Abstract: An improved flexure for supporting a read/write head adjacent to a relatively moving storage medium in a disk drive is disclosed. The flexure is a patterned flex circuit structure that is mounted to a load beam in an actuator assembly and includes integral wiring and bonding pads for electrically connecting the head to the electronics of the disk drive. The flexure also implements a high compliance gimbal with integral wiring.

Abstract: A magnetic storage tape includes a plurality of spaced-apart servo reference patterns formed along a longitudinal reference axis. The patterns result in a predetermined pattern of coherent magnetic signal disturbances to magnetic tracks written and read across the patterns. The tape drive decodes the disturbance pattern into a position error signal. A tape drive head position servo iteratively adjusts lateral position of a magnetic head relative to the tape, based on sequentially developed position error signals in order to bring the head rapidly into precise alignment with the longitudinal reference axis. A method for forming the reference patterns into the tape with laser beam ablation is also disclosed.

Abstract: An architecture that utilizes the cross-check code associated with the error correction code in a data communications system as a data integrity code to protect data stored in a temporary storage buffer within a data channel. In a preferred embodiment, a cross-check encoder and comparison circuit is added to an interface circuit which receives data from a host processing system. Incoming host data is encoded to produce redundant information according to the same Reed-Solomon code implemented in the cross-check circuitry already provided in the data path to detect miscorrections by the error correction code. Cross-check redundancy generated by the interface cross-check encoder is appended to its associated data block in the block memory buffer. The integrity of the data blocks passing through the buffer is checked by utilizing the cross-check circuitry to regenerate the redundant cross-check bytes and then performing a comparison of the regenerated cross-check bytes with the cross-check bytes from the buffer.

Abstract: An XY stage for precision movement for use in aligning a wafer in a microlithography system. A main stage supporting the wafer straddles a movable beam that is magnetically driven in a first linear direction in the XY plane. A follower stage, mechanically independent of the main stage, also moves in the first linear (X) difection and its motion is electronically synchronized by a control system with the main stage motion in the X direction. Electromagnetic drive motors include magnetic tracks mounted on the follower stage which cooperate with motor coils mounted on the edges of the main stage to move the main stage in a second linear (Y) direction normal to the X direction. Thus the main stage is isolated from mechanical disturbances in the XY plane since there is no mechanical connections and is lightened by removing the weight of the magnetic tracks from the beam.

Abstract: A lithographic system includes a chamber housing a stage mechanism and a linear motor coil that drives the stage mechanism. The linear motor includes a coil having two sidewalls, the coil being movable along a magnet track generating a magnetic field. A pair of jacket walls are attached to respective ones of each of the coil sidewalls. Each jacket wall has a pair of relatively thin non-magnetic plates of about 0.75 mm thickness bonded together, at least one facing surface of each of the plates including a liquid flow channel. The plates are made of a non-conductive (and non-magnetic) material, e.g. ceramic such as alumina. Coolant liquid from a liquid source flows through the flow channel in each of the jacket walls. In one embodiment a cooling system is provided where the linear motor coil has a cooling and recirculation circuit including a tank which is kept at a negative pressure of from about -3 psig to about -13 psig.

Abstract: A projection lens system that is used to transfer a pattern from a reticle onto a wafer, incorporates a projection optical system that is capable of maintaining the same, or increased performance, as the current projection lens systems, and that achieves excellent aberration correction, has a numerical aperture of at least 0.6, an exposure field area of at least 18.7.times.18.7 mm or at least 26.45 mm diameter at the wafer plane, and has a total lens thickness to length ratio less than 0.64 and uses 5 or less aspherical lens surfaces.

Abstract: Projection lens systems for transferring a pattern on a reticle onto a wafer having an aplanatic lens element. The aplanatic lens element has a shape factor between 0.1 and 0.224, the projection lens system satisfies the condition:-2.0<f.sub.ap /F<-0.6251, where f.sub.ap is the focal length of the aplanatic lens element and F is the focal length of the projection optical lens system. The projection optical lens system further satisfies the condition 2.6<.vertline.f.sub.G3 /f.sub.G .vertline.<4.64.

Abstract: A lens distortion measurement system has a first grating of a first pitch on a transparent support such as a quartz reticle. The reticle is disposed between an illumination source and the lens system whose distortion is to be measured. An image sensor is provided within the image projection field of the lens system. A second grating of a second (different) pitch is provided on another transparent support, disposed between the lens system and the image sensor. Optionally, a relay lens is disposed between the second support and the image sensor. Illumination propagates from the illumination source through the first support, through the lens system, through the second support and is incident on the image sensor. The illumination forms a Moire fringe having a pitch orders of magnitude greater than the pitches of the first and second gratings.

Abstract: The pole pieces of a thin film head are formed by two thin film layers of the magnetic metal NiFe, each NiFe layer being about 20,000 angstroms thick. These two NiFe layers are separated by an electrically insulating layer of alumina (Al.sub.2 O.sub.3), ceramic or NiFe oxide that is about 100 angstroms thick. In one embodiment, a hard-baked photoresist layer is formed only around the edges of the first NiFe layer, the electrically insulating layer is deposited over the top surface of the first NiFe layer and over the hard-baked photoresist layer, and the second NiFe layer is then deposited, thus providing a three-layer metal/insulator/metal pole piece wherein the hard baked photoresist blocks edge short circuiting between the two thin film NiFe layers.

Abstract: A mass storage device includes a secondary bidirectional interface digital port connected to an embedded microcontroller, and a wireless communications path, such as an optical infra-red (IR) path, connected to the secondary bidirectional interface port for providing a wireless bidirectional secondary communications path between the embedded microcontroller and an external service unit which is not directly connected to the digital computer via a primary electrical bus structure.

Abstract: A two-level error correction encoder encodes m-bit data symbols in a first level of encoding in accordance with a distance d ECC over GF(2.sup.m+i) to produce (m+i)-bit ECC redundancy symbols and, during a second level of encoding, both modifies the set of ECC redundancy symbols, as necessary, to set i selected bits in each symbol in a predetermined truncation pattern and appends to the set of ECC symbols one or more pseudo redundancy symbols. The encoder includes d-1 Galois Field multipliers, and d-1 associated redundancy-symbol registers and an ECC symbol modifier lookup table that has stored therein information that the encoder uses during the second level of encoding. After the first level of encoding, the d-1 registers contain the (m+i)-bit ECC redundancy symbols.

Abstract: An improved magnetic read/write head actuator assembly for use within a storage disk system that reduces average access time. The actuator assembly includes an actuator arm mounted on pivotal hub. A read/write head is supported at a distal end of the actuator arm such that the head is positioned in close proximity to a rotating magnetic storage disk. An actuator motor cooperates with the actuator arm to provide pivotal motion to the actuator arm about a central pivot axis. The actuator motor includes an asymmetric rotor winding connected to the actuator arm at an end opposite the distal end and an asymmetrical stator magnet structure that is statically mounted in close proximity to the asymmetric rotor winding. The actuator motor, further includes a flux conductive member that forms a closed flux path through the rotor winding and the asymmetrical stator magnet structure.

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface. The DMT is generally fabricated using a two-level partitioning process. Several prepared glass substrates, i.e., one for each mirror type, are initially sliced into bars having predetermined geometries. A bar from each substrate is sequentially aligned to a master reference and bonded to adjacent bars to form an intermediate bar stack. The stack is then segmented into a plurality of DMT components, each having a plurality of prism members.

Abstract: A flex circuit for a tape drive includes an elongated flexible printed circuit substrate carrying a pattern of electrical circuit interconnections and divided into a read channel portion for direct connection to multiple read and write heads of a tape head array and carrying a plurality of read channel preamplifiers connected to receive and amplify read signals from a plurality of read heads; a write channel portion including an external connection region for enabling signal and power connections to be made with a host circuit module, the write channel portion including a plurality of write channel drivers; and, a dynamic flexing portion separating and interconnecting the read channel portion and the write channel portion, the dynamic flexing portion adjusting in contour as positional adjustments are made to the head array by a head positioning mechanism.

Abstract: A method is provided for elimination of periodic inter symbol interference (ISI) resulting in timing phase steps and channel amplitude control steps occurring following a periodic preamble pattern, such as a 1/4T sine wave pattern and at the beginning of a random pattern user data field in a partial response, maximum likelihood digital magnetic data storage channel. The method comprises the steps of:determining a periodicity of periodic ISI events in relation to main magnetic flux transitions during playback of a periodic signal waveform thereof,writing a new preamble field to the magnetic data storage channel of a periodic signal waveform preceding the user data field in which the phase of the periodic signal waveform is shifted, e.g.

Abstract: A voice coil motor (VCM) driver has four field effect transistors connected to a motor coil as an H-bridge. A sense resistor in series with the coil and the H-bridge senses coil current. A feedback amplifier provides a feedback signal from a voltage developed across the sense resistor. A summing junction sums current command signals with the feedback signal. A transconductance loop compensation amplifier has an inverting input connected to the summing junction, has a non-inverting input connected to a reference level, and has an output control signal node. The control level is connected to control linear transconductance differential driver amplifiers including the four field effect transistors during a linear drive mode.

Abstract: A process resulting in enhanced pole performance, relative to permalloy poles, in narrow track magnetic devices. A preferred process includes increasing the anisotropy field of the pole material while maintaining an acceptable coercivity level and near zero magnetostriction. One embodiment utilizes a NiCoFe alloy containing 22% cobalt by weight, heat treated in an easy axis magnetic field in a non-oxidizing atmosphere. This process achieves favorable domain structures at narrow pole tip widths.

Abstract: An analog-to-digital converter circuit in a sampling data detection channel of a disk drive synchronously samples user data in the data track areas at a first quantization resolution and samples servo bursts from the spoke areas at a second quantization resolution effectively greater than said first quantization resolution. An offset circuit provides a predetermined analog offset signal to a combining circuit which combines it with an incoming analog signal to provide a composite signal during a spoke servo burst sampling interval. An analog-to-digital converter samples the composite signal during the servo spoke burst sampling interval, and synchronously samples the analog signal during a user data sampling interval. A digital averaging circuit averages the servo spoke samples over a predetermined averaging interval to provide averaged burst samples having increased bit resolution.

Abstract: A low stiffness apparatus supporting a read/write transducer head slider for reduced pitch and roll bias in flying conditions. The apparatus comprises an actuator arm, a load beam, and a flexure in combination. The flexure is comprised of an outer portion, an inner portion, and a bight portion. The bight portion connects the inner portion to the outer portion and provides a one step double bend resulting in a spaced relation between the inner and outer portions along the z-axis. The inner portion also has a dimple formed therein for pivoting against the load beam and is located substantially near the bight. The low stiffness is created from the bight portion and the location of the dimple. The apparatus also prevents the problem of wire overhang, where the wire crashes onto the disc during flying conditions. The apparatus furthermore permits the transducer head slider to move more closely to the hub of the disc, thus allowing the system to read more data.

Abstract: An error correction system includes an encoder that uses a modified Reed-Solomon code to encode m-bit data symbols over GF(2.sup.m+i) and form a preliminary code with d-1 (m+i)-bit ECC symbols. The encoder then modifies the ECC symbols by combining the preliminary code word with a combination of one or more modifying code words to produce modified ECC symbols that have i bits set in a pre-selected pattern. This combination also results in "R" pseudo redundancy symbols that include the i-bit pattern being appended to the modified ECC symbols. The encoder truncates the i-bit pattern from each of the ECC symbols and the pseudo-redundancy symbols, to produce a data code word that has symbols that are elements of GF(2.sup.m).