Abstract: A lens apparatus capable of realizing better optical performance by suppressing an inclination of each lens unit more reliably while shortening the overall length in a collapsed position to the smallest possible level is disclosed. The lens apparatus comprises a fixed member which makes up the body of the apparatus, first and second lens holding members which hold their respective lens units and are movable in the direction of the optical axis with respect to the fixed member and a driving member which engages the first and second lens holding members and drives these first and second lens holding members in the direction of the optical axis.

Abstract: A device for adjusting optical elements, in particular, for X-ray analysis, comprising a holding device (2) for receiving the optical element and at least two adjusting units at least one of the two longitudinal ends of the holding device (2), wherein the adjusting units each comprise one plunger (6, 6a, 6b, 6c, 6d), characterized in that each adjusting unit comprises a rotatably disposed adjusting ring (4, 4a, 4b, 4c, 4d) with an eccentric recess, and the optical element is mechanically coupled to the inner surfaces (7) of the adjusting rings (4, 4a, 4b, 4c, 4d) via the plungers (6, 6a, 6b, 6c, 6d). The adjusting device is compact, can be flexibly used and provides simple adjustment of the optical element.

Abstract: The invention is directed to a microscope objective with axially adjustable correction mounts and is applicable in connection with different cover slips and/or different immersion liquids and/or at different work temperatures. In the microscope objective according to the invention, helical springs which are uniformly distributed along the circumference and act in axial direction are fixed by a first ring which has pins in axial direction on which the helical springs are arranged. The pins engage in bore holes of a second ring. The bore holes are at least deep enough to ensure the required spring path. The two rings with the helical springs arranged therebetween on the pins form a spring retainer which ensures a movement of the parts without play and/or in a springing manner. In principle, the proposed solution can be substituted for all pressure springs in microscope objectives and other objectives and can overcome the disadvantages of using individual springs.

Abstract: A lens module includes a lens set, a rotation base, an outer case, elastic members, a driving device having a stepping motor and a base frame. The lens set is fixed inside the rotation base that is elastically arranged between an upper case and a lower case by elastic members. By clockwise/counterclockwise rotation of the stepping motor outside the rotation base, the rotation base is driven to rotate. Furthermore, a plurality of sloped grooved surface that goes from shallow to deep and faces downwards is disposed on circular bottom surface of the rotation base and each sloped grooved surface presses homogeneously on a corresponding supporting point of the power case by elastic members. When the rotation base rotates, the sloped grooved surface moves relative to the supporting point so that the gap between the shallow and deep grooved surfaces becomes focusing travel. Furthermore, the base frame assembles or disassembles with the lens module by a fastening mechanism.

Abstract: A movable member supporting mechanism includes a support ring; first and second rotatable members provided inside the support ring and supported thereby to be integrally rotatable and to be movable relative to each other in an axial direction thereof; a linearly moving member provided inside the support ring and coupled thereto to be integrally movable with the first rotatable member in the axial direction; a biasing device biasing the first and second rotatable members in opposite directions; and first and second position limiting surfaces formed on an inner peripheral surface of the support ring and are provided apart from each other in the axial direction. The linearly moving member is biased by the biasing device via the first rotatable member. The first and second position limiting surfaces limit positions of the linearly moving member and the second rotatable member in the axial direction, respectively.

Abstract: A system for implementing Berek-type variable retarder plate tipping capability in two orthogonal directions via tipping about a single axis, in combination with a means for rotating the orientation of the axis, having application in ellipsometer and polarimeter and the like systems.

Abstract: There is described a lens barrel including; a plurality of lens units; an actuator to move at least a lens unit included in the plurality of lens units; and a housing member. The actuator includes: a vibrating device constituted by two vibrating members, each of which includes piezoelectric elements aligned in a line, so that the two vibrating members intersect each other at a predetermined angle and vibrate in response to high-frequency electric signals; a driven member, coupled to the lens unit, to be moved by vibrations generated by the vibrating device; and a supporting member that is rotatably mounted on a shaft disposed opposite to the vibrating device in such a manner that the vibrating device press-contacts the driven member. The driven member is disposed at a side of the lens unit, while the vibrating device and the supporting member are disposed at a side of the housing member.

Abstract: Improved optical alignment precision to a passive optical cavity is provided by including a combination of a weak focusing element and a translation plate in the input coupling optics. Adjustment of positions and angles of these optical elements, preferably after all other input optical elements are fixed in place, advantageously provides for high-precision optical alignment to the cavity, without requiring excessively tight fabrication tolerances. Fabrication tolerances are relaxed by making the optical power of the weak focusing element significantly less than the optical power of a strong focusing element in the input optics. The position and angles of the beam with respect to the cavity can be adjusted, as can the size of the beam at the cavity. Differential adjustment of the beam size in two orthogonal directions (e.g., tangential plane and sagittal plane) at the cavity can also be provided.

Abstract: A lens barrel, including, a moving frame (2) to hold a lens (8), a direct-advance ring (4) provided on an outer periphery of the moving frame and movable relative to the moving frame in an optical direction, a resilient member (6) provided between the moving frame and the direct-advance ring, and a control part (10) provided on the moving frame to control an amount of movement of the direct-advance ring in the optical direction.

Abstract: A retainer for holding an optical element having three first grooves includes a first support member that supports the optical element through the first grooves, and a second support member that has three second grooves corresponding to the first grooves, and supports the first support member through the second grooves.

Abstract: An optical assembly includes a barrel including a slot, a lens installed inside the barrel for magnifying an image, a magnification-adjusting mechanism installed outside and around the barrel including an adjusting loop installed outside the barrel in a rotatable manner including a groove on a side facing the barrel, and a roller installed between the adjusting loop and the barrel. The optical machine further includes a rod for adjusting the magnification of the lens. One end of the rod is installed inside the slot of the barrel in a slidable manner, and another end of the rod is installed inside the groove of the adjusting loop in a slidable manner.

Abstract: An image entering from the left side of the figure passes through a correcting lens unit, and forms an image on an image pickup device on the right side of the figure. The correcting lens unit includes a cylindrical outer frame and a lens arranged therein, and at coupling points, coupled to one end of each of electrostrictive coils and suspended thereby. Electrostrictive coils strain in response to voltages applied from a voltage applying unit, causing displacement of electrostrictive coils. The displacement is transmitted to correcting lens unit through the coupling points, and therefore, in accordance with the displacement from electrostrictive coils, position and/or direction of correcting lens unit changes.

Abstract: In an apparatus for positioning an optical element in a structure, particularly in an objective housing of a projection objective for microlithography, the optical element is connected to the structure via fastening elements. The position of the optical element is set by means of adjusting fasteners. The fastening elements are arranged in such a way and the adjusting fasteners can be actuated in such a way that the optical element can be tilted about three mutually independent axes and can additionally be displaced in a translatory fashion in one axial direction.

Abstract: A focusing module includes a casing, at least one fixed magnetic element, a membrane, a movable magnetic element, and a lens. The fixed magnetic element is fixed in the casing for generating a first magnetic field. The membrane is received and retained in an upper section of the casing. The membrane defines a central hole. The movable magnetic element is attached to the membrane, surrounding the central hole of the membrane. The movable magnetic element receives a control signal and in response thereto generates a second magnetic field, which interacts with the first magnetic field of the fixed magnetic field to induce a force acting on the membrane to cause elastic deformation of the membrane. The lens is fixed to the central hole of the membrane whereby the lens is movable with respect to the casing due to the elastic deformation of the membrane caused by magnetic interaction between the first and second magnetic fields of the fixed and movable magnetic elements so as to effect focusing operation.

Abstract: A lens barrel is provided and includes a barrel main body; lens frames supported by the barrel main body so as to be movable in the direction of an optical axis; a focus ring and a zoom ring which are rotatably supported by the barrel main body and move the lens frames in the direction of the optical axis; and a diaphragm device attached to the barrel main body. The focus ring and the zoom ring come into contact with a rotation regulatory section of the diaphragm device, whereby rotation of the focus ring and rotation of the zoom ring are regulated.

Abstract: An axis-adjustable optical device includes: a base; a first adjustment unit including a biasing component disposed between a support seat and the base, and a plurality of screw fasteners for coupling the support seat to the base; a second adjustment unit including a guide hoop coupled and pivotable relative to a pivot seat on the support seat; and a lens unit including a barrel that defines an optical axis, and that has a first segment having a universal coupling relation with a holding seat on the support seat, and a second segment having the guide hoop sleeved thereon. Pivotal movement of the guide hoop relative to the pivot seat drives movement of the barrel to adjust the optical axis.

Abstract: An opening direction of guide grooves formed in sub bearing portions 55, 58 are different from an opening direction of guide grooves formed in the main bearing portions 54, 57. Therefore, when the first, second lens holders 31, 32 can easily be assembled to the main guide shaft 50 and the sub guide shaft 51 by one operation that after the fitting of the sub guide shaft 51 into the guide groove of the sub bearing portion 55, 58 in the first, second lens holder 31, 32, the first, second lens holder 31, 32 is rotated and slid against the sub guide shaft 51 so that the guide groove of the main bearing portion 54, 57 is fitted to the main guide shaft 50 in Y direction.

Abstract: This sliding track for optical apparatus provides a system for mounting and easily moving lens cells and/or other portions of an optical apparatus that are co-axially arranged with respect to an optical axis of the apparatus along said optical axis while maintaining axial alignment. It does so by positioning the lens cells on two linear precision rods placed parallel to the optical axis of the lens cells and optical apparatus. Low-friction plastic inserts are mounted to or in the moving lens cells so that they support said cells on the parallel rods and provide a low friction sliding contact that does not require lubrication. Low-friction plastic holding pads are mounted via springs to the moving cells and are biased against the opposite side of the parallel rods so as to hold the moving cells firmly in position against the parallel rods, but without hampering the cells from sliding smoothly along the rods.

Abstract: The compact image pickup module includes an imaging lens, a lens-barrel holding the imaging lens, an image pickup element, an image pickup element holder holding the pickup element and into which the barrel is fitted so as to be rotatable about an optical axis of the imaging lens and movable in a direction of the optical axis, a cylindrical cam having as an upper or a lower surface thereof, an annular cam surface whose center is set at the optical axis and being formed in one of the barrel and the element holder and an abutment member being abutted against the cam surface under a state where the barrel is fitted into the element holder and formed in the other. After focusing is performed through relative rotation of the barrel and the element holder, the barrel and the element holder are fixed to each other. The lens unit includes the barrel and the imaging lens having multiple lenses held by the barrel.

Abstract: The present invention is directed to an optical pick-up adapted for moving an object lens (7) supported by a lens holder (2) in a focus direction in parallel to the optical axis direction thereof and in a tracking direction perpendicular to the focus direction, and for performing control of tilt angle serving to tilt the optical axis of the object lens following inclination of an optical disc. At the lens holder, there are provided a pair of focus coils (20) and a pair of tracking coils (30).

Abstract: A lens driving device provided with a stator having a cylindrical shape, for generating a magnetic field therein; a rotor located within the stator and being rotation-driven by a magnetic field created by the stator; a lens holder located further inside the rotor, for holding a plurality of lenses with a small lens thereof being located at an arrangement end of the plurality of lenses; a converting mechanism for converting the direction of force of rotation driving of the rotor into direction along the optical axes of the lenses and transmitting the force in the direction thus converted to the lens holder; and a rotation stopper mechanism formed beside the small lens, for preventing the rotation of the lens holder.

Abstract: A holding mechanism for holding an optical element includes a rear side block that includes a rear side holding engagement part that is engageable with a rear side engagement part provided on a rear side of an optical element, a front side block that is coupled with the rear side block and includes a front side holding engagement part that is engageable with a front engagement part provided on a front side of the optical element or the holding member, wherein one of the rear side engagement part and the rear side holding engagement part has a groove and the other has a spherical part that has an at least partially spherical shape engageable with the groove, and wherein one of the front side engagement part and the front side holding engagement part has another groove, and the other has another spherical part that has an at least partially spherical shape engageable with the other groove.

Abstract: A lens-barrel cam mechanism includes first and second ring members; and cam grooves and cam followers formed on the first and second ring members. A single groove/follower set, including one cam groove and one cam follower, and a groove/follower group, including front and rear groove/follower sets at different positions in the optical axis direction, are at different positions single groove/follower set intersects those of the groove/follower group, and condition (a) and/or (b) are satisfied: (a) the cam groove of the single groove/follower set is wider than that of the groove/follower group, and (b) an interval between the cam groove of the single groove/follower set and that of the front groove/follower set and an interval between the cam groove of the single groove/follower set and that of the rear groove/follower set in the circumferential direction are different.

Abstract: An interferometric profiler includes an opening adapted to receive a removable compensating element in the reference arm. The compensating element is mounted on a holder adapted for slidable engagement within the opening. A retaining mechanism keeps the holder firmly in place in the opening. The reference mirror of the profiler is mounted on a slidable stage urged away from the compensating element by a spring-loaded mechanism. A knob is provided to manually push the stage inward to its operating position proximate to the compensating element. A stop ensures that the travel of the stage is limited to a safe distance from the compensating element and a lock is provided to releasably hold the stage in place during use. Multiple objectives with different magnifications may be coupled to the module for alternative use according to the needs of particular applications. An illumination module may also be coupled to the reference-arm module.

Abstract: A positioning structure having a positioning projection on attaching surface is provided. The attaching surface is inclined within an acute angle with respect to a direction orthogonal to an opening and closing direction of a mold for forming the surface. The positioning projection formed on the attaching surface is molded simultaneously by the metallic molding into a truncated right circular conical shape with a tapered trapezoid section that has a tapered surface inclined within an acute angle with respect to a direction perpendicular to the attaching surface on the outer circumference, and has a tapered front end extending in the perpendicular direction. When the angle of inclination of the attaching surface with respect to the direction orthogonal to the opening and closing direction of the mold is defined as “?”, and the angle of inclination of the tapered surface with respect to the direction perpendicular to the attaching surface is defined as “?”, ???>0 is satisfied.

Abstract: An extension spring installation structure of a lens barrel includes relatively movable members, one of which supports an optical element, including an extension coil spring biasing the relatively movable members toward each other; and a spring-hook portion and a tilt-restriction portion formed on a relatively movable members. An engaging portion of the extension coil spring is engaged with the spring-hook portion by movement of the extension coil spring toward the spring-hook portion. The spring-hook portion is shaped so as to be prevented from being disengaged from the engaging portion of the extension coil spring even if moved along the axis of the coil spring portion thereof with the engaging portion engaged with the spring-hook portion. The tilt-restriction portion prevents the coil spring portion from moving in a radial direction of the coil spring portion with the engaging portion engaged with the spring-hook portion.

Abstract: An image pickup module comprises a substrate mounting an image pickup element thereon, a holder mounted on the substrate so as to cover the image pickup element, the holder including a barrel portion for supporting a light receiving lens, the barrel portion having a stopper portion at its inner circumferential surface, a lens holder holding the light receiving lens, the lens holder being screwed and fixed into the barrel portion of the holder, and a spacer interposed between the stopper portion of the holder and the lens holder, the spacer being integrally formed with a sheet-like infrared ray cut film.

Abstract: There is provided a collapsible lens barrel including plural barrels of different outside diameters from one another and enabled to move coaxially and perform relative movement in an axial direction, and an image-capturing optical system disposed within the plural barrels; wherein the image-capturing optical system includes at least two lens holding frames arranged in a direction of an optical axis of the image-capturing optical system; and, considering an object side is set as a front side and an opposite side is set as a rear side, each of a rearmost lens holding frame, placed at a rearmost position, and one of the lens holding frames placed immediately in front of the rearmost lens holding frame, are respectively movably supported by a corresponding guide mechanism to move in the direction of the optical axis and to move in the direction of the optical axis by a corresponding drive mechanism.

Abstract: An arrangement serves for the adjustment of an optical element (1), in particular of a lens in an optical system, in particular in a projection lens system for semiconductor lithography. The optical element (1) is mounted in a mount (3) by means of a number of bearing feet (2) distributed over the circumference of the optical element (1) and is selectively deformable by actuators (5). At least some of the bearing feet (2) are engaged by the actuators (5) in a region of the respective bearing foot (2) in such a way that the respective bearing foot (2) can be displaced in the direction of the optical axis (7).

Abstract: An optical system to attain a clear image of an object when the object is photographed in a state where an optical axis of a lens is inclined relative to the object, includes a lens which refracts light radiating from the object, an image producing surface on which the image of the object is produced according to the light refracted by the lens, and an image producing surface control unit which controls the image producing surface to move with respect to the lens. The image producing surface control unit includes an angle control unit to control an angle between an optical axis of the lens and the image producing surface.

Abstract: A lens device includes: a housing formed with a module-mounting hole that has a hole axis, and provided with a mounting surface that is disposed radially and outwardly of the module-mounting hole; a lens module having a lens axis; and an alignment correction unit for mounting the lens module on the housing at the module-mounting hole. The alignment correction unit includes a module barrel coupled to the lens module, an elastically deformable component clamped by the module barrel toward the mounting surface of the housing, and a set of screw fasteners for fastening the module barrel onto the mounting surface at angularly spaced apart locations relative to the hole axis. Depths of threaded engagement of the screw fasteners with the mounting surface are independently adjustable to permit adjustment of the lens axis of the lens module relative to the hole axis of the module-mounting hole.

Abstract: In an optical unit having a holding structure which brings a junk ring or the like into contact with an optical surface of a lens, the optical surface suffers from a serious elastic deformation leading to deterioration of optical performance. Upon holding the lens, therefore, a face other than the optical surface is provided on the lens so that the lens is held by applying a force to the face from element holding members.

Abstract: A lens tube of a microscope includes a plurality of observation ports, and first and second optical path switching portions that move relative to each other for switching an optical path to an arbitrary one of the observation ports. The first optical path switching portion can switch for guiding light from a specimen to the second optical path switching portion through a first optical element of the first optical path switching portion, or for guiding the light to the second optical path switching portion iwthout passing through the first optical element. The second optical path switching portion can switch for guiding the light from the first optical path switching portion to an arbitrary one of the observation ports through a second optical element of the second optical path switching portion, or for guiding the light to an arbitrary one of the observation ports without passing through the second optical element.

Abstract: When a voltage is applied between outside electrodes and a common electrode that constitute driving parts of a driving unit provided between a holder holding a lens and a lens barrel, as shown in FIG. 9, respective dielectric elastomers provided in the driving parts are slightly deformed in a direction that is crushed in an X1–X2 direction. Thus, the entire lens can be slightly moved in the direction of an arrow (X2-direction). This enables an optical axis O?—O? of the lens to coincide with or get closer to a reference optical axis.

Abstract: A guide bar used in a video lens barrel in the related art has problems of deterioration in supporting accuracy of the lens retaining frame, high manufacturing cost, and upsizing of the lens barrel. Also, in a cam pin type lens barrel, how the lens retaining frame is supported by the cam pins may not be clear. Therefore, by providing a plurality of guiding members on the inner surface of the fixed barrel of the lens barrel, and allowing a plurality of engaging portions on the lens retaining frames to engage the guiding members, the lens retaining frames are supported so as to be capable of moving in the direction of the optical axis. By differentiating the length of engagement of the respective engaging portions, the roles of the respective engaging portions on the lens retaining frames for supporting the lens unit in a space are clarified.

Abstract: A highly versatile optical mount fabricated from a single solid structural body provides accurately centered secured fixturing of a large array of optical components or objects. Fixturing is provided by a unique screw-tensioned strapping mechanism.

Abstract: A magnetically positioned precision holder for optical components in an optical device comprises a carrier for replaceably holding at least one optical component. The carrier is arranged in positionally adjustable fashion in a housing recess including a precision stop surface. Magnet pairs (A1/A2 and B1/B2) are oriented with identical polarity being provided in order to achieve a continuous contact pressure of the carrier (2; 3) against the stop surface (6), in such a way that the one magnet (A1, B1) is located in the recess and the corresponding magnet (A2, B2) is located in the carrier. The use of identically poled magnet pairs for movable precision holders and for precision positioning systems is also proposed.

Abstract: A lens mounting plate to which a projection lens unit is fixed is brought into contact with a sliding base. The lens mounting plate is pressed against the sliding base by the urging of a coiled spring. The pressing force is set such that the position of the projection lens unit can be held and shifted. A cover is provided with a pipe-shaped projection so as to surround the projection lens unit with a clearance corresponding to the shifting width of the projection lens unit between the pipe-shaped projection and the projection lens unit. A user shifts the position of the projection lens unit with his or her fingers laid on the pipe-shaped projection and the projection lens unit.

Abstract: For the purpose of miniaturizing a zoom lens barrel, a zoom lens of the present invention comprises one lens group which moves at the time of variable power, one diaphragm member which moves at the time of variable power, and a cam member which has a cam section for a lens group, which guides the movement of the above-mentioned lens group at the time of variable power, and a cam section for a diaphragms which guides the movement of the above-mentioned diaphragm member at the time of variable power, wherein the above-mentioned cam section for a lens group and the above-mentioned cam section for a diaphragm are coupled.

Abstract: A retainer for holding an optical element having three first grooves includes a first support member that supports the optical element through the first grooves, and a second support member that has three second grooves corresponding to the first grooves, and supports the first support member through the second grooves.

Abstract: Aspects of the invention can provide a projector can include an illumination device that outputs illumination light, a color separation system that divides the illumination light output from the illumination device into blue light, red light, and green light and guides the blue light, red light, and green light to first to third optical paths, respectively, and first to third light modulation devices disposed in the first to third optical paths to be illuminated by the blue light, red light, and green light. In the projector, a distance from the illumination device to the third optical modulation device can be longer than a distance from the illumination device to the first optical modulation device and a distance from the illumination device to the second optical modulation device, a relay system having a first lens disposed at the light incident side, a second lens disposed at the light exit side, and a third lens disposed between the first and second lenses can be provided in the third optical path.

Abstract: A lens apparatus includes a movable optical member, a position detection unit for detecting a position of the movable optical member, a control unit for recognizing position information obtained by the position detection unit and controlling driving of the movable optical member, and a signal input/output unit for synthesizing virtual and photographed pictures. The signal input/output unit can transmit the position information from the position detection unit linked with the movable optical member by three methods based on an analog voltage signal, a digital pulse train and data communication from the control unit.

Abstract: A support mechanism for supporting an optical element includes a first support member for supporting the optical element, a second support member coupled to the first support member via an elastic member, and a forcing member for applying a force to the elastic member to adjust a position and/or an orientation of the optical element.

Abstract: A lens barrel includes a) a plurality of lens groups each having at least one lens, b) a plurality of lens retaining frames, including a retractable lens retaining frame, c) lens retaining frame driving devices, d) a main-guide shaft member in parallel to the optical axis to support the retractable lens retaining frame rotatably in longitudinal and circumferential directions of the main-guide shaft member, and e) a sub-guide shaft member to guide the retractable lens retaining frame along the optical axis and to allow the retractable lens retaining frame to be retracted toward the retracted position at a retracting point on the main-guide shaft member and to guide the retractable lens retaining frame on the main-guide shaft member along the optical axis at other than the retracting point.

Abstract: A method of manufacturing an optical system comprises assembling an optical element on a mounting frame thereof. The mounting frame is disposed on a rotary table having an axis of rotation, and the mounting frame is adjusted such that a predefined axis of symmetry thereof is parallel to the axis of rotation. The optical element is placed on the mounting frame, and an interferometric measurement of a surface of the optical element is performed. The interferometric measurement is analyzed to arrange the optical element relative to the mounting frame such that a predefined axis of the optical element is parallel to the axis of rotation.

Abstract: A projection lens unit includes a main body; a lens fixed to the main body; and a hood disposed to one end of the main body close to a screen. The hood defines the outermost boundary of a view angle stretching with respect to the center of the lens and includes a light-shielding plate and a light-shielding barrel. When the shielding height of the light-shielding plate and the length of the light-shielding barrel are respectively represented by H and L, the shielding height H and the length L are set so as to satisfy the equation tan(?/2)=H/L, in relation to the view angle ?. More particularly, these dimensions are set so as to satisfy the condition that the ratio H/L lies in a range from 0.74 to 0.94. The inner surface of the light-shielding barrel is subjected to surface treatment so as to absorb unnecessary light thereby, reflect it thereat, or scatter it thereat. To be more specific, the light-shielding barrel has scattering grooves disposed on the inner surface thereof.

Abstract: A holding system for holding an optical element. The holding system includes a ring-like inner holding member, disposed at an outer periphery of the optical element, for supporting the optical element by use of at least a pair of pieces, in which the inner holding member has at least a pair of driving units with an actuator, for supporting the optical element through the actuators, a ring-like outer holding member disposed at an outer periphery of the inner holding member and connected to the inner holding member at plural points, and three elastic members for supporting the holding member. The inner holding member supports the optical element by use of one pair of the pieces, which are disposed opposed to each other, in which one pair of the driving units of the inner holding member is disposed opposed to each other and provided on the inner holding member at two points. Each point is defined between the one pair of opposed pieces.

Abstract: Disclosed is an optical system of a zoom-camera comprises a plurality of lens groups so that the path of a light can be multi-directionally refracted. The optical system comprises a base member, a first lens group mounted on the base member for refracting a light reflected and incident from an object to a first direction, a second lens group for effecting a zoom function, a third lens group for refracting the light passing through the second lens group to a second direction, a fourth lens group for effecting a zoom function as well as a focusing function while compensating a variation of an image plane caused by the zoom function, and power transmission means for transmitting power for sliding the second and fourth lens groups.

Abstract: A lens barrel and an optical device that can be reduced in size while maintaining high optical performance. A lens barrel has a cam ring (3) that is disposed for rotation about an optical axis. A linked member (37) can advance and recede in a direction of the optical axis with rotation of the cam ring about the optical axis. First and second cam grooves (3d, 3e) is formed in the cam ring for guiding advancement and receding of the linked member in the direction of the optical axis. First and second cam-followers (8a, 8b) are provided in the linked member and are engageable with the first cam groove and the second cam groove, respectively. The second cam-follower is disengageable from its corresponding second cam groove. A depth of the second cam groove in a position where the second cam-follower is introduced into the second cam groove is deeper that of the second cam groove at a different position.

Abstract: A sphere mount for a ball mounted retro-reflector having a perimeter recess and a base shank. The sphere mount is configured to receive a ball mounted retro-reflector in a centrally disposed conical nest, such as a three-point conical nest, and to position it with a high degree of precision over the central axis of the base shank to within ±0.0005 of an inch. The perimeter recess is in the form of a single oblique scallop, orientated from the upper surface to the lower surface, and permits a maximum negative acceptance angle for incident light to a mounted spherical retro-reflector with no occlusion by the sphere mount perimeter.