Abstract: The present invention discloses a zoom lens assembly with capability of assuring concentricity of at least a lens group even during activity. The zoom lens assembly includes a plurality of optical lenses, at least two internal barrels, a lens holder and an alignment element wherein the lenses can be divided into at least two lens groups. The two internal barrels are used to respectively retain corresponding lens group therein to define a first and second lens sets. The lens holder is utilized to accommodate the first and second lens set therein. After twice alignment procedures in an assembled method, an internal barrel retained with one lens group is accommodated within the other internal barrel retained with another lens group to be precisely coupled. The two lens sets with mating structures are coupled to a guiding groove defined on the lens holder thereby the lens sets can slide inside the lens holder.

Abstract: A zoom lens includes a most object-side lens unit remaining fixed on the optical axis when the magnification of the zoom lens is changed and a focusing operation is performed; a most image-side lens unit remaining fixed when the focusing operation is performed; and a plurality of moving lens units lying between the most object-side lens unit and the most image-side lens unit, moved along the optical axis when the magnification is changed. The most object-side lens unit includes, in order from the object side, a negative lens component, a reflective optical component having a reflecting surface for bending the optical path, and a positive lens component. The most image-side lens unit has at least one aspherical surface. An electronic imaging device includes an electronic image sensor located on the image side of the zoom lens.

Abstract: A lens device in which a first movable lens holding frame and a second movable lens holding frame are moved along an optical axis by rotating a cam cylinder rotatably provided on a lens barrel, an escape channel for escapement of a portion of the second movable lens holding frame being formed in the first movable lens holding frame, the lens device comprising: a light shielding member moved along the optical axis by the rotation of the cam cylinder, the light shielding member being moved to a position at which the light shielding member closes the escape channel of the first movable lens holding frame.

Abstract: A zoom lens has first to fifth lens groups G1 to G5 having positive, negative, positive, positive, and negative refractive power, in order from an object side. The first lens groups G1 includes a prism L2 for bending a light path. Zooming is performed by adjusting a focal length by linear movement of the second lens group G2 and fourth lens group G4 and compensating an image surface position by nonlinear movement of the fifth lens group G5. Focusing is performed by moving the fifth lens group G5.

Abstract: A zoom lens includes a most object-side lens unit remaining fixed on the optical axis when the magnification of the zoom lens is changed and a focusing operation is performed; a most image-side lens unit remaining fixed when the focusing operation is performed; and a plurality of moving lens units lying between the most object-side lens unit and the most image-side lens unit, moved along the optical axis when the magnification is changed. The most object-side lens unit includes, in order from the object side, a negative lens component, a reflective optical component having a reflecting surface for bending the optical path, and a positive lens component. The most image-side lens unit has at least one aspherical surface. An electronic imaging device includes an electronic image sensor located on the image side of the zoom lens.

Abstract: A lens barrel has its length which is reduced by dispensing with guide rods or a travel mechanism long extending from a base which fixes an image pickup device. The optical axes of multiple lens groups can be easily aligned. An image taking apparatus has its body which has the lens barrel incorporated into it. A second lens group, third lens group and, via the travel mechanism, a fourth lens group are supported by a straight-ahead key ring, and the straight-ahead key ring also supports a front tube holding the first lens group. A zoom motor and a focus motor are also supported by the straight-ahead key ring.

Abstract: A lens barrel is retractable in electronic equipment having an image-generating device, such as a CCD. During photographing, the lens barrel relocates a first lens group and a second lens group to a predetermined position in an optical axis to zoom the image of an object. During collapsing, the first lens group and the second lens group adjacent to the object side are transferred to a side of a CCD which is away from the optical axis and a focus driving mechanism drives the third lens group along the optical axis. The focus driving mechanism is disposed inside the lens barrel.

Abstract: A zoom lens mechanism foldable and retractable to be used in a digital still camera to control zooming of the zoom lens uses programmed data written in a micro controller unit (hereinafter referred to as MCU) instead of the conventional cylindrical grooved cams that are usually used to mechanically control zooming of a zoom lens of a digital still camera, and the assembly of the second lens group is rotatable inside the lens barrel, and the first lens group can be folded and retracted into the space provided by the rotation of the second lens assembly.

Abstract: The lens barrel with an adjustable focus comprises an external mounting unit, an optical unit and a control unit including a focusing motor and the like. The external mounting unit comprises a fixed frame covering the optical unit, a distance ring, an outer circumferential cover, a zoom ring, a back end cover. The optical unit contains a plurality of frame member units that respectively support a plurality of lens groups. Furthermore, after the unitized optical unit is inserted into the fixed frame, the distance ring, outer circumferential cover, zoom ring, back end cover and the like are successively engaged with the outer circumferential part of the fixed frame from the rear side, so that these parts are easily assembled.

Abstract: A zoom lens barrel includes a linear guide ring; a moving frame having a male helicoid; a rotatable ring coupled to the linear guide ring; a female helicoid formed on the rotatable ring, and engaged with the male helicoid; a switching ring coupled to the rotatable ring; a switching member; and a switching-member moving groove including a first inclined section, a switching section, a second inclined section and an assembling section. The lead angle of the first inclined section is the same but has an opposite inclination to that of the female helicoid. The follower projection is inserted in the first inclined section. The switching section extends parallel to the optical axis. The second inclined section extends parallel to the first inclined section. The assembling section extends rearwards from a front end of the second inclined section to be parallel to the optical axis.

Abstract: A mechanism element for optical devices has a light-incident part on which light having a wavelength of 700 nm or more is incident, and the light-incident part is made of aluminum or an alloy of aluminum or magnesium. An anodizing process treatment to form an anodized coating is performed at least on the light-incident part, and then the surface of the light-incident part is colored to be black by a secondary electrolytic coloring method.

Abstract: An imaging optical instrument causes light emitted from a plurality of light sources arranged adjacent an object to image on recording surfaces of a photosensitive or thermosensitive material. The optical instrument includes a two-sided telecentric optical system having a first lens disposed adjacent an entrance end of a lens barrel, and a second lens disposed adjacent an exit end of the lens barrel, and an aperture stop disposed adjacent a meeting point of a rearward focus of the first lens and a forward focus of the second lens. The aperture stop has an aperture formed centrally thereof for allowing passage of beams that should contribute to image formation, and a refracting portion surrounding the aperture for refracting beams that should be intercepted and causing these beams to leave the lens barrel from the exit end thereof.

Abstract: A light shielding structure of a retractable lens barrel includes a lens system, a lens frame to which a lens group is fixed; at least one movable annular member into which the lens frame is screw-engaged, and which is moved along the optical axis in a predetermined moving manner; a light shield member which is supported by the movable annular member to be movable along the optical axis relative to the movable annular member, and having a rearward movement extremity relative to the movable annular member; and a biasing member which is positioned between the light shield member and the lens frame in a compressed fashion to bias the light shield member toward the rearward movement extremity thereof relative to the movable annular member.

Abstract: A retracting mechanism of a zoom lens barrel includes first, second and third lens groups, wherein the first and third lens groups are integrally moved along an optical axis during variation of a focal length, and wherein at least one of the first and third lens groups is moved relative to the other to reduce a distance therebetween when the zoom lens barrel is fully retracted. The retracting mechanism includes first, second and third lens group moving rings; a cam mechanism for independently moving the first and second lens group moving rings; a second lens group support frame; an intermediate member fixed to the second lens group support frame; and a biasing device for biasing the third lens group moving ring away from the first lens group moving ring. The biasing device functions between the intermediate member and the third lens group moving ring.

Abstract: A cam mechanism includes a cam ring including a cam rib which is formed on a peripheral surface of the cam ring; and a follower ring which is concentric with the cam ring, the follower ring including a pair of cam followers which hold the cam rib between the pair of cam followers. Upon the cam ring and the follower ring being engaged with each other in an assembly process thereof, an inner cam follower of the pair of cam followers first approaches an end of the cam rib in a lengthwise direction thereof, and an outer cam follower of the pair of cam followers subsequently approaches the same end of the cam rib. A portion of the outer cam follower is extended outwards from a position of a peripheral surface of the inner cam follower in a circumferential direction of the follower ring.

Abstract: An eccentricity-prevention mechanism includes a pair of lens-supporting rings for supporting a pair of lens groups, respectively; and a pair of positioning recesses and a follower projection formed on one and the other of opposed surfaces of the pair of lens-supporting rings, such that the follower projection engages with one of the pair of positioning recess to define a relative position of the pair of lens-supporting rings with respect to the optical axis, at a mutually close position and at a mutually distant position. At least three pairs of the positioning recesses and at least three follower projections are provided at different positions in a circumferential direction, so that eccentricity between the pair of lens-supporting rings is eliminated when all of the follower projections are concurrently brought into engagement with corresponding positioning recesses.

Abstract: A retracting mechanism of a zoom lens barrel includes a first through third lens group moving rings; a first linear guide projection formed on the first lens group moving ring to be engaged in a linear guide slot from outside the second lens group moving ring, the first linear guide projection including a hanging groove formed therealong, a rear end of the hanging groove being closed; a second linear guide projection formed on the third lens group moving ring to be engaged in the linear guide slot from inside the second lens group moving ring; and a linear moving key projecting from a front end of the second linear guide projection to be engaged in the hanging groove. A rear moving limit of the third lens group moving ring is determined by contact of the linear moving key with the closed end of the hanging groove.

Abstract: A lens distance-varying mechanism for varying a distance between first and second lens groups includes a first lens frame; a second lens frame rotatable relative to the first lens frame; a relative-moving mechanism for moving the first and second lens frames to change a relative position therebetween on an optical axis when the second lens frame is positioned at each of forward and reverse rotation extremities thereof relative to the first lens frame; a differential linking ring which rotates together with the second lens frame; a differential ring which is rotated relative to the differential linking ring by a first angle of rotation greater than a second angle of rotation of the second lens frame relative to the first lens frame; and a biasing member, positioned between the differential ring and the differential linking ring, for absorbing a difference between the first and second angles of rotation.

Abstract: A lens barrel includes a cam ring which is rotated about an optical axis to move a lens group in the optical axis direction via a cam groove formed on the cam ring, and a rotational ring which transfers a rotational motion to the cam ring. The rotational ring includes a rotation-transmission arm extending in the optical axis direction. The cam ring includes an engaging recess formed on an outer peripheral surface of the cam ring, and in which the rotation-transmission arm is slidably inserted to be movable in the optical axis direction, and an outer flange formed on an outer peripheral surface of the cam ring to form a slot penetrating therethrough in the optical axis direction between the outer flange and a bottom radial surface of the engaging recess so that the rotation-transmission arm is slidably fitted in the engaging recess through the slot.

Abstract: A soft focus lens barrel includes a stationary barrel; a distance operation ring, a soft focus operation ring, and an image surface operation ring, supported by the stationary barrel; a focus guide mechanism which varies a focal position of first through fourth lens groups by moving first and second lens group frames in the optical axis direction without varying the distance therebetween via rotation of the distance operation ring; a spherical aberration guide mechanism which varies spherical aberrations of the first through fourth lens groups by moving third and fourth lens group frames in the optical axis direction via rotation of the soft focus operation ring; and a field curvature guide mechanism which varies curvature of field produced by the first through fourth lens groups by solely moving the first lens group frame in the optical axis direction via rotation of the image surface operation ring.

Abstract: A focusing apparatus applied to a telescopic lens system includes more than two lens groups. The focusing apparatus includes two focusing mechanisms which are operable independently from each other, and are adapted to vary both absolute and relative positions of two lens groups in the optical axis direction.

Abstract: A driving device includes a first member, an annular second member arranged outside the first member, an annular first plate for connecting the first and second members to each other, and an annular second plate for connecting the first and second members to each other. The first and second members are moved relative to each other by supplying or exhausting a fluid into or from a space surrounded by the first and second members and the first and second plates. Also, at least one of (i) an inner diameter a1 of a portion of the second member at which the second member is connected to the first plate is different from an inner diameter a2 of a portion of the second member at which the second member is connected to the second plate and (ii) an outer diameter b1 of a portion of the first member at which the first member is connected to the first plate is different from an outer diameter b2 of a portion of the first member at which the first member is connected to the second plate.

Abstract: A lens barrel includes a stationary barrel, first through third lens support rings, and a lens drive ring including a first guide engaged with a guide formed on the stationary barrel; an engaging portion engaged with a guide formed on the first lens support ring, the lens drive ring and the first lens support ring being relatively rotatable and integrally movable in the optical axis direction; a second guide, engaged with a guide formed on the second lens support ring, to move the second lens support ring in the optical axis direction relative to the lens drive ring via rotation of the lens drive ring; and a third guide engaged with a guide formed on the third lens support ring to move the third lens support ring in the optical axis direction relative to the lens drive ring via rotation of the lens drive ring.

Abstract: A photographing lens apparatus includes a moveable lens frame having a shaft fixing portion to which a shaft for guiding movements of another moveable lens frame is affixed, and a lens retaining frame mounted to the moveable lens frame that integrally retains a plurality of lenses of different apertures and a predetermined diaphragm member disposed among the plurality of lenses. The shaft fixing portion is disposed such that at least a portion thereof overlaps a projected plane defined by a large aperture lens among the plurality of lenses retained by the lens retaining frame as viewed from a front face, and is also disposed in the vicinity of an outer peripheral portion of a small aperture lens among the plurality of lenses retained by the lens retaining frame.

Abstract: A zoom lens system including a first to third lens groups, and zooming is performed by respectively moving the first to third lens groups.

Abstract: A lens barrel is provided with a front lens group facing a subject, that moves only during zooming, and an internal focusing lens group, different from the front lens group, moving at least during focusing. A first cam ring having a cam groove for causing the front lens group to move, and a second cam ring that is separate from the first cam ring, is driven by the same drive source as the first cam ring, rotates together with the first cam ring, and has a cam groove for causing lens groups other than the front lens group to move, are also provided.

Abstract: In order to provide a zoom lens which has excellent optical performance with a compact configuration using a small number of constituent lenses, a zoom lens according to the present invention comprises a first lens unit having a negative optical power, a second lens unit having a positive optical power, and a third lens unit having a positive optical power, which are sequentially arranged from the object side, wherein the gap between the first and second lens units is decreased, the space between the second and third lens units is increased in zooming from the side angle end to the telephoto end, the third lens unit has a cemented lens formed by cementing a positive lens element to a negative lens element, and is moved along the optical axis for zooming, and letting NLi be the number of lensess constituting the ith lens unit, a condition,

Abstract: A lens barrel in accordance with the present invention has a stationary frame, a cam frame, a first lens frame, and a second lens frame. The cam frame has an external cam formed on the external surface thereof and an internal cam formed on the internal surface thereof. The first lens frame is freely movable in directions along an optical axis relative to the stationary frame when driven by the external cam of the cam frame. The second lens frame can freely slide in the optical-axis directions with its rotation restrained by the internal surface of the first lens frame when driven by the internal cam of the cam frame.

Abstract: A lens barrel according to the present invention includes a first lens group; a second lens group; a third lens group; a first actuator for driving the first lens group; a second actuator for driving the second lens group; and third and fourth actuators for driving the third lens group. At least one of the first through fourth actuators is provided at a position such that magnetic flux leakage from at least one of the first through fourth actuators is canceled.

Abstract: In a lens barrel having a first holding tube holding a first optical system and a second holding tube holding a second optical system, support rollers are arranged at three parts on the periphery of each of the first and second holding tubes to restrain these optical systems from tilting. The positions of the support rollers are arranged to be respectively shifted from the centers of gravity of the holding tubes either forward or rearward in the direction of an optical axis.

Abstract: A zoom lens system for forming an image of an object on a solid state imaging device includes a first lens unit having a positive optical power and being movable in a zooming operation; a second lens unit having a negative optical power; and a third lens unit having a positive optical power. The system satisfies at least one the following conditions: 0.8<M1WM/M1MT<2.5; 0.2<&Dgr;&bgr;3/&Dgr;&bgr;2<1.0; 0.7<m1/Z<3.0; 1.0<img*R<15.0; 1.0<max(T1, T2, T3)<4; and 4.

Abstract: A zoom lens system has, sequentially from enlarging side to reducing side, first lens unit having negative optical power; second lens unit having positive optical power, the second lens unit having a positive lens element positioned nearest the reducing side; diaphragm; third lens unit having positive optical power, the third lens unit comprising, sequentially from enlarging side to reducing side, a cemented lens unit having a positive lens element and a negative lens element with a concave surface facing the reducing side, and a positive lens element having a concave surface facing the reducing side; fourth lens unit having negative optical power; and fifth lens unit having positive optical power. The second, third, and fourth lens units move from enlarging side to reducing side when zooming from telephoto end to wide angle end. The zoom lens system satisfies a predetermined condition.

Abstract: A portable telephone 1 is provided with a body 2 and a camera unit 3. In the camera unit 3, photography is switched to macro photography by pressing a macro button 22 on the body 2. In this way, the convenience of the portable telephone 1 is improved because an object in the very near distance can be photographed. The camera unit 3 is constructed so as to be freely rotatable in a direction Rc on a shaft of a connector C. Accordingly, a user can freely modify the photography direction of the camera unit 3, thereby increasing the freedom of photography and providing greater improvement in the convenience of the portable terminal.

Abstract: The invention relates to a compact zoom lens system which can maintain sufficient image-formation capabilities at a wide-angle end of greater than 70° and at a zoom ratio of greater than about 10, and has a proper focusing mode. The zoom lens system comprises a first lens group G1 having positive refracting power, a second lens group G2 having negative refracting power, a third lens group G3 having positive refracting power, a fourth lens group G4 having negative refracting power and a fifth lens group G5 having positive refracting power. For zooming from a wide angle end to a telephoto end of the zoom lens system, the first lens group G1 to the fifth lens group G5 are all movable. During said zooming, the first lens group G1 and said third lens group G3 move toward the object side in such a way that the spacing between the first lens group G1 and the second lens group G2 becomes wide and the spacing between the third lens group G3 and the fourth lens group G4 becomes wide.

Abstract: A vari-focal lens includes power varying lens groups including a focusing lens group; a zooming ring; a focusing ring; a focusing lens frame supporting the focusing lens group; an intermediate moving frame supporting the focusing lens frame; a zoom cam ring; a focus cam ring which rotates with the zoom cam ring and is relatively movable thereto in the optical axis direction; and first and second cam followers formed on the focusing lens frame and intermediate moving member, respectively, which are engaged with focus cams of the focus cam ring. The focus cam ring moves in the optical axis direction relative to the focusing lens frame and the intermediate moving frame and rotates about the optical axis while being guided by the focus cams to thereby change a position of engagement of the first cam followers and the second cam followers relative to the focus cams.

Abstract: An auxiliary lens with which lenses are held within a mount has an afocal magnification of 0.8 and serves as a wide-angle conversion lens when attached to the front face of a taking lens with a small aperture. On the other hand, when attached to the front face of a taking lens with a large aperture, the auxiliary lens serves as a ratio conversion lens for an aspect ratio switchable camera which can switch an aspect ratio of the imaging area from 16:9 to 4:3.

Abstract: A zoom lens having both manual mode and auto focus mode of focus adjustment. The zoom lens includes, in order from the object side, a focus portion, a zoom portion, and a main portion. Zooming is accomplished by moving some or all of the lens elements in the zoom portion along the optical axis. What would otherwise be a fluctuation of the image surface with change of object distance is corrected in manual mode by manually moving some or all of the lens elements of the focus portion along the optical axis based on visual observation of the object through the zoom lens as the adjustment is made. In auto focus mode, what would otherwise be a fluctuation of the image surface with change of object distance is corrected by micro-vibrating some or all of the lens elements of a lens group in the light path following the focus portion.

Abstract: A zoom lens includes a first lens unit with a positive refractive power, a second lens unit with a negative refractive power, a third lens unit with a positive refractive power, and a fourth lens unit with a positive refractive power, which are arranged in this order from an object side. At least the first, third and fourth lens units are moved along an optical axis to vary spatial distances of the lens units to thereby change magnification. The third lens unit includes a first lens subunit with a positive refractive power, and a second lens subunit with a negative refractive power, and the second lens subunit is moved to have at least a perpendicular vector component with respect to the optical axis to thereby displace an image.

Abstract: A zoom lens system including a first through third lens groups. The combined power of the first and second lens groups is positive. Upon zooming from the short focal length extremity towards the long focal length extremity, all the three lens groups are moved from the image towards the object.

Abstract: In a short-focal-length side zooming range, a moveable sub-lens group of a zoom lens system is made stationary at one of the object-side and the image-side end. At the intermediate switching focal length, the moveable sub-lens group is moved to the other of the object-side and the image-side end.

Abstract: A zoom lens system including a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group. Upon, all the lens groups move towards the object. A lens group other than the first one is a lens group for focusing, and a ratio K of traveling distance of the first to that of the second lens groups is made constant in any part of the focal length range.

Abstract: A zoom lens system includes a first lens group, a second lens group, and a third lens group, in this order from the object. Zooming is performed by moving the first through third lens groups. The zoom lens system satisfies the following conditions: 1 0.62 < ( d T12 - d W12 ) / f W < 1.

Abstract: It is an object of the present invention to provide a very compact zoom assembly with a minimum number of parts. Another object of this invention is to provide a zoom assembly which does not require guide rods and utilizes with only one motor for both zooming and focusing. Briefly summarized, according to one aspect of the present invention, a zoom assembly includes a zoom lens defining an optical axis. This zoom lens is capable of operating in a plurality of different zoom positions and of focus adjustment for different object distances in each of the zoom positions. The zoom positions are (i) two extreme zoom positions (a wide angle position and a telephoto position), and (ii) a plurality of intermediate zoom positions. The zoom lens includes at least a first movable lens group and a second movable lens group. These first and second lens group are separated from one another by a variable distance.

Abstract: A zoom lens, especially, suitable for a stepped-zoom zoom lens system, which includes a zoom lens and a zoom lens barrel. The zoom lens barrel houses a zoom lens possessing a plurality of movable lens groups. The lens barrel includes a guide assembly to guide the movable lens groups along an optical axis to prescribed positional states. The zoom lens system is such that the total zoom lens length is not excessively long even during short-distance focusing. Also, during short-distance focusing, the lens barrel is configured such that the most imagewise negative lens group moves objectwise in the extreme wide-angle positional state and imagewise in the extreme telephoto positional state. Also, when the zoom lens is in the extreme telephoto positional state, short-distance focusing is accomplished by causing one or more of the multiple groups of the zoom lens to move imagewise. The zoom lenses of the zoom lens system preferably satisfy at least one of a number of design conditions.

Abstract: A cylindrical mount (1) for optical components of a variable-power objective, includes an inner straight-line guide (2, 3), with a cam control (13) which is capable of being actuated via a rotary ring (15) arranged on the outside of the mount and which is intended for the adjustment of carriers, (4, 4', 5) for lenses or lens groups relative to one another in order to change the focal length. A further rotary ring (19) is provided for adjusting a holder (10) for lenses or lens groups for setting the focus of the objective. The holder (10) is arranged on a linear guide (8, 9) which is adjustable in the direction of the optical axis (24) and which is fastened to a carrier (4') displaceable with the change in focal length. The further rotary ring (19) has, on its inner cylindrical surface, a cam carrier (18) which is held displaceably in the direction of the optical axis (24) on the cylindrical surface.

Abstract: The first, movable encloses the front, middle and rear lens groups. The front and rear lens groups are supported by a front and a rear lens cell, respectively. At least one of the front and rear lens cells is an integral part of the front lens barrel. The front and rear lens cells are located at a fixed distance with respect to one another. The middle lens group is supported by a mid-lens cell. The mid-lens cell is slidably movable within the first, movable barrel and has at least three external cam followers. The second, movable barrel engages and at least partially encloses the first barrel and includes three cam grooves engaging the cam followers. The motor is operatively connected to the second, movable barrel. The motor rotates the second, movable, so that the second, movable barrel moves along the optical axis with respect to the first, movable barrel.

Abstract: Sequentially from the object side: a first lens unit having positive optical power; a second lens unit having negative optical power; and a third lens unit having positive optical power, wherein said first and second lens units normally move in opposite directions whereas the third lens unit moves linearly to the object side during zooming from the wide angle end to the telephoto end, and wherein the following conditional equation is satisfied:0.2<M1/Z<2.0where M1 represents the amount of movement of the first lens unit during zooming from the wide angle end to the telephoto end, Z represents the zoom ratio (fT/fW), fT represents the overall focal length of the total system at the telephoto end, and fW represents the overall focal length of the total system at the wide angle end.

Abstract: A zoom lens comprises a plurality of lens units movable along an optical axis for zooming and a lens unit movable along the optical axis for focusing, wherein the focusing lens unit moves integrally with one lens unit of the plurality of lens units in at least one zooming zone, and, in another zooming zone, moves while varying a separation thereof relative to the one lens unit.

Abstract: A controller determines the presence/absence of change in focal length caused by a zooming operation, and determines the necessity of correcting image plane shift caused by said change in focal length. Blur correction is prohibited when executing correction of image plane shift, and image plane shift is corrected by calculating the amount of movement of the focusing lens based on set focal length information, current position information of the focusing lens, and correction information stored in memory. When correction is unnecessary, the controller determines blur correction is permitted when the drive of the focusing lens ends, and executes the correction. The blur correction and the image plane shift correction are not executed simultaneously.

Abstract: Zoom lens system having a high zoom ratio including, in order from the object end: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a positive refractive power. When the zoom lens system is operated from its maximum wide-angle state to its maximum telephoto state, the air-space separation between the first lens group and the second lens group is increased, the air-space separation between the second lens group and the third lens group is decreased, the air-space separation between the third lens group and the fourth lens group is increased, and the air-space separation between the fourth lens group and the fifth lens group is decreased, and the following condition (1) is satisfied:2.3<D.sub.IT -D.sub.IW /fw<10 (1)where D.sub.