Abstract: Provided is a zoom lens comprising, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a rear unit including at least one lens unit, in which the second lens unit is configured to move during zooming, an interval between each pair of adjacent lens units is changed during zooming, the rear unit has a positive refractive power over an entire zoom range, and the first lens unit includes a diffraction surface formed at a cemented surface of two optical elements cemented to each other. A focal length of the first lens unit, an amount of movement of the second lens unit during zooming from a wide angle end to a telephoto end and a back focus at the wide angle end are appropriately set.

Abstract: A variable magnification optical system includes, in order from an object: a first lens group (G1) having a negative refractive power; a second lens group (G2); a third lens group (G3); a fourth lens group (G4) having a negative refractive power; and a fifth lens group (G5) having a positive refractive power, the system performing varying magnification by changing the distance between the first and second lens groups, the distance between the second and third lens groups, the distance between the third and fourth lens groups, and the distance between the fourth and fifth lens groups, and the fourth lens group including a 42nd lens group (G42) configured to be movable so as to have a component in a direction orthogonal to an optical axis and a 41st lens group (G41) disposed at an object-side of the 42nd lens group.

Abstract: Provided is a zoom lens including, 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; a fourth lens unit having a negative refractive power; a fifth lens unit having a negative refractive power; and a sixth lens unit having a positive refractive power, wherein an interval between adjacent lens units is changed during zooming, wherein the first lens unit is configured to move toward the object side during zooming from a wide angle end to a telephoto end, and wherein a focal length of the first lens unit, a focal length of the sixth lens unit, and a back focus at the wide angle end are appropriately set.

Abstract: An optical path folding element includes an incident surface, a path folding surface and an exiting surface. The incident surface allows a light ray to pass into the optical path folding element. The path folding surface folds the light ray from the incident surface. The exiting surface allows the light ray to pass through and depart from the optical path folding element. At least one of the incident surface and the exiting surface includes an optical effective portion and at least one engaging structure symmetrically disposed around the optical effective portion. The engaging structure includes an annular surface portion and an inclined surface portion. The annular surface portion surrounds the optical effective portion, and the inclined surface portion is located between the annular surface portion and the optical effective portion. An angle between the annular surface portion and the inclined surface portion satisfies a specific condition.

Abstract: A zoom lens includes a front-side lens unit, a rear-side lens unit, and an aperture stop. The front-side lens unit includes either one lens unit having a negative refractive power or two lens units having a negative refractive power, and has a negative refractive power as a whole. The rear-side lens unit is disposed on an image side of the front-side lens unit, and has a positive refractive power as a whole at a telephoto end. The rear-side lens unit includes a plurality of lens units, and includes an object-side positive lens unit having a positive refractive power which is disposed nearest to object and the following conditional expressions (1), (2), and (3) are satisfied: 1.2?|MGB_t|?6??(1), 10??dGn_min_p?27??(2), and ?0.03?TpGn_min_p?0.014??(3).

Abstract: An optical element switchable to a first state and a second state includes a first material and a second material, each of optical properties of the first and second materials changes between the first state and the second state, and refractive indices of the first and second materials and Abbe's numbers of the first and second materials satisfy a predetermined relationship.

Abstract: The present invention provides a zoom lens that can perform favorable correction of chromatic aberration in the entire zoom range, and can have higher performance and a smaller size than conventional ones; and an imaging apparatus including the zoom lens. To achieve the object, provided are a zoom lens and an imaging apparatus including the zoom lens. The zoom lens includes, in order from an object side: a positive first lens group G1; a negative second lens group G2; and a GR group including one or more lens groups. In the zoom lens, changing focal length is performed by varying intervals between the lens groups. The GR group has at least two cemented surfaces having negative refractive power, convex lenses GpH and GpL satisfying predetermined conditional expressions. An aperture stop is arranged in the first lens group or after. The zoom lens satisfies predetermined conditional expressions.

Abstract: A zoom lens system according to an example embodiment includes, sequentially from an object side to an image plane side along an optical axis, a first lens group having a negative refractive power and including at least one doublet lens, the doublet lens including two lenses, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, wherein the first lens group and the second lens group are configured to move along the optical axis to perform zooming and focusing, and the zoom lens system satisfies 3.0<Vdf/Vdr<6.0, where Vdf denotes an Abbe number of a lens arranged at the object side in a doublet lens, and Vdr denotes an Abbe number of a lens arranged at the image plane side in a doublet lens.

Abstract: An image pickup apparatus includes an image forming optical system which includes an aperture stop that sets an axial light beam, and a diffracting optical surface disposed at a position different from a position where the aperture stop is disposed, and an imager which is disposed on an image side of the image forming optical system, and has a light-receiving surface which is not flat and is curved to be concave toward the image forming optical system, wherein the diffracting optical surface satisfies the following conditional expression (1). 0.1<|DSD/TL|?1.

Abstract: A zoom lens includes in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a rear-side lens unit, and an aperture stop. The second lens unit includes a first sub-unit having a negative refractive power and a second sub-unit having a negative refractive power, and the rear-side lens unit includes a third lens unit having a positive refractive power which is disposed nearest to object. The first lens unit includes at least a negative lens and a positive lens and the first sub-unit includes at least a negative lens and a positive lens. The third lens unit includes at least two lens components having a positive refractive power, and the following conditional expressions (1) and (2) are satisfied: 61??d1G_max_p??(1), and ?0.03?Tp2Ga_min_p?0.0165??(2).

Abstract: Comprising a first lens group G1 having positive refractive power, disposed at the most object side, and an image side lens group disposed at a side closer to an image than the first lens group G1, upon zooming, at least a distance between the first lens group G1 and the image side lens group being varied, the image side lens group comprising a vibration reduction lens group GVR which is moved so as to have a component in a direction perpendicular to the optical axis and a focusing lens group GF which is moved along the optical axis upon focusing, thereby providing a variable magnification optical system which has a higher optical performance, an optical apparatus and a method for manufacturing a variable magnification optical system.

Abstract: An image capturing optical assembly includes, in order from an object side to an image side, a first lens group, a second lens group and a third lens group, wherein the first lens group includes a first lens element and a second lens element, the second lens group includes a third lens element, a fourth lens element and a fifth lens element, and the third lens group includes a sixth lens element, a seventh lens element and an eighth lens element. At least one surface of at least one of the lens elements of each lens group is aspheric. At least one surface of at least one of the lens elements includes at least one inflection point.

Abstract: A projection optical system includes a first lens unit and a second lens unit interposing an intermediate image therebetween. The first lens unit includes two aspherical lenses (a first lens unit first lens and a first lens unit ninth lens), and a first lens unit cemented lens. The projection optical system satisfies the following Conditional Expressions (1) and (2) when the number of lens elements of the first lens unit and the number of lens elements of the second lens unit are set to be Num1 and Num2, respectively. In addition, refractive indexes and Abbe numbers of three lenses constituting the first lens unit cemented lens satisfy a predetermined conditional expression. Num2?7??(1) 1.5?Num1/Num2?2.

Abstract: A projection optical device includes a fourth lens group movable along an optical axis, a fifth lens group provided in a position maintained within the projection optical device, a fourth lens frame holding the fourth lens group and having cam pins, a guide tube having a rectilinear groove, the cam pins inserted into the rectilinear groove, and a cam tube rotated with respect to the guide tube to guide the cam pins with the rectilinear groove and the cam groove, and moving the fourth lens frame along the optical axis, wherein the cam pins are formed on an upstream side in an optical path of the fourth lens group in a direction along the optical axis, and the fifth lens group is provided on the upstream side in the optical path of the fourth lens group.

Abstract: An optical lens including a first lens group and a second lens group is provided. The first lens group is arranged between a magnified side and a minified side. The first lens group includes a lens closest to the magnified side. A refractive power of the lens is negative, and at least one surface of the lens is an aspherical surface. The second lens group is arranged between the first lens group and the minified side. A distance between the first lens group and the second lens group is smaller than 0.7 millimeter. The optical lens is complied with conditions of 0.53<EFL/IH<0.7, FOV?150 degrees, and F?2.8, where EFL is an effective focal length, IH is an image height on an imaging plane at the minified side, FOV is a maximum field of view, and F is f-number.

Abstract: A zoom lens which include, in order from an object side: a unit A including a unit configured to move for zooming; an aperture stop; and a positive unit B configured not to move for zooming, in which the unit B includes front and rear units with an air interval therebetween longest between the aperture stop and an image plane of the zoom lens, in which the front unit consists of, in order from the object side, a positive first front unit, a negative second front unit configured to move perpendicular to an optical axis of the zoom lens to perform image stabilization, and a third front unit having a positive refractive power, in which a lateral magnification of the second front unit, focal lengths of the first front unit, the second front unit, and the third front unit are set appropriately.

Abstract: The purpose of the present invention is to provide an optical device capable of rotationally adjusting a lens system with a flare-cut member incorporated therein. For this purpose, the flare-cut member according to the present invention is characterized by including a light shield surface for shielding the light flux incident on the periphery of a lens, and an opening formed in the light shield surface and causing the light flux incident on a lens element to pass therethrough, wherein the opening is formed in a rotationally symmetrical shape.

Abstract: The zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power and remains stationary during zooming, a second lens group that moves during zooming, and a subsequent lens group. The first lens group has a negative lens at a position closest to the object side. The subsequent lens group has, successively in order from a position closest to the image side, a final positive lens group that remains stationary during zooming, a positive lens group that moves during zooming, a stop, and a negative lens group that moves during zooming. The stop moves integrally with the positive lens group during zooming. The stop first moves to the object side, and reversely moves during zooming from the wide-angle end to the telephoto end. Predetermined conditional expressions are satisfied.

Abstract: A first lens group (G1) having a positive refractive power, a second lens group (G2) having a negative refractive power, a third lens group (G3) having a positive refractive power, a fourth lens group (G4) having a negative refractive power, and a fifth lens group (G5) having a positive refractive power are arranged in order along an optical axis from an object, and distances between each lens group change when zooming, and the first lens group (G1) is composed of two lenses, and the following expression (1) is satisfied: 0.07<D1/fw<0.46 where D1 denotes a thickness on the optical axis of the first lens group (G1), and fw denotes a focal length of the zoom lens (ZL) in a wide-angle end state.

Abstract: Provided is a zoom lens including, 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; a fourth lens unit having a positive refractive power; and a rear lens group including at least one lens unit, the first lens unit, the second lens unit, the third lens unit, the fourth lens unit, and the rear lens group having an interval between each pair of adjacent lens units changed for zooming. The third lens unit is configured to move for focusing, and at least a part of the fourth lens unit forms a lens system IS, which is configured to move in a direction including a component of a direction perpendicular to an optical axis for image stabilization.

Abstract: The imaging lens consists of a first lens group fixed to an image plane during focusing, an aperture stop, a second lens group having a positive refractive power which moves along an optical axis during focusing, and a third lens group fixed to the image plane during focusing, in order from an object side. The first lens group includes at least two negative lenses among three lenses from a lens closest to the object side to a third lens, a negative lens of the at least two negative lenses closest to the object side being a negative meniscus lens with its convex surface toward the object side, the second lens group includes at least three lenses, and the third lens group includes at least three lenses.

Abstract: A camera head is provided that includes a first lens group, including at least one deformable lens with variable curvature, a second lens group moveable relative to the first lens group, and an image sensor for capturing a light beam received from an endoscope, wherein the first lens group is fixed relative to the image sensor and the aperture of the first lens group is smaller than the aperture of the second lens group. A method is also provided for capturing of an image utilizing a zoom system including a variable power first lens group and a movable second lens group.

Abstract: A first lens group (G1) having positive refractive power, a front-side lens group (GX), an intermediate lens group (GM) having positive refractive power, and a rear-side lens group (GR) are arranged in order from an object side. The front-side lens group (GX) is composed of one or more lens groups and has a negative lens group At least part of the intermediate lens group (GM) is a focusing lens group (GF). The rear-side lens group (GR) is composed of one or more lens groups. Upon zooming, the first lens group (G1) is moved with respect to an image surface, a distance between the first lens group (G1) and the front-side lens group (GX) is changed, a distance between the front-side lens group (GX) and the intermediate lens group (GM) is changed, and a distance between the intermediate lens group (GM) and the rear-side lens group (GR) is changed.

Abstract: Compact folded lens systems are described that may be used in small form factor cameras. Lens systems are described that may include three lens elements with refractive power, with a light folding element such as a prism, located between a first lens element on the object side of the lens system and a second lens element, that redirects the light refracted from the first lens element from a first axis onto a second axis on which the other lens elements and a photosensor are arranged. The lens systems may include an aperture stop located behind the front vertex of the lens system, for example at the first lens element, and an optional infrared filter, for example located between the last lens element and a photosensor.

Abstract: An optical imaging lens including a first lens element to an eighth lens element arranged in sequence from an object side to an image side along an optical axis is provided. The first lens element has positive refracting power. At least one of the object-side surface and the image-side of the second lens element is an aspheric surface. At least one of the object-side surface and the image-side of the third lens element is an aspheric surface. At least one of the object-side surface and the image-side of the fourth lens element is an aspheric surface. The object-side surface and the image-side of the fifth lens element are both aspheric surfaces. The object-side surface and the image-side of the sixth lens element are both aspheric surfaces. An optical axis region of the image-side surface of the seventh lens element is concave. An optical axis region of the object-side surface of the eighth lens element is concave.

Abstract: Ophthalmic lenses providing an extended depth of focus include anterior and posterior faces, wherein at least part of the anterior or posterior face has a curvature based upon the summation of a cubic and/or pentic phase profile, and methods relating to same. The ophthalmic lens may be a contact lens, an intraocular lens (IOL), or other corrective lens.

Abstract: A zoom lens has in order from the object side, at least a foremost, first lens group having positive refractive power, a succeeding, second lens group having negative refractive power, a third lens group having positive refractive power, and a rearmost lens group having negative refractive power. The zoom lens meets requirements as defined in formulas regarding a displacement of the first lens group, a focal length of the zoom lens at the wide-angle end, a focal length of the zoom lens at the telephoto end, a focal length of the first lens group, and a focal length of the third lens group.

Abstract: The present disclosure provides an imaging device including a wide-angle camera and a telephoto camera. A field of view of the telephoto camera is located in a field of view of the wide-angle camera, the telephoto camera includes a telephoto lens. The telephoto lens includes: at least one first lens element, a light reflecting element and at least one second lens element arranged sequentially from an object side to an image side along a light axis. The light reflecting element is configured to make the light axis to reflect from a first direction to a second direction. An electronic device including the imaging device is further provided. In the imaging device and the electronic device above, the light axis of the telephoto camera is reflected, lowering a height of the telephoto lens and a height of the telephoto camera.

Abstract: A miniature wide-angle imaging lens has a miniaturization ratio, of a total track length from the center of a first surface to a focal plane by an image circle diameter, with a value less than 3.0. The imaging lens includes, starting from an object side of the lens, a first group of at least three optical elements, a second group including an aperture stop and an optical element immediately in front of or behind the aperture stop, and a third group of at least two optical elements.

Abstract: Provided is a zoom lens, including, in order from an object side to an image side: a first lens unit to a fourth lens unit having negative, positive, negative, and negative refractive powers; and a rear lens group. In the zoom lens, an interval between each pair of adjacent lens units is changed during zooming, the rear lens group has a positive refractive power over an entire zoom range, the third lens unit is configured to move in an optical axis direction during focusing, and each of a focal length of the zoom lens at a wide angle end (fw), and a focal length of the third lens unit (f3) is appropriately set.

Abstract: An image-capturing element includes: a first substrate; a plurality of first pixels disposed in a matrix on the first substrate, each of the first pixels having a first light receiving element; a second substrate disposed at a position overlapping the first substrate and on a side opposite to a light receiving surface side of the first substrate when viewed from the light receiving surface side of the first substrate; a plurality of second pixels disposed in a matrix on the second substrate, each of the second pixels having a second light receiving element and a Fabry-Perot filter disposed on the light receiving surface side of the second light receiving element; and a plurality of optical systems disposed corresponding to the plurality of second pixels between the first substrate and the plurality of second pixels, the optical systems having negative refractive power.

Abstract: On embodiment of the invention discloses an optical lens including five lens group and an aperture stop. Each lens group includes at least one lens with refractive power, and the aperture stop is fixed in a position between a second lens group and a third lens group. Further, a distance between a first lens group and a fifth lens group remains fixed during zooming or focusing, and respective distances of the second lens group and a fourth lens group relative to the fifth lens group vary during zooming or focusing.

Abstract: An arrangement for lightsheet microscopy. In the arrangement, a detection objective includes a first adaptive optical detection correction element arranged in the beam path or which can be introduced into the latter. Alternatively, or in addition, an illumination objective includes a first adaptive optical illumination correction element arranged in the beam path or which can be introduced into the latter. With the two correction elements, aberrations which occur because of the inclined passage through boundary surfaces of the separating layer system of light to be detected or of light for illuminating the sample can be reduced for a predetermined range of detection angles (?) or of illumination angles (?) and/or for a predetermined range of the thickness of the at least one layer of the separating layer system.

Abstract: The imaging lens includes, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power. In a case of changing focus from an object at infinity to an object at the closest distance, the first lens group is immovable, and the second lens group and the fourth lens group are moved in an optical axis direction along different trajectories from each other. The third lens group is moved in a direction intersecting the optical axis to perform camera shake correction.

Abstract: The zoom lens includes, in order from an object side, a positive first lens group G1, a negative second lens group G2, a positive third lens group G3, a diaphragm, and a fourth lens group G4. During zooming, only the second lens group G2 and the third lens group G3 move. The first lens group G1 includes, in order from the object side, a cemented lens that is formed by cementing a positive lens and a negative meniscus lens convex toward the object side, a positive lens, and a negative lens. A conditional expression (1): ?0.8<f1a/f1b<0 is satisfied, where f1a is a composite focal length of the first to third lenses from the object side of the first lens group G1, and f1b is a focal length of the fourth lens.

Abstract: A variable magnification optical system is an optical system in which, a magnification ratio varies from a lower magnification end to a high magnification end, and includes at least a first lens unit having a positive refractive power, which is disposed nearest to an object, and a second lens unit having a positive refractive power, which is disposed on an image side of the first lens unit. At the time of varying magnification, a distance between the first lens unit and the second lens unit changes, and the following conditional expression (1) is satisfied: 0<1/?HG1<1??(1), where, ?HG1 denotes an imaging magnification of the first lens unit at the high magnification end.

Abstract: A lens barrel of this technique includes a movable lens barrel unit section, and a master flange unit having a lens unit, and is switched between a collapsed state where the movable lens barrel unit section is stored in the master flange unit and an extended state where the movable lens barrel unit section is extended from the master flange unit. The master flange unit has a moving frame supported to be movable in an optical axis direction via a first elastic member extendable in the optical axis direction, and a lens frame supported to be movable in the optical axis direction via a second elastic member extendable in the optical axis direction relative to the moving frame. In the collapsed state, the movable lens barrel unit section presses the lens frame such that the moving frame and the lens frame get closer to the master flange against repulsive forces of the first elastic member and the second elastic member.

Abstract: An image display device includes a high-performance projection zoom lens with a very wide field angle and an image display device including a projection zoom lens of a five-lens-group type, which achieves high performance across the entire zoom area. The image display device is configured to project an image onto a target projection surface and display a magnified image of the image, which uses a projection zoom lens having a five-lens-group configuration in which first to fifth lens groups G1 to G5 are arranged from the magnification side toward the reduction side, and each of the constituent lens groups or lenses included in the lens groups has a combination of negative and positive refractive powers, and in the lens configuration, focal lengths of the constituent lens groups, relative travel distances, lens distances to the image display element, and constituent lens shapes are properly selected.

Abstract: A zoom lens includes, in order from an object side to an image side, a positive first lens unit, a negative second lens unit, a middle lens group including at least one lens unit, a negative N minus second lens unit, a negative N minus first lens unit, and a positive Nth lens unit, where N is an integer of six or more, in which distances between the adjacent lens units change during zooming, the first lens unit moves toward the object side during zooming from a wide-angle end to a telephoto end, the N minus second lens unit moves during focusing, and a total lens length at the wide-angle end, a backfocus at the wide-angle end, and a lateral magnification of a combined system of the N minus first lens unit and the Nth lens unit at the wide-angle end are set appropriately.

Abstract: Embodiments provide a lens moving apparatus including a housing for supporting a first magnet, a bobbin including a coil disposed on an outer surface thereof and inside the first magnet so as to move in the housing in a first direction parallel to an optical axis by electromagnetic interaction between the first magnet and the coil, and upper and lower elastic members, each of which is provided at the bobbin and the housing and includes an inner frame coupled to the bobbin and an outer frame coupled to the housing, wherein at least one of the upper and lower elastic members is constituted by a printed circuit board.

Abstract: A macro lens includes: a first focus lens group having negative refractive power; and a second focus lens group arranged closer to an image side than the first focus lens group is arranged and having positive refractive power. At time of performing a focusing operation from an object at infinite to an object at a close distance, the first focus lens group travels toward the image side, and the second focus lens group travels with a traveling amount different from a traveling amount of the first focus lens group. The second focus lens group is configured of only one positive lens.

Abstract: Provided is a zoom lens, including, in order from an object side to an image side, first, second, and third lens units having positive, negative, and positive refractive powers, respectively. The second lens unit moves toward image side during zooming from a wide angle end to a telephoto end, and an interval between adjacent lens units is changed during zooming. The first lens unit includes a lens pair of a positive lens (LP1) and a negative lens (LN1) that are arranged adjacent to each other. A refractive index of a material at 400 nm wavelength, a refractive index of a material at 1,050 nm wavelength, a refractive index of a material at 1,700 nm wavelength, an Abbe number and a partial dispersion ratio of a material, Abbe numbers and partial dispersion ratios of materials for the positive lens (LP1) and the negative lens (LN1) are each appropriately set.

Abstract: A first lens group (G1) having positive refractive power, a front-side lens group (GX), an intermediate lens group (GM) having positive refractive power, and a rear-side lens group (GR) are arranged in order from an object side. The front-side lens group (GX) is composed of one or more lens groups and has a negative lens group At least part of the intermediate lens group (GM) is a focusing lens group (GF). The rear-side lens group (GR) is composed of one or more lens groups. Upon zooming, the first lens group (G1) is moved with respect to an image surface, a distance between the first lens group (G1) and the front-side lens group (GX) is changed, a distance between the front-side lens group (GX) and the intermediate lens group (GM) is changed, and a distance between the intermediate lens group (GM) and the rear-side lens group (GR) is changed.

Abstract: A first lens group (G1) having positive refractive power, a front-side lens group (GX), an intermediate lens group (GM) having positive refractive power, and a rear-side lens group (GR) are arranged in order from an object side. The front-side lens group (GX) is composed of one or more lens groups and has a negative lens group At least part of the intermediate lens group (GM) is a focusing lens group (GF). The rear-side lens group (GR) is composed of one or more lens groups. Upon zooming, the first lens group (G1) is moved with respect to an image surface, a distance between the first lens group (G1) and the front-side lens group (GX) is changed, a distance between the front-side lens group (GX) and the intermediate lens group (GM) is changed, and a distance between the intermediate lens group (GM) and the rear-side lens group (GR) is changed.

Abstract: There is provided an electric lens including a first lens and a second lens adjacent to each other, and a variable-refractive-index body that is held between a lens face of the first lens and a lens face of the second lens mutually having the same curved surface, and changes refractive index according to an externally applied electrical signal. A thickness of the variable-refractive-index body is uniform in at least a portion that transmits a light ray contributing to image formation.

Abstract: A lens system having, in order from an object, at least a first lens group G1 having positive refractive power, and second to fourth lens groups G2 to G4, wherein the first lens group G1 includes a front portion lens group G1a, and a rear portion lens group G1b which is disposed to an image side of the front portion lens group G1a with an air distance therebetween, and performs focusing by shifting the rear portion lens group G1b in the optical axis direction, and the fourth lens group G4 includes, in order from the object, a negative lens and a positive lens (cemented negative lens L41), a negative lens L42, and an aperture stop S, and is fixed in the optical axis direction with respect to an image plane I upon zooming from a wide angle end state to a telephoto end state.

Abstract: Provided is a zoom lens, including, in order from an object side to an image side: a first lens unit to a fourth lens unit having negative, positive, negative, and negative refractive powers; and a rear lens group. In the zoom lens, an interval between each pair of adjacent lens units is changed during zooming, the rear lens group has a positive refractive power over an entire zoom range, the third lens unit is configured to move in an optical axis direction during focusing, and each of a focal length of the zoom lens at a wide angle end (fw), and a focal length of the third lens unit (f3) is appropriately set.

Abstract: A projection optical system projects, while enlarging, an image displayed on an image display surface and performs zooming by moving a plurality of lens groups arranged along a same optical axis. The projection optical system includes, from an enlargement side: a first lens group having a negative refractive power; a second lens group having a negative refractive power and movable during zooming; a third lens group having a positive refractive power and movable during zooming; and a lens group disposed at a most reduction-side position. The first lens group includes, from the enlargement side: a front group having a negative refractive power; and a rear group having a positive refractive power and including, from the enlargement side, a negative lens element and a positive lens element. For zooming from a wide-angle end to a telephoto end, the third lens group moves toward the enlargement side monotonically.

Abstract: An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. At least one lens among the first to the fifth lenses has positive refractive force. The fifth lens can have negative refractive force. The lenses in the optical image capturing system which have refractive power include the first to the fifth lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: Provided is a telephoto lens including a first lens group, the first lens group including: a first lens element including: an object side lens surface facing an object side; and an image side lens surface facing an image side; and a prism configured to bend an optical path within the first lens element, wherein the first lens element and the prism are formed as a single body, wherein an inclined surface of the prism is provided between the object side lens surface and the image side lens surface, and wherein the following relationship is satisfied: 1.3?L1/Li, where L1 corresponds to a length of an optical path within the first lens element along an optical axis of the first lens elements and Li corresponds to a length of an optical path between an optical element provided closest to an image plane and the image plane along the optical axis.