Abstract: An imaging lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element and a third lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element with refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The third lens element with refractive power has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface of the third lens element has at least one convex shape in an off-axis region thereof, and both of an object-side surface and the image-side surface are aspheric. The imaging lens assembly has a total of three lens elements with refractive power.

Abstract: A wafer-level lens system includes a first substrate, a first lens having a planar surface in contact with the first substrate and a concave aspheric surface, a second substrate, a second lens having a convex aspheric surface facing the first lens and a planar surface in contact with the second substrate, a third lens having a planar surface in contact with the second substrate and a concave aspheric surface, a third substrate, a fourth lens having a convex aspheric surface facing the third lens and a planar surface in contact with the third substrate, and a fifth lens having a planar surface in contact with the third substrate and a concave aspheric surface.

Abstract: An optical unit that is configured of a three-group wide-angle lens, that is capable of suppressing optical distortion to a small amount, that has favorable optical characteristics, and that is tolerant of reflow, and an image pickup apparatus are provided. An optical unit 100 includes: a first lens group 110 including a first lens element 111; a second lens group 120 including a second lens element 121, a first transparent member 122, and a third lens element 123 that are arranged in order from object plane toward image plane; and a third lens group 130 including a fourth lens element 131, a second transparent member 132, and a fifth lens element 33 that are arranged in order from the object plane toward the image plane, the first lens group 110, the second lens group 120, and the third lens group 130 being arranged in order from the object plane toward the image plane.

Abstract: A zoom lens system includes, in order from the object side to the image side, a first, a second, and a third lens groups. The first lens group includes, in order from the object side to the image side, a first and a second lenses. The second lens group is capable of floating to realize an image stabilizating function and includes, in order from the object side to the image side, a third to sixth lenses. The zoom lens system satisfies various formulas, including 0.3<d2a/D2<0.4, wherein d2a is the distance between image-side surfaces of the fifth lens and of the sixth lens, and D2 is a width of the second lens group along an optical axis of the zoom lens system.

Abstract: A single-focal-length imaging lens system achieves focusing by, while keeping first and third lens groups stationary relative to the image plane, moving a second lens group along the optical axis. The second lens group includes a positive lens element. The third lens group includes an aspherically shaped lens element having an inflection point at a position other than the intersection with the optical axis. The first and second air lenses formed by the intervals between the first and second and between the second and third lens groups have negative and positive refractive powers respectively. The conditional formula 0?|Fi1/Fi2|?|Fm1/Fm2|?10 is fulfilled (Fi1 and Fi2 representing the focal lengths of the first and second air lenses, respectively, when focusing on the infinite object distance; Fm1 and Fm2 representing the focal lengths of the first and second air lenses, respectively, when focusing on the closest object distance).

Abstract: A method of manufacturing a lens module including following is provided. A first lens plate having a plurality of first lens sections, a second lens plate having a plurality of second lens sections and a third lens plate having a plurality of third lens sections are provided. The first lens sections of the first lens plate are separated to form a plurality of first lens units. The second and third lens plates are connected. A relative position between each of the first lens units and one of the second lens sections corresponding to the first lens unit is adjusted. Each of the first lens units and the second lens section corresponding to the first lens unit are connected. The second and third lens sections are separated to form a plurality of second lens units and a plurality of third lens units connected to the second lens units.

Abstract: This invention provides an image capturing lens system comprising three non-cemented lens elements with refractive power: a first lens element with positive refractive power having a convex object-side surface, and both the object-side and image-side surfaces being aspheric; a plastic second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, and both the object-side and image-side surfaces being aspheric; and a plastic third lens element having a convex object-side surface and a concave image-side surface, and both the object-side and image-side surfaces being aspheric. By such arrangement, the space of the image capturing lens system can be allocated much more properly and thereby an image capturing lens system with shorter total track length can be obtained while retaining superior image quality.

Abstract: A wide-angle lens system includes, in an order from an object side toward an image surface side: a first lens group having positive or negative refractive power; a second lens group having positive refractive power; and a third lens group having negative refractive power. When an object position changes from an infinite distance to a nearest distance, the first and third lens groups are fixed, and the second lens group moves along an optical axis to perform focusing.

Abstract: An imaging lens includes: a first lens group; a second lens group having positive refractive power; and a third lens group having negative refractive power, which are arranged in order from an object side, wherein the first lens group includes a former lens group having a negative lens in a most object side, a diaphragm, and a rear lens group, and wherein, when focusing is performed, the second lens group is moved in the optical axis direction.

Abstract: A variety of optical arrangements and methods of modifying or enhancing the optical characteristics and functionality of these optical arrangements are provided. The optical arrangements being specifically designed to operate with camera arrays that incorporate an imaging device that is formed of a plurality of imagers that each include a plurality of pixels. The plurality of imagers include a first imager having a first imaging characteristics and a second imager having a second imaging characteristics. The images generated by the plurality of imagers are processed to obtain an enhanced image compared to images captured by the imagers.

Abstract: An imaging lens includes a first lens; a second lens; and a third lens arranged from an object side to an image plane side. The first lens has an object-side surface having a positive curvature radius R1f and an image plane-side surface having a negative curvature radius R1r. The second lens has an object-side surface and an image plane-side surface with negative curvature radii. The third lens has an object-side surface and an image plane-side surface with positive curvature radii and formed as aspheric surfaces having inflexion points. When the whole lens system has a focal length f, the first lens has a focal length f1, the second lens has a focal length f2, and the third lens has a focal length f3, the imaging lens satisfies the following conditional expressions: f1<f2<f3 1.0<f1/f<1.5 ?0.

Abstract: An image-capturing lens includes, in order from an object side: a meniscus-shaped first lens which has positive power near an optical axis; a second lens which has positive power near the optical axis and has negative power in the periphery of the second lens; and a meniscus-shaped third lens. The image-capturing lens satisfies the following conditional formulas: TL/f<1.10, 2.00<(r2+r1)/(r2?r1)<4.00, and 0.07<D2/f<0.19, where TL: the air-converted distance from the object-side surface of the first lens to the image-side surface thereof, f: the focal length of the entire system, r2: the radius of curvature of the first lens on the image side thereof, r1: the radius of curvature of the first lens on the object side thereof, D2: the distance between the first lens and the second lens.

Abstract: A photographing lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element and a third lens element. The first lens element with positive refractive power has an object-side surface being convex at a paraxial region. The second lens element with negative refractive power has an object-side surface being concave at a paraxial region and an image-side surface being concave or planar at a paraxial region, wherein the second lens element is made of plastic material and the surfaces thereof are aspheric. The third lens element with negative refractive power has an object-side surface being concave at a paraxial region, and an image-side surface being concave at a paraxial region and being convex at a peripheral region, wherein the third lens element is made of plastic material, and the surfaces thereof are aspheric.

Abstract: A method of manufacturing a lens module including following is provided. A first lens plate having a plurality of first lens sections, a second lens plate having a plurality of second lens sections and a third lens plate having a plurality of third lens sections are provided. The first lens sections of the first lens plate are separated to form a plurality of first lens units. The second and third lens plates are connected. A relative position between each of the first lens units and one of the second lens sections corresponding to the first lens unit is adjusted. Each of the first lens units and the second lens section corresponding to the first lens unit are connected. The second and third lens sections are separated to form a plurality of second lens units and a plurality of third lens units connected to the second lens units.

Abstract: A photographing lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element and a third lens element. The first lens element with positive refractive power has an object-side surface being concave at a paraxial region thereof and an image-side surface being convex at a paraxial region thereof. The second lens element has positive refractive power. The third lens element with negative refractive power made of plastic material, and has an image-side surface being concave at a paraxial region thereof and being convex at a peripheral region thereof, wherein an object-side surface and the image-side surface of the third lens element are aspheric.

Abstract: An imaging lens system includes, sequentially from an object side to an image side: a first lens having a positive refractive power; a second lens having a negative refractive power; and a third lens having a negative refractive power, wherein a viewing angle ? satisfies following condition, 0.3<|tan ?|<0.8.

Abstract: An imaging lens system includes, sequentially from an object side to an image side: a first lens having a positive refractive power; a second lens having a negative refractive power; and a third lens having a positive refractive power or a negative refractive power, wherein a viewing angle ? satisfies following condition,

Abstract: Provided are a macro lens system and an image pickup device including the macro lens system. The macro lens system includes a first lens group having a positive refractive power, a second lens group having a positive refractive power, and a 3-1 lens group having a positive refractive power and moving perpendicular to an optical axis to correct an image blur.

Abstract: An optical system for viewing a front object and a generally side object comprises, sequentially from the front object side, a first lens group having a negative refractive index, a second lens group including a reflective-refractive lens, an aperture stop, and a third lens group having a positive refractive index. The reflective-refractive lens is provided with a first surface formed on the front object side, a second surface formed on an image side, and a third surface formed circumferentially to surround an optical axis between the first surface and the second surface. The first surface is provided with a first transmission surface formed around the optical axis, and a first reflection surface that faces the image side and is formed around the first transmission surface. The first surface is defined by an aspherical surface consisting of a concave surface in the vicinity of the optical axis and a convex surface in the vicinity of the first reflection surface.

Abstract: A photographing lens system includes, in order from an object side to an image side, a first lens element with positive refractive power including a convex object-side surface and a convex image-side surface, and the object-side surface and the convex image-side surface of the first lens element being aspheric; a second lens element with negative refractive power including a concave object-side surface and a convex image-side surface, and the object-side surface and the image-side surface of the second lens element being aspheric; and a third lens element with negative refractive power including an object-side surface and a concave image-side surface, and the object-side surface and the image-side surface of the third lens element being aspheric. The second lens element and the third lens element are made of plastic. The image-side surface of the third lens element is concave near an optical axis and convex away from the optical axis.

Abstract: An optical lens system for image taking includes, in order from an object side to an image side, a first lens element with negative refractive power having a concave object-side surface and a concave image-side surface, a second lens element with positive refractive power having a convex image-side surface, and a third lens element with negative refractive power having a concave image-side surface of the third lens element near an optical axis and a convex image-side surface of the third lens element away from the optical axis. Both the object-side surface and the image-side surface of the third lens element are aspheric. The third lens element is made of plastic.

Abstract: An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a negative biconcave single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented together to form a cemented lens. The imaging lens is configured to satisfy a conditional expression (3) 0.9<dt3/f<1.3, and further configured to satisfy conditional expression (1) 31<?d2<55 or (1?): 35<?d2 and a conditional expression (2): ?10<?d1??d2<25.

Abstract: A single focal length lens system comprising: at least a front lens unit having positive or negative power, and being fixed in focusing; a focusing lens unit having positive power, and moving along an optical axis in focusing; and a rear lens unit having negative power, and being fixed in focusing, wherein the focusing lens unit includes: a cemented lens of a negative lens and a positive lens; and a positive single lens located on the image side relative to the cemented lens and having an aspheric surface, the rear lens unit is composed of one single lens, and the condition: ?0.5<fW/fGR<?0.1 (fW, fGR: focal lengths of the entire single focal length lens system, the rear lens unit) is satisfied.

Abstract: An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a biconcave negative single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented to form a cemented lens. The imaging lens is configured to satisfy conditional expressions (2): 0<fg2/f<1.3, (2b?): 0.5<fg2/f<1.25, and (6): 31<?d2<70 at the same time, where fg2 is combined focal length of the second lens group, f is focal length of the entire lens system, and ?d2 is Abbe number of the second group first lens.

Abstract: An imaging lens includes first, second, and third lens elements arranged from an object side to an image side in the given order. The first lens element has a positive refracting power, and has a convex object-side surface facing toward the object side. The second lens element has a concave object-side surface facing toward the object side, and a convex image-side surface facing toward the image side. The third lens element has an image-side surface facing toward the image side and having a concave portion in a vicinity of an optical axis of the imaging lens. The imaging lens satisfies |?1??2|<5, and |?1??3|>20, where ?1, ?2, and ?3 represent dispersion coefficients of the first, second, and third lens elements, respectively.

Abstract: The present invention provides a projection apparatus including an image generation device and a projection lens. The projection lens is disposed between a light valve of the image generation device and a projection screen, and the projection lens includes a plurality of lenses. The lenses include a first lens, a second lens and a third lens, and the first lens, the second lens and the third lens are aspherical lenses. An effective focal length of the projection lens is between 5 mm and 8 mm, and a sum of the effective focal length of the projection lens and a number of the lenses is between 14 and 17.

Abstract: A projection lens for projecting an image beam is provided. The image beam is converted by a light valve from an illumination beam irradiating the light valve. The projection lens includes a first lens group, a second lens group, and a third lens group. The first lens group is disposed on a transmission path of the image beam, and has a first optical axis. The second lens group is disposed on both a transmission path of the illumination beam and the transmission path of the image beam, and between the light valve and the first lens group. The second lens group has a second optical axis. The second optical axis is inclined with respect to the first optical axis. The third lens group is disposed on the transmission path of the image beam, and between the first lens group and the second lens group. A projection apparatus is also provided.

Abstract: An imaging lens includes: a movable lens group configured to travel to allow the imaging lens to come into focus; and a rearmost lens group arranged at a most-image-sided fixed position, and having negative refractive power. Following conditional expression is satisfied, ?2<ft/fr<?0.45??(1) where ft is a total focal length of the imaging lens in a condition that the imaging lens is in focus on an object at infinite, and fr is a focal length of the rearmost lens group.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit of a negative refractive power, a second lens unit of a positive refractive power, and a third lens unit of a positive refractive power, an interval between the first lens unit and the second lens unit and an interval between the second lens unit and the third lens unit being configured to change in zooming from a wide angle end to a telephoto end. The first lens unit includes, in order from the object side to the image side, a negative lens and a positive lens. The predetermined conditions are satisfied.

Abstract: An inner focus lens system includes from the object side, a first lens unit having a positive refractive power, an aperture stop, a second lens unit having a positive refractive power, and a third lens unit. The first lens unit includes a plurality of negative lenses and at least one positive lens, the lens located closest to the object side is a negative lens. The second lens unit includes at least one negative lens and at least one positive lens, and moves toward the object side for focusing from an infinite object distance to a close object distance such that the distance between the second lens unit and the aperture stop decreases and that the distance between the second lens unit and the third lens unit increases. The lens system satisfies the following conditions: 1<f1/f 14 (1), and 0.8<f23/f2<3 (2).

Abstract: This invention provides an imaging optical lens system comprising three lens elements with refractive power: a positive first lens element having a convex object-side surface at a paraxial region; a negative plastic second lens element having a convex or flat object-side surface and a concave image-side surface at a paraxial region, and both the object-side surface and the image-side surface being aspheric; and a negative plastic third lens element having a concave object-side surface at a paraxial region, the shape of the image-side surface thereof changing from concave when near an optical axis to convex when away from the optical axis, and both the object-side surface and the image-side surface being aspheric. The aforesaid arrangement can not only effectively correct the astigmatism of the system against defocus problems but also effectively reduce the back focal length for desirable space usage. Therefore, the lens system can be more compact.

Abstract: An optical system comprises a first lens element and a second lens element which are respectively shiftable to have a component in a direction perpendicular to the optical axis, the second lens element being composed of the first lens element and other lens element, and the first lens element or the second lens element being shifted to have a component in a direction perpendicular to the optical axis, thereby carrying out a correction of the image plane. Thus, there are provided an optical system having a suitable vibration reduction property, an image apparatus equipped with the optical system and a method for manufacturing the optical system.

Abstract: A photographic optical system 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 configured to move in an optical axis direction to perform focusing, and a third lens unit having positive or negative refractive power, wherein the position of an optical element (A) satisfies a predetermined condition.

Abstract: An imaging lens SL mounted in a digital single lens reflex camera 1 is composed of, in order from an object side, 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 positive refractive power, wherein upon focusing on a near-distance object point from an infinite-distance object point, at least one of the first lens group G1 and the second lens group G2 is moved so as to change a distance between the first lens group G1 and the second lens group G2, and the imaging lens satisfies a given conditional expression, thereby providing a downsized imaging lens suited to an imaging apparatus such as a single lens reflex camera, having a less of change in overall length and optimal to driving an intra-lens-barrel motor.

Abstract: The invention is directed to correcting compound lens forms for 3rd and 5th order ray aberrations. All lens design forms have limiting aberrations. The proposed classes of lenses can be corrected for all 3rd and 5th order ray aberrations. The limiting aberrations are seventh order or higher. A variety of these lenses are disclosed here for the sake of example. These lens design forms can be used in various applications including the objective lens for an endoscope or other optical instrument.

Abstract: A retrofocus-type wide angle lens includes a first lens group having negative refractive power as a whole, a second lens group having positive refractive power as a whole, a stop, and a third lens group having positive refractive power as a whole, which are arranged in this order from the object side of the retrofocus-type wide angle lens. Further, the first lens group includes two negative meniscus lenses, each having a convex surface facing the object side. Further, each of the second lens group and the third lens group includes a three-element cemented lens.

Abstract: The invention provides an ocular lens well corrected for aberrations through a sufficiently large angle of view and having a sufficient eye relief while ensuring avoidance of increasing the overall length and suppression of an increase in lens diameter, and provides an optical device including this ocular lens. An ocular lens 3 includes, in order from an object side, a first lens group G1 including a first lens component G1A in meniscus form having a convex surface facing the object side, a second lens group G2 including a lens component L21 having a convex surface facing a viewing eye side, and a third lens group G3 having a positive refractive power. An object-side focal plane I of the third lens group G3 is positioned between the second lens group G2 and the third lens group G3.

Abstract: This invention provides an injection-molded plastic optical lens comprising, in order from a center to an edge thereof: an optical effective portion, a connecting portion and a peripheral portion that are concentrically formed; wherein the lens has an outer diameter D, the optical effective portion has an edge thickness ET1 and a central thickness CT, the connecting portion has a minimum thickness ET2, and the plastic optical lens satisfies the following relations: CT?0.30 mm and ET2/ET1<1.0. At least one lens element with refractive power can be disposed at each of the object side and the image side of the plastic optical lens of the present invention to form an optical lens assembly.

Abstract: A small-size wide angle lens substantially consists of a first lens group having positive refractive power, a stop, a second lens group having positive refractive power, and a third lens group having negative refractive power, which are arranged in this order from the object side. Each of the first lens group, the second lens group and the third lens group includes a negative lens and a positive lens. Further, at least one of the second lens group and the third lens group includes an aspheric surface. Further, the small-size wide angle lens satisfies predetermined formulas.

Abstract: Example embodiments provide for an optical lens assembly and imaging lens with IR light filtering. The lens comprises a body having two surfaces and a plurality of layers of optical thin film layered along a direction formed on at least one surface. The optical thin films comprise less than 20 layers and thicker than 400 nm and thinner than 2000 nm thickness. Through the alternately layered layers of optical thin film, the transmittance of the lens for incident light in infrared ray band is reduced. Therefore, the infrared ray is mostly filtered without use of an additional infrared ray filter.

Abstract: An image lens module includes a first lens, a second lens, a third lens, and an image plane and satisfies: FB/TTL>0.16, G1R1/F1>1.04, and D1/D2<4.47. FB is a distance between an apex of an image-side surface of the third lens and the image plane. TTL is a distance between an object-side surface of the first lens and the image plane. G1R2 is a curvature radius of an image-side surface of the first lens. F1 is focal length of the first lens. D1 is a distance between the end of the effective diameter of an image-side surface of the second lens and an optical axis of the image lens module in a direction perpendicular to the optical axis. D2 is a distance between the end of the effective diameter of the image-side surface of the second lens and an apex of the image-side surface of the second lens along the optical axis.

Abstract: A photographing lens system including, in order from an object side to an image side: a first positive lens element having a convex object-side surface and a convex image-side surface; a second negative lens element, the object-side and image-side surfaces thereof being aspheric; a third lens element having a convex object-side surface and a concave image-side surface, the object-side and image-side surfaces thereof being aspheric and at least one of which being provided with at least one inflection point; and an aperture stop disposed between an imaged object and the second lens element; wherein there are three lens elements with refractive power.

Abstract: A lens module includes a lens barrel, a number of lenses, a number of opaque plates, and a filter glass. The barrel, the lenses, the opaque plates, and the filter glass all are received in the lens barrel. Each opaque plate is sandwiched between two adjacent lenses. Each lens includes an imaging portion and a non-imaging portion surrounding the imaging portion for engaging an inner sidewall of the lens barrel. The filter glass is arranged closer to an image-side of the lens module than the lens and the opaque plates. The projection of one of the opaque plates arranged closest to the filter glass, along the direction of incident light of the lens module, totally covers the non-imaging portion of the lens arranged closest to the filter glass.

Abstract: A macro lens and an imaging apparatus include, in the order from an object side to an image side, a first lens group, a second lens group, and a third lens group. Focusing is performed by fixing the first lens group and the third lens group, and by moving the second lens group having a positive refractive power as a whole on the optical axis in focusing from an infinite object to a close distance object. The first lens group has a plane S1 and a plane S2 of curvature radii of a same sign and satisfying a specified condition.

Abstract: An imaging lens SL installed in a single-lens reflex digital camera includes, in order from an object side, a first lens group G1, and a second lens group G2 having positive refractive power. The first lens group G1 includes, in order from the object side, a first lens component L11 having a negative meniscus shape with a convex surface facing the object side, a second lens component L12 having a negative meniscus shape with a convex surface facing the object side, and a third lens component L13. The third lens component L13 includes a double concave lens to the most object side. The imaging lens SL includes at least six lens components or more, thereby providing a sufficiently fast imaging lens having excellent optical performance, which is a large aperture, single-focal-length, wide-angle lens having an aspherical surface.

Abstract: A first lens unit performing communication with an image pickup apparatus with a first voltage and a second lens unit performing communication with the image pickup apparatus with a second voltage are selectively attached to the image pickup apparatus. The image pickup apparatus includes a controller configured to operate with a third voltage different from at least one of the first and second voltages to output a signal for the communication with the first and second lens units, and a determiner configured to determine the type of the lens unit attached to the image pickup apparatus. The controller is configured to produce, as a voltage of the signal for the communication, from the third voltage, one of the first and second voltages corresponding to a determination result of the determiner.

Abstract: A zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group, in that order from the object side, wherein upon zooming from the short focal length extremity to the long focal length extremity, the distance between the first lens group and the second lens group decreases, and the distance between the second lens group and the third lens group increases. The second lens group includes a positive first sub-lens group and a negative second sub-lens group, in that order from the object side. The second sub-lens group is a negative single lens element serving as an image-stabilizer lens group which moves in directions orthogonal to the optical axis to change the imaging position to correct image shake.

Abstract: A photographic 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 positive or negative refractive power, and a third lens unit having a positive or negative refractive power, focusing being performed by moving the second lens unit, wherein at least one diffractive optical element and at least one optical element made of solid material are provided closer to the object side than a position where a paraxial chief ray intersects an optical axis, and wherein a focal length obtained by only a diffraction component of the diffractive optical element, a focal length of the optical element made of solid material, a focal length of the first lens unit, and a relative anomalous partial dispersion of a material forming the optical element made of solid material are appropriately set.

Abstract: A zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group, in that order from the object side, wherein upon zooming from the short to long focal length extremities, the distance between the first lens group and the second lens group decreases, and the distance between the second lens group and the third lens group increases. The second lens group includes a positive first sub-lens group and a negative second sub-lens group, in that order from the object side. In at least part of the zooming range of the zoom lens system, the second sub-lens group and the third lens group each serves as a focusing lens group that is moved along the optical axis during a focusing operation.

Abstract: A photographic lens optical system including: a first lens, a second lens, and a third lens sequentially arranged from a side of an object toward an image sensor, wherein the first lens has a positive (+) refractive power and an incident surface that is convex toward the object, the second lens has a negative (?) refractive power and is convex toward the image sensor, the third lens has a negative (?) refractive power, and at least one of an incident surface and an exit surface thereof is aspherical, and wherein an angle of view (?) of the lens optical system, and a focal length (f) of the lens optical system satisfy the following inequality: 1.0<|tan ?|/f<2.0.