Abstract: The present disclosure relates to optical lens, and provides a zoom lens including, from an object side to an image side in sequence: a first lens having a negative refractive power, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, a fifth lens group having a negative refractive power; distances between adjacent lenses of the first lens, the second lens, the third lens and the fourth lens or between the fourth lens and the fifth lens group vary in the direction of the optical axis; the fifth lens group including a fifth lens having a positive refractive power and a sixth lens having a negative refractive power; wherein the zoom lens satisfies conditions of: f_Tele/f_Wide>1.8; 10.00?D12_Wide/D12_Tele?20.00; and 15.00?d9_Wide/d9_Tele?22.50.

Abstract: The present disclosure discloses a camera apparatus including a first optical system and a second optical system. The second optical system includes a secondary reflecting mirror, a main reflecting mirror with an opening in a center area thereof, and a lens group, which are sequentially arranged from an object side to an image side. Light from the object side is sequentially reflected by the main reflecting mirror and the secondary reflecting mirror, and then enters the lens group through the opening. A total effective focal length F1 of the first optical system and a total effective focal length F2 of the second optical system satisfy: F2/F1>10.

Abstract: An optical lens includes a first lens with a positive refractive power, a second lens having a diffractive optical surface and a negative refractive power, and a third lens with a positive refractive power arranged in order from a magnified side to a minified side. A total number of lenses with refractive powers in the optical lens is smaller than six, and the first lens, the second lens and the third lens are made of plastic.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit configured not to move for zooming, a plurality of zooming lens units configured to move in zooming, a front relay lens unit configured not to move for zooming, an extender lens unit insertable into and removable from an optical path for changing a focal length range of the zoom lens, and a rear relay lens unit configured not to move for zooming, and satisfies specific conditional expressions.

Abstract: An image capturing apparatus comprises an image sensor and a focus detection unit configured to, based on an image signal obtained by the image sensor while performing a scan operation that causes a focus lens to move along an optical axis of the imaging optical system, calculate a focus evaluation value and detect a position of the focus lens at which the focus evaluation value is a maximum, wherein the focus detection unit, in a case where the imaging optical system includes a reflective optical system in which a part of a light beam is blocked, sets a calculation method of the focus evaluation value or a control method of the focus lens during the scan operation based on information relating to a shape of the reflective optical system.

Abstract: A lens assembly for an optical imaging lens is disclosed, which includes a first lens, wherein the first lens has a negative power, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, wherein the sixth lens has a positive power, wherein the second lens and the third lens define a first cemented achromatic lens assembly, and the fourth lens and the fifth lens define a second cemented achromatic lens assembly, wherein the first lens, the first cemented achromatic lens assembly, the second cemented achromatic lens assembly and the sixth lens are orderly arranged along the direction from the object side to the image side.

Abstract: An internal focus large-aperture telephoto lens including, sequentially from an object side to an image side, a first lens assembly with positive focal power, a second lens assembly with negative focal power, an aperture stop, a third lens assembly with positive focal power, and a fourth lens assembly with negative focal power; the first lens assembly, the second lens assembly, the third lens assembly and the fourth lens assembly are all spherical lenses; when focusing from infinity to proximity, the second lens assembly moves along an optical axis towards the image side, the third lens assembly moves along the optical axis towards the object side, the first lens assembly and the fourth lens assembly remain static in position in relation to the image side. The present invention utilizes internal double lens movement to focus, thereby achieving high magnification and high resolution and increasing focusing speed.

Abstract: A variable magnification optical system comprising, in order from an object side, a first lens group having negative refractive power, a first intermediate lens group having positive refractive power, a second intermediate lens group having negative refractive power and a rear lens group; upon varying a magnification from a wide angle end state to a telephoto end state, a distance between the first lens group and the first intermediate lens group being varied, a distance between the first intermediate lens group and the second intermediate lens group being varied, and a distance between the second intermediate lens group and the rear lens group being varied; the rear lens group comprising at least one focusing lens group which is moved upon carrying out focusing from an infinitely distant object to a closely distant object; and predetermined conditional expressions being satisfied, thereby the focusing lens group(s) being reduced in weight.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a positive refractive power. The first lens unit includes a negative lens B1Ln with a concave surface facing the object side. The second lens unit includes at least one negative lens. During zooming from a wide-angle end to a telephoto end, the first lens unit moves, and the fourth lens unit is fixed or moves from the object side to the image side. A predetermined condition is satisfied.

Abstract: A 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 subsequent unit having a positive refractive power as a whole. A distance between adjacent lens units changes during zooming. The first lens unit includes a single lens, and the subsequent unit includes a third lens unit having a positive refractive power closest to the object side in the subsequent unit and a lens unit LP having a positive refractive power closest to the image side among the zoom lenses. During zooming from a wide-angle end to a telephoto end, the second lens unit moves toward the object side. A predetermined condition is satisfied.

Abstract: A zoom lens module includes first to eighth lens elements sequentially arranged from an object end to an image end. The number of lens elements with refractive power in the zoom lens module is eight. The first lens element and the second lens element form a first lens element group. The third lens element and the fourth lens element form a second lens element group. The fifth lens element and the sixth lens element form a third lens element group. The seventh lens element and the eighth lens element form a fourth lens element group. The first lens element group and the fourth lens element group remain fixed during zooming. The second lens element group and the third lens element group move during zooming.

Abstract: The present application provides a camera module array, comprising at least two camera modules, wherein at least one of the camera modules has a free-form lens sheet, and the free-form lens sheet performs active alignment according to an actual imaging result received by a photosensitive chip, so that a difference between an actual reference direction of the free-form lens sheet and a reference direction determined by an optical design is not greater than 0.05 degrees. The present application further provides a corresponding assembly method for camera module array. In the present application, a TTL of the camera modules can be reduced by means of the free-form lens sheet so as to, for example, make a TTL of a wide-angle module equal or approximately equal to a TTL of a telephoto module, so that a dual-camera module composed of the wide-angle module and the telephoto module is easily mounted in a terminal device such as a mobile phone.

Abstract: A 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, a third lens unit having a positive refractive power, and one or more rear lens units. The first lens unit does not move for zooming. An interval between each pair of adjacent lens units changes in zooming. The first lens unit includes a positive lens made of material with an Abbe number less than 30. A predetermined condition is satisfied.

Abstract: A zoom lens includes, in order from an object along an optical axis: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; a fourth lens group; and a fifth lens group. When the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis.

Abstract: The disclosure provides an infrared optical imaging lens, a camera module and a DMS. From an object side to an image side along an optical axis, the infrared optical imaging lens sequentially includes a stop, a first lens with a positive refractive power, a second lens with a positive refractive power, a third lens with a negative refractive power, and a filter. An object side surface of the first lens is convex, an image side surface of the first lens is concave. An object side surface of the second lens is concave, an image side surface of the second lens is convex. A paraxial portion of an object side surface of the third lens is convex, and a paraxial portion of an image side surface of the third lens is concave.

Abstract: A lens system (10) for image pickup includes, in order from an object side (11), a first lens group (G1) that has negative refractive power and is fixed during focusing, a second lens group (G2) that has positive refractive power and moves during focusing, a third lens group (G3) that has positive refractive power and is fixed during focusing, and a fourth lens group (G4) that has a stop disposed on the object side, is disposed closest to an image plane side, has positive refractive power, and is fixed during focusing. The first lens group includes a first lens (L11) with positive refractive power that is disposed closest to the object side.

Abstract: A distance measuring camera 1 includes a first optical system for collecting light from a subject to form a first subject image, a second optical system for collecting the light from the subject to form a second subject image, an imaging part for imaging the first subject image formed by the first optical system and the second subject image formed by the second optical system, and a distance calculating part 4 for calculating a distance to the subject based on the first subject image and the second subject image imaged by the imaging part S. The first optical system and the second optical system are configured so that a change of a magnification of the first subject image according to the distance to the subject is different from a change of a magnification of the second subject image according to the distance to the subject.

Abstract: A zoom lens includes a first lens group having negative refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power and a fourth lens group having positive refractive power. Upon varying magnification, distances between the first lens group and the second lens group, between the second lens group and the third lens group and between the third lens group and the fourth lens group vary. The second lens group includes a front lens group, an aperture stop, and a rear lens group. Each of the front lens group and the rear lens group includes at least one positive lens. At least a part of the lenses in the second lens group is moved as a group to have a component in a direction perpendicular to an optical axis.

Abstract: A zoom optical system (ZL) comprises a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power that are disposed in order from an object. Upon zooming from a wide angle end state to a telephoto end state, the lens groups are moved along an optical axis to change distances between the lens groups. The fifth lens group (G5) comprises at least one positive lens and at least one negative lens. Certain conditional expressions are satisfied.

Abstract: An imaging optical system includes a plurality of lenses, and the plurality of lenses includes a lens pair consisting of two lenses arranged near each other, in which radii of curvature of two surfaces arranged near each other is close to each other, and which satisfies predetermined conditional expressions.

Abstract: A display control apparatus, in which a user can easily recognize “taste of bokeh” of a captured image before the image is recorded, is disclosed. The display control apparatus controls so as to display, together with a first item that indicates either one of a setting value of an F-number or a T-number, a second item that indicates information that relates to an F-number and an amount of variance of a T-number that correspond to a current setting value.

Abstract: The zoom lens consists of, in order from the object side, a first lens group that has a negative refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; and a fourth lens group that has a positive refractive power. During zooming, in each lens group, distances between the adjacent groups in the direction of the optical axis are changed. The first lens group consists of, in order from the object side, a first lens having a negative refractive power, a second lens having a negative refractive power, and a third lens having a positive refractive power. The third lens group consists of a negative lens. During focusing, only the third lens group moves along the optical axis. The zoom lens satisfies predetermined conditional expressions.

Abstract: The present disclosure relates to the field of optical lenses and provides a camera optical lens. The camera optical lens includes, from an object side to an image side: a first lens; a second lens having a negative refractive power; a third lens having a negative refractive power; a fourth lens; a fifth lens; and a sixth lens. The camera optical lens satisfies following conditions: 3.00?f1/f?10.00; and 5.00?R11/d11?15.00. The camera optical lens can achieve a high imaging performance while obtaining a low TTL.

Abstract: The autofocus control system of a projector includes a projector and an imaging unit. The projector includes a lens actuator that drives a projection lens, and a first controller that projects a first or a second pattern image selected, the second pattern image being mesh-shaped more coarsely than the first pattern image. The imaging unit includes an imaging part that images the first or second pattern image selected to generate imaged data, a user interface part that acquires a zoom magnification, and a second controller that transmits a focus control command to the first controller based on the imaged data. The second controller transmits to the first controller, an instruction signal for selectively projecting the first pattern image when the zoom magnification is smaller than a given magnification, and an instruction signal for selectively projecting the second pattern image when the zoom magnification is the given magnification or larger.

Abstract: The zoom lens consists of a positive first lens group, a negative second lens group moving during zooming, a positive third lens group moving during zooming, and a positive fourth lens group which does not move during zooming in order from an object side. Only the third lens group moves during focusing. A lens surface closest to an object is a convex surface. A conditional expression of 5<TL2/(Y×ft)<9.5 which is related to a total optical length TL at a telephoto end, a maximum image height Y, and a focal length ft of the entire system at the telephoto end in a state in which an object at infinity is in focus is satisfied.

Abstract: A wide-angle lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The first lens has negative refractive power and includes a concave surface facing an image side. The second lens has negative refractive power and includes a concave surface facing the image side. The third lens has negative refractive power and includes a concave surface facing the image side. The fourth, fifth, seventh and eighth lenses have refractive power. The sixth and ninth lenses are biconvex lenses with positive refractive power. The first to ninth lenses are arranged in order from an object side to the image side along an optical axis.

Abstract: An optical imaging system includes a plurality of lenses disposed along an optical axis, and a reflection member disposed to be closer to an object than all of the plurality of lenses and having a reflection surface configured to change a path of light. The plurality of lenses are spaced apart from each other by preset distances along the optical axis, and the condition 0.8<TTL/ft<1.1 is satisfied, where TTL is a distance from an object-side surface of a lens closest to the object among the plurality of lenses to an imaging plane of an image sensor, and ft is an overall focal length of an optical system including the plurality of lenses.

Abstract: An otoscope includes an instrument head, a tip element and an optical system. The instrument head has a distal insertion portion for insertion into an ear of a human or veterinary subject. The distal insertion portion has a distal opening. The tip element is releasably attached to the distal insertion portion. The tip element has a distal opening. The optical system is contained within the instrument head. The optical system includes a plurality of optical components. The optical system further comprises a viewing component for viewing of an image of a target of interest aligned along an optical axis disposed within said distal opening. The optical system is configured to provide a field of having a diameter equaling at least 7 mm at a distance of at least 15 mm from a distal opening of said attached tip element. The optical system is further configured to simultaneously provide a distance range of optimal focus having a range of at least 8 mm.

Abstract: The zoom lens consists of, in order from the object side, a first lens group that has a negative refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; and a fourth lens group that has a positive refractive power. During zooming, in each lens group, distances between the adjacent groups in the direction of the optical axis are changed. The first lens group consists of, in order from the object side, a first lens having a negative refractive power, a second lens having a negative refractive power, and a third lens having a positive refractive power. The third lens group consists of a negative lens. During focusing, only the third lens group moves along the optical axis. The zoom lens satisfies predetermined conditional expressions.

Abstract: An optical system includes a reflective optical system on a magnification side along an optical path of the projection optical system and a refractive optical system on a reduction side along the optical path. The reflective optical system includes one reflective optical element having a power. The refractive optical system includes a front group on the magnification side and a rear group on the reduction side. The front group having, in order from the magnification side toward the reduction side, a first lens group with a positive or negative refractive power, a second lens group, and a third lens group with a positive refractive power. The rear group has a positive refractive power. The first lens group moves to the magnification side, and the second lens group and the third lens group move to the reduction side in a change in focus from a long distance to a short distance.

Abstract: Comprising, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; an aperture stop S; a third lens group G3 having positive refractive power; and a fourth lens group G4 having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, the distance between the first lens group G1 and the second lens group G2, the distance between the second lens group G2 and the aperture stop S, the distance between the aperture stop S and the third lens group G3, and the distance between the third lens group G3 and the fourth lens group G4 being varied, and the distance between the aperture stop S and the fourth lens group G4 being constant; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which is compact in size and has a high variable magnification ratio and high optical performance, an optical apparatus, and a method for manufacturi

Abstract: A zoom lens including, in order from an object side, a positive first unit configured not to be moved for zooming, a negative second unit configured to be moved for zooming, a positive third unit configured to be moved for zooming, a zooming lens group including a lens unit and configured to be moved for zooming, and a positive unit configured not to be moved for zooming, wherein the third unit includes positive and negative lenses, the second and third units move to an image side for zooming from a wide-angle end to a telephoto end, and focal lengths at the wide-angle end and the telephoto end, a zoom ratio, a space between the second unit third units and is maximum in a zoom range from the telephoto end to a predetermined focal length, and a space between the second third units at the telephoto end are properly set.

Abstract: A variable power optical system 3 used in a parallel stereoscopic microscope apparatus 100 and the like includes a plurality of optical paths in which optical axes are arranged substantially parallel, includes a plurality of lens groups that change the magnification of a diameter of a luminous flux entering substantially parallel to each of the optical paths to eject the luminous flux as substantially parallel luminous fluxes, and at least two lens groups move along the optical axis in each optical path according to the change in the magnification. At least two lens groups of at least one optical path among the plurality of optical paths move in a direction including a component perpendicular to the optical axis according to the change in the magnification at at least part of a section where the magnification is changed from a high-power end state to a low-power end.

Abstract: The imaging lens includes at least one negative lens that satisfies predetermined Conditional Expressions (1) to (3) indicating conditions in which dispersion is relatively low and refractive index is high while having a negative rate of change of the refractive index. A positive lens having a largest Abbe number at the d line among positive lenses included in the imaging lens satisfies predetermined Conditional Expressions (4) and (5).

Abstract: A variable power optical system 3 used in a parallel stereoscopic microscope apparatus 100 and the like includes a plurality of optical paths in which optical axes are arranged substantially parallel, includes a plurality of lens groups that change the magnification of a diameter of a luminous flux entering substantially parallel to each of the optical paths to eject the luminous flux as substantially parallel luminous fluxes, and at least two lens groups move along the optical axis in each optical path according to the change in the magnification. At least two lens groups of at least one optical path among the plurality of optical paths move in a direction including a component perpendicular to the optical axis according to the change in the magnification at at least part of a section where the magnification is changed from a high-power end state to a low-power end.

Abstract: An image-space telecentric lens includes, in order from a magnified side to a minified side, a first lens group of negative refractive power, an aperture stop, and a second lens group of positive refractive power. The first lens group has at least one aspheric surface, and the second lens group has at least one aspheric surface. The second lens group has a cemented lens of positive refractive power, and the cemented lens is nearest the aperture stop as compared with other lens in the second lens group. The image-space telecentric lens satisfies the condition: TT<100 mm, where TT denotes a length measured along an optical axis and between two outermost opposite lens surfaces of the image-space telecentric lens.

Abstract: A wide-angle lens system that includes four lens groups arranged from object to image and having a field of view greater than 90 degrees is described. The lens elements within each of the four groups are selected for optimization of performance factors of low chromatic aberration, low optical distortion and manufacturability. Design methods are included and shown through exemplary optimized designs.

Abstract: A zoom optical system and automated luminaire are provided. The zoom optical system includes a light source and compensator, variator, and objective lens groups. The light source illuminates an object in an object plane. The compensator lens group is optically coupled to the object without intervening lenses, has a positive optical power, six lenses, and moves relative to the object plane. The variator lens group is optically coupled to the compensator lens group without intervening lenses, has a negative optical power, three lenses, and moves relative to the object plane and the compensator group. The objective lens group is optically coupled to the variator lens group without intervening lenses, has a second positive optical power, three lenses, remains in a fixed position relative to the object plane, and projects an image of the object without intervening lenses between the objective lens group and the projected image.

Abstract: A zoom lens includes, in order from an object along an optical axis: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; a fourth lens group; and a fifth lens group. When the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis.

Abstract: A zoom lens including: a positive first lens unit; a negative second lens unit; and a positive rear lens group, an interval of adjacent lens units is changed during zooming, the rear lens group includes from an object side: a positive lens system; an aperture stop; and a negative partial lens system, the first lens unit and the aperture stop are positioned closer to the object side at a telephoto end than at a wide angle end, and a combined focal length of a front lens system between the first lens unit and the aperture stop at the wide angle end, an absolute value of a distance on an optical axis from a first lens surface to the aperture stop at the wide angle end, a focal length of the first lens unit, and a focal length of the zoom lens at the wide angle end is appropriately set.

Abstract: A zooming optical system includes a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power, in that order from an object side. The first lens group has at least one cemented lens having positive refractive power. Each of the first lens group, the second lens group, the third lens group, and the fourth lens group are configured to move along a direction of an optical axis in zooming. Conditional expression (1) below is satisfied: ?10.0<f2/f1<?2.0??(1), where f1 is a focal length of the first lens group, and f2 is a focal length of the second lens group.

Abstract: A variable magnification optical system 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 at least one lens unit. A second predetermined positive lens element satisfies conditional expressions (1) and (2) and a second predetermined negative lens element satisfies the following conditional expressions (3) and (4). The second lens unit includes three sub-lens units and the following conditional expressions (5) and (6) are satisfied: 0.520<(?g,F)G2p<0.610??(1), 0.680<(?C,t)G2p<0.900??(2), 0.520<(?g,F)G2n<0.560??(3), 0.750<(?C,t)G2n<0.900??(4), ?0.25<fG21/fG22<0.90??(5), and ?0.70<fG21/fG23<0.40??(6).

Abstract: An apparatus is described for determining surface topography of a three-dimensional structure. The apparatus can include a probe and an illumination unit configured to output a plurality of light beams. In many embodiments, the apparatus includes a light focusing assembly. The light focusing assembly can receive and focus each of a plurality of light beams to a respective external focal point. The light focusing assembly can be configured to overlap the plurality of light beams within a focus changing assembly in order to move the external focal points along a direction of propagation of the light beams. The apparatus can include a detector having an array of sensing elements configured to measure a characteristic of each of a plurality of light beams returning from the illuminated spots and a processor coupled to the detector and configured to generate data representative of topography of the structure based on the measured characteristic.

Abstract: A zoom lens includes, in order from the object side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having negative refractive power, and a fourth lens unit having positive refractive power. At a time of zooming from a wide-angle end to a telephoto end, the distance between the first lens unit and the second lens unit is reduced, the distance between the third lens unit and the fourth lens unit is increased, and the fourth lens unit is fixed.

Abstract: A zoom lens unit includes, in order from an object side to an image side, a first lens group having positive refractive power and a focus function, a second lens group having negative refractive power, which moves when changing a magnification, a third lens group which moves when changing a magnification, and a fourth lens group having positive refractive power, which is fixed when changing a magnification, wherein the following condition (1) is fulfilled: |M2W·M3W·M4W|<0.14 ??(1) where M2W represents an imaging magnification of the second lens group at a wide-angle end, M3W represents an imaging magnification.the third lens group at the wide-angle end, and M4W represents an imaging magnification of the fourth lens group at the wide-angle end.

Abstract: A photographing lens system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, and a fourth lens element. The first lens element has positive refractive power. The second lens element has negative refractive power. The third lens element having positive refractive power has an image-side surface being concave, and an object-side surface and the image-side surface thereof being aspheric. The fourth lens element has an object-side surface being concave, and the object-side surface and an image-side surface thereof being aspheric. The photographing lens system further includes an aperture stop, and no lens elements are disposed between the aperture stop and the first lens element. The photographing lens system has a total of four lens elements.

Abstract: Provided are a zoom lens, a projection display device including the zoom lens, and an imaging apparatus including the zoom lens. The zoom lens forms an intermediate image at a position conjugate to a reduction side imaging plane and forms the intermediate image again on a magnification side imaging plane. The zoom lens includes: a first optical system on the magnification side; and a second optical system on the reduction side. The intermediate image is formed between the magnification side and the reduction side. The second optical system includes two movable lens groups, which move by changing spacings between the groups adjacent to each other in a direction of an optical axis during zooming, and two stationary lens groups which remain stationary with respect to the reduction side imaging plane during zooming. One stationary lens group is disposed to be closest to the reduction side, and has a positive refractive power.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a rear lens group including a lens unit having negative refractive power arranged along an optical axis thereof. A focal length fw of the zoom lens at a wide-angle end, a focal length ft of the zoom lens at a telephoto end, an amount of movement M1 of the first lens unit on the optical axis in zooming from the wide-angle end to the telephoto end, and a focal length frn of a lens unit Lrn that is a lens unit having a shortest focal length among lens units having negative refractive power included in the rear lens group are appropriately set based on predetermined mathematical conditions.

Abstract: An optical imaging lens includes a plurality of lens elements arranged in order from an object side to an image side along an optical axis, and each lens element has an object-side surface and an image-side surface. There is at least one variable gap between the lens elements, and one of the lens elements closest to the object side has positive refracting power. The optical imaging lens satisfies: ?G/Gv?0.1. Here, ?G is an absolute value of a difference between a first value and a second value of the length of the at least one variable gap along the optical axis when an object having an infinite object distance and an object having an object distance of 500 millimeters are focused respectively, and Gv is the second value.

Abstract: A zoom lens including 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. The first through fifth lens groups are arranged sequentially from an object side to an image side of the zoom lens, and the first lens group includes a doublet lens and a lens having a positive refractive power. The second lens group includes a first sub-lens group having a negative refractive power and a second sub-lens group having a negative refractive power that is arranged to perform a focusing function. Each of the lens groups is arranged to move when the zoom lens is zoomed.