Abstract: A zoom lens configured by arranging a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group in order from the object side to the image side, and further having an aperture diaphragm on the object side of the third lens group. In the first lens group, a first lens, a second lens, and a third lens are located in order from the object side to the image side. In the second lens group, a fourth lens, a fifth lens, and a sixth lens are located in order from the object side to the image side. The third lens group is made up of a seventh lens which is a convex lens, the fourth lens group is made up of at least two or more cemented lenses, the third lens group and the fourth lens group include at least one surface formed into an aspherical surface.

Abstract: A zoom lens and an image pickup apparatus are disclosed. The zoom lens includes, in order from an object side to an image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive refractive power. The fifth lens group includes a fixed group having a negative refractive power, and a movable group having a positive refractive power and being movable in a direction substantially orthogonal to the optical axis. The image formed on an image surface is movable in a direction substantially orthogonal to the optical axis by moving the movable group of the fifth lens group in the direction substantially orthogonal to the optical axis. The fifth lens group is satisfied predetermined conditions.

Abstract: Providing a wide-angle lens having high optical performance, an optical apparatus using the same, and a method for focusing the wide-angle lens. The lens comprising, in order from an object, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third group G3 having positive refractive power. Upon focusing from an infinity object to a close object, the first lens group G1 is fixed, and the second lens group G2 and the third lens group G3 are moved to the object. Given conditional expressions are satisfied.

Abstract: A zoom lens includes a first optical system having a positive focal length, the first optical system, a second optical system having a negative focal length, a third optical system having a positive focal length, a fourth optical system having a negative focal length, and a fifth optical system having a positive focal length, which are arranged in order from an object side to an image side and an aperture stop provided at an object side of the third optical system. The following condition is satisfied: 0.5<(T23w/Y?)/(ft/fw)<1.0 where T23w is an interval between the second optical system and the third optical system at the short focus end, Y? is a maximum image height of the zoom lens, ft is a focal length of the zoom lens at the long focus end, and fw is a focal length of the zoom lens at the short focus end.

Abstract: Rear focusing zoom lens capable of attaining the desired brightness as much as 1.

Abstract: There is provided a zoom lens system, compact and light in weight and having high image formation performance over the zoom entire range irrespective of object lens while covering the range from the broad angle side up to the telescopic end state side, which is used in video camera and/or digital still camera.

Abstract: A zoom lens system comprising a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units among the lens units is changed so that an optical image of an object is formed with a continuously variable magnification, a first lens unit arranged on the most object side among the lens units includes a lens element having a reflecting surface for bending a light beam from the object, and any one of the lens units, any one of the lens elements, or alternatively a plurality of adjacent lens elements that constitute one lens unit move in a direction perpendicular to an optical axis; an imaging device including the zoom lens system; and a camera employing the imaging device.

Abstract: A zoom lens includes in order and from the side of an object, a first lens group having a positive refractive power and fixed in position, a second lens group having a negative refractive power and movable in position for providing mainly zooming, a third lens group having a positive refractive power and fixed in position, a fourth lens group having a positive refractive power and movable in position for performing a focal position correction due to the zooming and for focusing, and a fifth lens group including a single lens fixed in position. Each of the lens groups from the third lens group to the fifth lens group has at least one aspheric surface, and conditional equations (1) and (2) below are satisfied. |f4/f5|<0.12??(3) 0.9<?5<1.2??(4) where f4 is a focal length of the fourth lens group, f5 is a focal length of the fifth lens group, and ?5 is a transverse magnification of the fifth lens group.

Abstract: A zoom lens comprises the following lens groups in the order from an object side: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; and a fourth lens group having a positive refracting power; wherein, upon zooming, at least the first lens group and the fourth lens group move to the object side; and wherein, upon focusing, the fourth lens group comprises a front lens group, and a rear lens group arranged with an air space on an image side of the front lens group, and the rear lens group is moved in a direction of an optical axis of the zoom lens.

Abstract: A zoom lens unit includes, in order from an object side to an image side: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a negative refracting power; a fifth lens group having a positive refracting power; and a sixth lens group having a negative refracting power, an aperture stop is disposed between the second lens group and the third lens group, and when changing magnification from a wide-angle end to a telephoto end, at least the second lens group, the third lens group and the fifth lens group are moved, and the first lens group includes a reflecting optical element which bends a light path in the first lens group to obtain a predetermined light path length.

Abstract: A dual field of view lens system comprising a first lens group aligned along an optical axis and a third lens group aligned along the optical axis and positioned a predetermined distanced from the first lens group. A second lens group, having an optical stop attached thereto, is aligned along the optical axis and disposed between the first and third lens groups such that the second lens group and the optical stop are moveable along the optical axis between a first position and a second position. Positioning the second lens group and the optical stop in the first position provides a wide field of view and moving the second lens group and the optical stop to a second position provides a narrow field of view.

Abstract: A zoom lens comprises the following lens groups in the order from an object side: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; and a fourth lens group having a positive refracting power; wherein, upon zooming, at least the first lens group and the fourth lens group move to the object side; and wherein the third lens group comprises a negative meniscus lens with a convex surface on an image side and with both side faces thereof being exposed to air, which is located nearest to the image side.

Abstract: There is provided a zoom lens having, in an order of an object-to-image direction, a first lens group having a positive refractive power and fixed with respect to an image plane; a second lens group having a negative refractive power; a third lens group having a positive refractive power and fixed with respect to an optical axis direction; a fourth lens group having a positive refractive power; and a fifth lens group having a positive refractive power and fixed with respect to the optical axis direction. The fifth lens group is composed of a fifth-a lens group having a negative refractive power; a fifth-b lens group having a positive refractive power; and a fifth-c lens group having a positive refractive power, arranged in the order of the object-to-image direction.

Abstract: A three-unit zoom lens includes, in order from the object side, a negative first lens unit G1, a positive second lens unit G2 and a third lens unit G3, wherein during zooming from the wide angle end to the telephoto end the distance between the first lens unit G1 and the second lens unit G2 decreases and the distance between the second lens unit G2 and the third lens unit G3 changes. The first lens unit G1 is composed of one negative lens component including, in order from the object side, a negative lens having a concave surface directed toward the image side and a positive lens having a convex surface directed toward the object side. The second lens unit G2 includes at least one negative lens and a plurality of positive lenses, wherein at least three lenses among these lenses are cemented to adjacent lenses, the total number of lens components included in the second lens unit G2 is two or less. The third lens unit is composed of one lens component composed of two or less lenses.

Abstract: A zoom lens system consists, in order from an object side to an image-forming side, of a first negative lens group G1, a second positive lens group G2, and a third positive lens group G3. The first lens group G1 consists of one negative lens and one positive lens, the second lens group G2 consists of a cemented lens composed of a positive lens and a negative lens, and one meniscus lens that is concave on the image-forming side, the third lens group G3 consists of a single positive lens, and a combined focal length f2 of the second lens group, a focal length Lf23 of the meniscus lens of the second lens group, a combined focal length fw of the zoom lens system at a wide angle end, a combined focal length f3 of the third lens group, a radius of curvature Ro of an object side surface of the positive lens in the cemented lens, and a radius of curvature Ri of an image-forming side surface of the positive lens in the cemented lens satisfy the following conditions. 0<|f2/Lf23|<0.3 ?2.0<Ri/Ro<?1.

Abstract: A zoom lens system that has five lens groups with respectively positive, negative, positive, positive, and positive refractive powers in that order from an object side to an image forming side is provided. The third lens group consists, in order from the object side, of a first positive lens, a negative lens, and a second positive lens, the first positive lens and the negative lens composing a cemented lens. The fourth lens group consists, in order from the object side, of a first positive lens, a negative lens, and a second positive lens, the negative lens and the second positive lens composing a cemented lens. In the zoom lens system, zooming (operation) between a wide-angle end and a telephoto end is carried out without moving the first lens group and the fifth lens group, and focusing is carried out by moving the fifth lens group.

Abstract: The invention provides a zoom lens including at least a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, in order from an object side, and an aperture stop between the second lens group and the third lens group, wherein, in changing magnification from a wide angle end toward a telephoto end, at least the first lens group and the third lens group move toward the object side so as to increase a spacing between the first lens group and the second lens group, and to decrease a spacing between the second lens group and the third lens group.

Abstract: A rear-focusing type zoom lens includes in order from an object side: a positive first group that is fixed, a negative second group that is moved toward an image plane along an optical axis during zooming from a wide-angle end to a telephoto end, a negative third group that is fixed in an optical axis direction, and a positive fourth group that moves along the optical axis direction to correct image plane variation, which is caused by the zooming, and to perform focusing. The first group includes a first subgroup having a negative refractive power as a whole and a second subgroup having a positive refractive power as a whole. The first subgroup includes, in order from the object side, a negative meniscus lens having a convex surface directed toward the object side, a first negative lens, a positive lens, and a second negative lens.

Abstract: A rear-focusing type zoom lens includes, in order from an object side, a positive first group being fixed, a negative second group moving toward an image plane along an optical axis during zooming from a wide-angle end to a telephoto end; a negative third group being fixed in an optical axis direction, and a positive fourth group moving along the optical axis direction to correct image plane variation being caused by zooming. The first group includes a first subgroup having a negative power as a whole and a second subgroup having a positive power as a whole. The first subgroup includes a negative meniscus lens having a convex surface directed toward the object side and a negative lens. The second subgroup includes a positive lens group having at least one positive lens, a negative lens, a positive lens, and another positive lens group having at least one positive lens.

Abstract: A zoom lens system includes, in order from an object side, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, and a fourth lens unit G4 having a positive refracting power, and at the time of zooming from a wide angle end to a telephoto end, a space between the lens units changes, and the first lens unit includes two lenses namely, a negative lens and a positive lens, and satisfies the following conditional expression ?0.75<SF1p<?0.1??(1) where, SF1p is defined as SF1p=(R1pf+R1pr)/(R1pf?R1pr), when R1pf is a paraxial radius of curvature of a surface on the object side, of the positive lens in the first lens unit, and R1pr is a paraxial radius of curvature of a surface on an image side, of the positive lens in the first lens unit.

Abstract: The invention relates to a bent type zoom optical system comprising a positive first lens group having a reflecting member and remaining fixed upon zooming and a second lens group adapted to move upon zooming, and having a high zoom ratio and a short entire-length, and an imaging apparatus or the like incorporating the same. The zoom optical system comprises the positive first lens group G1 adapted to remain fixed upon zooming and the negative second lens group adapted to move upon zooming. The positive first lens group G1 comprises, in order from the object side, a negative single lens, a reflecting member P and a positive lens unit. The zoom optical system satisfies condition (1) for prevention of fluctuations in the entrance pupil position, condition (2) about the focal length of the first lens group G1, and condition (3) for putting in order the shape of the negative single lens in the first lens group G1.

Abstract: An optical system includes at least one of a movable lens unit movable in an optical axis direction and a fixed lens unit that is not movable in the optical axis direction. The at least one lens unit includes a plurality of refractive optical elements. The refractive optical elements are made of resin and have focal lengths of the same sign. When ?i is a refractive power, with respect to d-line, of the ith refractive optical element from an object side, ?G is a refractive power of a negative lens in the lens unit including the refractive optical elements, and ?a is an average refractive power, with respect to d-line, of the refractive optical elements, ?i, ?G, and ?a are adequately set.

Abstract: A zoom lens includes, in order along an optical axis from a side nearest to a photographic subject to an imaging site, a first lens group I that comprises a positive refraction index and is anchored in place when performing a magnification of an image, a second lens group II that comprises a negative refraction index, a third lens group III that comprises a positive refraction index, a fourth lens group IV that comprises a positive refraction index, a fifth lens group V that comprises a negative refraction index, and a sixth lens group VI that comprises a positive refraction index, wherein, when magnifying from a wide angle end to a telephoto end, the magnification thereof is performed by moving the second lens group II, the fourth lens group IV, and the fifth lens group V, at a minimum, the first lens group I comprises a reflective optical element, which is for refracting a light path therein, an additional lens group VII, comprising a negative refraction index, is interposed between the lens groups of the z

Abstract: A focusing group G1 is disposed on an object side relative to a variator group G2. The focusing group G1 includes, in order from the object side, a first group G11 having a positive refractive power, a second group G12 having a positive refractive power, and a third group G13 having a positive refractive power. The first group G11 has, in order from the object side, at least one concave lens (L11) and at least one convex lens. When focusing from an infinitely distant object to a close object, the second group G12 and the third group G13 are moved so that with respect to a change in an object distance, an amount of movement of the second group G12 becomes large in a region near infinity, while an amount of movement of the third group G13 becomes large in a close range.

Abstract: The invention relates to a bent type zoom optical system that is reduced in terms of the whole size and thickness albeit including two reflecting surfaces in an optical path and having a high zoom ratio, and an apparatus incorporating the same. The zoom optical system comprises the positive first lens group G1 adapted to remain fixed upon zooming, the negative second lens group G1 adapted to move upon zooming, and the third lens group G3 adapted to remain fixed upon zooming. The positive first lens group G1 includes the first reflecting member P1, and the third lens group includes the stop S and the second reflecting member P2. The second reflecting member P2 is located in such a way as to bend the optical path in a direction orthogonal to a plane defined by an optical axis of the first lens group G1 on its entrance side and an optical axis bent by the first reflecting member P1, and condition (1) necessary for the proper location of an entrance pupil position is satisfied.

Abstract: A zoom lens and an imaging apparatus are disclosed. The zoom lens includes, in order from an object side to an image-plane side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power. During a change of a lens zoom position from a maximum wide angle state to a maximum telephoto state, at least the second lens group moves toward an image side, the third lens group moves toward an object side, and the fourth lens group is fixed in an optical-axis direction. An aperture stop is disposed near the object side of the third lens group. The first to fifth lens groups satisfy predetermined conditions.

Abstract: A zoom lens having five lens groups arranged in succession. The zoom lens is configured such that when zooming from a short focal length end toward a long focal length end, the second lens group lens moves toward the third lens group and the fourth lens group moves toward a side of the third lens group, and the fifth lens group corrects the zooming and a shift in a position of an imaging plane of the zoom lens caused by movement of the third lens group and the fourth lens group.

Abstract: An electronic imaging apparatus includes a zoom optical system having, in order from the object side, a first lens unit with positive power, a second lens unit with negative power, and an aperture stop, in which the first lens unit is composed of a single positive power unit and the second lens unit has a single negative lens element located at the most object-side position, both surfaces of which are concave, and a positive lens component located at the most image-side position; an electronic image sensor located on the image side of the zoom optical system; and an image processing section electrically processing image data obtained by the electronic image sensor to change the form thereof.

Abstract: A zoom lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power in that order from an object side to an image side. Zooming is performed by changing distances between the lens units. The first lens unit includes two or less lenses and the second lens unit consists of a negative lens and a positive lens in that order from the object side to the image side. The zoom lens satisfies the following condition: ?1.3<m1/?{square root over ((fw·fT))}<?0.8 where fw and fT are focal lengths of the entire lens unit at wide-angle and telephoto ends, respectively, and m1 is an amount of movement of the first lens unit in an optical axis direction during zooming from the wide-angle end to the telephoto end.

Abstract: A zoom lens for capturing images that enhances the image aberration correction rate to achieve high resolution and zooming ratio. The zoom lens includes, in sequence from an object side to an image side, a first lens group with positive refraction power, a second lens group with negative refraction power, a third lens group with positive refraction power, a fourth lens group with positive refraction power, a fifth lens group with positive refraction power and a sixth lens group with positive refraction power. The positions of first and sixth lens groups are fixed during photographing. When the zoom lens is made to zoom from a wide-angle end to a telephoto end thereof, the second lens group moves toward the image side while the fourth and fifth lens groups move toward the object side. In addition, the zoom lens has a reflection element so as to fold the image light entering thereof.

Abstract: A telephoto zoom lens system includes a positive first lens group, a negative second lens group as a focusing lens group, a diaphragm, a positive third lens group, and a positive fourth lens group, in this order from the object. Upon zooming from the short focal length extremity to the long focal length extremity, all the lens groups move toward the image. The second lens group includes a first 2a sub-lens group, and a second 2b sub-lens group, in this order from the object. The telephoto zoom lens system satisfies the following conditions: 1.6<fs/|f2|<2.1??(1) 0.45<|f2bn|/f2bp<0.8??(2) wherein fs: the focal length of the zoom lens system at the short focal length extremity; f2: the focal length of the negative second lens group (f2<0); f2bn: the focal length of the biconcave negative lens element of the second 2b sub-lens group (f2bn<0); and f2bp: the focal length of the biconvex positive lens element of the second 2b sub-lens group (f2bn>0).

Abstract: A taking lens system is provided with, from the side of the object to be photographed, a first lens unit (G1) having positive optical power, a second lens unit (G2) having negative optical power, a third lens unit (G3) having positive optical power and a fourth lens unit (G4) having positive optical power. Zooming is performed by moving the first to fourth lens units (G1) to (G4), and focusing is performed by moving the fourth lens unit (G4). When the distance from the most object-to-be-photographed side surface (r1) of the first lens unit (G1) to the imaging surface at the wide angle end is TLw, the overall focal length of the taking lens system at the telephoto end is ft, the overall focal length of the taking lens system at the wide angle end is fw, and the focal length of the first lens unit (G1) is fl, relationships 0.5?TLw/ft?1.0 and 6.0?fl/fw?20.0 are satisfied.

Abstract: A zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group, in this order from the object. Upon zooming from the short focal length extremity to the long focal length extremity, the distance between the negative first lens group and the positive second lens group decreases, and the distance between the positive second lens group and the positive third lens group increases. The negative first lens group includes a negative first lens element, a positive or negative lens element having a weaker refractive power, and a positive third lens element, in this order from the object. The zoom lens system satisfied the following condition: ?0.25<f1/fp<0.25(f1<0) ??(1) wherein f1 designates the focal length of the negative first lens group; and fp designates the focal length of the positive second lens element.

Abstract: The zoom lens 100 comprises, sequentially from the object side, a stationary first lens group 110 having positive refractive power; a second lens group 120, having negative refractive power, and that moves on the optical axis when changing the magnification; a stationary third lens group 130 that has positive refractive power; and a fourth lens group 140, having positive refractive power. The first lens group 110 comprises six lenses. The second lens L2 is a meniscus lens that is formed so as to have at least one aspherical surface. The aspherical surface of the second lens L2 is formed at the shape wherein there is no displacement in the thickness from the center portion to the edge portion. Doing so enables the effective correction of distortion and off-axis aberration on the wide-angle side, and the provision of a high-performance zoom lens that is small and has a high variable magnification.

Abstract: A compact zoom lens includes, from the object side to the image side, a negative first lens group (1), a positive second lens group (2) and a positive third lens group (3). The first lens group is stationary, and both the second and third lens groups are movable along the optical axis. The compact zoom lens is zoomed by varying the distance between the first and second lens groups, and the focal length is adjusted by varying the distance between the second and third lens groups. The zoom lens is composed of only four single lenses in three groups, of which three (10, 31, 32) are plastic aspheric lenses and one (20) is a glass spherical lens.

Abstract: A zoom lens system comprises a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and a third lens unit having a positive refractive power, and during zooming from a wide-angle end to a telephoto end, a space between a first lens unit and a second lens unit and a space between the second lens unit and a third lens unit are changed, the space between the first lens unit and the second lens unit is enlarged in the telephoto end as compared with the wide-angle end, and the space between the second lens unit and the third lens unit is narrowed in the telephoto end as compared with the wide-angle end.

Abstract: A zoom lens includes, in order from an object side thereof: a first lens group having a negative optical power and comprising a reflection optical element; a second lens group having a positive optical power; a third lens group having a negative optical power; a fourth lens group having a positive optical power; and, a fifth lens group. The first lens group and the fourth lens group are positioned at a fixed distance and at least the second lens group, the third lens group and the fifth lens group move along an optical axis, for varying a power of the zoom lens from a wide-angle end to a telephoto end. The zoom lens satisfies a predetermined expression relating to a focal length of the first lens group, and a focal length of the zoom lens at the wide-angle end.

Abstract: Providing a zoom lens system having excellent optical performance, an optical apparatus, and a method for zooming the zoom lens system. The zoom lens system includes, in order from an object, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. Upon zooming from a wide-angle end state W to a telephoto end state T, each distance between adjacent lens groups is varied. The second lens group G2 includes, in order from the object, a front group G2a having positive refractive power, and a rear group G2b. Focusing on the object is carried out by moving the front group G2a along an optical axis. Given conditional expressions are satisfied.

Abstract: In the zoom lens, the second lens group includes at least one surface that is an aspheric surface, and during changing magnification, the second lens group, the third lens group, and the fourth lens group are respectively capable of moving independently, with the position of the aperture moving along a convex trajectory on the optical axis from the image side to the object side during changing magnification. Through operation in this manner, the zoom lens of the invention is inexpensive and compact, and efficiently corrects various types of aberration. Thus, at a high magnification ratio of 5× or greater, the zoom lens of the invention affords a wide field exceeding approximately 78 degrees at the wide angle end, and affords a high performance compact zoom lens whose distortion is held to 3% or less.

Abstract: A zoom lens system comprising a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units among the lens units is changed so that an optical image of an object is formed with a continuously variable magnification, a first lens unit arranged on the most object side among the lens units includes a lens element having a reflecting surface for bending a light beam from the object, and any one of the lens units, any one of the lens elements, or alternatively a plurality of adjacent lens elements that constitute one lens unit move in a direction perpendicular to an optical axis; an imaging device including the zoom lens system; and a camera employing the imaging device.

Abstract: A zoom lens includes: a first lens unit of positive refractive power; a second lens unit of negative refractive power; a third lens unit of positive refractive power; and a fourth lens unit of positive refractive power, being disposed in that order from an object side to an image side, in which the second and fourth lens units are moved in a direction parallel with an optical axis of the zoom lens during zooming, the first lens unit consists of one negative lens and three or fewer positive lenses, being disposed in that order from the object side to the image side, and the following condition is satisfied: 25.1<Z×BD1/BD2<4.1×Z, where BD1 and BD2 are lengths of the first and second lens units along the optical axis, and Z is a zoom ratio.

Abstract: An image pickup apparatus includes a zoom lens including at least two movable lens groups; an image pickup element that converts an optical image formed with the zoom lens into an electric signal; and an image processor that electrically corrects a lateral chromatic aberration to be generated at the zoom lens. The zoom lens satisfies Conditional Expressions (1) and (2) as follows, ?5.0<W_ate(X)/T_ate(X)<?0.2??(1) 0.003<|Max_ate(10)/Himg |<0.03??(2) where W_ate(X) is an aberration amount of the lateral chromatic aberration from the C-line to the g-line, at a wide-angle end, corresponding to a (X×10) % image height, T_ate(X) is an aberration amount of the lateral chromatic aberration from the C-line to the g-line, at a telephoto end, corresponding to a (X×10) % image height, Max_ate(X) is one of W_ate(10) and T_ate(10), the one having a larger absolute value, and Himg is a diagonal length of the image pickup element.

Abstract: A three-unit zoom lens system includes in order from an object side thereof, a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, and a third lens unit having a refracting power. The first lens unit includes a biconcave negative lens component nearest to the object side, and the biconcave negative lens component is the only negative lens component in the first lens unit. The second lens unit includes a cemented lens component which includes in order from the object side thereof, at least three lenses cemented mutually on an optical axis, namely a first positive lens, a negative lens, and a second positive lens. A surface on the image side of the negative lens is a concave surface, and the negative lens has an Abbe's number smaller than the Abbe's number for the first positive lens and the second positive lens, and has a refractive index higher than a refractive index of the second positive lens.

Abstract: An image pickup apparatus includes an image pickup element and an optical system configured to form an image on the image pickup element. The optical system includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and including a reflecting member configured to deflect an optical axis, and a rear lens unit having a positive refractive power and including at least one lens unit having a positive refractive power. The second lens unit is stationary for zooming. During zooming, the image pickup element moves, and an interval between the first lens unit and the second lens unit and an interval between the second lens unit and the rear lens unit vary.

Abstract: A zoom lens made up of a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power, and a fourth lens group having positive refracting power, which are disposed in order from an object side, in which the first lens group and the third lens groups are stationary, and the zoom lens performs mainly variable power by shifting the second lens group in an optical axis direction, and performs correction for image position fluctuations and focusing by shifting the fourth lens group in the optical axis direction, is characterized in that the first lens group is composed of five lenses: a concave lens; a convex lens with a strong convexity facing to an image side; a cemented lens made up of a concave lens with a strong concavity facing to the image side, and a convex lens; and a convex lens with a strong convexity facing to the object side, which are disposed in order from the object side, and by satisfying each of the fo

Abstract: Providing a zoom lens system having a high zoom ratio being compact with high optical performance. The system includes, in order from an object along an optical axis, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, at least one lens group having positive refractive power, and an n-th lens group GN being disposed to the most image side. The n-th lens group GN with positive refractive power includes, in order from the object, a front group GNa and a rear group GNb having positive refractive power. Focusing on an object is carried out by moving the rear group GNb along the optical axis, and a given conditional expression is satisfied.

Abstract: The invention relates to a zoom lens that can achieve higher performance easily. In order from the object side of the zoom lens, it comprises a positive first lens group G1, a negative second lens group G2, a positive third lens group G3 and a positive fourth lens group G4, wherein zooming is implemented by a change in the space between the respective lens groups. Upon zooming from the wide-angle end to the telephoto end, while the space between the first lens group G1 and the second lens group G2 grows wide, the space between the second lens group G2 and the third lens group G3 becomes narrow and the space between the third lens group G3 and the fourth lens group G4 becomes narrow, the first, the third, and the fourth lens group moves toward the object side only, and the second lens group G2 moves in a convex orbit toward the image plane side. The second lens group G2, and the fourth lens group G4 has at least one aspheric surface, and the zoom lens satisfies the following conditions: 0.1<|f2/f1|<0.

Abstract: A projection exposure system, intended in particular for microlithography, is used for generating, in an image plane, an image of a mask arranged in an object plane. The projection exposure system has a light source emitting projection light and projection optics arranged between the mask and the image. Starting from the mask, the following are arranged in the beam path of the projection optics: a first group of optical components with an overall positive refractive power; a second group of optical components with an overall negative refractive power; a third group of optical components with an overall positive refractive power; a fourth group of optical components with an overall negative refractive power, and, a fifth group of optical components with an overall positive refractive power. At least three optical subgroups having at least one optical component can be displaced along the optical axis of the projection optics.

Abstract: A zoom lens system is disclosed which comprises in order from an object side to an image side: a first lens unit with a positive optical power (inverse of the focal length), a second lens unit with a negative optical power; and one or more lens units; and with which at least one of the first lens unit and the second lens unit is moved during zooming. By specifying the optical characteristics (shape, material, focal length, etc.) of the lens elements making up the second lens unit in the zoom lens system, a high zoom ratio is obtained with a simple arrangement, and an optical system, which can adequately accommodate even the use of a solid-state image pickup element with a large number of pixels, is realized.

Abstract: The invention provides a zoom lens system that is reduced in terms of both size and cost. The zoom lens system comprises a first positive lens group G1, a second negative lens group G2, a stop S, a third positive lens group G3 and a fourth positive lens group G4. During zooming from a wide-angle end to a telephoto end of the system, while the first lens group G1 remains fixed, the second lens group G2 moves from an object side to an image plane side of the system, the third lens group G3 moves from the image plane side to the object side, and the fourth lens group G4 moves to keep an image plane at a constant position.