Abstract: A projection module includes a base, a light source, a light valve, a lens module, and an adjustment module. The light source is disposed on the base and capable of providing an illumination beam. The light valve is disposed on the base and capable of converting the illumination beam into an image beam. The lens module is slidably disposed on the base and capable of projecting the image beam. The adjustment mechanism includes a rolling wheel and a slide pin. The rolling wheel is pivotably mounted to the base and includes a slide groove. The slide pin is fixed to the lens module and extends into the slide groove. The rolling wheel is capable of pivoting to drive the slide groove to pivot and the slide groove moves the slide pin to drive the lens module to move with respect to the base when the slide groove pivots.

Abstract: A focus adjustment device for adjusting a focus state of a projection lens unit in an image projection apparatus is provided. The focus adjustment device includes a focus adjustment member rectilinearly movable in a first direction; a rotational shaft; a first movement-converting member for converting a rectilinear movement of the focus adjustment member into a rotary movement of the rotational shaft; and a second movement-converting member for converting the rotary movement of the rotational shaft into in a rectilinear movement of the projection lens unit along a focusing direction.

Abstract: A lens barrel that causes base portions of cam followers in a first optical member and a second optical member to follow a single straight-ahead movement guide groove along an optical axis even when circumferential phases of the cam followers are staggered, so that the optical members can move straight ahead while being inhibited from rotating. The base portion of the cam follower of one of the first optical member and the second optical member has a slide portion that is guided along both inner wall surfaces of a straight-ahead movement guide groove which face each other in a circumferential direction of a straight-ahead moving cylinder. The slide portion has a guide surface that guides the base portion of the cam follower of the other one of the first optical member and the second optical member in the direction of the optical axis.

Abstract: A voice coil motor assembly includes a housing, a voice coil motor, a cover, and a transparent board. The voice coil motor is received in the housing. The cover is secured to the voice coil motor and resists the top surface of the housing. The cover includes a top surface defining an aperture. A limiting element protrudes from the top surface of the cover. The transparent board is adhered to the top surface of the cover and covers the aperture. The movement of the transparent board is limited by the limiting element.

Abstract: A lens barrel includes a lens frame which is movable while supporting a lens; and a restriction portion configured to restrict movement of the lens frame by contacting the lens frame. The lens frame and the restriction portion contact each other at a plurality of points.

Abstract: A lens drive unit includes a movable member with lenses; and a guide portion configured to movably guide the movable member back and forth along a predetermined direction and rotatably guide the movable member about a predetermined rotational axis in a plane perpendicular to an optical axis of the lens. A distance r between the gravity center of the movable member and the rotational axis satisfies the following expression (A): r??{square root over (0.2J/M)}??(A).

Abstract: An exemplary voice coil motor includes a movable unit, a fixed unit, and a resilient plate. The movable unit includes a hollow lens barrel for accommodating a number of lenses, and at least one fine pattern coil fixed on a sidewall of the lens barrel and configured for electrical connection to a power source. The fixed unit includes a hollow frame structured bracket and a number of magnets mounted on the bracket. The bracket accommodates the movable unit. The magnets surround and are spaced apart from the at least one fine pattern coil. The resilient plate is resiliently connected between the bracket and the lens barrel to hold the lens barrel on the bracket.

Abstract: Disclosed is a lens device including a click mechanism of a ring member that is rotated with respect to a lens barrel body, slides in the optical axis direction, has high slidability during a click operation and high durability, and can prevent one-sided abrasion due to the inclination of the ring member. A click mechanism of a first focus ring includes: elastic members for clicking provided at three equally divided positions on the circumference of a front fixed ring of a lens barrel body; and a contact portion that is formed in a central portion of the inner circumferential surface of the first focus ring and comes into contact with a convex portion of the elastic member for clicking. The elastic member for clicking is made of polyacetal with high slidability. Therefore, it is possible to reduce the abrasion of the elastic member for clicking during a click operation.

Abstract: A fixing device includes a stationary frame and a number of elongated resilient tabs. The stationary frame defines a central axis and includes four sidewalls for receiving a number of magnets. Each sidewall includes a receiving hole and at least one protrusion formed on each sidewall at a lower portion thereof. A slot is defined in each protrusion. The tabs correspond to the magnets. Each tab includes an engagement portion, an angled portion, and a contact portion. The angled portion is interconnected between the engagement portion and the contact portion. The engagement portions engage in the respective slots. The contact portions resiliently abut against the corresponding magnets. Each tab is configured to apply a force on the corresponding magnet in a direction toward the central axis.

Abstract: An objective comprises: a first group including a plurality of lens groups arranged at a predetermined interval; a second group composed of a single lens-group; a pressing ring which is screwed in, the pressing ring being for fixing the first group; and an outer frame accommodating the first group, the second group, and the pressing ring, wherein the outer frame includes a first hole at a position facing the second group.

Abstract: A voice coil motor includes a stationary member and a moveable member. The stationary member defines a central axis. The stationary member includes a first receiving room, four sidewalls surrounding the first receiving room and four guide rails formed on the respective sidewalls and located in the receiving room. The moveable member is received in the stationary frame. The moveable member includes a moveable frame. The moveable frame includes four side surfaces. A plurality of restricting posts extend from each side surface and are aligned in a line parallel to the corresponding guide rail. The restricting posts slidably engage in the corresponding guide rails.

Abstract: The size of a driving apparatus to be mounted in a mobile terminal is desired to be reduced. In a driving apparatus according to the present invention, an arm member supports a member to be driven in a slidable manner. A first biasing member has a predetermined spring constant and biases the member to be driven via the arm member. A second biasing member has a spring constant that is smaller than the spring constant of the first biasing member and, by biasing the member to be driven in a direction that goes against the first biasing member, supports the member to be driven along with the arm member. A shape-memory alloy swings the arm member against the first biasing member by contracting when a drive current is supplied. The member to be driven is slid, when the arm member swings, by the second biasing member while keeping contact with the arm member.

Abstract: A lens barrel includes: a variable focal length lens system including at least three movable lens groups; and guiding means for moving the variable focal length lens system forward and backward in an optical axis direction. The variable focal length lens system includes at least first, second and third lens groups having positive, negative and positive refracting power, respectively, arranged in this order from an object side. When a lens position setting is changed from a wide angle end state to a telescopic end state, at least the first and third lens groups are moved toward the object side such that air separation between the first and second lens groups monotonically increases and air separation between the second and third lens groups monotonically decreases. The guiding means includes a fixed frame, a rotating frame, a rectilinear guiding frame, a first guide frame, and a second guide frame.

Abstract: The present invention relates to an image photographing device, and is invented to absorb vibration of the plate spring when the lens holder is moved, thereby stabilizing rapidly the lens holder. According to one example, the small camera provided with a damper includes a lens holder provided with lens and driven in an optical axial direction, a fixing unit housing the lens holder, a plate spring which is arranged to the upper part or lower part of the lens holder and connects the lens holder to the fixing unit and supports it so that the lens holder is moved in an optical axial direction, a driving unit for driving the lens holder in an optical axial direction, a support unit arranged on the lower parts of the lens holder and the fixing unit, and a damper member attached to the plate spring for absorbing vibrations of the plate spring wherein the damper member is made with polymer chemical having an elastic force and the elastic force of the damper member is smaller than that of the plate spring.

Abstract: A zoom lens barrel capable of attaining a higher photographing magnification by reducing spacing between lens groups in a telephoto state. A first lens group barrel holds a first lens group. A second lens group holding member supported by a third cam barrel holds a second lens group. A spring member urges the holding member toward the first lens group. Cam followers are formed at an opposite end of the holding member from the first lens group. Cam grooves for engagement with the cam followers are formed on the third cam barrel. When the holding member is urged by the spring member in a non-shooting region, each cam groove is brought into contact via one cam surface with the associated cam follower. In a shooting region, the cam groove is brought into contact with the cam follower via two cam surfaces.

Abstract: A lens module includes a lens and a lens barrel receiving the lens therein with a gap maintained between a peripheral surface of the lens and an inner surface of the lens barrel. The lens barrel includes a plurality of hole portions with through holes defined therein and facing the peripheral surface of the lens, and a glue applied in the gap to adhere the lens to the hole portions.

Abstract: A lens drive device formed in a substantially quadrangular shape may include a movable body holding a lens, a fixed body movably holding the movable body, and a drive mechanism for driving the movable body in the optical axis direction. The drive mechanism may include first drive magnets respectively disposed on four side faces of the lens drive device, a second drive magnet for restraining inclination which is disposed on at least one of four corners of the lens drive device, and a drive coil which is wound around in a substantially octagonal shape. Magnetic flux passing through the drive coil at one of the four corners of the lens drive device is different from magnetic fluxes passing through the drive coil at the other three corners, or magnetic fluxes passing through the drive coil at two corners adjacent to each other of the four corners of the lens drive device are different from magnetic fluxes passing through the drive coil at the other two corners.

Abstract: The present invention provides a lens barrel that has a first barrel member and a second barrel member, and arranges the first barrel member on an outer circumference of the second barrel member to enable the first barrel member to move in an optical axis direction. The lens barrel includes a plurality of engaging members configured to be held by the first barrel member and engaged with an engagement groove formed in the second barrel member, and to move in the optical axis direction along the engagement groove when the second barrel member rotates, and an annular urging member provided in an outer circumferential portion of the first barrel member and configured to urge the plurality of engaging members to the engagement groove formed in the second barrel member.

Abstract: A video projection device includes: a video display element, a projection lens, a converter lens, and a video processing part. The video display element displays a video by an electrical video signal. The projection lens projects on a screen the video displayed on the video display element. The converter lens is attachably and detachably provided for the projection lens. The video processing part outputs different video signals to the video display element in accordance with whether or not the converter lens is attached.

Abstract: Provided is a drive mechanism comprising a stationary support member, a lever member having a displacement input portion for receiving a moving force from the outside and a bearing portion for abutting against the support member, so that the lever member engages with a driven member and swings on the bearing portion relative to the support member in response to the input of the moving force to the displacement input portion, thereby moving the driven member in a predetermined first axis direction, and a shape-memory alloy actuator for applying the moving force to the displacement input portion. The drive mechanism is characterized in that a displacement input member having the displacement input portion and a bearing member having the bearing portion are formed, in the lever member, of a material different from that of the lever member.

Abstract: A method for driving a lens and a lens driving apparatus, the lens driving apparatus including a base in which a guide member is disposed; a lens support member comprising an installation unit disposed on one side thereof to slidingly move along the guide member, wherein at least one lens is mounted in the lens support member; a driving structure configured to move the lens support member and comprising a lead screw; a working member having one portion contacting the driving structure and another portion contacting one side of the installation unit; an elastic member for providing the installation unit with an elastic force; and wherein a predetermined space is disposed between the installation unit and the base, and wherein the installation unit is configured to be moved to the base by a means other than the driving structure.

Abstract: An interchangeable lens has a zoom lens, a zoom driver operable to drive the zoom lens along an optical axis, a focus lens, a focus driver operable to drive the focus lens along the optical axis, and a storage unit operable to store link information which links position information indicating a position of the zoom lens on the optical axis with information about a variation in magnification caused by the focus lens advancing and retreating on the optical axis with the zoom lens located at the position indicated by the position information.

Abstract: A lens barrel is provided with which manufacturing costs can be reduced. The lens barrel (3) has a first lens group (G1), a second lens group (G2), a third lens group (G3), a first support frame (10) that supports the first lens group (G1), a second support frame (20) that supports the second lens group (G2), a third support frame (30) that supports the third lens group (G3), a first driving unit (50), a second driving unit (60), and a shutter unit (29) that is fixed to the second support frame (20). The first lens group (G1) has an overall negative refractive power, and includes a prism (PR). The second support frame (20) is driven along a second optical axis (A2) by the first driving unit (50). The third support frame (30) is driven along the second optical axis (A2) by the second driving unit (60).

Abstract: A variable focal length lens, as well as a focal length adjusting device and an imaging device using the same. A variable focal length lens has a lens, a positive electrode, and a negative electrode. A second layer and a first layer constituting the lens are formed from polyvinyl chloride with which a plasticizer has been mixed. The hardness of these layers is adjusted by adjusting the mixing quantity, plasticizer type, etc. The second layer is formed so as so cover at least a light transmission region of the first layer. When a voltage is applied between the positive electrode and the negative electrode, the second layer and first layer are deformed to be pulled to the positive electrode, and thereby the curvature of the variable focal length lens is varied to vary the focal length.

Abstract: According to one embodiment, a camera module includes an insulating substrate having an imaging device, solder balls, a cylindrical lens holder, a shield, and a mounting board. The solder balls are formed on a rear face of the substrate. The lens holder is fixed on the substrate and includes an upper larger-diameter portion and a lower smaller-diameter portion. The shield includes a cylindrical side portion fitted onto the small-diameter portion and fixed on the rear face of the large-diameter portion and a plate-shaped bottom portion in contact with the rear face of the substrate and having an opening. The mounting board is on an upper surface of which the plate-shaped bottom portion is mounted to come in contact with the upper surface and the insulating substrate or the imaging device is connected with the upper surface by the plurality of solder balls.

Abstract: A lens drive device may include a movable body holding a lens, a fixed body movably holding the movable body, and a drive mechanism for driving the movable body in the optical axis direction. The drive mechanism may include a drive magnet part formed in a substantially triangular prism shape and disposed at least in one of four corners of the lens drive device, a drive coil wound around in a substantially triangular tube shape and attached to the movable body, and a coil protection member attached to at least one of an object side and an opposite-to-object side of the drive coil. The coil protection member may include a first coil protection end part and a second coil protection end part which are superposed on an outer side end of the drive coil or protruded toward an outer side from the outer side end of the drive coil to prevent the drive coil from contacting with the fixed body such as a case body.

Abstract: A lens apparatus can be easily set even in cases where the lens body and demands are distant from each other upon shooting without a decrease in reliability. A lens body mounted on a camera body is provided with a command signal converting unit, a time-series position signal converting unit, a wireless communication unit, a communication condition monitoring unit and a communication process switch unit. A signal converting unit, to which a zoom demand and a focus demand are connected, is provided with a time-series command signal converting unit, a position signal converting unit and a wireless communication unit. The lens body and the signal converting unit are configured to wirelessly communicate with each other to eliminate the use of connection cables, thereby improving operationality while enabling highly reliable wireless communication.

Abstract: A varifocal lens barrel includes a plurality of lens groups, each of which are linearly movable in the optical axis direction thereof without rotating about the optical axis during a zooming operation and during a focusing operation, including a base barrel which is linearly movable in the optical axis direction by rotation of a zoom operational ring, wherein lens frames of the respective lens groups are each supported by the base barrel.

Abstract: Distance information is displayed at the time of manual focusing but is not displayed at the time of automatic focusing. By rotating a focus switching ring around an optical axis for automatic focusing, an intermediate ring coupled thereto by a cam and a distance display ring rotatably coupled to the intermediate ring are moved along the optical axis to an image side. At this time, the distance display ring and the manual focus ring are uncoupled from each other. With this switching, the distance information written on the distance display ring is also moved to the image side. Therefore, the distance information, which is visible through an information display window of the focus switching ring at the time of manual focusing, becomes invisible.

Abstract: The ranging apparatus of the present invention measures the distance to an object to be imaged by an imaging apparatus using the principle of triangulation ranging, and has a measurement unit in which a maximum distance that can be ranged to an object is not less than ½ of a maximum value of the hyper focal length of the imaging apparatus.

Abstract: A 3-D image pickup apparatus includes a lens portion that includes a lens system; and an adjustment ring portion that includes plural coaxially rotatable rings. Each ring adjusts a respective one of plural optical parameters of the lens system.

Abstract: An imaging apparatus has in a first cam groove a first cam surface whose lead is lying with respect to the rotating direction of a drive ring, and a second cam surface whose lead is steep with respect to the rotating direction of the drive ring, and when transition is effected from an accommodated state to a use state, a follower member passes the first cam surface, and when transition is effected from the state where the follower member is engaged with a second cam groove to the accommodated state, the follower member passes the second cam surface.

Abstract: A lens apparatus of the present invention includes a cam ring 7 having an inner circumferential surface on which first, second, and third cam groove portions 7a, 7b, and 7c with which first, second, and third cam followers 25, 26, and 6 provided on first, second, and third lens holding members 1, 2, and 3 engage. The cam ring introduces the first and second cam followers from an insertion opening 7d and includes an introducing groove portion 7b4 for introducing the third cam follower and a connecting groove portion 7a5. The third cam groove portion is divided at a middle of the introducing groove portion which connects the insertion opening with the second cam groove portion.

Abstract: An interchangeable lens has a zoom lens, a zoom driver operable to drive the zoom lens along an optical axis, a focus lens, a focus driver operable to drive the focus lens along the optical axis, and a storage unit operable to store link information which links position information indicating a position of the zoom lens on the optical axis with information about a variation in magnification caused by the focus lens advancing and retreating on the optical axis with the zoom lens located at the position indicated by the position information.

Abstract: A lens barrel capable of increasing the degree of freedom of installation of a detection unit and capable of making the lens barrel compact in size. The lens barrel includes third and fourth lens groups disposed adjacent to each other and movable in a common optical axis direction. In a first movement section, the third lens group moves in unison with the fourth lens group. In a second movement section adjacent to the first movement section, only the third lens group moves. When a photointerrupter fixed to a cover of the third lens group is light-shielded by a light shield plate formed on a lens holder of the fourth lens group, it is detected that a distance between the third and fourth lens groups becomes a predetermined distance.

Abstract: A gear support mechanism for supporting two gears and an intermediate gear which meshes with the two gears to transfer rotation of one of the two gears to the other, includes a gear-shaft support member(s) which supports a gear shaft of the intermediate gear; and a spring member installed between the gear-shaft support member and the intermediate gear. The spring member includes a gear contacting portion which is in contact with the intermediate gear, and resilient support legs extend radially from the gear contacting portion and are in contact with the gear-shaft support member, the spring member biasing the intermediate gear in a direction of an axis of the gear shaft. Each of the two gears is positioned in an inter-leg space between adjacent resilient support legs as viewed in a direction along the axis of the gear shaft.

Abstract: A lens barrel includes a movable lens unit movable in an optical-axis direction, an actuator configured to move the movable lens unit in the optical-axis direction, a guide member configured to guide the movable lens unit in the optical-axis direction, and a guide-member-holding portion holding the guide member. The guide member is held by the guide-member-holding portion with one end thereof being in a press-fitted state and the other end thereof being in a non-press-fitted state.

Abstract: A lens barrel showing a satisfactory property in assembly and a high dust-proof and drip-proof performance includes: a first member; a lens holding frame configured to hold lens units moving in an optical axis direction to either zoom or focus the lens units; and an elastic member held between respective optical-axis-orthogonal surfaces of the first member and the lens holding frame, wherein the elastic member can be compressed in the optical axis direction during a zooming or focusing operation.

Abstract: A lens driving device for use with a lens to photograph or image an object to be photographed or imaged may include a moving member holding the lens and made movable in the direction of an optical axis, and a supporting member for supporting the moving member through a spring member, wherein the lens is displaced and driven in the optical axis direction thereby to focus the image of the object. The supporting member may include a yoke having a cover portion having an entrance window for introducing the reflected light from the object into the lens, and a case portion for covering the outer circumference of the moving member. The cover portion and the case portion are formed integrally with each other.

Abstract: A lens module includes a barrel and a parallelogram-shaped filter. The barrel defines a through hole bounded by an inner circumferential surface thereof. The barrel includes an end surface substantially perpendicular to the inner circumferential surface. The barrel further defines four positioning cutouts extending from the end surface to the inner circumferential surface. The parallelogram-shaped filter includes four corners fixed in the four positioning cutouts of the barrel.

Abstract: Disclosed is a lens driving apparatus. The lens driving apparatus includes a base formed at a center thereof with a first opening; a housing coupled with the base and having a second opening corresponding to the first opening; a yoke installed on the base and including a horizontal plate having a third opening corresponding to the first opening and a vertical plate protruding upward from the horizontal plate; a bobbin movably installed in the yoke and coupled with a lens module; a coil fixedly disposed around the bobbin; a plurality of magnets provided at the vertical plate of the yoke to face the coil; and a spring installed on at least one of upper and lower portions of the yoke to return the bobbin, which has moved up due to interaction between the magnet and the coil, to its initial position.

Abstract: A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.

Abstract: An integrated lens barrel for a miniature camera is disclosed. The lens barrel can include components such as a shutter, an autofocus mechanism, a zoom mechanism, and/or an image stabilization mechanism. These and/or components can define a portion of the lens barrel that increases the length of the lens barrel. An electrostatic MEMS actuator can be used to effect movement of the autofocus mechanism, zoom mechanism, and/or image stabilization mechanism. Integrating the shutter, autofocus mechanism, zoom mechanism, and/or image stabilization mechanism into the lens barrel facilitates the construction of a substantially smaller camera that is suitable for use in personal electronic devices, such as cellular telephones.

Abstract: Provided is an optical apparatus including: two magnets which are constituent components of drive member for moving a lens holder (21); three balls (25); and two bias members (23) for applying biases such that hook portions disposed in one and the other ends of each of the two bias members are engaged with a base member (28) and the lens holder, respectively, and the three balls are held between the base member and the lens holder. Two magnets (22A and 22B), the three balls, and the two bias members are arranged so that a center of gravity within a plane of the base member, a lens, and the two magnets is positioned in a triangle formed by the three balls, and a line segment within a plane formed by the two bias members steps over two sides of the triangle.

Abstract: The lens barrel has a first lens unit that is disposed at the object side and changeable between a first state, a spacing of the lenses is a predetermined spacing, and a second state, the spacing of the lenses is narrower than in the first state; a second lens unit that is disposed at the image side and capable of changing a focusing state by moving along the optical axis; a restricting member that restricts the change of the first lens unit from the first state to the second state; and driving unit that, in a state in which the change to the second state is restricted by the restricting member, moves the second lens unit toward the image side, wherein the restricting member releases the restriction in association with a completion of the movement of the second lens unit by the driving means.

Abstract: This invention provides a lens driving device with a driving coil connected thereto that can avoid possible damages on the ends of the driving coil and any adverse effect on the spring members or the lens holder. When the ends of the driving coil are connected to the electric terminals mounted on a casing respectively, the coiling pull start section of the driving coil which begins from the beginning end of the driving coil to the electric terminal and the coiling pull finish section of the driving coil which begins from the finish end of the driving coil to the electric terminal are made into L-shaped structures. Such L-shaped structure comprises a lens holder lateral section extending horizontally and a terminal lateral section extending vertically.

Abstract: A lens barrel having an image forming optical system including a first optical system and a second optical system which is moveable independently from the first optical system, a first driving portion which drives the first optical system during a magnification changing operation of the image forming optical system, and a second driving portion which drives the second optical system during the magnification changing operation, along with driving the second optical system during a focus adjustment of the image forming system.

Abstract: Provided are a lens driving unit that generates a precise linear motion in a spatially limited structure by using a bending vibration piezoelectric motor having a new structure, and a camera module comprising the lens driving unit. The lens driving unit includes: a lens carrier supporting a lens and comprising a guide axis exposed at least partially to the outside and extending in a direction substantially perpendicular to the lens; and a piezoelectric driving unit having a center portion contacting the guide axis according to a bending motion of a piezoelectric element and moving the lens carrier in a direction in which the guide axis extends.

Abstract: A cam locus of the cam surface on the image plane side of the first group cam groove of the rotating cylinder has an angle to a flat surface where the optical axis crosses perpendicularly. When the cam follower engages with the cam surface on the image plane side, an impact force is dispersed into the optical axis direction and the rotating direction of the rotating cylinder, and a load on the cam follower and male helicoid is reduced. When the first group lens system is pressed by a light load, the cam follower of the first group lens movement frame engages with the cam surface on the image plane side, and an angle of the cam surface is equal to an angle of a force occurring in the rotating direction. Therefore, the rotating cylinder does not rotate easily, and returns to its previous position when the load is removed.

Abstract: A lens drive device for use with at least one lens may include a movable body holding a lens, a fixed body movably holding the movable body, and a drive mechanism for driving the movable body in the optical axis direction. The drive mechanism may include a drive coil fixed to the movable body and a plurality of drive magnets which is fixed to the fixed body and magnetized so that magnetic poles are different from each other in the optical axis direction. The fixed body may include an outer peripheral side magnetic member and an end face side magnetic member and an inner peripheral face of the outer peripheral side magnetic member and a side face of the drive magnet are faced each other through a predetermined space. The drive coil is disposed between the drive magnet and the inner peripheral face of the outer peripheral side magnetic member.