Abstract: Provided is an optical system, comprising, in order from an object side: a positive first unit; a negative second unit; and a positive third unit, in which, during focusing from infinity to a close distance, the second unit moves toward the image side, and an interval between adjacent units is changed, in which the first unit consists of, in order from the object side: a negative first sub-unit, which does not move for image stabilization; a positive second sub-unit, which moves during the image stabilization; and a third sub-unit, which does not moves for the image stabilization, and in which a distance from a lens surface closest to the object side in the first unit to an image plane when focusing at infinity, and a distance from a lens surface closest to the object side in the second sub-unit to the image plane when focusing at infinity are appropriately set.

Abstract: A lens moving apparatus includes a bobbin of which a first coil is provided, a first magnet disposed to face the first coil, a housing for supporting the first magnet, a second coil disposed under the housing so as to face the first magnet, a printed circuit board on which the second coil is mounted, a base on which the printed circuit board is mounted, and a yoke disposed between the printed circuit board and the base.

Abstract: A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group and a positive fourth lens group, in that order from the object side, wherein distances between adjacent lens groups thereof change during zooming. The third lens group includes a positive first sub-lens group, a positive second sub-lens group and a negative third sub-lens group. The third sub-lens group consists of a single negative lens element. The following conditions (1) and (2) are satisfied: 6.0<f1Gp/fw<9.0??(1), and 1.3<f3Gp/f4Gp<2.0??(2), wherein fw designates the focal length of the entire zoom lens system at the short focal length extremity, f1Gp, f3Gp and f4Gp designate the focal lengths of the first, third and fourth lens groups, respectively.

Abstract: A lens driving device is provided, the lens driving device includes: a housing; a bobbin disposed at an inner side of the housing; a support member coupled to the bobbin and the housing; and a sensor sensing a position of at least one of the bobbin and the housing, wherein the support member may include a first support unit, and a second support unit disposed not parallel to the first support unit, wherein the sensor may be disposed more adjacent to the first support unit than to the second support unit, and wherein an elastic modulus of the first support unit may be lower than an elastic modulus of the second support unit.

Abstract: An image stabilization mechanism includes: a sensor holder unit configured to hold an image sensor; a rear frame; a front frame; a first ball; a second ball; and a cylinder unit configured to press the first ball against the sensor holder unit. The cylinder unit has a cylinder on the rear frame so that an axial direction thereof is parallel to an optical axis direction, a piston movably positioned in the cylinder, and a spring configured to urge the piston toward the sensor holder unit. The first ball is between an end surface of the piston and the sensor holder unit.

Abstract: A lens driving device including a first lens driving unit for auto focusing, and a second lens driving unit for handshake correction is proposed, the lens driving device including a base, a holder member mounted with a magnet and positioned at an upper side of the base by being spaced apart from the base at a predetermined distance, a plurality of support members configured to elastically support the holder member relative to the base, an upper stopper protrusively formed at an upper surface of the holder member, and a bottom stopper protrusively formed at a bottom surface of the holder member to form a shock point between the base and the holder member when there is generated a shock.

Abstract: An imaging apparatus includes a front lens group, which constitutes part of an imaging optical system, at a fixed position with respect to an optical axis direction, wherein the front lens group includes a front lens element and a reflector and the reflector reflects light rays exiting from the front lens element; a movable lens group provided closer to the image plane side than the front lens group and movable along the optical axis; a support which supports the reflector; a movable frame which supports the front lens element and is supported by the support to be movable along a plane orthogonal to the optical axis of the front lens element; a front cover fixed to the support; and a driver which drives the movable frame in the plane, in accordance with vibrations applied to the photographing optical system, to reduce image shake.

Abstract: An electro-mechanical shutter is described. The fast operation is based on a coil operated via a current, where the coil can move within a set of magnets to provide opening and closing of a shutter. The shutter can comprise a mirror connected to the coil, so that the mirror can be moved into the path of an optical beam. The mirror can block the beam light in the closed state, and allow the beam light in the open state.

Abstract: A lens barrel includes a frame body, a support frame, and a refracting lens frame. The support frame is configured to be supported by the frame body and move within a plane perpendicular to the optical axis with respect to the frame body. The refracting lens frame includes a lens support portion and is configured to retract around a retraction shaft. The frame body includes an opening portion. The opening portion is configured to open outward with respect to the optical axis. The opening portion is configured to house part of the lens support portion during a transition period between an imaging enabled state and a housed state. The support frame includes a light blocking portion. The light blocking portion is provided in front of part of the opening portion in an optical axis direction in order to block light rays.

Abstract: A zoom lens system includes a first lens group having a positive power, a second lens group that has a negative power and includes one lens element, a third lens group that has a positive power and includes at least two lens elements, and a subsequent lens group that has a positive power as a whole and includes at least two lens groups in order from an object side to an image side. In zooming operation, at least the first lens group to the third lens group move along an optical axis, and a condition of ?9.0<fG1/fG2<?2.0 is satisfied. Where fG1 represents a focal distance of the first lens group and fG2 represents a focal distance of the second lens group.

Abstract: A variable-magnification optical system has five lens groups, namely, from object side, positive, negative, positive, positive, and negative lens groups, and achieves magnification variation by varying all axial distances between the lens groups. Focusing is achieved by moving the fourth lens group along an optical axis. Vibration correction is achieved by moving all or part of the fifth lens group perpendicularly to the optical axis. Fulfilled are formulae 4.0<|f1/f2|<6.0, 1.0<f4/f1<1.5, and 2.0<|f4/fv|<4.0, f1 representing a focal length of the first lens group, f2 a focal length of the second lens group, f4 a focal length of the fourth lens group, and fv a focal length of the vibration correction group.

Abstract: Embodiments provide a lens moving apparatus including a bobbin in which a lens is mounted, a first coil and a magnet configured to electromagnetically interact with each other so as to move the bobbin, a housing configured to accommodate the bobbin therein, an elastic member including an inner frame coupled to the bobbin, an outer frame coupled to the housing, and a frame connection portion configured to connect the inner frame and the outer frame to each other, and a support member connected to the elastic member and configured to support the housing, and the outer frame includes a first coupling portion coupled to the housing, a second coupling portion coupled to the support member, the second coupling portion being spaced apart from the first coupling portion, and a single connection portion configured to connect the first coupling portion and the second coupling portion to each other.

Abstract: An embodiment includes a bobbin provided at an outer circumferential surface thereof with a first coil, a first position sensor disposed on the outer circumferential surface of the bobbin and spaced apart from the first coil, a first magnet disposed so as to be opposite to the first position sensor, a second magnet disposed so as to be opposite to the first coil, the second magnet being configured to move the bobbin in a direction parallel to an optical axis via electromagnetic interaction with the first coil, a housing configured to support the first magnet and the second magnet; and upper and lower elastic members coupled to the bobbin and the housing, wherein the first position sensor is moved along with the bobbin.

Abstract: Provided is a technology which: has a structure that is advantageous for size reduction and power saving; and, moreover, is useful when automatic focusing using a closed-loop control system. A lens driving device comprising: an autofocus driving unit; a Hall element which separates an autofocus magnet section in the optical axis direction and is disposed in a position corresponding to one opposing corner section of the autofocus magnet section and in a manner such that the detection direction matches the optical axis direction; a first position detection magnet which is disposed near the Hall element and in a manner such that the magnetisation direction matches the optical axis direction; and a second position detection magnet which has the same configuration as the first position detection magnet and is disposed in a point symmetrical position relating to the first position detection magnet and the optical axis direction.

Abstract: A lens driving device includes a housing having a base, an upper cover engaged with the base, and a receiving space formed by the base and the upper cover; a permanent magnet mounting base arranged on the base; a permanent magnet fixed on the permanent magnet mounting base; a lens barrel used for holding a lens group therein and movable along a direction parallel to an optic axis of the lens group; a driving coil surrounding an outer surface of the lens barrel, and opposite to the permanent magnet mounted on the permanent magnet mounting base; an anti-shake coil opposite to the permanent magnet mounted on the permanent magnet mounting base; an elastic part suspending and connecting with the lens barrel; an OIS elastic part fixed to an upper surface of the permanent magnet mounting base for restoring the permanent magnet mounting base to a predetermined position.

Abstract: A lens driving device, includes a shell providing an accommodating space, a supporting frame accommodated in the accommodating space, a lens module received in the supporting frame and comprising at least one lens and a lens holder for holding the at least one lens, a circuit board accommodated in the accommodating space and having at least two adjacent surfaces, each of the at least two adjacent surfaces having a position sensor and an anti-shake coil arranged thereon and apart from each other, a magnet assembly having at least two first magnets and at least two second magnets fixed to the supporting frame, each of the at least two second magnets abutting against a corresponding first magnet and be adjacent to a corresponding position sensor. Comparing to the relevant technologies, the lens driving device has good performance and high reliability.

Abstract: A camera apparatus is described that includes a frame housing and a camera module affixed to the frame housing. The camera module may include a lens and an image sensor. The camera apparatus may include a reflective element and a motor. The reflective element may be disposed within the frame housing, the reflective element being movable relative to the lens to select a direction from which the lens collects light. The motor may be adapted to move the reflective element in response to detecting a magnetic field change generated by at least one magnet disposed within the frame housing.

Abstract: The present invention provides a zoom lens that is compact in general and has an F-number to implement brightness even in the telephoto end side, and an imaging apparatus equipped with the zoom lens. The zoom lens includes, in order from an object side: a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; and a fourth lens group having positive refractive power. At the time of zooming from the wide-angle end state to the telephoto end state, the third lens group moves so that the distance between the second lens group and the third lens group increases, and the distance between the third lens group and the fourth lens group decreases.

Abstract: Embodiments provide a lens moving apparatus including a first magnet, a housing, a bobbin, around which a coil is wound and which moves in a first direction in the housing, an upper elastic member disposed on upper surfaces of the bobbin and the housing, a lower elastic member disposed under lower surfaces of the bobbin and the housing, and a damping member disposed between the upper or lower elastic member and the bobbin.

Abstract: An AF unit of a lens holder driving device includes a lens holder, a focusing coil, a permanent magnet having a plurality of permanent magnet pieces having first surfaces opposed to the focusing coil, a magnet holder holding the permanent magnet, and first and second leaf springs supporting the lens holder in a direction of an optical axis shiftably. An image stabilizer portion includes a fixed portion disposed near the second leaf spring, a supporting member swingably supporting the AF unit with respect to the fixed portion, an image stabilizer coil having a plurality of image stabilizer coil portions disposed so as to oppose to second surfaces of the plurality of permanent magnet pieces that are perpendicular to the first surfaces, and a plurality of Hall elements. Each Hall element is disposed at a position where the image stabilizer coil portion is separated into a plurality of coil parts.

Abstract: A zoom lens consists of 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 positive refractive power in this order from an object side. The third lens group consists of a 3-1st lens group having positive refractive power and a 3-2nd lens group having negative refractive power in this order from the object side. A hand shake blur is corrected by moving the 3-2nd lens group in a direction perpendicular to optical axis. Magnification is changed by changing distances between the lens groups while the fifth lens group is fixed.

Abstract: The present invention discloses a camera lens composed of five ultrathin and high-luminous flux wide angle lenses with excellent optical properties. The lenses are lined up in turn from the object side as follows: a first lens with positive refractive power, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power a fifth lens with negative refractive power. The camera lens meets specific conditions.

Abstract: An actuator driving apparatus includes an inductor disposed on a housing to face a magnetic body attached to a lens carrier, a detector configured to apply a reference signal to the inductor and detect an inductor current flowing through the inductor, a calculator configured to determine a position of the lens carrier based on the inductor current, and a driver configured to drive an actuator based on the position of the lens carrier and a position control signal.

Abstract: In a zoom lens including a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power that are arranged in order from an object side to an image side, a movement locus of each of the lens units, an amount of movement of the third lens unit when zooming from a wide angle end to a telephoto end, and a focal length of the third lens unit are set as appropriate.

Abstract: A zooming optical system includes, in order from an object side along an optical axis: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group is varied, a distance between the second lens group and the third lens group is varied, and a distance between the third lens group and the fourth lens group is varied; the third lens group is composed of one positive lens; and a focus from an infinite-distance object up to a near-distance object is conducted by moving the third lens group in a direction of the optical axis.

Abstract: A zoom lens includes, in order from the object side: a positive first lens group; a negative second lens group; a positive third lens group; a negative fourth lens group; and a positive fifth lens group. The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle to the telephoto end. The first lens group includes, in order from the object side, a negative lens, a positive lens, and a positive lens. The fourth lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens, and moves toward the image side when focusing from a far distance to a close distance.

Abstract: In a zoom lens system, a distance between a first lens group and a second lens group is increased, a distance between the second lens group and a third lens group is reduced, and a distance between the third lens group and a fourth lens group is reduced. The third lens group includes, in order from an object side, a front lens group and a rear lens group separated from each other by a widest air gap on an optical axis in the third lens group. Camera-shake correction is performed by moving whole or part of the front lens group as a camera-shake correction lens group perpendicularly to the optical axis. Conditional formula below is satisfied: ?3.0<fis/f3<?0.9, where f3 represents a focal length of the third lens group and fis represents a focal length of the camera-shake correction lens group.

Abstract: A zoom lens includes: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; a fourth lens unit having a positive refractive power; and a fifth lens unit having a positive refractive power or a negative refractive power, in which the first lens unit and the fifth lens unit do not move for zooming, and the second lens unit and the fourth lens unit move during zooming, in which a focal length fw of the zoom lens at a wide angle end, a focal length f2 of the second lens unit, and a focal length of a positive lens, which is included in the second lens unit are suitably set.

Abstract: A zoom lens includes, in order from an object side to an image side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; a fourth lens unit having a positive refractive power; and a fifth lens unit having a negative refractive power, in which: at a telephoto end as compared to a wide angle end, an interval between first lens unit and second lens unit is increased, and an interval between second lens unit and third lens unit is decreased; an interval between each pair of adjacent lens units is changed during zooming; and focal lengths of a focusing mechanism and the third lens unit, a movement amount of the fifth lens unit during zooming from the wide angle end to the telephoto end, and other factors are appropriately set.

Abstract: In a zoom lens including a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power that are arranged in order from an object side to an image side, a movement locus of each of the lens units when zooming, a configuration of the second lens unit, a focal length of the second lens unit, a focal length of the third lens unit, and a focal length of the zoom lens at the wide angle end are set as appropriate.

Abstract: A lens assembly includes a first lens holder that holds a first lens, a first guiding shaft that guides the first lens holder in a parallel direction to an optical axis of the first lens, a first driver that drives the first lens holder in an axial direction of the first guiding shaft, a second lens holder that holds a second lens that is different from the first lens, and a second driver that drives the second lens holder in a direction of the optical axis. Here, the first guiding shaft, the second driver, and the first driver are arranged in the stated order in a circumferential direction of a circle that is centered on the optical axis.

Abstract: A rod lens that includes a rod-shaped lens unit made of a rod-shaped lens element or a plurality of lens elements cemented to one another, wherein, on the circumferential face thereof, the lens unit includes at least one axially magnetized magnet arrangement. The invention also relates to an endoscope with a lens arrangement, which includes at least a first and, arranged adjacent to the first, a second rod lens, and to a method for assembling such an endoscope.

Abstract: The disclosure relates to an optical system for inspecting an eye, having an OCT system which is configured to generate a measurement beam, which is incident on an object region in a converging manner to form a measurement focus. The OCT system has a beam expander which is disposed along the measurement beam between the scanning system and the objective lens and generates an intermediate focus between the scanning system and the objective lens. The OCT system is configured to generate different values of a beam waist diameter of the beam waist by means of controlling the controllable beam expansion of the beam expander. At the different values of the beam waist diameter, an axial beam waist position of the beam waist is substantially identical.

Abstract: A sense amplifier driving device, and more particularly, a technology for improving the post overdriving operation characteristic of a semiconductor device. A sense amplifier driving device includes a driving signal generation block configured to compare a reference voltage set by a voltage trimming signal and a level of a power supply voltage, and generate a pull-up driving signal for controlling an operation of a sense amplifier; and a sense amplifier driving block configured to supply a driving voltage to a pull-up power line of the sense amplifier for an active operation period in correspondence to the pull-up driving signal, the driving signal generation block including a voltage divider configured to divide the power supply voltage, and output a divided voltage; and a voltage comparison section configured to compare the reference voltage and the divided voltage, and output a control signal for controlling an overdriving operation of the sense amplifier.

Abstract: An imaging lens consists essentially of, in order from the object side, a positive first lens group, a negative second lens group, a stop, and a positive third lens group. Focusing is effected by moving only the second lens group along the optical axis direction. Each of the first lens group and the third lens group includes at least three positive lenses and at least two negative lenses. The imaging lens satisfies the condition expression (1) below: 0.53<?f2/f<0.9??(1), where f2 is a focal length of the second lens group, and f is a focal length of the entire system when the imaging lens is focused on an object at infinity.

Abstract: A lens apparatus includes an optical system including multiple lens units, the optical system including: a first lens unit which is disposed closest to an object side in the optical system and is rotatable about a point in a vicinity of an optical axis of the optical system; and at least one lens unit which is movable in a direction including a component in a direction perpendicular to the optical axis. The following conditional expression is satisfied: 1.0<ft/|f1|<2.2, where ft represents a focal length of the optical system at a telephoto end, and f1 represents a focal length of the first lens unit. At least one of rotation of the first lens unit or movement of the at least one lens unit in the direction including the component in the direction perpendicular to the optical axis changes an image formation position in the direction perpendicular to the optical axis.

Abstract: In an optical system in which a focal length of an entire system is shorter than a back focus, an image stabilizing lens unit, is at a position adjacent to an aperture on an image side and a cemented lens obtained by cementing a positive lens and a negative lens is on an object side of the aperture diaphragm, and the focal length of the entire system, a focal length of the image stabilizing lens unit, a focal length of the cemented lens, a distance on the optical axis from the aperture to a lens surface on the object side of the image stabilizing lens unit, and a distance on the optical axis from a first lens surface on a side closest to an object to a final lens surface on a side closest to an image when an infinite-distance object is brought into focus are set.

Abstract: A long-range optical device has at least one optical channel, which has a housing and an arrangement of optical elements, wherein at least one of the optical elements is movable relative to the housing for image stabilization in the event of perturbing movements of the housing. The device further has a first passive stabilization system based on mass inertia for the at least one movable optical element, which, in the event of displacement of the at least one optical element relative to the housing, generates a first restoring force proportional to the displacement and a second restoring force proportional to the displacement velocity. The first stabilization system is designed for image stabilization in the event of perturbing movements in a first frequency range.

Abstract: The zoom lens comprises five or more groups of lens pieces, namely, the foremost or first lens group of positive refractive power located the closest to an object, the succeeding second lens group of negative refractive power, the third lens group of positive refractive power, the fourth lens group of positive refractive power, and the fifth lens group all arranged in this order, and if any, the rearmost lens group(s) closer to the imaging plane than the fifth lens group. The zoom lens meets requirements as defined in the conditional expression regarding a combined magnification of the fifth lens group and, if any, the rearmost lens group(s) closer to the imaging plane than the fifth lens group while the zoom lens is taking a telephoto position.

Abstract: Systems and methods are provided for generating a pseudo-random bit sequence at an output frequency using a clock signal operating at a first frequency that is lower than the output frequency. A first bit sequence of a particular type is generated using a clock signal operating at a first frequency. A second bit sequence is generated using the clock signal operating at the first frequency, where the second bit sequence is a delayed version of the first bit sequence. A delayed version of the first bit sequence is generated using the second bit sequence and another bit sequence, wherein the delayed version is delayed based on the particular type and a difference between the output frequency and the first frequency. The first bit sequence and the delayed version are combined to generate a pseudo-random bit sequence at the output frequency.

Abstract: A zoom lens having a plurality of lens units comprises in order from an object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, and a rearmost lens unit having a negative refractive power, and the rearmost lens unit is positioned nearest to an image in the plurality of lens units, and at the time of zooming from a wide angle end to a telephoto end, distances between the lens units change, and the first lens unit G1 moves toward the object side, and following conditional expression (1) is satisfied: 0.2<(?lt/?lw)/(ft/fw)<0.7??(1).

Abstract: A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group and a positive fourth lens group, in that order from the object side. Upon zooming from the short to long focal length extremities, each of the first through fourth lens groups move along the optical axis thereof. The following conditions (1) and (2) are satisfied: 1.05<ft/f1<1.75??(1), and 3.7<M3t/M3w<6.3??(2), wherein f1 designates the focal length of the first lens group, ft designates the focal length of the entire zoom lens system at the long focal length extremity, and M3t and M3w designate the lateral magnifications of the third lens group when focusing on an object at infinity at the long and short focal length extremities, respectively.

Abstract: An image shake correction device comprising a first image shake correction lens and a second image shake correction lens for correcting an image shake of a subject image caused by shaking is provided. The image shake correction device executes correcting the image shake caused by the drive of the first image shake correction lens and the second image shake correction lens after correcting a drive deviation between the first image shake correction lens and the second image shake correction lens.

Abstract: Provided is a zoom optical system which includes, in order from an object, a first lens group having negative refractive power and other lens groups, and in which an interval between each lens group changes upon zooming, wherein the first lens group includes a first negative lens which is disposed closest to the object and has a diffractive optical element on an image side lens surface, and a positive lens disposed closer to the image than the first negative lens, and the glass material used for the positive lens satisfies the following conditions expressions: ?1p?35 and ?(?g, F)?0.

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 teleconverter according to the present invention includes a master lens apparatus side mount portion, an image pickup apparatus side mount portion, and a converter lens section having a negative refractive power as a whole. The converter lens section includes in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power. The second lens unit is a lens unit in which, three lenses are cemented, and which includes in order from the object side to the image side, a first lens having a negative refractive power, a second lens having a positive refractive power, and a third lens having a negative refractive power. The teleconverter satisfies predetermined conditional expressions.

Abstract: An image capturing lens system includes, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element having an object-side surface and an image-side surface which are both aspheric; a fourth lens element with negative refractive power having an object-side surface and an image-side surface which are both aspheric; a fifth lens element having an object-side surface and an image-side surface which are both aspheric; and a sixth lens element having a concave object-side surface and a convex image-side surface which are both aspheric. With such arrangements, the convergent capability is mainly contributed from the object side of the lens assembly for higher portability of the lens system. Additionally, the peripheral image curve can be prevented while correcting the chromatic aberration and the peripheral image focus.

Abstract: A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. At the time of zooming, distances between the lens units change, and a distance between the first lens unit and the second lens unit at a telephoto end is shorter than at a wide angle end. An aperture stop is disposed on the image side of an image-side surface of the first lens unit, and on the object side of an image-side surface of the second lens unit. The second lens unit includes two sub lens units. The object-side sub lens unit in the second lens unit includes one lens component. The following conditional expressions are satisfied. 3.0<?D12/ERS<4.5 1.05<|f3/fUN21|<2.

Abstract: A zoom lens includes: a positive first lens group; a negative second lens group; and a positive third lens group. The first through third lens groups move such that the distance between the first lens group and the second lens group is greater, and the distance between the second lens group and the third lens group G3 is smaller at a telephoto end compared to a wide angle end. The third lens group is constituted by a positive 3-1 lens group and a 3-2 lens group. The 3-1 lens group is fixed when camera shake occurs and during focusing operations. The 3-2 lens group includes a shake preventing lens group that moves in a direction perpendicular to an optical axis to correct camera shake, and a focusing lens group provided toward an image side of the shake preventing lens group that moves along the optical axis during focusing operations.

Abstract: A dichroic beamsplitter has a composite prism that has at least first and second prism elements that are coupled together along facing surfaces, wherein the respective facing surfaces of the first and second prism elements are equidistant from each other. The composite prism has a first flat external surface that lies within a first plane, a second flat external surface that lies within a second plane that is perpendicular to the first plane, a third flat external surface that lies within a third plane that is parallel to the second plane, and a coated surface internal to the composite prism and having a multilayer thin-film dichroic beamsplitter coating, wherein the coated surface lies within a fourth plane that intersects at least one of the first, second, and third planes at an angle that is less than about 25 degrees.