Abstract: The zoom lens includes, in order from object side to image side, a positive first lens unit, a negative second lens unit, a positive third lens unit, and a rear lens group including at least one lens unit, in which intervals between adjacent lens units are changed during zooming. The third lens unit includes at least two negative lenses and at least three positive lenses. An average value of partial dispersion ratios of two negative lenses having strongest refractive powers of the at least two negative lenses, an average value of partial dispersion ratios of three positive lenses having strongest refractive powers of the at least three positive lenses, an average value of Abbe numbers of the two negative lenses, an average value of Abbe numbers of the three positive lenses, a back focus, and a focal length of zoom lens at wide angle end are appropriately set.

Abstract: A camera module includes a circuit board, a bracket arranged on the circuit board, and at least one electronic component embedded in the bracket and/or arranged on an inner side wall of the bracket. The electronic component is electrically coupled to the circuit board.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. A distance between the first lens unit and the second lens unit changes during zooming. The second lens unit includes an aperture stop and two or more negative lenses. The zoom lens satisfies specified conditional expressions.

Abstract: The present disclosure discloses an optical imaging lens group including, sequentially from an object side to an image side along an optical axis, a first lens having a positive refractive power; a second lens having a negative refractive power; a third lens having a refractive power; a fourth lens having a refractive power, and an image-side surface thereof being a concave surface; a fifth lens having a refractive power; a sixth lens having a refractive power, and an object-side surface thereof being a convex surface; and a seventh lens having a negative refractive power. A distance TTL along the optical axis from an object-side surface of the first lens of the optical imaging lens group to an imaging plane of the optical imaging lens group and a total effective focal length f of the optical imaging lens group satisfy TTL/f<1.

Abstract: An optical system includes a front lens group consisting of at least one lens unit that moves during focusing and having a positive refractive power, and a rear lens group consisting of a lens unit that is immobile during focusing and having a negative refractive power. The rear lens group includes at least two negative lenses and one positive lens. The front lens group and the rear lens group satisfy a predetermined inequality.

Abstract: The present disclosure discloses a camera optical lens. The camera optical lens including, in an order from an object side to an image side, a first lens, a second lens having a positive refractive power, a third lens having a positive refractive power, a fourth lens, a fifth lens, and a sixth lens. The first lens is made of plastic material, the second lens is made of plastic material, the third lens is made of glass material, the fourth lens is made of plastic material, the fifth lens is made of glass material, and the sixth lens is made of plastic material. The camera optical lens further satisfies the following conditions: ?3?f1/f??1; v3?60; 1.7?n5?2.2; 0.03?d3/TTL?0.058. The camera optical lens has the advantage of high performance and satisfies the design requirement of low TTL.

Abstract: A photographing lens system includes seven lens elements, the seven lens elements being, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element. Each of the seven lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The first lens element has positive refractive power. The image-side surface of the seventh lens element is concave in a paraxial region thereof and has at least one inflection point in an off-axis region thereof.

Abstract: The imaging lens consists of, in order from the object side, a positive first lens group that moves to the object side during focusing from a long distance to a short distance, and a second lens group that does not move during focusing. The first lens group has a first-B sub-lens group. The first-B sub-lens group consists of, in order from the object side, a positive b1 lens, a negative b2 lens concave toward the image side, an aperture stop, a negative b3 lens concave toward the object side, and a positive b4 lens. The second lens group consists of, in order from the object side, a negative lens, a positive lens, and a negative lens. Predetermined conditional expressions are satisfied.

Abstract: The present disclosure provides a camera assembly and an electronic device. The camera assembly and the electronic device may both include a first plate, a second plate, a first electromagnetic component, a second electromagnetic component and an elastic component. The elastic component is connected between the second plate and the second electromagnetic component. The first electromagnetic component may be configured to generate or eliminate electromagnetic force between the first electromagnetic component and the first plate. The second electromagnetic component may be configured to generate or eliminate electromagnetic force between the second electromagnetic component and the second plate. The camera module may be driven to move under the generation or elimination of the electromagnetic force and the elastic force of the elastic component. Thus, the adaptability of the camera assembly may be improved.

Abstract: The present disclosure discloses a camera optical lens. The camera optical lens including, in an order from an object side to an image side, a first lens, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens, a fifth lens, and a sixth lens. The first lens is made of glass material, the second lens is made of plastic material, the third lens is made of glass material, the fourth lens is made of plastic material, the fifth lens is made of plastic material, and the sixth lens is made of plastic material. The camera optical lens further satisfies specific conditions.

Abstract: An electronic device includes an auto-focus camera module. The auto-focus camera module comprises a lens module equipped with at least one lens and including an cylindrical insertion unit formed therein; and a carrier formed with a hollow portion, into which the insertion unit of the lens module is inserted in an optical axis direction of the lens, wherein the lens module includes a first rotation prevention portion, the carrier includes a second rotation prevention portion formed at a position corresponding to the first rotation prevention portion, and in a state where the insertion unit of the lens module is inserted into the hollow portion of the carrier, the first rotation prevention portion and the second rotation prevention portion are engaged with each other so as to prevent the lens module from being rotated with respect to the carrier.

Abstract: A compact, low-profile, low-cost imaging lens with an F-value of 2.5 or less and a wide field of view which corrects aberrations properly. Its elements are arranged from an object side to an image side: a first positive optical element group including a first positive lens having a convex object-side surface, a second negative lens having a concave image-side surface, and a third positive lens having a convex object-side surface; a second positive optical element group including a fourth positive lens having a convex image-side surface; and a third negative optical element group including a fifth negative double-sided aspheric lens having a concave image-side surface. The fifth lens image-side surface has at least one pole-change point off an optical axis. A double-sided aspheric aberration correction optical element with virtually no refractive power is located in an air gap nearer to the image plane than the first optical element group.

Abstract: A plurality of imaging optical systems includes at least two imaging optical systems, and each imaging optical system includes an identical diaphragm member. Each imaging optical system includes in order from an object side, a front lens unit having a positive refractive power, a focusing lens unit having a negative refractive power, and a rear lens unit having a positive refractive power. The diaphragm member is disposed near the focusing lens unit. At the time of focusing, only the focusing lens unit moves on an optical axis. Each imaging optical system satisfies the following conditional expression (1), and the plurality of imaging optical systems satisfies the following conditional expressions (2) and (3). 0.5<fff/ffb<1.9??(1) 1?AP?max/AP?min?1.15??(2) 1.02<ffoLA/ffoSM<2.

Abstract: The 1st positive lens unit is located closer to the object side at the telephoto end than at the wide angle end. The distance between the 1st negative lens unit and the 1st positive lens unit is larger at the telephoto end than at the wide angle end. The distance between the image side lens unit group and the 1st negative lens unit varies during zooming from the wide angle end to the telephoto end. The image side lens unit group comprises a 2nd positive lens unit and a 3rd positive lens unit. The distance between the 2nd positive lens unit and the 1st negative lens unit is smaller at the telephoto end than at the wide angle end. The distance between the 3rd positive lens unit and the 2nd positive lens unit varies during zooming from the wide angle end to the telephoto end.

Abstract: A plurality of imaging optical systems includes at least two imaging optical systems having different focal lengths. Each imaging optical system includes in order from an object side, a front lens unit having a positive refractive power, a diaphragm member, a focusing lens unit having a negative refractive power, and a rear lens unit. The front lens unit includes one of a positive lens and a negative lens as a common lens, and each of at least two imaging optical systems from among the plurality of imaging optical systems includes at least one common lens. At the time of focusing, only the focusing lens unit moves on an optical axis. Each imaging optical system satisfies the following conditional expression (1), and the plurality of imaging optical systems satisfy the following conditional expression (2). 0.06<|ffo/f|<0.4??(1) 1.02<ffoLA/ffoSM<2.50??(2).

Abstract: There is provided a lens module including: a first lens group including a plurality of lenses mounted in a lens barrel in a state in which optical axes thereof are aligned with each other by coupling therebetween; and a second lens group including a plurality of lenses sequentially mounted in the lens barrel, such that optical axes thereof are aligned with each other.

Abstract: An optical image capturing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first, the second and the third lens elements all have refractive power. The fourth lens element with refractive power has both surfaces being aspheric. The fifth lens element with refractive power has both surfaces being aspheric. The sixth lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof and both surfaces being aspheric. The seventh lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof, wherein both surfaces being aspheric, and at least one surface has at least one inflection point thereon.

Abstract: An image-capturing apparatus includes an image-capturing device having an image-capturing surface, a shutter unit having an aperture configured to allow light from an object to pass through the aperture, and a controller that controls the shutter unit. The shutter unit includes a curtain unit that selectively executes an opening operation of opening the aperture and a closing operation of closing the aperture, and an actuator that drives the curtain unit. The controller is operable to control the shutter unit to execute: an image-capturing operation in which the shutter unit executes the closing operation after resetting an electric charge stored in the image-capturing device; and a pre-driving operation in which the actuator drives the curtain with a small motion before executing the image-capturing operation.

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 rear lens group having a positive refractive power as a whole and including at least one lens unit. An interval between the first lens unit and the rear lens group at the telephoto end is smaller than that at the wide angle end. The first lens unit includes a first aspheric lens having a positive aspheric amount, and a second aspheric lens having a negative aspheric amount on the image side of the first aspheric lens. The predetermined conditional expressions are satisfied.

Abstract: An optical image capturing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first, the second and the third lens elements all have refractive power. The fourth lens element with refractive power has both surfaces being aspheric. The fifth lens element with refractive power has both surfaces being aspheric. The sixth lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof and both surfaces being aspheric. The seventh lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof, wherein both surfaces being aspheric, and at least one surface has at least one inflection point thereon.

Abstract: An imaging lens includes a first lens group having a positive refractive power on an object side and including at least three positive lenses and at least two negative lenses, and a second lens group having a negative refractive power on an image side and having a negative lens, the first and second lens groups arranged in this order from the object side with a widest air space in-between, wherein in focusing an object from infinity to a close range, only the first lens group is moved to the object side and the second lens group is fixed relative to an image plane.

Abstract: An objective lens for an endoscope, comprising a first lens group having a negative power, an aperture stop, and a second lens group having a positive power arranged in this order from an object side, wherein the first lens group comprises at least a negative front group lens having a concave surface facing an image side, and a positive front group lens having a convex surface facing the image side arranged in this order from the object side, and the second lens group comprises at least a positive rear group lens having a convex surface facing the image side and a cemented lens formed by cementing together a negative lens and a positive lens being arranged in this order from the object side, and wherein the objective lens for an endoscope is configured to satisfy a predetermined condition.

Abstract: The projection zoom lens substantially consists of a first lens group having negative refractive power, a second lens groups through a fourth lens group all having positive refractive power, a fifth lens group having positive or negative refractive power, and a sixth lens group having positive refractive power, arranged in this order from the magnification side; wherein the reduction side is telecentric. Further, the first lens group and the sixth lens group are fixed and the second lens group through the fifth lens group move along the optical axis while changing magnification. The fourth lens group substantially consists of only one positive meniscus lens with a concave surface toward the reduction side. The projection zoom lens satisfies conditional expression (1) below: 1.2<f3/f4<10.0??(1), where f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group.

Abstract: A camera apparatus includes an image sensor to output an image signal, a stop aperture, a lens assembly, and a controller. The lens assembly is disposed between the image sensor on an image side of the lens assembly and the stop aperture on an object side of the lens assembly. The lens assembly includes a plurality of lens elements that collectively induce axial chromatic aberration between red, green, and blue light. The controller is coupled to receive red, green, and blue channels of the image signal. The controller includes logic that causes the controller to use the blue channel without the red or green channels of the image signal to perform image recognition on objects captured in a near-field of the lens assembly and to use the blue, red, and green channels collectively when capturing images in a far-field of the lens assembly.

Abstract: An objective lens OL comprises: a first lens group G1 disposed on an object side, having positive refractive power as a whole and having a positive lens (plano-convex lens L1) which is disposed closest to the object and of which lens surface closest to the object is a plane or a surface having a low curvature, and at least one cemented lens (cemented lens CL12 or the like); a second lens group G2 disposed on an image side, having negative refractive power as a whole, and having a concave surface facing the image and a concave surface facing the object, which face each other; and a diffractive optical element GD in which two diffractive element constituents made from different optical materials are cemented, which has a diffractive optical surface D formed with diffraction grating grooves on the cemented surface, and which is disposed closer to the object than a position where a principal ray crosses the optical axis.

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

Abstract: A zoom lens comprises a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, and a plurality of lens units G3 and G4. Zooming from a wide angle end to a telephoto end is carried out by changing a distance between the lens units. One of the first lens unit G1 and the second lens unit G2 has, or both the first lens unit G1 and the second lens unit G2 have a specific arrangement.

Abstract: Provided is a lens optical unit, including at least one lens arranged at an object side of a solid-state image sensor. An imaging plane of the image sensor has a non-planar shape causing a sag amount in an optical axis direction to increase as a distance from an optical axis increases, and satisfies the expression: ?×Sag>0, where ? represents a Petzval curvature of an optical unit represented by ?: ? = ? k ? ? 1 r k · ( 1 n k ? - 1 n k ) , rk represents a curvature radius of a kth lens surface from the object side, nk represents a refractive index of a medium before being incident to the kth lens surface from the object side, n?k represents a refractive index of a medium after being emitted from the kth lens surface from the object side, and Sag represents a sag amount in the optical axis direction related to a given point other than the optical axis on the imaging plane.

Abstract: A tele-side converter lens including a first unit having a positive refractive power and a second unit having a negative refractive power, in which: the first unit includes one or two positive lenses; the second unit includes one negative lens and one or two positive lenses; and average Abbe constant and partial dispersion ratio of materials of positive lenses constituting the first unit, average Abbe constant and partial dispersion ratio of materials of positive lenses constituting the second unit, an Abbe constant and a partial dispersion ratio of materials of the negative lenses constituting the second unit, combined Abbe constants of materials of the lenses constituting the respective first and second units, focal lengths of the first and second units, a refractive index of a material of a positive lens disposed closest to the object side, and a magnification of the tele-side converter lens are appropriately set, respectively.

Abstract: A projection type image display apparatus in which shortening of the projection distance (widening of the angle of view) and miniaturization of the projection optic system are realized is provided. It comprises, in a traveling direction of the light, an image display element, a lens group including a plurality of lenses, a first lens, a second lens, and a mirror to reflect light emitted from the second lens to be projected obliquely on a screen in this order. The refractive power of the first lens is positive and the refractive power of the second lens is negative. The first and the second lenses are moved in an interlocked relationship with each other along an optical axis of the lens group and a movement amount of the first lens is made larger than a movement amount of the second lens.

Abstract: A zoom lens system comprising a plurality of movable lens units which individually move along an optical axis at the time of zooming from a wide-angle limit to a telephoto limit during image taking, wherein at least two of the movable lens units are focusing lens units which move along the optical axis at the time of focusing from an infinity in-focus condition to a close-object in-focus condition in at least one zooming position, and among the focusing lens units, a lens unit having the absolute value, which is not the greatest absolute value, of a wobbling value at a wide-angle limit is a wobbling lens unit which senses a moving direction of the focusing lens units at the time of focusing by wobbling itself in a direction along the optical axis; an interchangeable lens apparatus; and a camera system are provided.

Abstract: An imaging lens includes a first lens group having a positive refractive power on an object side and including at least three positive lenses and at least two negative lenses, and a second lens group having a negative refractive power on an image side and having a negative lens, the first and second lens groups arranged in this order from the object side with a widest air space in-between, wherein in focusing an object from infinity to a close range, only the first lens group is moved to the object side and the second lens group is fixed relative to an image plane.

Abstract: A varioscope optical unit has a positive member (9) with a positive refractive power and a negative member (11) with a negative refractive power arranged along an optical axis (OA) so that the negative member follows the positive member along an observation direction (B). At least one of the members is displaceable along the optical axis. Each member has a first termination lens surfaces (23, 27) counter to the observation direction (B) and second termination lens surface (25, 29) in the observation direction. The second termination lens surface of the positive member and the first termination lens surface of the negative member are concave when viewed in the observation direction (B) and have radii of curvature of at most 500 mm. The second termination lens surface of the negative member is convex when viewed in the observation direction (B) and has a radius of curvature of at most 70 mm.

Abstract: A close-distance correcting lens system includes a positive first lens group and a negative second lens group, wherein traveling distances of the first lens group and the second lens group toward the object side differ from each other when carrying out a focusing operation on an object at infinity to an object at a close distance. The first lens group includes a positive first sub lens group, a negative second sub lens group, a diaphragm, and a positive third sub lens group, in that order from the object side. The second sub lens group includes an image-stabilizing lens group which is arranged to move in a direction orthogonal to the optical axis to change an imaging position of the object image to thereby correct any image shake of the object image.

Abstract: A zoom lens comprises a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, and a plurality of lens units G3 and G4. Zooming from a wide angle end to a telephoto end is carried out by changing a distance between the lens units. One of the first lens unit G1 and the second lens unit G2 has, or both the first lens unit G1 and the second lens unit G2 have a specific arrangement.

Abstract: A zoom lens includes a first lens unit having a positive refractive power and arranged closest to an object side. 0.50<Ym5/Yw30<1.00 is satisfied at a predetermined zoom position except for a wide-angle end and a telephoto end where Yw30 denotes an image height that provides a relative illumination of 0.3 at the wide-angle end, and Ym5 denotes an image height that provides the relative illumination of 0.05 at a predetermined zoom position except for a wide-angle end and a telephoto end.

Abstract: A zoom lens, including: a first lens unit and a second lens unit, in which the first lens unit includes: a first lens sub unit which does not move; a second lens sub unit which moves for focusing; and a third lens sub unit which does not move; and in which the following expression is satisfied, ?2.27×10?3<(?p??na)/(?p??na)<?1.9×10?3, where ?na and ?na represent an average value of an Abbe number ? and an average value of a partial dispersion ratio ? of negative lenses included in the first lens sub unit, respectively, ?p and ?p represent an Abbe number and a partial dispersion ratio of a positive lens having a smallest Abbe number among lenses constituting the first lens sub unit, respectively, ?=(Ng?NF)/(NF?NC), and Ng, NF and NC denote refractive indexes at the g-line, the F-line and a C-line, respectively.

Abstract: A lens component of the present invention is made by cementing a lens LA and a lens LB having a refracting power smaller than a refracting power of the lens LA, and satisfies predetermined conditional expressions. Moreover, in an image forming optical system of the present invention which includes a lens group B having a negative refracting power, a lens group C having a positive refracting power and which moves only toward an object side at the time of zooming from a wide angle end to a telephoto end, and one or two more lens groups additionally, one of the lens components of the present invention is used in the lens group B.

Abstract: An image capturing device may include a detector including a plurality of sensing pixels, and an optical system adapted to project a distorted image of an object within a field of view onto the sensing pixels, wherein the optical system expands the image in a center of the field of view and compresses the image in a periphery of the field of view, wherein a first number of sensing pixels required to realize a maximal zoom magnification {circumflex over (Z)} at a minimum resolution of the image capturing device is less than a square of the maximal zoom magnification times a second number of sensing pixels required for the minimum resolution.

Abstract: An imaging lens system with two lenses is provided. The imaging lens system with two lenses, along an optical axis from an object side to an image side, includes an aperture stop; a first lens having positive refractive power and being a plano-convex lens with a convex surface on the image side; and a second lens having negative refractive power and being a meniscus lens with a concave surface on the object side and a convex surface on the image side.

Abstract: A video projection device has one of a plurality of types of projection lenses replaceably loaded and projects a video on a screen at a fixed position. The video projection device includes: a converter lens which is composed of a plurality of lenses, which is afocal as a whole, and which is detachably provided in front of the projection lens to convert projection magnification; and a gap adjustment mechanism changing a predetermined gap in the converter lens to a setting in accordance with at least one of a projection distance to the screen and the type of the projection lens loaded.

Abstract: An zoom lens includes a front unit having positive refractive power, an aperture stop, and a rear unit. The front unit has a positive lens Gp1 and the rear unit has a negative lens Gn1. When an Abbe number of a material of the positive lens Gp1, and a partial dispersion ratio of the material thereof for a g-line and an F-line is defined as ?dp1 and ?gFp1 respectively, and a refractive index and an Abbe number of a material of the negative lens Gn1 for a d-line, and a partial dispersion ratio of the material thereof for the g-line and the F-line is defined as Ndn1 ?dn1 and ?gFn1 respectively, satisfying the following conditions: 75<?dp1<99, 0.020<?gFp1?0.6438+0.001682×?dp1<0.100, 1.75<Ndn1<2.10, and 0.020<?gFn1?0.6438+0.001682×?dn1<0.100.

Abstract: An optical element unit is provided comprising an optical element group for projecting light along an optical axis of the optical element group and a housing having an inner housing part partly defining a first space and a light passageway between the inner housing part and a second space. The inner housing part receives the optical element group. The optical element group comprises an ultimate optical element located in the region of the light passageway. A load-relieving device is provided adjacent to the ultimate optical element, the load relieving device partly defining the first space and the second space and at least partly relieving the ultimate optical element from loads resulting from pressure differences between the first space.

Abstract: An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the positive lens group is disposed at an object side of the aperture stop, the positive lens group has a cemented lens which is formed by cementing a plurality of lenses, in a rectangular coordinate system in which a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens is included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and of an area determined by following conditional expressions (2a) and (3a). 1.45<?<2.15??(1a) 1.30<Nd<2.

Abstract: It is possible to use the magnification of an objective lens as is, substantially without changing the observation magnification, even when the working distance of the objective lens is changed. The invention provides a focus-adjusting unit disposed on an optical axis between an objective optical system that collects light from a specimen and an image-forming optical system that images the light collected by the objective optical system at a prescribed position, comprising a front optical system and a back optical system, sequentially disposed along the optical axis direction from a front side, with the objective optical system serving at the front side and the image-forming optical system at the back; and a lens driving part that relatively moves these optical systems in the optical axis direction, wherein the front optical system and the back optical system have refractive powers of different sign and focal lengths of substantially equal absolute value.

Abstract: The invention relates to an eyepiece-connected taking optical system well fit for TV camera heads using a small-format imaging device. The taking optical system comprises a field direction turning member 1P, 2P, a positive first group and a negative second group. The first group comprises a positive cemented lens convex on its object side, a positive single lens convex on its object side and a positive cemented lens convex on its object side, and the second group comprises a negative single lens. Focus adjustment is implemented by changing a spacing t2 between the first group and the second group. The taking optical system satisfies condition (1) for defining the position of the front focus with respect to the taking lens, condition (2) for defining the refracting power of each lens group, condition (3) for defining the imaging magnification of the second group, and condition (4) for defining the profile of refracting power in the first group.

Abstract: A zoom lens assembly and zoom lens module are provided, including a first lens, a second lens, a plurality of guiding blocks, a sheathing tube, a plurality of linking members and an adjusting tube. The first lens includes a plurality of curved surfaces disposed on a second lens surface toward a first lens surface. The second lens includes a plurality of driving rods disposed on a third lens surface and abutting the curved surfaces. The guiding blocks are respectively fixed on the first lens. The sheathing tube sheathes the first lens and the second lens and comprises a plurality of guiding notches to receive the guiding blocks, and a plurality of slits. The linking members pass through the slits and are fixed on the second lens. The adjusting tube sheathes the sheathing tube and comprises a plurality of driving notches to receive the linking members.

Abstract: Disclosed is a zoom lens system in which a first lens unit having negative optical power and a second lens unit having positive optical power are arranged in the stated order from an object side to an image side, and in which an interval between the first lens unit and the second lens unit changes in zooming. In such a zoom lens system, the first lens unit includes a first lens component having negative optical power, a second lens component joined to a lens surface of the first lens component, and a third lens component having positive optical power so as to provide the zoom lens system having excellent optical performance by appropriately setting a material forming the first lens component.

Abstract: In an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the negative lens group is disposed at an image side of the of the aperture stop, the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1), and a line when an upper limit value is in a range of the following conditional expression (1), and an area determined by following conditional expressions (2) and (3). 1.45<??2.15??(1) 1.30<Nd<2.20??(2) 3<?d<12??(3) Here, Nd denotes a refractive index, and ?d denotes an Abbe's number.

Abstract: An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the positive lens group is disposed at an image-plane side of the aperture stop, the positive lens group has a cemented lens which is formed by cementing a plurality of lenses, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1), and a line when an upper limit value is in a range of the following conditional expression (1), and in an area determined by following conditional expressions (2) and (3) 1.45<??2.15??(1) 1.30<Nd<2.