Abstract: A zoom lens includes a positive first lens unit G1, a negative second lens unit G2 and a rear group having a positive refracting power having at least one lens unit. The lens unit located closest to the object side in the rear grout is a third lens unit G3 having a positive refracting power. The zoom lens has an aperture stop S disposed closer to the image side than the second lens unit G2 and closer to the object side than the lens surface located closest to the image side in the third lens unit G3. The zoom lens satisfies a prescribed conditional expression.

Abstract: A zoom lens includes, in order from the object side thereof, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, and a third lens unit G3 having a positive refracting power, wherein zooming is performed by changing distances between the lens units, the second lens unit has two negative lens elements and one positive lens element, and the lens element located closest to the object side is a negative lens element. The zoom lens satisfies the following conditions: 0.60<?d2G/Imw<1.95??(1-1) and 1.830<N2ave<2.000??(1-2), where the term “lens element” refers to an optical member that satisfies 0.1<L/Imw.

Abstract: A zoom lens comprises, in order from its object side, a first lens group of positive refracting power, a second lens group of negative refracting power, and a third lens group of positive refracting power located on an image side with respect to the second lens group. Upon zooming from the wide-angle end to the telephoto end, the spacing between the first lens group and the second lens group grows wider at the telephoto end than at the wide-angle end, and the spacing between the second lens group and the third lens group becomes narrower at the telephoto end than at the wide-angle end. The first lens group comprises a negative lens and a positive lens, and the number of the negative lens in the first lens group is only one. At least one positive lens in the first lens group satisfies the following conditions (1) and (2): 1.80<ndlp<2.0??(1) 50.0<?dlp<70.

Abstract: A zoom lens system comprises, in order from an object, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. The first lens group has a first-a partial lens group and a first-b partial lens group arranged on an image side of the first-a partial lens group with an air space and is constructed such that the first-b partial lens group moves along an optical axis direction upon focusing from infinity to a close-range object. The third lens group is constituted by a third-a partial lens group having a positive refractive power and a third-b partial lens group having a negative refractive power arranged on the image side of the third-a partial lens group with an air space.

Abstract: The invention provides a zoom lens capable of achieving a half angle of view over 38 degrees at the wide-angle end, a magnification ratio 6.5 to 10 or more, and a resolving power corresponding to an imaging element of 5 to 8 million pixels, with a configuration of as few as 10 to 11 pieces of lenses. The zoom lens of the invention includes a first lens group through a third lens group I to III of positive/negative/positive in order from the object side, or further includes a fourth lens group of positive IV. In the zoom lens, when changing magnification from a wide-angle end toward a telephoto end, a spacing between the first lens group and the second lens group increases and a spacing between the second lens group and the third lens group decreases.

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: An electronic imaging apparatus comprises a zoom lens including at least two lens groups and adapted to implement zooming by changing the spacing between the respective lens groups, and an electronic imaging device. The zoom lens includes at least one positive lens on an imaging device side with respect to an aperture stop, and satisfies the following conditions (1), (2) and (3). |?t??w|>8 ??(1) 1.0×10?3<P<4.

Abstract: A zoom lens system according to the present invention comprises a plurality of lens units, in order from an object side to an image side, including at least: a first lens unit having positive optical power; a second lens unit having negative optical power; and a third lens unit having positive optical power, wherein magnification change is performed by changing an interval between the individual lens units, wherein the second lens unit, in order from the object side to the image side, comprises: a lens element A having negative optical power; a lens element B that has an aspheric surface and has negative optical power; and a lens element C having positive optical power, and wherein the second lens unit satisfies the following conditions (1): 1.85<NdA<2.20 and (2): 1.88<NdC<2.20, where NdA is the refractive index to the d-line of the lens element A and NdC is the refractive index to the d-line of the lens element C.

Abstract: A zoom lens achieves a high zoom ratio and high optical performance in an entire zoom range. The zoom lens 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 a rear unit which includes at least one lens unit. At least the second lens unit is moved during zooming such that a distance between the first and second lens units is larger at a telephoto end than at a wide-angle end. The first lens unit includes at least a first lens element made of a material which satisfies Nd1a>2.3?0.01·?d1a and 1.65<Nd1a<2.70. The first and second lens units satisfy 2.5<|f1/f2|<12.0.

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 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: 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 magnifying optical system for endoscope which can be set at least in a usual observing condition (at a wide position) and a condition for observing a magnified image of an object at a short distance (at a tele position) by moving any of one of lens units, and is configured so as to satisfy a condition mentioned below, thereby providing a sufficient observation depth in each observing condition: f(W)/F(T)>0.93.

Abstract: A zoom lens includes a plurality of lens groups having at least first, second and third lens groups arranged in order from an object side. The first lens group has a positive refractive power which is firmly secured when the magnification is changed, the second lens group has a negative refractive power which is shifted to the image side when the magnification is changed from the wide angle end to the telescopic end, and the third lens group has a positive refractive power which is firmly secured when the magnification is changed. The first lens group is configured by arranging, in order from the object side, a single lens having a negative refractive power, a prism having a reflection surface to create a 90° bend in a light path, and at least one single lens having a positive refractive power.

Abstract: To provide a compact, high-performance zoom lens having a small lens aperture for enlarging an image from a light valve such as a DMD for forming an image by changing a reflecting direction of light and projecting the image so enlarged on to a screen or the like, the zoom lens includes, in order from a magnifying side, a first lens group having a positive or negative refractive power as a whole, a second lens group having a negative refractive power as a whole and a third lens group having a positive refractive power as a whole, wherein changing the magnification of a whole lens system thereof is attained by configuring such that while a magnification varying operation is in effect, the first lens group is left fixed, and the second lens group and the third lens group are made to move on the optical axis.

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: The invention relates to a zoom lens which, albeit being of simplified construction, makes sure brightness and holds back fluctuations of astigmatism, and facilitates making sure being fast and the angle of view and the zoom ratio at the wide-angle end. The zoom lens comprises a first group G1 of positive power, a second group G2 of negative power and a third group G3 of positive power, with a stop S between the second group G2 and the third group G3. Upon zooming from the wide-angle end to the telephoto end, the first group G1, the second group G2, and the third group G3 moves; the second group G2 moves toward the object side after moving toward the image side; the first group G1 and the third group G3 are positioned on the object side at the telephoto end with respect to the wide-angle end.

Abstract: A zoom lens includes, in order from the object side to the image side, 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. The first lens unit and the third lens unit move in the optical axis direction during zooming. The following conditions are satisfied: 0.60<m3/m1<0.90, and 0.080<|f2/ft|<0.120, where m1 and m3 are maximum moving distances in the optical axis direction of the first lens unit and the third lens unit, respectively, during zooming from the wide-angle end to the telephoto end, ft is a focal length of the zoom lens at the telephoto end, and f2 is a focal length of the second lens unit.

Abstract: A lens unit according to the present invention is capable of varying power for forming an image onto an image pickup element. The lens unit includes: a plurality of lens groups, a diaphragm, and a shutter. In the plurality of lens groups, a distance between a k-th lens group counting from an object side and a (k+1)-th lens group arranged at an image side of the k-th lens group changes for varying power. The diaphragm is arranged between a position at an image side of the k-th lens group and a lens surface facing the object side of a lens closest to the image in the (k+1)-th lens group. The shutter is provided with an aperture in a noncircular shape and fulfills the predetermined conditional formulas.

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: 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 optical system at least includes in the order from an object side: a first lens group having a positive optical power; a second lens group having a negative optical power; and a third lens group having a positive optical power. In zooming from a wide angle end to a telephoto end, a distance between the first lens group and the second lens group is increased, and a distance between the second lens group and the third lens group is decreased. The first lens group includes at least one negative lens element, and the second lens group includes a negative lens element closest to the object side, with a lens surface of the negative lens element being concave toward an image side.

Abstract: The invention relates to a zoom lens in which tweaks to the mode of movement of lens groups and the first lens group contribute more to making sure the desired zoom ratio and optical performances and ensuring that the whole length of the zoom lens is kept short while carrying it around. The zoom lens comprises a positive first lens group G1, a negative second lens group G2 and a positive third lens group G3, and includes an aperture stop S located between the second G2 and the third lens group G3. Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves in unison, and the second lens group G2 moves in unison. The first G1 and the second lens group G2 are positioned nearer to the object side at the telephoto end than at the wide-angle end, with an increasing spacing between the first G1 and the second lens group G2 and a decreasing spacing between the second G2 and the third lens group G3.

Abstract: A zoom lens system includes a rear lens group having 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, and a third lens unit G3 having a positive refracting power, and an aperture stop S which is disposed between the second lens unit G2 and the third lens unit G3. At the time of zooming from a wide angle end to a telephoto end, when focused on an object at a longest distance, each of the first lens unit G1, the second lens unit G2, and the third lens unit G3 moves such that a distance between the first lens unit G1 and the second lens unit G2 is widened (increased), and a distance between the second lens unit G2 and the third lens unit G3 is narrowed (decreased). The aperture stop S moves such that a distance of the aperture stop S from the second lens unit becomes small (is decreased).

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 is changed so that an optical image is formed with a continuously variable magnification, any one of the lens units, any one of the lens elements, or a plurality of adjacent lens elements that constitute one lens unit move in a direction perpendicular to an optical axis, the zoom lens system comprises a first lens unit having positive power, a second lens unit that includes a lens element having a reflecting surface and has negative power and subsequent lens units including at least one lens unit having positive power, and the condition (1): 1.50<M1/fW<3.00 (M1 is an amount of optical axial movement of the first lens unit, fW is a focal length of the entire zoom lens system at a wide-angle limit) is satisfied.

Abstract: An imaging apparatus including a first lens unit with positive power in which the most object-side surface is concave and the most image-side surface is convex, an aperture stop, a second lens unit with positive power in which the most object-side surface is convex and the most image-side surface is concave, and a third lens unit with positive power; and an image sensor. Air spacing between the second lens unit and the third lens unit assumes the shape of a biconvex air lens. The imaging apparatus satisfies the following condition: 1.4?|r 2R|/IH?15.0 where IH is the maximum photographic image height, which is a half of the diagonal length, in an effective imaging area, of the image sensor, and r 2R is the radius of curvature, measured along the optical axis, of the most image-side surface of the second lens unit.

Abstract: The present invention is a compact lens system for use as a wide-field photographic objective with small format digital image sensors having a pixel dimension less than 0.010 mm. The f-number of the lens system is 2.9740, and the effective focal length of the system is 3.85 mm. The full angular field of view of the lens system is 61 degrees, and the chief ray incidence angles on the image plane are less than 18 degrees. The system comprises three plastic lenses, each having two aspheric surfaces. At least one of the aspheric surfaces in the system is coated with a multilayer infrared cut-off filter for blocking infrared wavelengths from the image sensors. The lens system has a reduced sensitivity to manufacturing tolerances, particularly lateral misalignment of optical elements and surfaces.

Abstract: An imaging lens (100) comprising, arranged sequentially from the object side, a positive-meniscus first lens (1) with its convex plane facing the object side, a negative-power-meniscus second lens (2), and a positive-power third lens (3), the second and third lenses (2, 3) functioning as correction lenses. The first lens (1) has a strong power, and both the second and third lenses (2, 3) are aspherical on opposite planes. When the synthetic focal distance of the imaging lens is f, the focal distance of the first lens f1, the distance from the incident surface on the object side to the imaging surface of the first lens (1) ?d, and the Abbe number of the second lens ?d2, the following conditional expressions are satisfied. 0.50<f1/f<1.5 (1) 0.50<?d/f<1.5 (2) 50>?d2 (3). Accordingly, a small, low-cost imaging lens capable of high-quality imaging can be realized.

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 is changed so that an optical image is formed with a continuously variable magnification, the zoom lens system comprises a first lens unit having positive power, a second lens unit that includes a lens element having a reflecting surface and has negative power and subsequent lens units including at least one lens unit having positive power, and the condition: 0.50<(C?S)/H<1.00(C=?{square root over ( )}(2R·dR?dR2), S is a sag of the image side surface of the most object side lens element in the second lens unit at height H, H is one-half of an optical axial thickness of the lens element having a reflecting surface, R is a radius of curvature of the image side surface, and dR is an interval between the most object side lens element and the lens element having a reflecting surface) is satisfied.

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 lens barrel including a telescopic cylinder configured to be accommodated within a fixed frame; a plurality of lens groups configured to be retained in the telescopic cylinder; a lens driving device configured to drive the plurality of lens groups along a longitudinal axis of the telescopic cylinder between a collapsed position in which at least one portion of the plurality of lens groups is stored in the fixed frame and an extended position in which the at least one portion of the plurality of lens groups is extended out of the fixed frame; and a retractable lens group configured to be retracted into the fixed frame through an opening in a wall of the fixed frame when the telescopic cylinder is in the extended position.

Abstract: A zoom lens includes, in order from the object side to the image side, 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. The first lens unit and the third lens unit move in the optical axis direction during zooming. The following conditions are satisfied: 0.60<m3/m1<0.90, and 0.080<|f2/ft|<0.120, where m1 and m3 are maximum moving distances in the optical axis direction of the first lens unit and the third lens unit, respectively, during zooming from the wide-angle end to the telephoto end, ft is a focal length of the zoom lens at the telephoto end, and f2 is a focal length of the second lens unit.

Abstract: The invention relates to a new mechanism for permitting a zoom lens to focus on a short distance subject by moving a focusing lens group in an amount that varies in an optical axis direction depending on a zooming position. The zoom lens comprises, in order from its object side, a positive first lens group, a negative second lens group and a positive third lens group. Zooming is implemented while the space between adjoining lens groups is varied, and focusing on a short distance subject is implemented by moving the negative second lens group in an amount that varies in the optical axis direction depending on a zooming position. The negative second lens group comprises a negative front unit G2F and a negative rear unit G2R. The space between the negative front unit G2F and the negative rear unit G2R is varied depending on a subject distance but that space remains constant wherever the zooming position lies.

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 zoom lens in which tweaks to the mode of movement of lens groups and the first lens group contribute more to making sure the desired zoom ratio and optical performances and ensuring that the whole length of the zoom lens is kept short while carrying it around. The zoom lens comprises a positive first lens group G1, a negative second lens group G2 and a positive third lens group G3, and includes an aperture stop S located between the second G2 and the third lens group G3. Upon zooming from the wide-angle end to the telephoto end, the first lens group G1 moves in unison, and the second lens group G2 moves in unison. The first G1 and the second lens group G2 are positioned nearer to the object side at the telephoto end than at the wide-angle end, with an increasing spacing between the first G1 and the second lens group G2 and a decreasing spacing between the second G2 and the third lens group G3.

Abstract: A computer based method, system and computer program product to assign a quality metric to an airspace design and optionally to compare it against design metrics, to determine a comparative quality metric. Factors contributing to quality of the airspace sector design are identified via user input and quantified to calculate a quality metric for the airspace sector design as a function of the quantified factors. Categories for each of the identified factors, and parameters for each of the identified categories are also identified via user input. Each parameter has an associated weight and a range of thresholds with associated multipliers. An associated multiplier from the range of thresholds for each identified parameter is also identified. The identified multiplier is multiplied with the associated weight for each identified parameter. The products for each identified parameter are then summed to obtain a quality metric.

Abstract: Providing a zoom lens system that satisfies making the focusing lens light and reducing a moving amount for focusing, simultaneously. The zoom lens system includes a first lens group having positive power, a second lens group having negative power and a third lens group having positive power. When zooming from a wide-angle end state to a telephoto end state, at least the first and third lens groups are moved such that a distance between the first and second lens groups increases, and a distance between the second and third lens groups decreases. The first lens group is composed of a front lens group with positive power having at least one negative lens and at least one positive lens, and a rear lens group with positive power having one positive lens. Focusing from infinity to a close object is carried out by moving only the rear lens group to the object.

Abstract: At least one exemplary embodiment is directed to a zoom lens configured to correct chromatic aberration and having a high optical performance over the entire zoom range. The zoom lens includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, and a third lens unit of positive refractive power. During zooming, an interval between respective adjacent lens units varies. The third lens unit includes an optical element made of a solid material having an Abbe number (?d) and a relative partial dispersion (?gF) satisfying the following condition: ?gF?(?1.665×10?7·?d3+5.213×10?5·?d2?5.656×10?3·?d +0.755)>0.

Abstract: A zoom lens of the invention has three lens groups. In the zoom lens, magnification change is performed by moving only one lens group among the three lens groups, and focus adjustments is performed by moving one of a first lens group and a second lens group counted from an enlargement conjugate side among the three lens groups. In addition, the zoom lens is approximately telecentric on reduction conjugate side thereof.

Abstract: A zoom lens unit includes: a positive first lens group; a negative second lens group; and a positive subsequent lens group as a whole, the subsequent lens group includes a third lens group, and an aperture stop is disposed between the second lens group and the third lens group, and a lens construction including the first and the second lens groups satisfies the condition (1): 1.0<ri/ri+1<5.0, in which ri and ri+1 are curvature radii of lens surfaces Si and Si+1 in the lens construction, respectively, the lens surfaces Si and Si+1 being “i”th and “i+1”th lens surfaces, respectively, counted from the object side, and a reflectivity-reducing treatment adapted to reduce intensity of a ghost image is performed on each lens surface forming at least one of pairs of lens surfaces satisfying the condition (1).

Abstract: At least one exemplary embodiment is directed to a zoom lens system having a telephoto-type configuration at the telephoto end. When assuming that an Abbe number is vd, and a partial dispersion ratio is ?gF, this zoom lens system includes a refractive optical element having positive refracting power made up of a solid material that can satisfy the following conditions: ?2.100×10?3·vd+0.693<?gF 0.555<?gF<0.9 Thus, facilitating the configuration of a zoom lens system capable of appropriately correcting and/or reducing various aberrations, including a chromatic aberration straddling the entire zoom area.

Abstract: There is provided an imaging lens including a first lens having a positive refracting power, a second lens having a concave surface on an object side and having a negative refracting power, and a third lens having a positive refractive power and a meniscus shape having a convex surface on the object side and at a vicinity of an optical axis, in order from the object side. The imaging lens satisfies conditional equations below. f designates a focal length of the total system, f1 designates a focal length of the first lens, D2 designates an interval between the first lens and a second lens on an optical axis, v123 designates an average of Abbe numbers of the first lens, the second lens and the third lens, and v2 designates the Abbe number of the second lens. 0.7<f1/f<1.3 ??(1) 0.25<D2/f<0.

Abstract: Providing a compact zoom lens system having a high zoom ratio. The zoom lens system includes, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. When a state of lens group positions varies from a wide-angle end state W to a telephoto end state T, at least the first lens group G1 and the third lens group G3 are moved along the optical axis to the object. Given conditional expressions are satisfied.

Abstract: The invention is concerned with a zoom lens that is well fit for a digital type single-lens reflex camera, has improved optical performance, and is bright all over the zooming zone. The zoom lens comprises a first group G1 of positive power, a second group G2 of negative power and a third group G3 of positive power. Upon zooming, the first group G1 remains fixed, and the second G2 and the third group G3 are movable. The first group G1 comprises a subgroup 1A of negative power and a subgroup 1B of positive power, and the second group G2 comprises a first negative lens, a cemented positive lens, a second negative lens and a third negative lens. The zoom lens satisfies conditions (1) and (2) with respect to the focal length of the subgroup 1A and the focal length of the second group G2.

Abstract: At least one exemplary embodiment is directed to a zoom lens configured to correct chromatic aberration and having a high optical performance over the entire zoom range. The zoom lens includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, and a third lens unit of positive refractive power. During zooming, an interval between respective adjacent lens units varies. The third lens unit includes an optical element made of a solid material having an Abbe number (?d) and a relative partial dispersion (?gF) satisfying the following condition: ?gF?(?1.665×10?7·?d3+5.213×10?5·?d2?5.656×10?3·?d+0.755)>0.

Abstract: An imaging lens (100) comprising, arranged sequentially from the object side, a positive-meniscus first lens (1) with its convex plane facing the object side, a negative-power-meniscus second lens (2), and a positive-power third lens (3), the second and third lenses (2, 3) functioning as correction lenses. The first lens (1) has a strong power, and both the second and third lenses (2, 3) are aspherical on opposite planes. When the synthetic focal distance of the imaging lens is f, the focal distance of the first lens f1, the distance from the incident surface on the object side to the imaging surface of the first lens (1) ?d, and the Abbe number of the second lens ?d2, the following conditional expressions are satisfied. 0.50<f1/f<1.5 (1) 0.50<?d/f<1.5 (2) 50>?d2 (3). Accordingly, a small, low-cost imaging lens capable of high-quality imaging can be realized.

Abstract: Object is to provide an inner-focusing type zoom lens system carrying out focusing by moving a portion of a first lens group suitable for an auto-focus SLR camera. A zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first and the second lens groups increases, and a distance between the second and the third lens groups decreases. The first lens group is composed of, in order from the object, a 1A lens group G1A having positive refractive power, and a 1B lens group G1B having positive refractive power. Focusing from infinity to a close-range object is carried out by moving only the 1B lens group G1B to the object.

Abstract: A telephoto lens is provided and has three lens groups as a whole. A first lens group includes a first positive lens having a meniscus shape and having a convex surface on an object side thereof, a negative lens arranged on an image side of the first positive lens and having a concave surface on the image side thereof, and a second positive lens arranged on the image side of the negative lens and having a convex surface on the object side thereof. Further, the following Condition Equations are satisfied. ?11 designates an Abbe number of the first positive lens, ?12 designates an Abbe number of the negative lens, ?13 designates an Abbe number of the second positive lens.

Abstract: A zoom lens system, in order from the object side to the image side, comprises: a first lens unit having positive optical power; a second lens unit that includes a reflective optical element having a reflecting surface for bending object light and that has negative optical power; and a subsequent lens unit including more than one lens unit having positive optical power, and that satisfies the condition: ?5.70<f1/f2<?2.00 (Z=fT/fW>5.0, f1 is the composite focal length of the first lens unit, f2 is the composite focal length of the second lens unit, fW is the focal length of the entire zoom lens system at a wide-angle limit, fT is the focal length of the entire zoom lens system at a telephoto limit, Z is the magnification variation ratio), and is held in a compact lens barrel.

Abstract: An exemplary embodiment is directed to a zoom lens system configured to impart an appropriate refractive power to an image stabilizing lens unit. The zoom lens system can include: a first lens unit; a second lens unit; and a rear lens group. The plurality of lens units constituting the rear lens group can contain a lens component, where the lens component can include: a front lens sub-component; and a rear lens sub-component. Moreover, in at least one further exemplary embodiment at least a part of the front lens sub-component or the rear lens sub-component can be moved.