Abstract: A method and apparatus for texturing a landing zone on a substrate of a magnetic disk to reduce stiction between a magnetic transducer head and the disk is provided. The method includes projecting discrete pressurized fluid droplets to impact a substrate surface of the substrate with sufficient momentum to form cavities in a selected annular area of the substrate surface, the selected annular area with cavities therein being of sufficient width to provide a textured landing zone for the magnetic transducer head. A magnetic disk for storing data readable by a transducer head is also provided. The disk includes a rigid substrate. A textured landing zone is provided on the disk for engaging the transducer head. The textured landing zone is formed by the steps of directing a stream of discrete pressurized fluid droplets against the substrate to create roughness therein and moving the substrate and stream of droplets relative to one another in order to create an annular area of roughness.

Abstract: A method provides for waiting for a cache hit in the operation of a disk drive. The drive has an intelligent interface for communicating with a host, a magnetic disk, and a cache. The cache is divisible into a number of segments, and the cache employs a cache control structure. The drive receives a first command and a second command wherein the second command has a requested data range. The method comprises the steps of: (a) initializing a read in response to the first command to provide prefetch data to the cache in a prefetch data range wherein the prefetch data range has a first logical block address; and (b) waiting for a cache hit in response to the second command wherein the beginning of the requested data is within the prefetch data range and does not request the first logical block address.

Abstract: A disk drive has a base, a cover, a spindle motor mounted to the base, and a disk coupled to the spindle motor. A rotary actuator comprising a head stack assembly is coupled to the base by a pivot bearing assembly. The pivot bearing assembly provides a stationary member, a bearing, and a sleeve member for rotatably supporting the actuator. The pivot bearing assembly further provides an elastomeric interface between the stationary member and the actuator such that vibratory motion imparted to the head stack assembly is dampened by the elastomeric interface.

Abstract: A magnetic disk drive includes a base which supports a head stack assembly having a coil portion, a flex circuit cable having a grounding portion, and a flex clamp and in which a voice coil motor (VCM) is formed from the coil portion's interaction with upper and lower VCM plates that carry at least one permanent magnet. The disk drive includes a Z-shaped grounding portion which wraps around one end of the flex clamp and permits a single screw to secure that end of the flex clamp to the base and simultaneously make grounding contact with the grounding portion and an elongated protrusion extending from one of the VCM plates that is adjacent to the flex clamp to hold that end of the flex clamp against the base when the VCM plates are fastened to the base.

Abstract: A magnetic disk drive with a head stack assembly includes a body portion, a coil portion cantilevered from one side of the body portion, and an actuator arm cantilevered to the opposite side of the body portion, wherein the body portion includes a plastic inner sleeve to provide a quick, press-fit connection with a pivot bearing cartridge. The body portion further includes a non-plastic outer portion which is preferably part of an aluminum E-block having integrally formed actuator arms. The plastic inner sleeve and non-plastic outer portion preferably include a spline and a recess, respectively, that are firmly compressed together by the press-fit connection to prevent relative angular motion. The plastic inner sleeve preferably includes a flat that is aligned with the spline and recess in order to contact the pivot cartridge along the flat and thereby ensure that the press-fit forces are focused onto the spline and recess.

Abstract: A method of managing commands is provided for a disk drive having an intelligent interface for communicating with a host. The drive also has a magnetic disk, host side programs, disk side programs, and a cache wherein the cache is divisible into a number of segments. The cache employs a cache control structure including a cache entry table, a buffer counter, a block count, a host pointer and a disk pointer. The drive receives a first command and a second command with a cache access type. The method of managing commands comprises the steps of: processing the first command to assign the first command to a cache segment having a prefetch area; determining the cache access type of the second command; and if the cache access type of the second command is a skip ahead sequential access then decrementing the buffer counter and incrementing the host pointer to skip leading nonrequested data in the prefetch area for the first command.

Abstract: A method of operating a disk drive having a cache provides for adapting the amount of prefetch. The drive also has an intelligent interface for communicating with a host, and a magnetic disk. The cache is divisible into a number of segments, and employs a cache control structure including a cache array with a cache array entry. When the drive receives a first command, the method provides a step of performing a scan of the cache to assign the first command to a segment. The method further includes the step of maintaining the cache array with a cache array entry for each one of the number of segments, where each cache array entry classifies a segment by a cache access type, wherein the cache access type is selected from a plurality of access types including sequential and random. The method further includes the step of determining a limit on the amount of prefetch based on the cache access type for the first command and a cache environment variable. The limit may be a minimum prefetch or a maximum prefetch.

Abstract: A head disk assembly includes a base, a cover attached to the base and a spindle motor mounted to the base. The spindle motor includes a shaft, an inner cylindrical portion surrounding the shaft, and an outer cylindrical portion surrounding the inner cylindrical portion. The outer cylindrical portion has an annular surface and the inner cylindrical portion has a cylindrical surface which extends above the annular surface. The head disk assembly also includes a disk mounted on the spindle motor such that the disk surrounds the outer cylindrical portion; the disk includes a recording surface which is substantially co-planar with the annular surface. The head disk assembly also includes a disk clamp for clamping the disk to the spindle motor and a washer positioned between the disk clamp and the recording surface for transferring radial loads to the inner cylindrical portion of the spindle motor.

Abstract: Apparatus and means for attaching the head-suspension assembly to the actuator arm in a disk drive. A head-suspension assembly in a first fabrication step is permanently fastened to a nut plate, for example, by laser welding. The nut plate is fastened to the suspension assembly on the suspension surface that faces away from the nearby recording disk when the disk drive is fully assembled. Another aspect of this invention is the use of heat-activated thermosetting adhesive. The head-suspension assembly with the affixed nut plate is fastened to an actuator arm with a heat-activated adhesive film. In one embodiment, the adhesive is applied to both sides of a thin plastic film for ease of handling and application. In another embodiment, the adhesive is made electrically conductive to provide an electrically-conductive path between the actuator arm and the head-suspension assembly.

Abstract: A disk drive actuator assembly adapted for assembly in one of several configurations from a single line of modular components without a manually-supervised aligning step. The actuator improves manufacturability and inertia by introducing a common set of self-aligning modular piece parts. Each of several self-aligning modular components can be used to assemble any of several different actuator assembly designs. That is, a head-stack assembly (HSA) providing from one to six heads can be assembled using elements selected from single set of standardized modular components. The assembly process relies entirely on the self-aligning features of the standardized modular components, thereby eliminating the elaborate and error-prone manual assembly and alignment procedures known in the art.

Abstract: A method for manufacturing a recording medium on a hard disk includes forming a data recording layer on the disk, forming a nitrogenated carbon overcoat layer over the data recording layer, (with or without intervening layers), and the processing data recording layer to protect it from the nitrogen used in the process of forming the nitrogenated carbon. In one approach, the step of processing the data recording layer is accomplished by forming a buffer layer between the data recording layer and the overcoat layer by depositing carbon on the data recording layer using a carbon deposition process excluding nitrogen, then forming the overcoat layer by depositing carbon on the buffer layer using a carbon deposition process that includes a nitrogen source.

Abstract: A system for balancing devices having motors and rotating masses to be coupled to the motors utilizes a momentum transfer mechanism to shift the rotating mass based on sensed imbalance. In this manner the mass is shifted to a position which accounts for the inherent imbalance in both the motor and the mass. A controller receives imbalance information from a velocity sensor and controls a solenoid to strike a base coupled to the motor to shift a lightly clamped mass relative to the motor. In one embodiment, a disk drive has disks initially biased by the system against a hub, and then shifted during rotation to create a disk drive having concentrically aligned disks offsetting imbalance inherent in a motor used to rotate the disks. In one embodiment, the disks are held to the hub by a clamp having screws. The screws are driven simultaneously through the same angle of rotation to ensure that the axial clamping force of each one is substantially equal.

Abstract: A magnetic latch assembly for immobilizing a read/write head of a disk drive is provided which magnetically couples to an actuator assembly housing the read/write head with enhanced force. A disk drive which includes the magnetic latch assembly is also provided. The magnetic latch assembly includes a magnet and a magnet holder including ferromagnetic material which at least partially surrounds the magnet and provides a medium through which flux produced by one pole of the magnet travels to an opposing pole of the magnet. The latch assembly magnetically couples the actuator assembly by contacting the actuator assembly in an area adjacent one of the poles of the magnet. In one embodiment, the magnet holder includes ferromagnetic material which surrounds the magnet. In another embodiment, the magnet holder includes a plurality of ferromagnetic flanges which at least partially surround the magnet.

Abstract: A rotating disk memory apparatus includes an actuator assembly electrical interconnect. Flex circuit tape retainers are provided to substantially reduce and ideally eliminate torque forces on the actuator due to flex circuit bending. The retainers includes a tape guide having an inner wall to conform those portions of the flex circuit proximate both an actuator body member and a base plate connector member to predetermined configurations, such as loops providing a design specific exit angle for the flex circuit at each retainer. The looped portion of the flex circuit is held in the guide by a selectively detachable guide post device. The predetermined configuration is designed to minimize the torque on the actuator from inherent spring forces generated due to bending of the flex circuit during actuator motion relative to the rotating disk.

Abstract: A head disk assembly for a disk drive comprises a base, a bearing cartridge, a head stack assembly, and an elongated member. The bearing cartridge includes an inner shaft and an outer sleeve, the shaft being attached to the base and defining a pivot axis and the outer sleeve being rotatable relative to the pivot axis. The outer sleeve has a cylindrical sleeve surface. The head stack assembly includes an actuator body. The actuator body has a bore and a slot located adjacent to the bore such that the slot opens into the bore. The bore has a bore surface that defines a pair of ridges extending parallel to the length of the bore. The bearing cartridge is disposed within the bore.

Abstract: A head disk assembly (HDA) for a hard disk drive includes vibration damping structure. The HDA also includes an enclosure, a disk, a pivot bearing cartridge, and a head stack assembly (HSA). The enclosure includes a base that preferably includes integral side walls. The disk has a recording surface that has an annular landing zone. The pivot bearing cartridge includes a shaft fixed to the enclosure, and the head stack assembly is connected to the pivot bearing cartridge for rotation relative to the shaft. The HSA includes a head supported to be moved radially relative to the recording surface and to be brought to rest at a position in the landing zone. The base has a plurality of interior-facing surfaces including a major interior-facing surface parallel to the recording surface. Significantly, one of the interior-facing surfaces of the base serves as a bearing surface against which the vibration damping structure is compressed.

Abstract: A swing type structure for a head stack assembly of a disk drive includes a body portion, a coil portion, and at least one actuator arm structure. The actuator arm structure includes at least one elongated column, and a pair of wires in tension. The body portion has a bore defining a longitudinal axis, and the coil portion is cantilevered from the body portion. The elongated column is cantilevered from the body portion in an opposite direction from the coil portion and has a distal end. Each wire is positioned on an opposite side of the elongated column and converges on the distal end such that the elongated column is in compression as a result of the pair of wires.

Abstract: The invention resides in a load beam assembly forming part of a head stack assembly in a magnetic disk drive, the load beam assembly biasing a transducer head against a rotating magnetic disk. The load beam assembly normally has spring and hinge functions combined in a single "spring/hinge" portion of a load beam stamped from a stainless steel sheet. Here, however, the spring and hinge functions are uniquely separated from one another in separate spring and hinge members. The preferred load beam assembly has a base portion, a load beam, and a hinge member joining them so that the load beam pivots relative to the base portion. The load beam is further provided with a bearing surface that cooperates with a preferred spring member, one end of the spring member being fixed relative to the base portion and the other end contacting the bearing surface of the load beam.

Abstract: A disk clamp for holding a recording disk in a disk drive. The clamp is ring-shaped and includes stiffened inner and outer regions with a softened middle region located in between. The inner region is stiffened by bending the inner edge. The outer region is stiffened by involuting the outer edge back on itself A disk contact zone is included in this outer region. The clamps may be made of sheet metal, such as stainless steel.