group are satisfied to control aberrations in both the visible and the near-infrared regions.

Abstract: A compact two-group zoom lens that corrects aberrations in the visible and the near-infrared regions and that provides a comparatively high aperture ratio includes, in order from the object side, a first lens group of negative refractive power and a second lens group of positive refractive power. Both lens groups include three lens components and four lens elements. The first lens group includes, in order from the object side, lens elements having negative, negative, negative, and positive refractive powers, respectively. The second lens group includes, in order from the object side, lens elements having positive, positive, negative, and positive refractive powers, respectively. Aspheric surfaces are disclosed. Certain conditions relating to the focal lengths of the two lens groups, and the index of refraction and Abbe number of one lens element are satisfied to control aberrations in both the visible and the near-infrared regions.

Abstract: A lens system disclosed in the present application comprises: in order from the front to the rear, a first lens element having a meniscus shape whose concave surface is directed rearward and having a negative optical power; an aperture stop; a second lens element whose both lens surfaces have a convex shape; a third lens element whose both lens surfaces have a concave, and a fourth lens element whose rear surface has a convex shape and having a positive optical power. Thus, a lens system which maintains telecentricity and high optical performance despite a simple and small-sized structure is disclosed.

Abstract: A projection zoom lens includes, from an image side to an object side, a first lens group having a negative refractive power, consisting of a number of lens elements and being movable along the optical axis of the projection zoom lens; a second lens group having a positive refractive power, consisting of a number of lens elements and being movable along the optical axis of the projection zoom lens; and an aperture stop arranged between two lens elements of the second lens group and being axially movable therewith.

Abstract: An imaging lens for an image pickup device consists of two lens components that may each consist of a lens element. In order from the object side, these lens components have negative and positive refractive power, with each lens component having two aspheric surfaces. A stop is positioned between the lens components so as to be closer to the image-side lens component. Specified conditions are satisfied in order to miniaturize the imaging lens, reduce manufacturing and assembly costs, and improve imaging performance.

Abstract: The invention provides a zoom lens that comprises a reduced number of lens elements, is compact and simplified, and has high image-formation capability, thereby achieving thorough size reductions in video cameras or digital cameras, and an electronic imaging system using the same. The zoom lens comprises, in order from its object side, a lens group A (G1) having negative refracting power and a lens group B (G2) having positive refracting power. For zooming, the lens groups A and B are designed to move. The lens group B is composed of three meniscus lenses, each convex on its object side.

Abstract: A wide-angle projection lens includes, in order from an object side: a first lens group including four lenses and having a negative refractive power; and a second lens group including a cemented lens and having a positive refractive power. The first lens group includes an aspherical lens and a spherical lens having a positive refractive power. The wide-angle projection lens further includes an iris diaphragm located after the first lens of the second lens group from the object side, and satisfies the following conditional expressions fb/f>3, ?2.0<D12/f1<?1.3, and 0.8<Lr/Lf<1.2 where f denotes the focal length of the projection lens; fb denotes the retrofocal length of the projection lens; f1 denotes the focal length of the first lens group; Lf denotes the thickness of the first lens group; Lr denotes the thickness of the second lens group; and D12 denotes the distance between the first and second lens groups.

Abstract: A two-group zoom lens includes, in order from the object side, a first lens group that includes a negative lens component formed of a negative plastic lens element having at least one aspheric lens surface and a positive lens component, and a second lens group that includes a diaphragm, a positive lens component that is formed of a positive plastic lens element having at least one aspheric lens surface, and a negative lens doublet component. The first lens group and at least a part of the second lens group is movable along the optical axis for zooming, and either the first lens group or a lens component of the second lens group moves independently of the other lens components of the second lens group for focusing. Except for the negative lens doublet component, each lens component may be a lens element. The lens components and lens elements satisfy certain conditions.

Abstract: A focus lens and a zoom lens group having a first zoom lens and a second zoom lens are controlled separately from one another in an internal-focus camera. The positions of the focus lens and the second zoom lens in the zoom lens group are tracked, and are controlled to approach no closer to one another than a minimum safe distance to avert collisions between the focus lens and the second zoom lens.

Abstract: A comparatively low f-number, compact two-group zoom lens that corrects aberrations in the visible and the near-infrared regions includes, in order from the object side, a first lens group of negative refractive power and a second lens group of positive refractive power. The first lens group includes three lens components that are lens elements of negative, negative, negative, and positive refractive power, respectively, in order from the object side. The second lens group includes four lens components that are lens elements of positive, positive, negative, and positive refractive power, respectively, in order from the object side. Aspheric surfaces are disclosed. Certain conditions relating to the focal lengths of the two lens groups, the indexes of refraction, and Abbe numbers of various lens elements are satisfied to control aberrations in both the visible and the near-infrared regions.

Abstract: The invention provides a fisheye lens system having an angle of view of 170 degrees or more capable of being used with a plurality of cameras having different image formats in size. The lens system includes a first lens group G1 having negative refractive power disposed to the most object side and a second lens group G2 having positive refractive power disposed to an image side of the first lens group. A distance between the first lens group G1 and the second lens group G2 is variable. The lens system takes the maximum focal length state when the distance is minimum and the minimum focal length state when the distance is maximum. The maximum image height in the maximum focal length state is different from that in the minimum focal length state. In each focal length state, the fisheye lens system has an angle of view of 170 degrees or more.

Abstract: A three-group zoom lens includes first, second, and third lens groups, of negative, positive, and positive refractive power, respectively. The second lens group includes a stop and the third lens group moves for focusing. When zooming from the wide-angle end to the telephoto end, the first and second lens groups become closer together and the second and third lens groups become farther apart. The zoom lens preferably satisfies specified conditions that ensure compactness, case of manufacture, and favorable correction of aberrations. The zoom lens includes at least one aspheric lens surface defined by an aspheric lens equation that includes at least one non-zero coefficient of an even power of Y, and at least one non-zero coefficient of an odd power of Y, where Y is the distance of a point on the aspheric lens surface from the optical axis.

Abstract: A zoom lens includes in order from the object side to the image side, a first lens unit of negative optical power and a second lens unit of positive optical power. Zooming is effected by varying the interval between the first lens unit and the second lens unit. The second lens unit has, in order from the object side to the image side, an aspherical positive lens and an aspherical negative lens.

Abstract: A zoom lens is disclosed that is formed of only two lens groups. The first lens group includes, from the object side, a plastic lens element having negative refractive power and an aspheric surface, and a lens element having positive refractive power. The second lens group includes, from the object side: a biconvex lens element having an aspheric surface; a lens element having negative refractive power, a smaller curvature on its object side, and with its image-side surface joined to a biconvex lens element. The zoom lens satisfies specified conditions to: (a) allow for ease of manufacture and assembly while maintaining favorable correction of various aberrations, (b) assure that the zoom lens is compact in both the operational and retracted positions, (c) assure that the zoom lens is not easily damaged, and (d) assure that the optical performance is well-maintained despite changes in ambient conditions, such as temperature.

Abstract: An optical component for changing angular magnification of an imaging device. The optical component comprises a chamber having a first substrate on one side and a second substrate on the opposite side for separately disposing a first liquid drop and a second liquid drop along an optical axis. The chamber is also filled with a liquid, which is different from the first and second liquid drops. The optical component also has a first electrode adjacent to the first side, a second electrode adjacent to the second side, and a third electrode layer between the first and second electrode layers for applying different electric fields on the first and second liquid drops to change the focal lengths of the first and second liquid drops, without changing the sum of the focal lengths.

Abstract: An objective lens system having reconfigurable optical components that enable the inspection of inspection surfaces in the absence of a pellicle or through a thin membrane pellicle, and using the same system, also enabling the inspection of inspection surfaces through a thick pellicle. An objective lens system includes a first group and a second group of optical elements. The first group of optical elements enables high numerical aperture and beam contraction. The second group of optical elements is capable of two mode operation enabling, in one mode, inspection through a thin membrane pellicle or in the absence of a pellicle and in another mode, enabling inspection through a thick pellicle. The system can also be enhanced through the use of an interposable aberration corrector plate that is used to correct optical aberrations caused by the presence, absence, or thickness of pellicles.

Abstract: The zoom lens system and camera using the same include, in order from an object side, a first lens group having negative refracting power and a second lens group having positive refracting power. Zooming is carried out at least by changing the distance between the first and second groups. The first lens group includes six lenses, a first lens which is negative meniscus lens having a concave surface toward an image side, a second lens which is negative meniscus lens having a concave surface toward the image side, a third lens which is negative lens having a concave surface toward the image side, a fourth lens which is positive lens having convex surfaces, a fifth lens having negative power and a sixth lens having positive power. The second lens group includes six lenses and the following condition is satisfied. 0.07<d12/f2G<0.30 where d12 is an air space on an optical axis between the first lens and the second lens in the second lens group, and f2G is a focal length of the second lens group.