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: A zoom lens includes a cam barrel having first and second cam grooves formed on an inner peripheral surface thereof; and first and second lens frames having first and second cam followers, respectively engaged with the first and the second cam grooves. The cam dead end of the first cam groove and the second cam follower insertion opening of the second cam groove are formed at the same circumferential position. Upon assembly, the first cam follower is inserted into the first leading section via a first cam follower insertion opening, and the second cam follower is inserted into the second leading section via a second cam follower insertion opening.

Abstract: A lens barrel having a cam barrel is disclosed. The cam barrel is molded by die-cutting in radial and other directions relative to the optical axis so as to have raised cams without undercuts if the raised cams are even partially lined up fore and behind one another along the optical axis, and there is no parting line in either the cam grooves nor the raised cams. The cam barrel has its outer surface provided with raised cams and is made of synthetic resin, and each of the raised cams has at least one of cam faces inclined toward an opposite cam face off a radial direction relative to an optical axis of the cam barrel.

Abstract: A lens barrel for use in a zoom lens apparatus to address the needs of optical devices such as a liquid crystal projector equipped with higher magnification and higher accuracy is provided. That is, the lens barrel of the present invention includes: supporting projections provided on the outer periphery of a fixed barrel projecting therefrom to support a cam barrel in contact therewith in a small area for ensuring smooth rotation of the cam barrel; and alignment guides formed in the fixed barrel and the cam barrel to fit the cam barrel into the fixed barrel keeping a predetermined positional relationship therebetween, thereby enabling the operation for adjusting the position of transmission of light having passed through a liquid crystal panel within a projection lens to be performed without any trouble.

Abstract: A varifocal lens barrel includes movable lens groups including a focusing lens group which is moved by different amounts of movement at different focal lengths, a focus operation ring, a focus lens frame which supports the focusing lens group, a guide ring positioned around the focus lens frame, a bottomed focusing cam groove formed on the focus lens frame or the guide ring, a spherical follower which is supported by the focus lens frame or the guide ring, a biasing member for pressing the spherical follower against the bottomed focusing cam groove, and an adjustment mechanism which varies a relative moving range of the spherical follower in the bottomed focusing cam groove in accordance with a variation of the focal length to vary an amount of movement of the focusing lens group per unit of rotation of the focus operation ring.

Abstract: A lens driving apparatus which drives a first and a second lens group arranged in the optical axis by a first drive means and a second drive means, wherein the apparatus has a first and a second cam followers extending mutually parallel in a right angle direction to the optical axis from the first and second lens groups and cam member having first and second cams arranged along the optical axis and respectively engaging the first and second cam followers.

Abstract: A projection lens shifting mechanism comprises a projection lens unit in the shape of a cylinder for projecting incoming image light, a flange integrated with the projection lens unit, a projection lens mount for providing light emitted from a light valve in the shape of a plane to the projection lens unit, wherein the light valve can be optically modulated for each pixel based on image information, and the projection lens mount is concentric to an optical axis of the light emitted from the light valve, a first cam follower provided in the flange along an optical axis of the projection lens unit, a cam follower guiding portion provided in the projection lens mount for guiding the first cam follower in a direction perpendicular to the optical axis of the projection lens unit, a first lens shifting cam capable of being moved in a predetermined direction with respect to the projection lens mount and engaged with the first cam follower, for shifting the first cam follower in a direction guided by the cam follower

Abstract: A zoom lens barrel wherein its cam ring has three sets of three cam grooves for advancing or retracting a first group frame, a focus frame and third group frame. The three cam grooves include a cam follower introducing groove connected to ends of two cam grooves for the focus frame and a third group frame and a joint groove for joining two cam grooves for the first group frame and the focus frame. When inserting a cam follower of the first group frame into the cam groove, after it is inserted into the introducing groove, it is passed through the cam groove for the focus frame and then, passed through the joint groove and fit to the cam groove for the first group frame. Further, when inserting the cam followers of the focus frame and third group frame into the cam groove, after it is inserted from the introducing groove, it can be fit to the focus frame and third group frame separately.

Abstract: A zoom lens barrel in which a zoom lens is switched to a plurality of focal lengths by a moving member by which a plurality of lens groups are moved in the direction of optical axis. After a desired focal length has been selected, a focusing operation is conducted by the moving member. At least two lens groups, which are moved for switching focal lengths, are moved while a distance between lens groups is being changed so that the focusing operation can be conducted.

Abstract: A zoom lens barrel includes a cylindrical member which is provided with a female helicoid; a split helicoid cylinder having a rear helicoid ring portion which is provided with a male helicoid which is screw-engaged with the female helicoid, and a front cylindrical portion which is detachably connected to the rear helicoid ring portion so as not to relatively rotate; a linear movement cylinder provided in the split helicoid cylinder so as to move in the optical axis direction; and a connecting structure for connecting the linear movement cylinder to the split helicoid cylinder so as to relatively rotate and so as not to relatively move in the optical axis direction, so that the rear helicoid ring portion and the front cylindrical portion of the split helicoid cylinder maintain connected by the connecting structure without being disconnected in the optical axis direction.

Abstract: A zoom lens apparatus having an optical axis includes a zoom cam tube arranged to rotate around the optical axis and having a cam groove for moving a variator lens along the optical axis, and a focus cam tube having a cam groove for moving a focusing lens along the optical axis, wherein the focus cam tube rotates around the optical axis and moves along the optical axis in association with the rotation of the zoom cam tube during zooming, and wherein a rotational speed of the zoom cam tube and a rotational speed of the focus cam tube during zooming are different from each other, so that the zoom lens barrel has excellent zooming operability by reducing torque changes in operation due to the zooming operation.

Abstract: A barrier opening and closing apparatus for opening and closing a barrier according to a rotation of a lens barrel containing an optical lens system includes a ring member rotatable about an optical axis of the optical lens system and opening and closing the barrier according to rotation of the ring member. The ring member has rotational force transmitting parts extending rearward, parallel to the optical axis and engaging the lens barrel. The ring member is directly rotated by the rotational force transmitting parts engaged with the lens barrel, to open and close the barrier so the cost of the apparatus can be reduced.

Abstract: A projection exposure apparatus including an Irradiation optical system including a light source and irradiating a mask with irradiation light beams, a projection optical system for projecting an image of a pattern of the mask on a substrate, a plurality of first fly-eye type optical integrators each having an emission side focal plane disposed on a Fourier transformed surface with respect to the pattern of the mask in the irradiation optical system or on a plane adjacent to the same and having a center located at a plurality of positions which are eccentric from the optical axis of the irradiation optical system, a plurality of second fly-eye type optical integrators each having an emission side focal plane disposed on a Fourier transformed plane with respect to the incidental end of each of a plurality of the first fly-eye type optical integrators or on a plane adjacent to the same and being disposed to correspond to a plurality of the first fly-eye type optical integrators, and a light divider for dividing

Abstract: There is provided an optical device which comprises a fixed barrel, a movable cam ring, and collars and abutments. The movable cam ring is shifted relative to the fixed barrel to move an optical unit, the movable cam ring being fitted to the fixed barrel. Collars and abutments can be engaged with each other when the movable cam ring is in a predetermined positional relationship with respect to the fixed barrel. The collars and abutments preventing the movable cam ring from being disengaged from the fixed barrel and displaced in a direction along an optical axis relative to the fixed barrel.

Abstract: A zoom lens barrel includes a first cylindrical member having first and second bottomed grooves, which intersect each other, on an inner peripheral surface thereof; a first moving member which is provided with a first radial projection which is fitted in the first bottomed groove, the first moving member being movable relative to the first cylindrical member; and a second moving member which is provided with a second radial projection which is fitted in the second bottomed groove, the second moving member being movable relative to the first cylindrical member. The shapes of the first bottomed groove and the first radial projection and the shapes of the second bottomed groove and the second radial projection are such that the second radial projection cannot be fitted in the first bottomed groove and that the first radial projection cannot be fitted in the second bottomed groove.

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: In a collapsing mechanism of the projecting lens apparatus, when a focus ring is moved to the back over a moving range for adjusting the focus, the focus ring is connected to a zoom ring. Then, the zoom ring rotates by following the focus ring which moves to the back, and a first and a second zoom lenses are moved to the back over a moving range for adjusting the zoom. Therefore, the focus ring completely collapses into a body of a projector.

Abstract: A zoom lens mechanism includes a switching lens group frame which supports a first sub-lens group frame and a second sub-lens group frame; a shift cam mechanism provided on opposed surfaces of the first and second sub-lens group frames, respectively, the shift cam mechanism causing the first and second sub-lens group frames to move to a mutually close position or mutually distant position; an actuator ring for providing relative rotation between the first and second sub-lens group frames; a receiving surface provided on the switching lens group frame wherein a rear end surface of the actuator ring abuts against the receiving surface; and a biasing device for biasing the first sub-lens group frame toward the actuator ring to force the first and second sub-lens group frames, and the actuator ring against the receiving surface, so that the shift cam mechanism come into contact with each other.

Abstract: A zoom viewfinder includes an objective optical system having a frontmost lens group and a movable lens group positioned behind the frontmost lens group, and a guide shaft which extends parallel to an optical axis of the objective optical system to guide the movable lens group in the optical axis direction. The frontmost end of the guide shaft is positioned behind the frontmost lens group of the objective optical system.

Abstract: A barrel assembly of a zoom camera includes a front lens frame where a front lens group is installed, a front guide frame for supporting the front lens frame, a zoom ring advancing and retreating along an optical axis of the front lens group, an inner helicoid ring installed to be capable of advancing and retreating with respect to the zoom ring, a rear lens frame where a rear lens group which is arranged on the same optical axis as the front lens group is installed, and a cam unit formed at the zoom ring and an inner rotator which is installed at the inner helicoid ring to be capable of advancing and retreating, for adjusting the interval between the front lens group and the rear lens group as the front lens group moves.

Abstract: A step zoom lens camera having a zoom lens and a cam ring provided with a cam groove having step portions. The zoom lens camera includes a focusing lens group which serves also as a variable power lens group of the zoom lens; and an adjusting lens group, serving also as another variable power lens group of the zoom lens, which is guided by the cam groove and is moved in the optical axis direction in a non-linear relationship with respect to the rotation angle of the cam ring in each focal length step. The step portions of the cam groove are each provided with a path which enables the adjusting lens group to move so as to provide a linear relationship between the rotation angle of the cam ring and amount of movement of the focal position of an infinite distance object.

Abstract: A lens barrel (lens frame structure) using a cam mechanism with a cam follower presents a lens barrel where deviation of engagement of a frame member at the engaging part of a cam-follower is less likely to happen. A cam ring and a lens holding frame constituting the lens barrel of the present invention are connected through a cam-follower, the first cam groove running obliquely to an optical axis and the second cam groove along the periphery direction of the optical axis. The second cam groove comprises an oblique cam plane and the parallel wall plane, and the cam-follower has a conical surface in contacted with a sliding cam plane and a circular ring part contacted with sliding with a parallel wall plane. The circular ring part digs into the parallel wall part and deviation of a can ring is prevented, if cam ring comes to be distorted by applying careless stress to a cam follower.

Abstract: In a zoom lens device of the present invention, an aperture at a predetermined zooming step that is other than a telephoto end and a wide-angle end is smaller than apertures at the other zooming steps, and the predetermined zooming step is used only when a macro shooting mode is chosen. In the present invention, the predetermined zooming step between the telephoto end and the wide-angle end is set only for the macro shooting mode, and the aperture in the macro shooting mode is small enough to make the field depth large. Therefore, the simple and inexpensive lens device can perform the macro shooting.

Abstract: A lens moving device comprises a cam follower which is provided to a lens holding frame supporting a lens, and a cam gear with which the cam follower is engaged. The cam gear is rotated by a stepping motor, so that the lens holding frame and the lens move along the optical axis thereof. The cam gear is molded from synthetic resin and is provided with a stopper at the both ends of a non-operative area, in which the cam follower does not come in contact during a normal operation. The non-operative area has a gate mark, which is formed during the resin molding process. The stopper prevents the cam follower from interfering with the gate mark.

Abstract: A barrel is provided, having at least one cam groove and a helicoid on one and the other of outer and inner peripheral surfaces of the barrel, respectively; wherein a wall thickness of the barrel corresponds to the sum of a height of teeth of the helicoid and a depth of the cam groove, so that the cam groove forms through-holes in the wall of the barrel where no teeth exist.

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: A diopter adjusting device includes a diopter adjusting lens which is guided in an optical axis thereof; a cam member which is provided rotatable about an axis which is parallel to the optical axis of the diopter adjusting lens, the cam member being provided with a cam surface on an end surface thereof; a motion-transmission lever which is rotatable about a lever axis, the lever axis being positioned between the diopter adjusting lens and the motion-transmission lever and lying on a plane normal to the optical axis; a cam follower portion and an engaging portion formed on one and the other ends of the motion-transmission lever to be engaged with the cam surface and the diopter adjusting lens, respectively; and a spring for constantly bringing the cam follower portion into contact with the cam surface.

Abstract: In a lens barrel, a group-2 lens frame, which is movable forwardly and backwardly, is fit into an inner peripheral portion of an M-cam frame which is rotatably supported. A cam groove, into which a cam follower fits, is provided at the M-cam frame. A shaft hole, into which a shaft portion of the cam follower is press-fit and fixed, is provided at the group-2 lens frame. Two edge portions are formed at the shaft portion. Two conical slide faces are provided at a portion which slides at the cam groove of the cam follower. The two edge portions are provided at end portions of the slide faces. When the cam follower attempts to tilt, the edge portions of the shaft portion bite-into a cam face, and prevent a fit-together state of the shaft portion from coming out of place. Further, when an external force acts on the cam follower, the edge portions of the conical slide faces bite into the cam groove such that a fit-together state of the cam follower is prevented from coming out of place.

Abstract: A movable lens hood mechanism of a zoom lens includes a plurality of lens groups guided linearly in a direction of an optical axis to change a focal length of the zoom lens; a first cam barrel rotatably driven to move the plurality of lens groups in the optical axis direction; a movable hood barrel having a photographic aperture positioned in front of the frontmost lens group and guided linearly in the optical axis direction; and a feed mechanism which drives the movable hood barrel forward/rearward in the optical axis direction relative to the frontmost lens group by rotation of the first cam barrel so that a space between the photographic aperture of the movable lens hood and the frontmost lens group in the optical axis direction varies in accordance with a variation of a focal length of the zoom lens.

Abstract: A cam mechanism includes a linear guide barrel provided with a linear guide projection at one end thereof, extending radially outwards; a cam barrel fitted on the linear guide barrel, rotatable relative to the linear guide barrel and movable along the optical axis with the linear guide barrel, the cam barrel being provided with a cam groove on an inner surface thereof; a linear guide slot formed on the linear guide barrel extending parallel to the optical axis; at least one lens frame positioned inside the linear guide barrel; a projection formed on the lens frame to be slidably engaged in the linear guide slot; and a cam follower formed on the projection to be engaged in the cam groove. The linear guide projection and the linear guide slot are formed on the linear guide barrel at the same circumferential position of the linear guide barrel.

Abstract: A selectable assembling device of a zoom lens barrel includes a stationary barrel having a female helicoid, and linear guide grooves spaced at 120 degree intervals; a cam ring including bottomed cam grooves; a linear guide barrel provided with linear guide projections and linear guide slots spaced at 120 degree intervals; and a plurality of lens frames provided with sliding projections spaced at 120 degree intervals, which are engaged in the linear guide slots of the linear guide barrel, each of the sliding projections including a cam follower which is fitted in a corresponding bottomed cam groove of the cam ring. Upon assembly, a relative angular position of assembly for the cam ring and the linear guide barrel can be selected from among three circumferential positions spaced at 120 degree intervals. A device for guiding a flexible circuit board is also provided.

Abstract: A zoom lens includes a plurality of lens groups, and a cam barrel having a cam groove formed on an inner peripheral surface thereof. The cam barrel includes a first barrel having the cam groove on an inner peripheral surface thereof, and a second barrel which is fitted on a front part of an outer peripheral surface of the first barrel, the first barrel and second barrel being movable in the optical axis direction with a predetermined clearance provided therebetween in the optical axis direction while being rotatable together about the optical axis, so that an external force applied to the zoom lens from the outside of the zoom lens is transmitted to the first barrel via the second barrel.

Abstract: A cam barrel rotating mechanism of a zoom lens includes a plurality of lens groups guided in a direction of an optical axis without rotating about the optical axis to change a focal length of the zoom lens; a cam barrel rotatably supported to move the plurality of lens groups in the optical axis direction; a rotational barrel positioned around the cam barrel, the rotational barrel being rotatably driven; a plurality of rotation transmission grooves formed on an outer peripheral surface of the cam barrel, at an equi-angular intervals, extending parallel to the optical axis; and a plurality of inward projections formed on an inner peripheral surface of the rotational barrel to be engaged in the plurality of rotation transmission grooves, respectively.

Abstract: A lens barrel has a cam tube having a cam groove formed on an inner circumferential side thereof. The cam groove has a first cam groove area over which a lens unit slides when the lens barrel is used for photo-taking and a second cam groove area over which the lens unit slides when the lens barrel is not used for photo-taking. A taper angle of a side wall surface of the first cam groove area differs from a taper angle of a side wall surface of the second cam groove area. The large taper angle facilitates removal of a mold from the cam tube at the time of manufacture. The arrangement also permits the first cam groove area which is for photo-taking to have a small taper angle, so that the lens unit can be accurately moved in the first cam groove area.

Abstract: A zoom lens includes a cam barrel having bottomed cam grooves formed on an inner peripheral surface thereof, a lens frame guided in an optical axis direction, cam followers, and resilient supports which are resiliently deformable radially. Each bottomed cam groove includes a zoom section, and an accommodation section. Each bottomed cam groove is formed so that a depth of the accommodation section is greater than the zoom section. The resilient bias of each resilient support causes the cam followers to be biased against the bottomed cam grooves wherein the follower pins are fitted in the bottomed cam grooves so that no play occurs when the bottomed cam grooves are in the zoom section. Each resilient support is free from being elastically deformed so that the cam followers are inserted in the bottomed cam grooves with a predetermined amount of play when the bottomed cam grooves are positioned in the accommodation section.

Abstract: A zoom lens includes a cam barrel having first and second cam grooves formed on an inner peripheral surface thereof; and first and second lens frames having first and second cam followers, respectively engaged with the first and the second cam grooves. The cam dead end of the first cam groove and the second cam follower insertion opening of the second cam groove are formed at the same circumferential position. Upon assembly, the first cam follower is inserted into the first leading section via a first cam follower insertion opening, and the second cam follower is inserted into the second leading section via a second cam follower insertion opening.

Abstract: An optical instrument equipped with a zoom lens installed in a zoom lens barrel having a lens guide arrangement for zooming up and down and focusing which includes a zooming-up guide path for guiding the lens group and positioning it in one of fixed zoom positions during zooming-up, a zooming-down guide for guiding the lens group and positioning it in one of fixed zoom positions during zooming-down, and focusing guide paths arranged parallel to one another and connect the zooming-up and zooming-down guide path in the fixed zoom position for guiding the lens group during focusing after zooming up or down to one of the fixed zoom position.

Abstract: A different amount of movement is provided for the first lens unit L1 relative to the rotation angle of the drive ring 1 in at least one zoom lens section 12z-15z provided on a first cam 1d and a focus section 12f-15f corresponding to the zoom section. A different amount of movement is provided for the second lens element L2 relative to the rotation angle of the drive ring 1 in at least one zoom section 22z-25z provided on a second cam 1c and a focus section 22f-25f corresponding to the zoom section. The average inclination angle &thgr;3 of the retracting section 10s is increased to be greater than the average inclination angle &thgr;2 of the total section B2 excluding the retracting section 10s of the first cam 1d.

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 barrel is a lens barrel having a plurality of lens groups that change intervals in the direction of an optical axis at the time of a zooming operation and move in one-piece toward the optical axis at the time of a focusing operation thereby fixing the mutual intervals in the direction of the optical axis. Furthermore, the zoom lens barrel drives a second group lens frame toward the optical axis via a cam follower by a three-dimensional cam that rotates around the optical axis at the time of the zooming operation and moves toward the optical axis at the time of the focusing operation to perform zooming or focusing. According to this zoom lens barrel, it becomes possible to make the radial size small and further to easily maintain good optical performance.

Abstract: A zoom lens barrel has a stationary barrel, a rotatable cam barrel, a straight-movable barrel, a first lens component, and a second lens component. The stationary barrel is fixed to a camera body. The rotatable cam barrel is screw-engaged with the stationary barrel and moves along the optical axis while rotating about the optical axis. The straight-movable barrel is guided straight along the optical axis by the stationary barrel and is fitted to the rotatable cam barrel so as to be movable together therewith along the optical axis and rotatable independently thereof about the optical axis. The first lens component is fixed to the straight-movable barrel. The second lens component is guided straight along the optical axis by the straight-movable barrel and is cam-coupled to the rotatable cam barrel so as to be cam-driven along the optical axis by the rotatable cam barrel.

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: A zoom lens barrel includes a zoom ring supported by a fixed barrel constituting a barrel body so as to be freely rotative; a zoom cam ring disposed inside the zoom ring in the direction of an optical axis; a first connecting portion for connecting the zoom ring and the zoom cam ring; a first lens holder which moves in the direction of an optical axis; a driving ring which is supported by the fixed barrel at a position behind a lens from the first connecting portion by the fixed barrel; a straightly moving ring which is substantially disposed in a space defined between the zoom ring and the zoom cam ring, restrained from rotating by the fixed ring; and a lens holding ring which holds a second lens, which is disposed in front of the first lens from the first connecting portion and helicoidally coupled substantially with the straightly moving ring in a space, the lens holding ring being rotatively driven by the driving ring and relatively movable in the direction of the optical axis, wherein the lens holding ri

Abstract: Disclosed is an engaging structure of two cylindrical members. At least part of one of the two cylindrical members is coaxially fitted on the other cylindrical member. The engaging structure includes: a plurality of radial projections formed on the second cylindrical member; two annular flanges formed on the other cylindrical member to form a circumferential groove therebetween, the plurality of radial projections being fitted in the circumferential groove; and a plurality of cut-away portions, formed on one of the two annular flanges, through which the plurality of radial projections are respectively inserted into the circumferential groove. Each corresponding pair of the plurality of projections and the plurality of cut-away portions are formed to have a circumferential width different from those of the other corresponding pairs of the plurality of projections and the plurality of cut-away portions.

Abstract: There is disclosed a lens barrel which comprises a supporting frame for supporting lens groups, a cam barrel to be rotated around the optical axis to move the supporting frame in the direction of the optical axis in a predetermined range, a manual focusing ring to which the operator supplies a manual power, a manual power transmission mechanism to be moved by the manual power supplied to the manual focusing ring to rotate the cam barrel, a first limitation member for inhibiting the power transmission from the manual focusing ring to the cam barrel by limiting the movement of the manual power transmission mechanism when the supporting frame is moved to a vicinity of one end of the predetermined range by the rotation of the cam barrel, a motor power transmission mechanism for transmitting the motive power supplied from the motor to the cam barrel so as to rotate the cam barrel, and a second limitation member for limiting the rotation of the cam barrel, wherein the second limitation member is provided at a posit

Abstract: In a lens barrel or an optical apparatus using the lens barrel, a first holding frame which holds a first lens and a second holding frame which holds a second lens are arranged to engage one and the same cam member, a cam disposed in the cam member is arranged to move the first and second holding frames along an optical axis, while keeping the relative positions of the first and second holding frames unvaried when shooting is not performed, and the second holding frame is moved in the direction of the optical axis while the first holding frame is kept stationary in the direction of the optical axis when shooting is performed. The first lens is located nearest to an object side within the lens barrel while the second lens is arranged to be movable along the optical axis for varying a magnifying power.

Abstract: A lens barrel of the present invention includes a fixed frame, a plurality of lens groups disposed on the inner circumference of the fixed frame movably along an optical axis direction with respect to the fixed frame, at least three lens holding frames for holding at least one lens group of a plurality of the lens groups, a cam frame having bottomed cam grooves to be coupled with the inner circumference of the fixed frame through cams, bottomed cam grooves across each other to be coupled with the lens holding frames through cams and a bottomed cam groove which is discontinued on one end surface and continued from the other end surface.

Abstract: A lens barrel includes a plurality of lens units, a plurality of cams arranged to respectively cause the plurality of lens units which are being rotated around an optical axis during a focusing action to move in the optical axis direction, at least one of the plurality of cams being a range varying cam which causes a moving range of the associated lens unit to vary according to a magnification varying state, and a rotary driving member arranged to be rotated around the optical axis by a manual operation or by a motor, wherein the plurality of lens units are interlinked with the rotary driving member in such a way as to be movable in the optical axis direction relative to the rotary driving member independently of each other and rotatable integrally with the rotary driving member.

Abstract: A zoom lens in which a lens group is driven in response to an operation member provided on a body to which the zoom lens is attached, includes a rotary manual ring disposed on a lens barrel, and a driving part arranged to drive the lens group in accordance with a rotating state of the manual ring.

Abstract: An optical apparatus according to the present invention includes a cylindrical holding barrel, a lens moving mechanism including a cylindrical cam which is rotatably fitted on an outer surface of the holding barrel in such a manner that a plurality of moving lens frames held in the holding barrel are moved in an optical axis direction, a light quantity adjusting mechanism held in the holding barrel, for adjusting a quantity of light passing therethrough, lens moving mechanism driving sources for driving the lens moving mechanism, and light quantity adjusting mechanism driving sources for driving the light quantity adjusting mechanism. The lens moving mechanism driving sources and the light quantity adjusting mechanism driving sources are held in the holding barrel.