Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a third magnetic layer provided between the second magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first and second magnetic layers, a second non-magnetic layer provided between the second and third magnetic layers, a third non-magnetic layer provided between the first magnetic pole and the first magnetic layer, and a fourth non-magnetic layer provided between the third magnetic layer and the second magnetic pole. A first magnetic pole length is shorter than a second magnetic pole length. A first magnetic layer length is longer than a second magnetic layer length.

Abstract: Disclosed embodiments provide an integrated access control system. The integrated access control system includes both credential reader functionality and door controller functionality in the same package. In embodiments, the circuitry is miniaturized to fit within a standard “single gang” box such as those used for a standard light switch or receptacle. In this way, the integrated access control system of disclosed embodiments installs easily and unobtrusively in standard sized openings. To operate in a confined area such as a single gang box enclosure, a variety of thermal management and power management techniques are employed to provide reliable operation.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

Abstract: A passive alignment system is provided that comprises one or more first meltable elements disposed on a surface, one or more second meltable elements disposed on a surface and one or more first standoff devices. The first and second meltable elements transition from first and second pre-molten states, respectively, to first and second molten states, respectively, when subjected to first and second temperatures, respectively. In the first molten state, the first meltable elements control relative alignment between the surfaces in first and second dimensions. In the second molten state, the second meltable elements and the first standoff devices control relative alignment between the surfaces in a third dimension. The passive alignment system is suitable for use in a parallel optical communications module to precisely passively align ends of a plurality of optical fibers or waveguides with respective light sources or light detectors of the module.

Abstract: A coordinate measuring apparatus includes a base on which an object to be measured is mounted, a movable X-axis beam, a Y-axis column with a hollow part that is provided on the base and supports the X-axis beam, a control unit that is provided under the base and controls the movement of the X-axis beam, and a cable that is wired from the X-axis beam to the control unit through the hollow part of the Y-axis column.

Abstract: A magnetic head includes a slider defining an air bearing surface (ABS) and having a trailing face approximately orthogonal to the ABS. A transducer is disposed on the trailing face and includes a reader and a writer. The writer comprises a non-ferromagnetic writer encapsulate material, and includes a ferromagnetic write pole embedded in the non-ferromagnetic writer encapsulate material. The reader comprises a non-ferromagnetic reader encapsulate material, and includes a magnetoresistive sensor stack embedded in the non-ferromagnetic reader encapsulate material. The magnetic head further includes a novel dual overcoat having a writer overcoat material disposed on the writer, and a reader overcoat material disposed on the reader. The reader overcoat material comprises diamond-like carbon (DLC), and the writer overcoat material does not comprise DLC. An example method for fabricating the novel dual overcoat is also disclosed.

Abstract: Embodiments disclosed herein generally relate to a head slider within disk drive data storage devices. A head slider comprises a head body having a leading portion on a leading edge and a trailing portion on a trailing edge. The leading portion includes a first leading pad disposed at the MFS and a second leading pad disposed between the first leading pad and the leading edge. The second leading pad is recessed a first vertical distance from the MFS. One or more particle trapping holes are disposed between the first leading pad and the second leading pad. The one or more particle trapping holes are recessed a second vertical distance from the MFS, the second vertical distance being greater than the first vertical distance. Particles encountered by the leading portion may be suctioned into the one or more particle trapping holes, preventing the particles from building-up onto the MFS.

Abstract: A method of manufacturing a magnetic read-write head, including the steps of presenting a row bar to a processing location, the row bar including an air bearing surface, at least one read-write head, at least one electronic lapping guide, and at least one trigger device, wherein each electronic lapping guide is positioned at a different distance from the air bearing surface than each trigger device, and wherein the read-write head and at least one of the trigger devices include a multi-layer stack of materials; lapping the air bearing surface while measuring the electrical resistance of at least one electronic lapping guide and at least one trigger device until the resistance measurement of the trigger device provides an open circuit reading, and measuring an offset resistance value of the at least one electronic lapping guide concurrently with the measurement of the open circuit reading by the trigger device.

Abstract: Approaches to improving actuator settle time by damping vibrations resulting from coil modes, such as with a voice coil actuator in a hard disk drive, include a single-piece damper plate coupled to the voice coil actuator yoke. The damper plate may be a single U-shaped piece of metal that covers the area of the yoke that experiences the maximum strain energy during operation, between the voice coil and the pivot bearing housing.

Abstract: An apparatus includes a near-field transducer at or near an air bearing surface of the apparatus. A write pole is disposed at or near the air bearing surface and proximate the near-field transducer, respectively. A thermal sensor is disposed at the air bearing surface and within a protrusion region of the air bearing surface defined relative to at least one of the near-field transducer and the write pole. The thermal sensor is configured to produce a signal indicative of a temperature at the protrusion region.

Abstract: The present invention relates to a plasmon generator, in which a surface plasmon is excited by application of light. The plasmon generator extends along one direction. The plasmon generator includes a first end surface that is positioned on one end in the one direction and at which near-field light is generated along with the excitation of the plasmon; and a second cross section that is substantially parallel to the first end surface and is away from the first end surface. The first end surface has a polygonal shape that does not have a substantially acute inner angle. The second cross section has an upper part that has a shape substantially the same as or similar to that of the first end surface and a flare shaped lower part that is connected to the upper part and has a width that increases as it is far from the upper part.

Abstract: A magnetic read sensor having an antiferromagnetic located embedded within a magnetic shield of the sensor so that the antiferromagnetic layer can pin the magnetization of the pinned layer without contributing to read gap thickness. The sensor is configured with a pinned layer having a free layer structure located within an active area of the sensor and a pinned layer that extends beyond the free layer and active area of the sensor. The antiferromagnetic layer can be located outside of the active and exchange coupled with the extended portion of the pinned layer.

Abstract: A magnetic sensor having a novel pinning structure resulting in a greatly reduced gap spacing. The sensor has a magnetic free layer structure that extends to a first stripe height and a magnetic pinned layer structure that extends to a second stripe height that is longer than the first stripe high. A layer of anti-ferromagnetic material is formed over the pinned layer structure in the region beyond the first stripe height location. In this way, the antiferromagnetic layer is between the pinned layer and the second or upper shield and does not contribute to gap spacing.

Abstract: A magnetic medium for perpendicular magnetic data recording having improved corrosion characteristics and reduced surface roughness. The magnetic medium includes an under-layer and a perpendicular magnetic recording layer formed over the under-layer. The under-layer can be formed of MgO and has an oxygen concentration that is greater at the perpendicular magnetic recording layer than it is away from the perpendicular magnetic recording layer.

Abstract: A disk drive read circuit is disclosed comprising a read element for generating a read signal, and a sense amplifier comprising an input terminal coupled through a first capacitor to the read element and an output terminal coupled through a second capacitor to a transmission line, wherein the sense amplifier is for amplifying the read signal.

Abstract: A magnetic medium for perpendicular magnetic data recording, having improved magnetic properties through use of a novel seed layer. The magnetic medium includes a substrate having a seed layer, a magnetic under-layer and a magnetic recording layer formed there-over. The seed layer includes an element selected from a first group of Cr, Co, Fe and Ni, and at least one element that is selected from the other elements of the first group or from a second group consisting of W, Mo and Ru. A buffer layer may be included between the substrate and the seed layer.

Abstract: An apparatus includes a slider structure having a waveguide and a cavity configured to align a laser to the waveguide. The cavity includes a plurality of solder bumps on a bottom of the cavity configured to electrically and thermally couple the laser to the slider. At least one mechanical stopper is disposed in the cavity to facilitate vertical alignment between an output of the laser and an input of the waveguide. At least one solder bump is disposed on the mechanical stopper to facilitate lateral alignment between the output of the laser and the input of the waveguide in response to a reflow of the solder bumps.

Abstract: Techniques of the present invention include detecting a touchdown between a read/write head of a disk drive and a surface of a magnetic disk using multiple touchdown sensors located at an air-bearing surface (ABS). The multiple sensors increase the likelihood that a touchdown event—i.e., a portion of the ABS of the head contacting the underlying magnetic disk surface—will be detected. During touchdown, the portion of the head contacting the magnetic disk generates frictional heat which changes a characteristic (e.g., the electrical resistance) of at least one of the sensors located at the ABS. When the sensors are connected to a detection circuit, the changing characteristic may be monitored to identify a touchdown event. The touchdown sensors may be, for example, electrically connected in either series or parallel to the detection circuit. Thus, as long as the electrical resistance of one of the sensors is changed, a touchdown event may be detected.

Abstract: An MR element includes an MR part and upper and lower shield layers in a CPP structure. The MR element has side shield layers so as to interpose the MR part between the side shield layers in a track width direction. The MR part comprises a nonmagnetic intermediate layer and first and second ferromagnetic layers so as to interpose the nonmagnetic intermediate layer between the ferromagnetic layers. Each of the upper and lower shield layers has an inclined magnetization structure such that its magnetization is inclined relative to the track width direction. The side shield layers are magnetically coupled with the upper shield layer, respectively. The second ferromagnetic layer is indirectly magnetically coupled with the lower shield layer via an exchange-coupling functional gap layer. The side shield layer applies a bias magnetic field to the first ferromagnetic layer; and magnetizations of the first and second ferromagnetic layers are substantially orthogonal.

Abstract: An apparatus includes a near-field transducer at or near an air bearing surface of the apparatus. A write pole is disposed at or near the air bearing surface and proximate the near-field transducer, respectively. A thermal sensor is disposed at the air bearing surface and within a protrusion region of the air bearing surface defined relative to at least one of the near-field transducer and the write pole. The thermal sensor is configured to produce a signal indicative of a temperature at the protrusion region.

Abstract: Write enhancement circuitry on the head carrier of a magnetic recording disk drive provides additional write current overshoot beyond that provided by the write driver circuitry. The write enhancement circuitry is formed on the head carrier as ladder network blocks. A first ladder network block is a first capacitor C1 located in parallel with the write coil. The second ladder network block includes a second capacitor C2 having substantially the same inductance L2. The compensation circuitry is referred to as a ladder network because additional ladder blocks, like the second block but with different values of capacitance and inductance, may be located on the head carrier.

Abstract: A magnetic-recording head with touch-down detector incorporating a carbon nano-tube (CNT). The magnetic-recording head includes a write element, a read element and a touch-down detector. The write element is configured to write data to a magnetic-recording disk. The read element is configured to read data from the magnetic-recording disk. The touch-down detector includes a thermal sensor, and a CNT portion. The thermal sensor is configured to convert heat to a voltage signal. The CNT portion is configured to touch down on the magnetic-recording disk. The CNT portion is also coupled to the thermal sensor, and is configured to transfer heat generated by contact between the CNT portion and the magnetic-recording disk to the thermal sensor. A hard-disk drive (HDD) including the magnetic-recording head with touch-down detector incorporating a CNT, and a method for detecting contact between the magnetic-recording head and a recording surface of a magnetic-recording disk are also provided.

Abstract: The presently disclosed technology describes systems and methods for attaining a ball bond using less than 1 thousandth of an inch diameter gold wire using ultrasonic bonding energy and without heating an underlying bonding pad. The ball bond allows the use of particularly small bonding pads that are particularly close to adjacent microelectronic structures that limit the use of other bonding techniques that have shallow take-off angles.

Abstract: A multi-stage sensor is situated on the head transducer and configured to interact with a magnetic recording medium. A first sensor stage of the multi-stage sensor has a temperature coefficient of resistance. A second sensor stage of the multi-stage sensor is coupled to the first sensor and has a temperature coefficient of resistance. The first sensor stage is configured to preferentially sense asperities of the media relative to the second sensor stage, and the second sensor stage configured to preferentially sense proximity to, and contact with, a surface of the media relative to the first sensor stage. The first and second sensor stages may be connected in series or in parallel.

Abstract: A magnetic media having a novel cap layer that allows the cap layer having improved exchange coupling and reduced thickness. The cap layer is doped with a non-reactive element such as Ar, Kr, Xe, Ne or He preferably Ar. This doping reduces increases exchange coupling and reduces the dead layer, allowing the cap layer to be made thinner for reduced magnetic spacing and improved data recording performance.

Abstract: A magnetic head includes a main magnetic pole, a trailing shield that forms a magnetic circuit with the main magnetic pole, a spin torque oscillator that is provided between the main magnetic pole and the trailing shield, a first cooling layer that partially has a Heusler structure, and a second cooling layer that is provided on the first cooling layer and mainly comprised of silver. The first cooling layer and the second cooling layer are provided either between the main magnetic pole and spin torque oscillator or between the trailing shield and the spin torque oscillator, with either of the two cooling layers being disposed closer to the spin torque oscillator. A third cooling layer may be formed to be in contact with the first cooling layer.

Abstract: A magnetic head includes a main pole, a write shield, and a return path section. The write shield includes first and second shield portions located on opposite sides of the main pole in the track width direction. The return path section includes first and second yoke portions located on opposite sides of the main pole in the track width direction. The first yoke portion is connected to the first shield portion. The second yoke portion is connected to the second shield portion. A coil surrounds at least part of the entire outer periphery of the main pole when viewed from a medium facing surface.

Abstract: A writer includes a leading edge, a trailing edge, a longitudinal axis defined between the leading and trailing edges, and a transverse axis orthogonal to the longitudinal axis. A writer region is provided at a protruded section of the trailing edge oriented along the longitudinal axis. A write pole is arranged at the protruded section to write data to two locations spaced apart from one another relative to the transverse axis for a range of skew angles.

Abstract: According to one embodiment, there is provided a magnetic recording apparatus including a head slider including read and write elements, and a magnetic recording medium including magnetically recordable recording tracks with a width L1, a wide land track with a width L2 larger than the width L1 of the recording track, and non-recording sections with a width G1 each provided between adjacent recording tracks. The width L1 of the recording track is smaller than a bottom read width BRW of the read and write elements, and the width L2 of the wide land track is larger than the bottom read width BRW of the read and write elements.

Abstract: A magnetic read head having a reduced read gap and a stable magnetic pinned layer structure. The sensor includes a seed layer that has a surface formed with an anisotropic texture. A magnetic pinned layer formed over the seed layer has a body centered cubic structure which causes the pinned layer structure to have a magnetic anisotropy with an easy axis oriented perpendicular to the air bearing surface when deposited over the textured seed layer. A magnetic free layer structure formed over the pinned layer structure and over a non-magnetic barrier layer has a face centered cubic structure which causes the magnetic free layer to have a magnetic anisotropy with an easy axis oriented parallel with the air bearing surface.

Abstract: A control mechanism may control the height and/or position of a read/write head configured to interact with a rotating information storage surface. The control mechanism may be a reactionless control mechanism configured to apply a counterforce to offset movements of the read/write head and/or a slider. A topography detection mechanism may detect topography of a side read/write track while the read/write head is interacting with a current read/write track. A memory may store the detected topography. The control mechanism may adjust the height of the read/write head based on the stored topography. The topography detection mechanism may compute the detected topography from gap measurements using a dynamic filter including a model of read/write head dynamics.

Abstract: A first inner ring and a second inner ring respectively include inner ring rolling surfaces formed so that the external radius of inner end portions is smaller than a first separation distance and formed so as to have an external radius that become larger than the first separation distance, and a first outer ring and a second outer ring respectively include outer ring rolling surfaces formed so that the internal radius of outer end portions is larger than a second separation distance and formed so as to have an internal radius that becomes smaller than the second separation distance, and the first outer ring and the second outer ring are formed integrally with each other to form an outer ring.

Abstract: A microwave assisted magnetic recording write head having a spin torque oscillator capable of producing high strength high frequency magnetic oscillations with reduced applied current. The spin torque oscillator uses a magnetic field generation layer with a high moment material including such as Fe and Co that is formed on an interlayer having a face centered cubic (fcc) crystal structure, that functions as an under-layer. The high moment magnetic field generation layer has also reduced magnetic damping.

Abstract: According to one embodiment, a magnetic recording head manufacturing method includes forming a spin torque oscillator layer on a main magnetic pole layer, forming a mask on the spin torque oscillator layer, processing the spin torque oscillator layer by performing ion beam etching through the mask, and partially modifying the main magnetic pole layer through the mask. The partially modifying the main magnetic pole layer makes it possible to decrease the saturation flux density of the main magnetic pole layer in the modified portion, and form an unmodified main magnetic pole portion covered with the mask, and a modified portion around the main magnetic pole.

Abstract: A method for quasi-static testing a magnetic recording head read sensor is described. The method includes applying a first voltage to a heater in the magnetic recording head and measuring an output of the magnetic recording head read sensor while applying the first voltage to the heater and recording the measured output as a first set of measurements. The method further includes applying a second voltage to the heater in the magnetic recording head and measuring the output of the magnetic recording head read sensor while applying the second voltage to the heater and recording the measured output as a second set of measurements. The first and second sets of measurements are then compared.

Abstract: A magnetic recording device comprises a slider body having a slider interface surface and a magnetic transducer having a lower surface coplanar with an air bearing surface of the magnetic recording device. The magnetic transducer has a transducer interface surface perpendicular to the air bearing surface The magnetic recording device further comprises a piezoelectric actuator operably connecting the slider interface surface and the transducer interface surface. The piezoelectric actuator is configured to translate the magnetic transducer with respect to the slider body in a direction substantially parallel to the slider and transducer interface surfaces. The piezoelectric actuator comprises a plurality of elongate flexures disposed in parallel planes within a body of the piezoelectric actuator.

Abstract: A transducing device may include features for adjusting the fly height between the transducing device and a magnetic storage medium. In one example, the transducing device includes a transducing element, at least one heating element, a permanently deformable material portion, and a temporarily deformable material portion. In this example, the permanently deformable material portion is configured to permanently deform in response to heat from the at least one heating element, and the temporarily deformable material portion is configured to temporarily deform in response to heat from the at least one heating element. The fly height of the device may be adjusted using lower temperatures and less energy than some other types of devices.

Abstract: A row bar with smart sensor for forming sliders, which comprises a row of slider forming portions, each slider forming portion comprising a slider to be cut from the row bar and a medial region adjacent the slider; each slider comprises a slider body and a magnetic writer disposed in the slider body, with the magnetic writer having a main pole which includes a pole face for being lapped, and all the main poles are arranged in a row; the row bar has at least one smart sensor disposed therein, with the smart sensor having at least three dummy poles, whose structure is identical to that of said main pole, arranged in the row of the main poles, there is a space between every two adjacent dummy poles of said smart sensor, and there is a offset in the direction vertical with the pole face between every two adjacent dummy poles of said smart sensor. The invention also discloses a method of manufacturing the slider.

Abstract: A recording head includes a main magnetic pole generating a recording magnetic field in a direction perpendicular to a recording medium, a write shield magnetic pole facing a trailing side of the main magnetic pole, a recording coil exciting a magnetic flux in a magnetic circuit, and a spin torque oscillator provided between the main magnetic pole and the write shield magnetic pole. The main magnetic pole includes a trailing side end surface that faces the spin torque oscillator and is tilted toward a leading side of the recording head with respect to the direction perpendicular to the recording medium, and the spin torque oscillator has layers with tilted surfaces that are substantially in parallel with the trailing side end surface.

Abstract: Apparatus for two dimensional reading. In accordance with some embodiments, a magnetic read element has a bias magnet disposed between a plurality of read sensors. The bias magnet may be configured to concurrently bias each read sensor to a predetermined magnetization.

Abstract: A suspension substrate according to the present invention includes: an insulating layer; a spring material layer provided on one face of the insulating layer and having conductivity; and a plurality of wirings provided on the other face of the insulating layer. One wiring includes a head-side wiring part extending from the head portion, and a plurality of division wiring parts respectively bifurcated from the head-side wiring part. The spring material layer includes a spring material main body, and a wiring spring material part separated from the spring material main body, via a groove. A conductive connecting part extending through the insulating layer is provided in the insulating layer. Each of the division wiring parts of the one wiring is connected with the wiring spring material part, via the conductive connecting part.

Abstract: An apparatus includes a transducer assembly including a waveguide and a grating structured to couple electromagnetic radiation into the waveguide; and a body including an extended cavity vertical cavity surface emitting laser diode, and having an air bearing surface, wherein the transducer assembly is positioned adjacent to the body and the laser diode directs electromagnetic radiation onto the grating. A method of making the apparatus is also included.

Abstract: A patterned magnetic media having offset servo and data regions. The media can be constructed by a method that allows both a data region and a servo region to be patterned without the patterning of one region adversely affecting the patterning of the other region. The method results in a patterned data region a patterned servo region and intermediate regions between the servo and data regions. The intermediate regions, which are most likely, but not necessarily, asymmetrical with one another indicate that the method has been used to pattern the media.

Abstract: A method for determining the surface distortions of a disk in a spin-stand or single or multiple disk hard disk drive (HDD) utilizing a DFH type write head. A stepwise power curve is supplied to the DFH head, the head is flown over a chosen track on the disk, and the high frequency signal from a HDI sensor is analyzed in order to determine the step of an initial touchdown power and the step of a complete touchdown power as a function of individual sectors in a sector subdivision along a chosen track. The HDI sensor signal is averaged within each step of the power curve between these two steps and a Ratio variable, Ratio=(Max. amplitude)/(RMS amplitude) is calculated for each step and is averaged over each rotation of the disk during the step.

Abstract: A heat enabled magnetic media having a composite magnetic recording layer structure that includes first and second magnetic layers and an exchange coupling layer sandwiched between the first and second magnetic layers. The exchange coupling layer has a reduced Curie temperature that allows the magnetic layers to become decoupled a lower temperature. This reduced Curie temperature can be achieved the addition of an alloying element such as Ni or Cu into the exchange coupling layer. Therefore, the exchange coupling layer can be constructed of an alloy such as FePtNi FePtCu, and the magnetic layers can be constructed of a material such as FePt.

Abstract: A suspension substrate includes a metal substrate, a first insulating layer provided on the metal substrate, a first wiring line layer provided on the first insulating layer, a second insulating layer provided on the first insulating layer and the first wiring line layer, and a second wiring line layer provided on the second insulating layer. When a total of a thickness of the first wiring line layer and a thickness of the second insulating layer on the first wiring line layer is T1 and a thickness of the second insulating layer at a position where a surface of the second insulating layer is flat and which is away from the first wiring line layer by a predetermined distance is T2, T1?T2<4.5 ?m is satisfied.

Abstract: According to embodiments of the present invention, a piezoelectric actuator is provided. The piezoelectric actuator includes a shear mode piezoelectric material including a first arm and a second arm intersecting each other, the shear mode piezoelectric material having a polarization direction oriented at least substantially along a length of the first arm, wherein the shear mode piezoelectric material has a first surface and a second surface opposite to the first surface, the first surface and the second surface being adapted to undergo a shear displacement relative to each other along an axis at least substantially parallel to the polarization direction in response to an electric field applied between the first surface and the second surface in a direction at least substantially perpendicular to the polarization direction.

Abstract: According to one embodiment, a recording head includes a main pole formed of a soft magnetic material, a write shield pole formed of a soft magnetic material and on a trailing side of the main pole with a write gap, and side shields on both sides of the main pole in a track width direction and including nonmagnetic cavities formed of a nonmagnetic material in inner portions of the side shields. The side shields includes surfaces formed of a soft magnetic material and configured to be between a distal end portion of the main pole and the nonmagnetic cavity and between the recording medium and the nonmagnetic cavity.

Abstract: A magnetic data recording system wherein the wherein adjacent track interference during writing is avoided by modulating the size of a write bubble on the magnetic media in response to a position error signal. If the position error signal indicates that the magnetic head is off-track, circuitry within the magnetic data recording system adjusts the size of the write bubble temporarily to prevent the write bubble from encroaching on a neighboring data track. This adjustment of the write bubble can be accomplished by adjusting power to the write head. Adjustment of the write bubble can also be achieved by adjusting power to a magnetic oscillator in a microwave assisted magnetic recording system (MAMR) or adjusting power to a heating element in a thermally assisted magnetic recording system.

Abstract: A rotating device includes a fluid dynamic bearing unit. The fluid dynamic bearing unit includes a shaft encircling member that encircles a shaft, an intermediate encircling member that encircles the shaft encircling member, a shaft holder formed with a shaft hole into which an end of the shaft is fitted to fix the shaft, a base-side encircling member fixed to the shaft holder and encircling the intermediate encircling member, and a ring member fixed to the intermediate encircling member and encircling a rod encircling member. A lubricant is present between a rotating body and a fixed body. A first air-liquid interface is present between the base-side encircling member and the intermediate encircling member, and a second air-liquid interface is present between the ring member and the rod encircling member.