Abstract: Pump depletion modulation crosstalk between WDM channels in Raman amplified systems is virtually eliminated by exclusive use of backward pumping.

Abstract: A high speed optical receiver for receiving a substantially diminished optical signal. An optical amplifier amplifies the diminished optical signal at least several db and an ultra narrow-band filter filters the noise generated in the optical amplifier to produce a filtered amplified optical signal which is detected by a fast response photo detector. In a preferred embodiment the optical amplifier is a semiconductor laser amplifier. In this embodiment a Faraday filter provides the ultra narrow-band filtering, virtually eliminating the noise produced by the amplifier. Transmitters are described for transmitting information at a wavelength tuned to the ultra narrow-band filters.

Abstract: An optical receiver having a photodiode and a preamplifier includes a charge controller which charges a capacitor depending on an received voltage signal at each burst timing of the burst-mode signal and then discharges the capacitor with a predetermined time constant to produce an amplitude-varying offset component. The current signal of the photodiode is controlled so that the amplitude-varying offset component is canceled out.

Abstract: An optical arrangement is disclosed wherein an entering beam is converted into an exiting beam having a total cross section of light which is linearly polarized essentially in the radial direction by rotation. For this purpose, rasters of half-wave plates (41, 42, 4i), a combination of birefringent quarter-wave plate 420 and a circular plate 430 is suggested in combination with a conical polarizer 21′. This arrangement is preferably utilized in the illumination portion of a microlithographic projection exposure system. It is important that the arrangement be mounted behind all asymmetric or polarizing component elements 103a.

Abstract: There are provided a circular transparent electrode provided on a first substrate at the center thereof, a plurality of annular transparent electrodes which are disposed outside the circular transparent electrode concentrically and narrowed in width and interval as they are directed outward, extension electrodes which extend crosswise outward from the center to an external terminal electrode, and an alignment layer on these electrodes. There are also provided a transparent electrode on an entire surface of a second substrate, and an alignment layer on the transparent electrode, wherein the first and second alignment layers are subjected to a parallel aligning treatment. The first substrate and the second substrate are bonded to each other while keeping a given internal by gap members disposed outside the annular transparent electrodes, and a nematic liquid crystal is sealed in a gap between the first substrate and the second substrate.

Abstract: A micromachined linear light valve uses a linear array of cantilevers to stop an array of focused light beams. The response time is fast as the movement of the cantilever has to be about the size of the focused spot, which is below one micron. The focusing optics can be a cylindrical lens, covering the full length of the linear array or an array of aspheric lenslets.

Abstract: An improved memory cell (300) for use in applications, such as micromirror arrays, in which little space is available and a slow read-back cycle is tolerated. The memory (300) comprises a first input/output node (314) connected to the input of a first inverter and to the output of a second inverter. The first inverter is comprised of two transistors (304, 306) and drives a signal to a second input/output node (316). The input of the second inverter is connected to the second input/output node (316). When used to drive a typical micromirror cell, the address electrode of the micromirror cell are electrically connected to the first input/output node (314) and the second input/output node (316).

Abstract: An infrared ray blocking transparent film which can be very thin and have greater transparency and higher adhesion than that of conventional films; the cost for forming the film can be lower due to the reduced amounts of forming materials used for the infrared ray blocking layer, is disclosed. An infrared ray blocking layer is provided on a surface of a base film, by coating conductive materials including indium tin oxide powder and resin; a hard coat layer is provided on a surface of the infrared ray blocking layer; an adhesive layer is provided on a rear surface of the base film. Since resin employed in the infrared ray blocking layer is UV-curing resin including photo-cationic polymerization initiator, thickness of the layer is reduced, and transparency and adhesion thereof are improved.

Abstract: A confocal microscope apparatus includes a disk scanner for scanning a specimen with a laser beam, and camera main body for photographing a still image. An exposure time calculation circuit is arranged to generates an exposure time signal for the camera main body. A rotation sensor, a scan track start point/end point determination circuit, and a rotation period calculation circuit are arranged to generate a rotational period signal for the disk scanner. A comparator compares the exposure time signal with the rotational period signal, so that a motor controller and a motor driver control rotation of a motor of the disk scanner by a comparison output from the comparator.

Abstract: A video projection screen assembly for the viewing of images projected thereon and designed to be selectively disposed between an exposed, expanded position for viewing and a collapsed position for storage. A viewing screen is mounted on and supported by a support frame structured to dispose and maintain the viewing screen in the vertical, expanded position for viewing wherein the support frame includes a positioning assembly including one or more spring biased sets of arms wherein each arm set includes a gas spring mounted thereon and cooperatively structured to provide sufficient driving force for disposition of the viewing screen into the vertically oriented, expanded position for viewing when released from its collapsed position. The viewing screen is formed from a relatively heavy, durable, material having sufficient flexibility to be rolled upon itself or otherwise disposed in a collapsed position for storage of the screen and the support frame in an out-of-sight location.

Abstract: A speckle reduction system divides pulses of coherent radiation into successions of temporally separated and spatially aberrated pulselets. One or more beamsplitters divide the pulses into the successions of pulselets that are circulated through delay lines. Spatial aberrators located along the delay lines modify wavefront shapes of the pulselets. Together, the temporal separation and spatial aberration of the pulselets produce a succession of different speckle patterns that can be averaged together within the integration interval of a detector to reduce speckle contrast.

Abstract: A binocular includes a pair of objective lenses, a pair of eyepieces for observing images formed by the pair of objective lenses, and a connection member arranged to integrally interconnect at least respective parts of the pair of objective lenses, wherein optical images being observed are stabilized by driving and decentering the connection member with respect to optical axes of the pair of objective lenses.

Abstract: An objective lens includes a refractive lens having a positive refractive power, and a diffractive grating having a plurality of concentric ring-shaped steps that are formed on at least one lens surface of the refractive lens. The objective lens is a biconvex plastic lens of which first and second surfaces are aspherical. A diffractive grating is formed on the first surface of the objective lens. The diffractive grating is similar to a Fresnel lens, it is formed as many concentric rings each of which has a wedge sectional shape. The boundary between the adjacent rings is a step to give a predetermined optical path difference. The diffractive grating has wavelength dependence such that spherical aberration varies in the undercorrected direction as wavelength of incident light increases.

Abstract: The present invention is related to a system for transferring a beam of electromagnetic radiation having a vacuum wavelength. The system according to the invention includes a first dielectric medium, a second dielectric medium and a dielectric layer in between the first and the second medium. The dielectric layer has a periodicity of the dielectric properties parallel to the layer. The periodicity has a period that is smaller than the wavelength of the electromagnetic radiation in the second dielectric medium.

Abstract: A compact, efficient illumination system has many advantages over conventional illuminators based upon integrating spheres. An elliptical light source/concentrator, preferably controlled by a light stabilization system using optical feedback to control the light intensity, provides high spatial uniformity of high irradiance values can be produced over sizeable areas for testing large area detector arrays. The illuminator is simpler and more economical than traditional systems and provides extended wavelength coverage potential. The illumination system is easy to maintain.

Abstract: This specification discloses an image display apparatus of the see-through type having display means for displaying an image on a display surface, an image observation optical system for re-imaging the image forwardly of an observer, an exterior scene observation optical system for observing therethrough an exterior scene forward of the observer, visual axis detecting means for detecting the visual axis directions of the observer's both eyes, and control means for detecting the gaze distance of the both eyes on the basis of the visual axis directions of the observer's both eyes detected by the visual axis detecting means, and controlling the re-imaged position of the image on the basis of the gaze distance.

Abstract: In a color projection display system having a source of white light, an electro-optic light modulator for modulating the light in accordance with a display signal, a projection lens, and dichroic filters for separating the white light into color components prior to modulation, and for recombining the modulated color components prior to projection, the color uniformity of the display is improved by designing the filters to have different cut-off wavelengths of separation and recombination for at least one of the color components.

Abstract: A zoom lens including: a first lens array which has positive refractive power and which is in a fixed position relative to an image plane; a second lens array which has negative refractive power and which provides variable power by moving along an optical axis direction; a third lens array which has positive refractive power and which is in a fixed position relative to the image plane; a fourth lens array which has positive refractive power and which is capable of moving along the optical axis direction so as to maintain the image plane, which moves corresponding to movement of the second lens array and an object to be imaged, at a predetermined distance from a reference plane; a fifth lens array which has negative refractive power and which is in a fixed position relative to the image plane; and a sixth lens array which has positive refractive power and which is in a fixed position relative to the image plane.

Abstract: A zoom lens system has, from the object side, a first lens unit having a optical power, a second lens unit having a negative optical power a third lens unit having a positive optical power, and a succeeding lens unit. The first and the third lens units monotonically move toward the object side during zooming from the shortest focal length condition to the longest focal length condition. A number of predetermined conditions are disclosed which can be satisfied to ensure a high quality, compact zoom lens for a digital camera.

Abstract: A zoom lens of the negative lead type includes, in order from the object side, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of negative refractive power consisting of one negative lens, and a fourth lens unit of positive refractive power consisting of one positive lens, wherein, during zooming from the wide-angle end to the telephoto end, all the lens units move along an optical axis in such a manner that the separation between the first lens unit and the second lens unit decreases, the separation between the second lens unit and the third lens unit increases and the separation between the third lens unit and the fourth lens unit decreases.

Abstract: A correction element assembly for correcting misalignment of a beam of radiation with respect to a location on a target includes a correction element housing, and first and second piezo elements. The correction element is fixedly mounted in the housing and moveable therewith. The piezo elements are supported by a member having a first portion and a second portion. The first piezo element is mounted to the first portion of the member and to said housing, and moves the housing in a first direction. The second piezo element is mounted to the second portion of the member and to a base, and moves the housing in a second direction substantially perpendicular to the first direction.

Abstract: An optical imaging device, particularly an objective, is provided with at least one optical element, which is mounted in an inner ring, the inner ring being connected to an outer mount. A manipulator device serves for the displacement of the optical element in at least one direction that is perpendicular to the optical axis. By a system of peripheral slots between the inner ring and the outer mount with connecting members situated therebetween, a rotary joint between the inner ring and the outer mount, and at least one displacing rotary joint with an adjusting member between the inner ring and the outer mount as the manipulator device, a displacement of the optical element is attained with low deformation or controlled deformation of the optical element. The inner ring and the outer mount are preferably constituted monolithically.

Abstract: An emergency visual assistance device which provides an operator at an operator station access to operationally necessary visual information when that visual information is obscured by smoke or other vision-obstructing matter, and a method for using that device. In the device's basic version, a transparent panel is attached to either end of an elongated rigid hollow spacer tube in a manner which provides a substantially airtight seal. The preferred embodiment includes flexible skirts at each end of the device, and an illumination means mounted within the device. The flexible skirts serve mainly to exclude smoke from the operator's visual pathway, and the illumination means provides light for illuminating the visual information.

Abstract: A digital signal recording and reproducing apparatus includes a plurality of heads. A digital signal containing an information signal is recorded on a recording medium via heads among the heads while tracks are sequentially formed on the recording medium. The digital signal is reproduced from the recording medium via heads among the heads. A reproduced signal processing circuit operates for processing the reproduced digital signal at a changeable data processing rate to recover the information signal from the reproduced digital signal. During the recording, a speed of the heads, a speed of the recording medium, a data rate of the recording, and a number of used heads are set to changeable values respectively. The digital signal and a mode signal representative of the set values are recorded on the tracks at approximately a predetermined constant recording wavelength.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: A writing unit divides a sync byte into two sync bytes of a first sync byte and a second sync byte and also divides write data into two data of first data and second data and writes them. When a first sync byte pattern is detected, a reading unit demodulates the subsequent first data, second data, and an error detection correction code. When the first sync byte pattern SB1 is not detected but a second sync byte pattern SB2 is detected, the subsequent second data and error detection correction code are demodulated and the first data is reconstructed by the error detection correction code.

Abstract: This invention relates to a recording medium, data transmission apparatus, data receiver, and optical disk unit, and particularly applies to a system which transmits video data and other data or records them on an optical disk in a predetermined block unit, and permits each frame to be easily and correctly located by low volumes of identification data. At least contiguous synchronization patterns or/and contiguous synchronization patterns with one synchronization pattern interleaved therebetween are assigned with unique combinations.

Abstract: A technique for reading data from a magnetic disk includes the steps of providing the magnetic disk including a cylinder having a plurality servo sectors, a plurality of data sectors, and a zone data table, the plurality of servo sectors including a first servo sector, a second servo sector, a third servo sector, a fourth servo sector, and a fifth servo sector, the zone data table including at least a nominal timing latency between the fourth servo sector and a data sector from the plurality of servo sectors, reading the first servo sector, the second servo sector, the third servo sector, and the fourth servo sector from the magnetic disk, determining a first timing deviation for the first servo sector between the first servo sector and the second servo sector, determining a second timing deviation for the second servo sector between the second servo sector and the third servo sector, predicting a predicted third timing deviation for the fourth servo sector between the fourth servo sector and the fifth servo

Abstract: The present invention provides a magnetic disc apparatus comprising: a magnetic disc and a signal processor having functions of (i) setting measurement points at an interval which is smaller in the vicinity of an initial position of a window than in the vicinity of the maximum modification position; (ii) shifting the window from the initial position up to the maximum modification position; (iii) each time the window position is shifted according to the aforementioned interval, reproducing a check data recorded on the magnetic disc, so as to measure an error rate; and (iv) using the error rate measurement results so as to obtain an optimal position of the window.

Abstract: A timing error extractor (166) determines the phase angle between an input signal and a sampling clock by computing arctan(v/u)=arctan(alog(log(v)−log(u)), where (v) and (u) are the respective quadrature amplitudes of the input signal and sampling clock. The log function values are stored in a first lookup table (180) that is time-shared by a switching function (182) to provide both log(v) and log(u) values. A storage element (184) holds the log(u) value while the switching function routes magnitude (v) to the first lookup table. The resulting log(v) value and the stored log(u) are combined in a subtraction function (186) that generates log(v)−log(u), which result addresses a second lookup table (188) that returns the addressed arctan(alog(log(v)−log(u)) value. This phase estimating approach is advantageous because it is gain insensitive, does not include a costly and time-consuming divide operation, and requires a relatively small lookup table.

Abstract: A head drum for a magnetic tape apparatus includes a stationary lower cylinder and a rotating upper cylinder on which at least one write/read head is securely arranged and interacts with a magnetic tape with an exchange of electromagnetic signals. Also provided are at least one amplifier which rotates together with an upper cylinder and amplifies the signals coming from the write/read head, and a rotating transformer for transferring electrical signals between the stationary lower cylinder and the rotating upper cylinder. Storage means for electrical energy arranged on the rotating upper cylinder is capable of supplying electrical power to all the electronic components rotating together with the upper cylinder. A controller is securely arranged on the rotating upper cylinder for monitoring the charge state of the storage means and controlling the duration of the energy transfer as a function of the charge state.

Abstract: A magnetic disk unit lowers a possibility to cause data reproduction errors by setting a gain of a variable gain amplifier (VGA) at a predetermined fixed level for a predetermined time when an output from the VGA which amplifies an input signal is changed to a value smaller than an optimum value upon occurrence of a thermal asperity and then restoring a variable gain condition so that an output amplitude automatically has a certain preset value.

Abstract: A system for polling a preamplifier unit to remotely determine pre-established parametric values in a disk drive is disclosed. The disk drive comprises a controller, a preamplifier, and a plurality of transducers. The system for polling the preamplifier comprises means in the controller for generating a succession of serial bit characters each representative of a different pattern. A means is provided for successively transferring said serial bit characters from the controller to the preamplifier unit. A plurality of individual bit lines are provided in the preamplifier unit representative of at least one parametric value. A means is included in the preamplifier unit for comparing each serial bit pattern character received with said plurality of individual bit lines, and for generating a match signal when a serial bit pattern character received matches the plurality of individual bit lines. A means is provided for transferring the match signal from the preamplifier unit to the controller.

Abstract: A rotary head cleaning apparatus and method is disclosed, in which a control unit reserves recording times and operates a cleaning mechanism based on time information from a clock that measures time-of-day. The rotary head cleaning apparatus operates the cleaning mechanism when the time determined by the clock coincides with a non-reserved time other than times reserved for recording.

Abstract: A servowriter positioning apparatus for hard disk drives comprises an optical read head 2 for directing three focussed light beams on grating sections formed at the end of a grating member 1 connected to the servo write head(s) 3 in order to indicate the position and movement of the head(s) 3. The optical read head 2 may be based on CD or DVD technology. The servo write head(s) 3 are mounted on an actuator arm 5 to which the grating member 1 is fixed for rotation therewith and which are both driven in rotation by a rotary actuator. The grating member 1 comprises two grating sections 11,12 separated by a smooth section 13 for generating a focus error correction signal. The apparatus of the invention can be used to sense and control the position and movement of the servo write heads, or of the read/write heads of the hard disk themselves, thus eliminating the need for any servo pattern.

Abstract: A method formats disc surfaces in a disc drive for storage of data in a group of tracks on the disc surfaces. The disc drive performs seek operations to seek among cylinders on the disc surfaces as a function of time according to an actual seek profile. An approximation of the actual seek profile is determined such that the actual seek profile falls within the approximation. The disc surfaces are formatted according to the approximation of the actual seek profile.

Abstract: An improved disk drive includes an improved operating system, an improved eject system, an improved head retract system and an improved motor loading system. In a preferred embodiment of the operating system it includes a motor, an eject crank, a head crank and an actuator. The output of the motor can be selectively controlled by the actuator to power either the eject crank or the head crank. Powering the head crank, causes the disk drive heads to move, and powering the eject crank causes a disk cartridge to be ejected from the disk drive. The motor loading system may have a disk drive motor having a threaded exterior and a member extending from the exterior to interface with the eject system. Additionally, this motor loading system may include an aperture in the chassis of the disk drive that has a threaded ring running around the circumference of the aperture and a spring extending from the threaded ring.

Abstract: A compact media drive for use in personal computers has a media support and detector arm structure that ejects to extend external of the drive case at the insertion slot to receive corners of a unit of media during data operations. The arm(s) retract within the drive case or system case when no media is received. This allows a drive case to be proportioned with a drive hub for the media adjacent to the insertion slot to reduce the dimension there between from that for normal full disk insertion. The arm structure permits the drive to collect state information at the rear disk corners necessary to avoid incorrect data operations while a significant portion of the disk remains outside the insertion slot.

Abstract: A suspension for a disc drive includes a load beam, a flexure that is attached to the load beam and that has a tongue portion as a moving part, and a limiter member that is attached to the flexure and that is used to restrain the angle of inclination of the tongue portion. The flexure includes a pair of outrigger portions, left and right, and the tongue portion is situated between the outrigger portions. The tongue portion carries a head thereon. The limiter member includes arms, detachedly facing the outrigger portions of the flexure in the thickness direction thereof in order to control the angle inclination of the tongue portion, and a front edge portion detachedly facing the rear end portion of the tongue portion in the thickness direction thereof.

Abstract: The invention provides a thin film magnetic head having improved characteristics and a method of manufacturing the same in an accurate and stable manner, in which a magnetic path length of a thin film coil is shortened by decrease a distance between adjacent coil windings of at least one layer thin film coil. On a first magnetic layer 37, is formed an insulating layer 38, and then a first thin film coil half 40 is formed on the surface of the insulating layer such that a distance between successive coil windings is large. Then, a second thin film coil half 44 is formed such that its coil windings situate between successive coil windings of the first thin film coil half. First and second coil halves 47 and 48 of a second layer thin film coil are formed on the first layer thin film coil in a similar manner. After forming an insulating layer 52, a second magnetic layer 53 and overcoat layer 54 are formed.

Abstract: A thin film write head allowing substantially the same amplitude of input current to be used for writing both data transitions and equalization pulses onto a magnetic tape is described. Data transitions occur at a frequency no greater than a data frequency. Each equalization pulse is a signal written at an equalization frequency much greater than the data frequency. The thin film write head includes a top pole, a bottom pole, and a conductive coil between the top and bottom poles. The top pole, bottom pole, and conductive coil form an electromagnet for writing the write-equalized digital data stream onto the magnetic tape by converting an input current through the conductive coil into a head field. Conversion of the input current at the data frequency results in substantially the same head field amplitude as conversion of the input current at the equalization frequency. This may be achieved by increasing the gap depth to cause saturation at the data frequency.

Abstract: A read/write head is provided with an embedded planar dual coil write structure. The head includes generally parallel shield, shield/pole, and pole layers. The shield/pole layer abuts a generally coplanar planarization layer in one embodiment. A circuitous recess is defined in the shield/pole and planarization layer, spanning the junction twice and encircling a central hub of adjoining shield/pole and planarization layer material. A write structure is located in the recess, with the shield/pole layer, planarization layer, and embedded write structure forming a substantially flat surface for building the pole layer. The write structure includes first and second substantially co-planar multi-turn flat coils, where turns of the first write coil are interspersed with turns of the second write coil. The first and second write coils reside in the circuitous recess, winding around the central hub. An insulating material separates the first and second coils.

Abstract: A magnetic head having a pair of longitudinal channels in a tape bearing surface that flank each transducer. The channels reduce the effective height of debris in the channels near the transducers. The channel floors may have a transverse slope, and the tape bearing surface between channels may be tapered. Transverse slots help direct debris away from the transducers. The channels overlap the end sections of the transducers and help to define the shape and position of the transducer's active section. When applied to a two pole write transducers, the channels narrow and equalize the effective width of the top and bottom poles. Narrow equal-sized poles can write narrow data tracks with a track width that is independent of the magnetic medium's direction of motion.

Abstract: A tape cassette comprising a housing made up of upper and lower casings, a pair of reels around which a tape is wound and contained altogether in the housing, and a pair of cylindrical resin tape guides having a height greater than the width of the tape, said tape guides being securely fitted to corresponding tape guide posts also having a height greater than the width of the tape and provided in the lower casing. Each tape guide post has a press-fit rib formed in one piece with it on the side where the tape does not come in contact with the tape guide on it. The rib has a vertical height greater than half that of the tape guide and serves to make the dimensions of the tape guide post surface on the tape-contacting side greater than the inside diameter of the tape guide before being press-fitted.

Abstract: A base plate for a suspension assembly in a hard disk drive wherein the base plate has a hardened flange and soft hub. The base plate is stamped in a progressive die in a sequence of forging and coining operations. The base plate is subsequently fully annealed to allow the material to yield at a low stress level so that the hub will create a press fit against the inner wall of an actuator arm boss hole. The base plate is passed through a secondary coining operation following the annealing step to work-harden the flange portion only. The result is a base plate with a flange portion that is hardened and a hub portion that is softer than the flange portion. The advantage is that the hardened flange is more resistant to deformation of a load beam welded thereto and the hub is more disposed to plastically deform and harden during swaging which is desirable for maintaining a press fit.

Abstract: An electronic equipment, such as a tape recorder, having a loading section on one surface for loading a recording medium and a lid for opening/closing the loading section. This electronic equipment includes a lock mechanism for locking the lid in the closed position and an unlock mechanism for unlocking the lid. The unlock mechanism has an operating member extended along one lateral surface of the main body portion of the equipment and other lateral surfaces intersecting this one surface for covering the opening side of a recess formed at a corner of the main body portion. The unlock mechanism unlocks the lid by the operating member of the unlock mechanism being moved along the one lateral surface of the main body portion so that the operating member is partially immersed in the recess.

Abstract: A magnetic head slider assembly for a magnetic disk type recording/reproducing apparatus includes a slider body, a sliding pad provided on the slider body and projecting beyond a disk facing surface thereof, a thin film layer disposed at one end of the slider body, a magnetic head constituted by the thin film layer as an integral part thereof, and a core pad projection incorporating therein a core of the magnetic head and projecting beyond an adjacent disk facing surface of the slider body. The sliding pad is provided at a region of the slider body ahead of the core pad projection and prevents generation of a floating force by making use of a relative movement between the slider body and the magnetic disk.

Abstract: An improved bearing cartridge to rotationally couple an actuator block supporting a plurality of heads to a chassis of a disc drive. The improved bearing cartridge having increased radial stiffness and including first and second concentrically aligned elongated sleeves. The first sleeve is coupled to the chassis and the second sleeve is coupled to the actuator block. The first and second sleeves are spaced to define a rotation gap therebetween. The bearing cartridge includes first and second spaced bearings positioned proximate to opposed ends of one of said first or second sleeves and at least one intermediate bearing spaced from the first and second bearings and positioned between the first and second bearings to rotationally connect the first and second sleeves.

Abstract: A magnetoresistive element for a dual element read head should exhibit uniform current density for proper biasing and Barkhausen noise limiting. Each element is a thin film MR layer normal to the magnetic media. Each element includes a front edge parallel with the magnetic media surface. A back edge, longer than the front edge, is opposite the front edge. Conductors through which current enters and exits the MR layer are adjacent to either end of the back edge.

Abstract: A spin valve magnetoresistive sensor of the type used in a data storage system includes a free layer extending in a sensor plane. The free layer has a magnetization which changes in the presence of a magnetic field. An artificial antiferromagnet layer is used as a pinned layer. The artificial antiferromagnet layer includes a first ferromagnetic layer extending in the sensor plane which has a first ferromagnetic layer vector. A second ferromagnetic layer extends in the sensor plane and includes a second ferromagnetic layer vector. A spacer layer of non-magnetic material extends in the sensor plane and is positioned between the first and second ferromagnetic layers. The first and second magnetization vectors in the first and second ferromagnetic layers include vector components which are directed perpendicular to the air bearing surface which is parallel to the sensor plane due to a DC bias field provided by two permanent magnet poles.