Group III-nitride devices are described that include a stack of III-nitride layers, passivation layers, and conductive contacts. The stack includes a channel layer with a 2DEG channel, a barrier layer and a spacer layer. One passivation layer directly contacts a surface of the spacer layer on a side opposite to the channel layer and is an electrical insulator. The stack of III-nitride layers and the first passivation layer form a structure with a reverse side proximate to the first passivation layer and an obverse side proximate to the barrier layer. Another passivation layer is on the obverse side of the structure. Defected nucleation and stress management layers that form a buffer layer during the formation process can be partially or entirely removed.

Reverse side engineered iii-nitride devices

A magnetic head includes a slider, and a head portion provided at the slider. The slider and the head respectively have disk opposing surfaces opposite to a surface of a magnetic disk, and the disk opposing surface of the head portion is positioned more apart from the surface of the magnetic disk than the disk opposing surface of the slider. The head portion includes recording and reproducing elements at least partially exposing to the disk opposing surface, and a thermal expanding member arranged in the vicinity of the recording and reproducing elements to thermally expand the disk opposing surface in a direction of approaching the surface of the magnetic disk.

Magnetic disk apparatus

A head gimbal assembly includes a suspension of the type supporting a slider and a flex circuit. The suspension is formed of a load beam that supports the flex circuit, and a resilient flexure which is secured to the load beam and which supports the slider. The load beam is comprised of a flexure portion that defines a rear motion limiter and that engages the flex circuit and limits the slider movement when the head gimbal assembly is exposed to a shock load. The rear motion limiter extends intermediate the flex circuit and the flexure. The flex circuit includes a flexure section which is separated from the rear motion limiter by a gap, such that under a shock load condition, the gap collapses for limiting the travel of the slider along a first direction. The front motion limiter can be formed of one or a plurality of tabs or wings that extend integrally from the load beam. According to another embodiment, the head gimbal assembly includes a front motion limiter that engages a cantilevered free end of the flexure for limiting the travel of the slider along a second direction.

Read/write head with a limited range of motion relative to a load beam

A system for exchanging digital data among a plurality of hand-held computer devices. Digital signals are written by a first hand-held device to a mini-cartridge that mini-cartridge is inter-operable among a class of hand-held devices, each of which is equipped with a mini-disk drive. A common digital data format is employed to further facilitate exchange of data between devices.

Interchangeable cartridge data storage system for devices performing diverse functions

A prosthetic arm apparatus including a plurality of segments that provide a user of the prosthetic arm apparatus with substantially the same movement capability and function as a human arm. The segments are connectable to one another and connectable to a prosthetic support apparatus that may be adorned by the user. Each segment of the plurality of segments provides a portion of the movement capability, enabling the plurality of connected segments connected to the harness mount to provide substantially the same movement capability as that lacking in the user.

Arm prosthetic device

A read/write head gimbal is provided including a tab or extension on the end of the gimbal portion which is attached to the head/slider assembly, forming this tab such that, when the gimbal is assembled to the load beam, the formed tab passes through an opening created for this purpose in the load beam, and extends beyond the opening far enough to prevent its returning through the opening after the gimbal and load beam are spot welded together. The tab and opening in the load beam are dimensioned so that during normal read/write operations, there is no contact between the tab and the sides of the opening in the load beam. The tab/opening arrangement is such that shock forces in the direction of travel away from the load beam, or in parallel with the surface of the load beam bracing the gimbal, will result in contact between the tab and the sides of the opening in the load beam, thus preventing excessive motion of the gimbal which could result in permanent deformation of the gimbal.

Read/write gimbal with limited range of motion

The disclosure relates to a technique for effectively floating the rotor (37) of a disc drive motor, thereby permitting small motions in the axial (non-critical) direction while maintaining significant stiffness of the radial (critical) direction. This is achieved by providing an electromagnetic actuator inluding a stepper motor having a housing, a stator located within the housing, and a rotor (37) positionable relative to the stator driving a motor shaft to wind and unwind a band (14) and thereby position the carriage. The drive shaft (12) passes through ball bearings (30) which support the shaft for rotation. The ball bearings themselves fit within an annular end bell portion (39) of the motor housing which defines a channel for the bearing. An injected elastomer (33) forms a tight-fitting ring between the bearings and the internal wall of the end bell (39), thereby radially supporting the outer race of the bearing. Preload springs (36) are then installed on both sides of the rotor between the internal end walls of the end bells and both outer races of the bearing. the installation of these springs effectively floats the rotor to allow some distortion of movement of the rotor in the axial direction, while minimizing or eliminating the radial deflection components.

Bi-compliant rotor stepper motor for an actuator in a disc drive

The present invention proposes a memory device comprising a fixed disc on the surface of which data may be stored, and rotating transducers or heads which may be positioned to access any location on the disc. The rotating heads are mounted on transducer arms which are designed in such a manner that the transducer seeks outward as it is rotated. That is, similar to a flywheel governor in a steam engine, centrifugal force would impart a radial force on the arm which is movable in a low friction system along with the transducer, the radial force causing the transducer to move outward together with the radial arm with increasing rotational speed of the spindle motor. A counteracting spring having a force in a direction opposite to the radial force would provide a radially inward force on the transducer arm, so that at any given speed the location of the transducer and the arm, and therefore the transducer's positional relationship to a desired track, is precisely determined by the balance of the inwardly acting spring force and the outwardly driving centrifugal force.

Single motor data storage device utilizing centrifugal force and counteracting spring

A disc drive system having at least one hard disc of approximately 48 mm diameter having concentric tracks is supported by a hub positioned in a centrally located aperture of approximately 12 mm diameter. The disc is rotated at a constant speed by a brushless DC motor attached to the hub. A transducer means for communicating information with the hard disc is moved relative to the disc surface by a positioning means. The positioning means includes a voice coil motor for selectably and accurately positioning the transducer means over the tracks on the hard disc. The disc drive system is enclosed in a housing means constructed from ferrous material having a base portion and a shell portion. The positioning means has a shaft about which the positioning means rotates. To provide a small, rugged assembly, the shaft is mounted at each end between the shell portion and base portion of the housing. Additionally, the shaft of the brushless DC motor is mounted in the same manner. The miniature disc drive system of the invention is designed to be permanently mounted in a portable, lap-top or notebook computer. Alternatively, the design is adaptable to enable the disc drive system to be utilized as a portable memory unit which may be inserted and removed from a connector port in the host computer.

Miniature hard disc drive having low profile actuator arm voice coil and spindle motors

A pivot bearing assembly for a disc drive including the combination of a bearing surrounded on one side by a wishbone-shaped end of the actuator arm, and on the other side by a biasing spring metal strip whose ends are tightly attached to the split ends of the wishbone of the actuator arm. When the arm assembly is mounted in the disc drive, the bearing is mounted on its center of rotation, with the spring tensile force biasing the head of the actuator arm against the spindle of the stepper motor. By providing the distal end of the actuator arm with a gear sector having gear teeth on its face which mesh with a pinion on the motor shaft of the stepper motor, rotation of the motor shaft across the face of the gear sector causes movement of the actuator arm and with it the flexure and transducer across the surface of the disc. The head arm supporting the flexure and transducer extends from the side of the actuator drive arm at a point near the stepper motor driven end of the drive arm, reducing head arm length.

Sanjoy Ghose

Papers

Read/write gimbal with limited range of motion

Bi-compliant rotor stepper motor for an actuator in a disc drive

Single motor data storage device utilizing centrifugal force and counteracting spring

Miniature hard disc drive having low profile actuator arm voice coil and spindle motors

Design for an actuator arm for a disc drive