Abstract: In the zoom lens apparatus, a lens frame for a variable-magnification lens or a correcting lens is configured of an inner frame and an outer frame, and any focus blurring due to variations in wavelength of subject light can be compensated for accurately by shifting the inner frame holding the lens relative to the outer frame. The correcting lens frame for the correcting lens is configured of the inner frame and the outer frame, and the inner frame is shifted according to variations in wavelength of subject light. Any focus blurring can be thereby compensated for steplessly according to variations in wavelength of subject light.

Abstract: A mount for an optical element in an optical imaging device, in particular in a lens system (4) for semiconductor lithography, has at least one mounting ring (2) which bears the optical element (6). The mounting ring (2) is of at least partially hollow design in cross section.

Abstract: A cemented lens group includes two lens elements, cementing surfaces of the two lens elements being cemented to each other by an adhesive, wherein the adhesive forms an adhesive layer between the cementing surfaces. A filler made of minute solid material is dispersed throughout the adhesive layer. Alternatively, a spacer which determines the thickness of the adhesive layer is provided around the peripheral portions of the cementing surfaces.

Abstract: An apparatus for the precision positioning of an optical component a group of lenses or mirror, in the axial direction and/or for tilting the component and has an axial adjustment device and/or a tilting device. The axial adjustment device has an adjusting nut that includes a guide ring and a clamping ring. The two rings are connected to one another elastically via a blade. Individual clamping jaws are formed by axial incisions in the clamping ring and are braced with the guide ring via tensioning members. The tilting device has an inner and an outer tilting part. The inner tilting part is connected to the outer tilting part via torsion joints, and the outer tilting part is connected to a bearing part via torsion joints.

Abstract: In the case of a mounting apparatus, an optical element having an inner mount and an outer mount, in particular a lens in a projection lens system for semiconductor lithography, the inner mount is connected to the outer mount via three circumferentially distributed solid-state articulations. Manipulators, by means of which the inner mount can be displaced, act on the solid-state articulations. The solid-state articulations are T-shaped in cross section with a T-bar and a T-support. Attachment points between the inner mount and the outer mount are located in each case in the region of the outer ends of the T-bar. The manipulators act on the T-support in each case.

Abstract: Elastic lens holder with a lens mount and a lens, an annular groove being constructed on the circumferential surface of the lens, and there being present at the lens mount elastic segments whose free ends engage radially under pretension in the annular groove.

Abstract: An eyepiece attachment structure for attaching an eyepiece to an observation optical instrument is provided with an attaching sleeve protruding from the eyepiece, a holding member secured to the body, the holding member frictionally holding the attaching sleeve when the attaching sleeve is inserted in the observation optical instrument, and a rotation preventing mechanism that mechanically prevents rotation of the attaching sleeve relative to the holding device when the attaching sleeve is inserted into the observation optical instrument.

Abstract: A flexible lens mount for securing a flexible lens having a first side and a second side opposite the first side. The flexible lens mount comprises a resilient member, a base member, and a fastener. The resilient member includes a first end, a second end, and a first surface adapted to abut the second side of the flexible lens. The resilient member is adapted to be flexed to form a first arc of about degrees D of about radius R. The base member includes a second surface forming a second arc which complements the first arc. The second surface is adapted to abut the first side of the flexible lens such that the flexible lens is disposed intermediate the first and second surfaces. The base member further comprises a first retaining member disposed at one end to retain the first end of the resilient member, and a second retaining member disposed at an other end to retain the second end of the resilient member.

Abstract: A plastic lens molded through a gate in a molding process has a gate-located portion on an outer peripheral surface of the plastic lens, and a concave surface provided on at least a part of the gate-located portion.

Abstract: A lens guide mechanism includes a lens frame which supports a photographing lens group, the lens frame including a plurality of guide holes extending in a direction parallel with an optical axis; a support barrel in which the lens frame is provided; a gear holding member which is provided at a front end of the support barrel; a gear train which is held between the support barrel and the gear holding member, the gear train constituting a drive mechanism for the lens frame; and a plurality of linear movement guide rods provided in the gear holding member, which extend through the guide holes of the lens frame and support the lens frame to move linearly in the optical axis direction relative to the support barrel.

Abstract: A zoom lens barrel assembly includes a plurality of lens barrels including a rearmost lens barrel, secured to a camera body, and a frontmost lens barrel. At least one adjacent pair of lens barrels are connected to each other via a helicoid structure. The frontmost lens barrel and a first adjacent lens barrel are connected to each other via a cam structure. The helicoid structure allows the adjacent pair of the lens barrels to rotate and move in an optical axis direction relative to each other while the zoom lens barrel assembly moves from a retracted position to a minimally extended position for a photographing operation. At least a portion of the helicoid structure includes a slip region which allows the pair of adjacent lens barrels to rotate without relatively moving along the optical axis.

Abstract: A zoom lens barrel assembly includes a first lens group including first and second sub-lens groups; a second lens group; a sub-lens group switching mechanism for moving the first or second sub-lens group away from the other in a short focal length photographing range, and toward the other in a long focal length photographing range; and a zoom cam mechanism having front and rear lens group cam grooves. The rear lens group cam groove includes first and second portions corresponding to the short and long focal length photographing ranges, respectively, the first and the second portions connected to each other via a discontinuous portion. The front lens group cam groove includes a non-linear portion which corresponds to the short focal length photographing range and provides a non-linear path, and a linear portion which corresponds to the long focal length photographing range and provides a linear path.

Abstract: A lens barrel includes a stationary barrel, an outer ring, an inner ring, a cam ring and a movable lens frame, arranged in that order from outermost side, wherein the axes thereof coincide with a common optical axis, the outer ring being guided linearly in the optical axis direction by the stationary barrel, the inner ring being linearly guided in the optical axis direction by the outer ring, and the cam ring being rotatable to move the movable lens frame in the optical axis direction; and a lens barrier mechanism having an aperture positioned in front of the movable lens frame, the lens barrier mechanism being provided on a front opening of the inner ring, for opening and closing the aperture.

Abstract: A lens shutter mechanism includes, between front and rear support frames having photographing apertures, shutter sectors which open and close the photographing apertures; a shutter drive ring which is rotatable about the optical axis to drive the shutter sectors; diaphragm sectors which change an aperture diameter of the photographing apertures independently of the shutter sectors; and a diaphragm drive ring which is rotatable about the optical axis to drive the diaphragm sectors. The shutter drive ring and the diaphragm drive ring are located at different radial positions and at the same optical axis position. One and the other of the shutter drive ring and the diaphragm drive ring is provided with an inner flange and an outer flange respectively, which radically project toward each other so as to overlap in the axial direction, and engage so as to be relatively slidable in the circumferential direction.

Abstract: A multi-stage-extension zoom lens barrel assembly includes an inner peripheral helicoid ring having a first helicoid formed on the outer periphery thereof which is engaged with a second helicoid formed on an inner periphery of an outer peripheral helicoid ring; a first linear guide ring provided in the inner peripheral helicoid ring and is relatively rotatable and integrally movable therewith in the optical axis direction; and a first outer barrel for covering the first linear guide ring, the first outer barrel being supported on the first linear guide ring so as to relatively rotate and move together in the optical axis direction therewith, wherein the first outer barrel is detachably attached to the inner peripheral helicoid ring, the first outer barrel being integrally rotatable about the optical axis and integrally movable along the optical axis with the inner peripheral helicoid ring.

Abstract: A lens barrel includes first and second lens groups guided in an optical axis direction without rotating about the optical axis, first and second support frames which support the first and second lens groups and include first and second cam followers, respectively; and a cam ring which is rotatable about the optical axis and includes a cam groove. The cam groove is formed as a continuous groove and includes first and second groove portions via which the first and second cam followers are guided to move the first and second lens groups, respectively. One of the first cam follower and the second cam follower enters one of the first groove portion and the second groove portion after passing through the other of the first groove portion and the second groove portion in a preparation stage of the lens barrel.

Abstract: A stopper structure for use in a lens barrel assembly, the lens barrel assembly having a helicoid ring which includes a male helicoid, on the outer periphery of the helicoid ring, for engaging with a female helicoid on an inner periphery of a fixed barrel secured to a camera body; and gear teeth formed along the male helicoids to extend between the male helicoids and arranged in a circumferential direction about an optical axis, the helicoid ring moving along the optical axis while been driven by a pinion which is engaged with the gear teeth; wherein the stopper structure includes a stopper member which engages with at least one tooth of the gear teeth in order to prevent rotation of the helicoid ring.

Abstract: A lens barrel includes a cam ring which rotates about an optical axis while moving in the optical axis direction and has a cam groove formed on an inner peripheral surface thereof; a movable lens frame provided inside the cam ring so as to be movable in the optical axis direction without rotating about the optical axis; a cam mechanism for moving the movable lens frame in the optical axis direction by an amount of movement greater than that of the cam ring via rotation of the cam ring in accordance with a profile of the cam groove; and an outer ring which is provided around the cam ring and is engaged therewith so that the cam ring is rotatable about the optical axis relative to the outer ring and so that outer ring moves together with the cam ring in the optical axis direction.

Abstract: An assembly includes a part made of transparent material, in particular, quartz glass or calcium fluoride, and a metal part soldered. The following layer structure is present in the region of a solder joint: a transparent material of the transparent material part, an adhesion layer, a diffusion barrier layer, a first oxidation protection layer, a second oxidation protection layer, a solder layer, as required, a wetting auxiliary layer, and a metal of the metal part, respectively with transitions between the layers, in particular, in the typical manner for soldering, and possibly with diffusion of the two oxidation protection layers into the solder.

Abstract: A flexure-ring is provided for centering a lens in a bore of a housing with 3N lens contacting stubs, where N is an integer equal to or greater than one. The stubs are formed by increasing the inside diameter of the ring made to fit tightly around a lens except at 3N locations for the aforesaid stubs, and said ring having an outside diameter made to fit tightly inside the housing bore locations. Behind each stub, a segment of the ring is removed down to a chord perpendicular to a ring diameter passing through the center of each stub. That chord is selected to have a length greater than the lens contacting surface of the stub, thereby to produce a reduced cross section of the ring on both sides of the stub to serve as flexures in relieving stresses due to different coefficients of thermal expansion of the three parts involved due to changes in temperature while in use.

Abstract: An assembly comprising an optical element and a mount has a fastening flange 2, an intermediate element 3 in at least approximately the form of a funnel and an inner ring 4. The optical element 1 is mounted in the inner ring 4, which is connected to the fastening flange 2 via the intermediate element 3. The intermediate element 3 is connected on the side with the smaller diameter to the inner ring 4 and on the side with the greater diameter to the fastening flange 2.

Abstract: A shift mechanism includes first and second ring bodies which are relatively rotatable; a shift cam surface formed on the first ring body on an end surface thereof which faces the second ring body, the shift cam surface being inclined with respect to a circumferential direction of the first ring body; a follower projection formed on the second ring body for engaging with the shift cam surface; and a rotating mechanism for relatively rotating the first and second ring bodies. The shift cam surface and the follower projection are arranged to move the first and second ring bodies toward and away from each other in the axial direction as the first and second ring bodies are relatively rotated. An annular rib is formed along the circumference of the first ring body outside the shift cam surface over the follower projection of the second ring body.

Abstract: In the case of a lens system, in particular a projection lens system in semiconductor lithography, with a plurality of optical elements, such as lenses, which are mounted in mounts, the mounts being connected to one another, if appropriate by means of adjusting rings, at least one inner mount of an optical element which is intended for removal and/or later fitting is connected to an outer mount by means of a three-point mounting.

Abstract: A thermal birefringence compensator for a double pass laser system, which includes a polarization or conventionally outcoupled laser resonator, a gain medium and a compensator optically coupled to the gain medium. In one implementation, the compensator, which acts as an end reflector, includes a Benson prism, a first quarter waveplate with its principle axes aligned to the fold axis of the Benson prism, and a second quarter waveplate with its principle axes at 45° to the fold axis of the Benson prism. Alternatively, the compensation's prism can be a Porro prism.

Abstract: A releasable and stress-free securing assembly for an optical element (2, 3) positioned in a centered manner in a mount (1) is provided. The optical element (2, 3) is provided, in the border region which is to be retained, with a beveled surface (6) inclined in the direction of the mount (1). The mount (1) has a groove (4) which is open axially in front of the optical element (2, 3). A ring element (5) which is elastically deformable in the axial direction is pressed in between the beveled surface (6) and groove (4). The angle of inclination of the beveled surface (6) is between 40° and 50°. The boundary (11′) of the groove (4) in the region of the optical element (2, 3) is level with a bevel edge (8), which is oriented toward the mount (1), and the boundary (11) of the groove (4) in front of the optical element (2, 3) is undercut at an angle of from 10° to 15°. The depth of the groove (4) is greater than the radius of the ring element (5) by from 0.15 to 0.

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 comprises a ring member disposed rotatable about an optical axis of the optical lens system and adapted to open and close the barrier according to a rotation thereof, whereas the ring member forms a plurality of rotational force transmitting parts extending rearward therefrom in parallel to the optical axis so as to be engaged with the lens barrel. The ring member is directly rotated by way of the plurality of rotational force transmitting parts engaged with the lens barrel, so as to open and close the barrier, whereby the cost of apparatus can be cut down.

Abstract: A preloaded device includes a female component having a right-circular cylindrical internal surface and a first helical groove in the internal surface of the female component. A male component has a right-circular cylindrical external surface sized to be slidably received within the right-circular cylindrical internal surface of the female component, and a second helical groove in the external surface of the male component. The second helical groove has the same pitch as the first helical groove so that the second helical groove is in facing relationship along its length to the first helical groove when the male component is assembled to the female component. A spring component is received within the first helical groove and the facing second helical groove when the male component is assembled to the female component.

Abstract: A light flux deflecting device includes a light flux deflecting unit displacable along a predetermined plane for deflecting light flux, and a support unit for supporting the light flux deflecting unit in such a manner as to allow the light flux deflecting unit to move in a direction along the plane, but to restrain the light flux deflecting unit from moving in a direction vertical to the plane. The support unit includes a support portion comprising (1) at least three hinge portions having short sides arranged to lie in the direction along the plane, and (2) rigid members each positioned between two adjacent hinge portions and having a predetermined width in the direction along the plane.

Abstract: The present invention provides for significantly improved ultraviolet optical filters. This new class of optical filters benefits from improved optical performance, extended physical longevity, high imaging quality of transmitted radiation, transmitted wavelength stability, and minimal autofluorescence. Preferred filters of the invention do not require any sealing from the ambient, are stable, and do not degrade over time and exposure to UV irradiation, and offer superior transmittance for use as bandpass filters.

Abstract: A method and retainer assembly for securely retaining a lens in a cell or other holding structure so that the lens does not become displaced when the cell is subject to mechanical shock and vibration. The invention is particularly useful for use in retaining large, heavy optical elements, such as can be found in long focal length aerial reconnaissance camera systems. The method involves the step of seating and centering the lens into the cell. The lens has a peripheral surface having a beveled feature. A first rigid, e.g., metallic, ring having a complementary beveled surface is installed over the peripheral beveled surface of the lens. A second rigid, e.g., metallic, ring is installed over the first ring. A retaining ring is threaded onto the cells such that the retaining ring abuts against the second ring. The retaining ring is tightening onto the cell such that the second ring conforms to the retaining ring while maintaining the alignment of the lens in the cell.

Abstract: A zoom lens assembly for a zoom lens having at least two lens groups comprises at least one rotatable lens barrel equipped with a first guide cam for shifting one of the two lens group relative to the lens barrel along the optical axis, a rotatable ring member equipped with a second guide cam for shifting the lens barrel along the optical axis and an electromagnetically operated clutch mechanism for locking the rotatable ring member to permit relative rotation of the lens barrel to the ring member so as to shift the lens group according to the first and second guide cams for focusing the zoom lens and unlocking the rotatable ring member from the lens barrel to cause integral rotation of the rotatable ring member and the lens barrel so as to shift the lens group according to the first guide cam only for adjusting a zoom ratio of the zoom lens.

Abstract: A device for fastening an optical unit to an actuating ring of an actuating device including a fastening ring joined to the actuating ring and having a plurality of securing shims bonded to the optical unit and connected to the fastening ring by flexible axial tongues. The device can be applied to a triaxial laser gyrometer.

Abstract: A drive device for driving an optical element suitable to be attached to a camera shake correction device. The drive device employs items molded from a synthetic resin in which the elastic deformation of the synthetic resin allows the oscillation of a piezoelectric element to be adequately converted to drive power. The drive device includes an electromechanical conversion element, a baseplate equipped with a securing area secured to one end of the electromechanical conversion element, and a drive member that is securely linked to the other end of the electromechanical conversion element and displaced together with the electromechanical conversion element. The device further includes a transport member constructed from a rigid synthetic resin material with a Rockwell hardness of about 120 or more and which is frictionally linked to the drive member.

Abstract: An interlock ring is provided to transmit a rotational force of a casing of a lens unit to a attachment ring, and contact faces of a projection of the attachment ring and a projection of the interlock ring are slant. Thereby, the stress is prevented from concentrating at the base corners of the projections. Thus, the projections can be prevented from breaking due to over-fastening.

Abstract: A modified objective lens focus assembly of a night vision image intensif monocular for providing focus control travel adjustment that has substantially free movement for a full range of travel. The focus ring and lock ring are cemented together as one subassembly which is then cemented to the monocular housing. The objective cell is then rotational within the assembly without use of separate focus ring and lock ring.

Abstract: An objective lens for an endoscope has an optical lens system including a plurality of optical lens elements coaxially arranged at predetermined axial distances, at least an adjacent two of which are spaced at a specified relative axial distance by a thin ring member for restricting light rays entering the optical system.

Abstract: A lens frame supporting mechanism includes a spherical surface that is a specified region of the outer surface of a lens frame for holding an optical system and that acts as a driven and supported member. The spherical surface is supported by spherical rotators serving as supporting driving members. The lens frame is driven to rotate by means of the spherical rotators that are in contact with the lens frame, thus shifting the orientation of the optical axis of the optical system. The lens frame is rotated while being restrained from rotating about the optical axis by means of a guide ditch and a guide pin formed in the spherical surface of the lens frame. This lens frame supporting mechanism has materialized a simple supporting mechanism and a compact lens frame, and realizes a reduced load to a rotation actuator.

Abstract: A mounting seat for an optical element is decoupled from a surrounding annulus that fixes the mount in place in an optical system. The annulus can be one of a plurality of annuli that are interconnected to surround and enclose a coaxial array of optical elements. The decoupling is accomplished by three flexible fingers extending inward from the annulus to a seat for the optical element, which can be mounted either directly on the flexible fingers or on a concentric seating ring supported by the fingers. The flexible elements can be formed integrally with an annulus by cutting slots in its inner perimeter. The flexible elements are structured relative to the lens elements they support so that natural frequencies of vibration of the lens elements are higher than the frequencies of external vibration.

Abstract: A lens accessory attaching mechanism is provided to attach a lens accessory to a lens barrel. The lens attaching mechanism has four pairs of first and second rollers attached to the proximal end portion of the lens accessory into which the distal end of the lens barrel is inserted. The first and second rollers are equiangularly spaced in the circumferential direction of the lens accessory and are movable in a radial direction thereof. A ring spring arranged around all of the first and second rollers urges the rollers radially inwardly. An outer flange portion formed on the outer periphery of the lens barrel abuts the first and second rollers to restrict the movement of the lens accessory in the axial direction of the lens barrel.

Abstract: Compact and lightweight portable collimator for adjusting an optical system of a video camera is disclosed, the collimator comprises a chart piece holding a chart pattern for producing an image of the chart pattern placed at a focal point of a convex lens which converts a light from the chart pattern into a beam of parallel light and projecting the beam toward the video camera, a cylinder for housing the chart piece and the convex lens, and coupling device rotatably coupling the cylinder to a lens barrel of the video camera so that an orientation of the chart pattern can be changed and the optical system of the video camera can be adjusted to a distance of infinity. The chart piece may be made replaceable so as to place the chart pattern within a focal length of the convex lens to optically synthesize an object placed closer than the infinite distance with respect to an objective lens of the video camera.

Abstract: In a lens assembly for a telescope objective that comprises liquid lens elements contained between adjacent glass lens elements, each glass lens element is adhesively bonded to an interior surface of a corresponding cylindrical mounting ring by a sealant that is impervious to the liquid lens elements. The sealant is a proprietary fluorosilicone compound marketed as "DOW CORNING X5-8738". The cylindrical mounting rings (with the corresponding glass lens elements bonded thereto) are coaxially aligned so that planar end surfaces of adjacent mounting rings adjoin each other. Compressible O-rings made of Viton.RTM. are received in annular grooves formed on one end surface of each pair of adjoining end surfaces of adjacent mounting rings. Adjacent mounting rings are secured to each other to provide three-point mounting contact between adjacent mounting rings so as to obtain precise axial alignment of the glass lens elements.

Abstract: A conversion arrangement for mounting optical units on a camera such as a film or television camera has a generally cylindrical mounting body (12, 14) for attachment to the camera body, a generally cylindrical carrier (B) for attachment to the optical unit, the carrier being coaxially coupled to the mounting body for axial movement relative to the mounting body, and a focusing ring (22) which is coaxial with and coupled to both the mounting body (12, 14) and the carrier (B). The focusing ring is rotatable relative to the mounting body and carrier to move the carrier axially of the mounting body to focus the optical unit. Backlash during focusing is reduced to nil or negligible proportions by use of a gapped movement ring (34) which has a radially outer screw-thread engaging a cooperating screw-thread in a radially inner surface of the focusing ring.

Abstract: A unique lens or mirror mount having adjustable constraints at two key locations to allow for "X" and "Y" tilts of the mirror only. The device uses two pair of flexures of a type such that the pivots of the mirror gimble are rigidly fixed in all planes allowing the device to have zero stacking tolerance and zero wear over time.

Abstract: An apparatus for mounting the optical unit of an image forming apparatus so that when the optical unit is removed from its mounting, within the image forming apparatus, for maintenance or the like, it can be easily and accurately reinserted. The mounting apparatus has a bottom wall and vertical walls at opposite ends of the bottom wall, with supporting pads formed on the vertical walls for supporting and aligning the optical unit. A clamp is provided for securing the optical unit to the mounting. When the clamp is laid over the optical unit, the optical unit remains secured within the mounting. An adjustment thumbscrew is provided for moving the optical unit within the mounting.

Abstract: A zoom lens barrel has first and second groups of lenses supported by respective lens frames and a cam mechanism which controls the axial position of at least one of the lens groups. The cam mechanism comprises a guide pin which is provided on the lens frame of the associated lens group to be controlled by the cam mechanism, a cam ring which is provided on its one end face with a cam surface with which the guide pin comes into contact, and a cam ring rotating mechanism which rotates the cam ring.

Abstract: The present invention is a mount for optical instruments, and particularly, for a Berek compensator having a birefringent crystal, which can be both tiled and rotated by structure of adjustment rings which are concentric to the optical path of the device.

Abstract: The invention relates to a lens mount assembly used for various kinds of optical apparatus such as photographic camera, motion picture handy camera and video camera, characterized in that the stationary sleeve which has usually been employed to support the cam sleeve and the movable sleeve is eliminated. To this end, the movable sleeve is formed with a plurality of keying grooves and there is provided a supporting framework comprising a plurality of keying levers adapted to be slidably engaged into the respective keying grooves. The cam sleeve is rotatably mounted around the movable sleeve so that the movable sleeve is operatively associated with the cam sleeve and guided by the keying levers to be moved in the direction of the optical axis.

Abstract: Lenses, which include at least one plastic lens, are supported in a lens barrel by a lens holding structure which includes shoulder surfaces and inner circumferential surfaces of a lens barrel, at least one annular elastic member, and a retainer ring. The lenses are radially positioned in coaxial alignment with the lens barrel by the inner circumferential surfaces of the lens barrel, and axially positioned in engagement with the shoulder surfaces by the elastic member and the retainer ring. The elastic member elastically presses one of the lenses against one of the shoulder surfaces, and the retainer ring is threadedly mounted on the outer end of the lens barrel end holds the other lens against the other shoulder surface. Annular spacers may be disposed between the outer circumferential edges of the lenses and the inner circumferential surfaces of the lens barrel, for holding the lenses in coaxial alignment with the lens barrel.

Abstract: A rolling ball element mount and barrel interface comprises a barrel and an element mount sharing a common lateral (X, Y, Z) and angular (.THETA..sub.X, .THETA..sub.Y, .THETA..sub.Z) frame of reference located at a center of said barrel, the element mount adapted to fit inside the barrel axially along Z. A first component, including at least two rolling balls, is disposed between and adapted for contact with the element mount and the barrel for (i) constraining the element mount in lateral positions X and Y and angular positions .THETA..sub.X and .THETA..sub.Y and (ii) moveably coupling the element mount and the barrel in the axial direction. A second component, including at least one rolling ball, is disposed between and adapted for contact with the element mount and the barrel for (iii) constraining the element mount in angular position .THETA..sub.Z in cooperation with the first component and (iv) moveably coupling the element mount and the barrel in the axial direction.

Abstract: An optical magnifying lens installed in the hub of a plier-grip or similar instrument and which also holds the instruments's mating halves together in a snugly rotatable position.