Abstract: A method and apparatus is described by which, in magnetic disk storage systems where a triboelectric current can be observed to flow between slider and disk surface, a saving signal can be generated by which a saving action can be initiated to save the data on the storage system before they are lost irreversibly. The triboelectric current is monitored and checked during start phase, and if certain values and conditions are not fulfilled, the saving action is initiatable by the TRIC signal, which is generated by an evaluation and analyzer circuit upon the occurrence of certain events such as the triboelectric current not reaching at least a predetermined threshold value during start phase, the triboelectric current becoming negative, or the triboelectric current reaching a non-zero value when the magnetic disk storage system reaches operational speed.

Abstract: A thermal drop-on-demand ink jet print head in which a heat delay means is provided covering a predetermined part of the resistive element. Upon connection of an electrical signal to energize the resistive element, nucleation occurs at an uncovered location on the resistive element and formation of the bubble proceeds in a direction toward the covered part of the resistive element to thereby utilize the inertial effect of the controlled bubble motion to eject a drop of ink in a more energy-efficient manner.

Abstract: A thermal drop-on-demand ink jet print head in which an array of heating means is provided on one surface of a substrate member. A common electrode provides electrical contact to the heating means, and an array of data electrodes provides electrical contact to individual ones of the heating means. An array of feed through conductors is provided which pass through to the opposite surface of the substrate member to provide electrical contact between one of the data electrodes and one of an array of conductors leading to spaced solder pads on the opposite surface of the substrate member. A nozzle plate is mounted adjacent to the substrate member with a nozzle adjacent to each of the heating means so that, upon connection of an electrical signal to one of the solder pads, the corresponding heating means is energized and a drop of ink is ejected from the adjacent nozzle.

Abstract: A magnetoresistive (MR) read transducer assembly in which the thin film MR layer is longitudinally biased only in the passive regions by exchange bias developed by a thin film of antiferromagnetic material that is deposited in direct contact with and continuously covering a thin film of soft magnetic material which extends across the transducer assembly. The longitudinal bias is developed by exchange coupling between the thin film of antiferromagnetic material and both the MR layer and the thin film of soft magnetic material in the passive regions. However, the thin film of soft magnetic material is separated from the MR layer in the active region only of the MR layer by a decoupling layer which interrupts the exchange coupling so that transverse bias is produced only in the active region upon connection of a bias source to conductor leads which are connected to the MR layer within the passive region.

Abstract: A magnetoresistive (MR) read head in which an insulator layer defines the effective track width over which the read head is sensitive. The insulator layer is deposited or patterned to extend a predetermined distance over the MR element, and the predetermined distance is chosen equal to the desired track width. Conductor leads are deposited in contact with the regions of the MR element not covered by the insulator layer with the conductor leads extending up to, and possibly overlapping, the edges of the insulator layer so that the read signal is sensed over the length of the MR element covered by the insulator layer.

Abstract: A method and apparatus for measuring the flying height of a slider supporting a magnetic transducer in-situ in a direct manner in an operational magnetic disk storage system. The method and apparatus produce relative motion between the magnetic transducer and a magnetic recording medium at a first velocity so that the resulting air bearing positions the magnetic transducer slider at a first flying height from the magnetic medium. A single signal of constant periodicity is written over a predetermined area of the recording medium by the magnetic transducer, and a readback signal is sensed from the predetermined area of the recording medium to produce a first signal. The flying height of the magnetic transducer slider is lowered to substantially zero, and a readback signal is sensed at the lowered flying height to produce a second signal. The first flying height is then calculated as the ratio, expressed in decibels, of the first and second signals times the wavelength divided by a constant.

Abstract: A magnetoresistive (MR) read transducer assembly in which the thin film MR layer is longitudinally biased directly only in the end regions by exchange bias developed by a thin film of antiferromagnetic material that is deposited in direct contact only in the end regions of the MR layer. A thin film of soft magnetic material extends across only the central region of the MR layer. However, the thin film of soft magnetic material is separated from the MR layer by a decoupling layer which interrupts the exchange coupling so that transverse bias is produced only in the central region upon connection of a bias source to spaced conductor leads which are connected to the MR layer. The transverse bias is produced in that part of the central region of the MR layer in which the bias current and the decoupling layer are both present.

Abstract: An ink jet drop-on-demand print head comprises a plurality of electromechanical transducers, and ink from a manifold is conveyed to the transducers. The fluid path between the transducers and the corresponding nozzle in the nozzle array comprises a resilient dual function means. The dual function means not only provides the fan-in section but also seals the fluid path in fluid tight relation without the use of any adhesive or bonding material.

Abstract: A magnetic head support arm for a disk file comprises a relatively rigid arm structure and a magnetic head suspension assembly fixed at one end to the head support arm having means on the other end to support a transducing head, and having a tapered elongated flat load beam connecting the ends. A means of damping the structure against vibrations comprises a layer of damping material fixed to the elongated flat load beam and a constraining member fixed in contact with the damping material so that the vibration energy is damped due to shear energy absorption in the layer of damping material.

Abstract: A semiconductor integrated pressure transducer in which a semiconductor substrate incorporates a hermetically sealed system comprising a first chamber communicating with a second chamber via a capillary. The first chamber contains a fluid and has at least one portion of a wall in the form of a deformable membrane separating the atmosphere within the chamber from that external to the sensor. The second chamber contains a compressible gas and has rigid walls. The capillary is partially filled with electrically conducting liquid, and the liquid physically separates the fluid in the first chamber from the gas in the second chamber. The wall of the capillary is electrically conductive at least in two separated regions such that in use, at a predetermined external atmosphere pressure, the electrically conductive liquid makes contact with both electrically conductive regions thereby completing an electrical circuit.

Abstract: A time modulated source of frequency doubled laser radiation is described in which a non-linear crystal part of a stripline electrical circuit is mounted within a laser cavity so that the laser beam at a fundamental frequency impinges on and propagates through the non-linear crystal. A high bandwidth electrical data signal is coupled into the stripline electrical circuit to produce an electric field across the non-linear crystal so that an output beam is produced at a wavelength corresponding to the second harmonic of the fundamental frequency which represents a frequency doubled output beam modulated in accordance with the high bandwidth data signal, an alternate embodiment for producing the time modulated source of frequency doubled laser radiation has the non-linear crystal placed in a resonant microwave cavity.

Abstract: An air bearing slider is provided for supporting a magnetic transducer and the slider comprises a pair of coplanar side rails disposed on the sides of an air bearing surface of the slider to form a recessed section between the side rails which is open at both the leading and trailing ends of the slider. The side rails have a tapered height section at the leading end and a width that decreases to a break point located between the ends. The air bearing structure produces a combined pressure profile which causes the slider to fly with the leading end at a desired pitch angle relative to a moving magnetic medium, with the minimum spacing between the slider and the magnetic medium at the trailing end, where the magnetic transducer is mounted.

Abstract: A thin film magnetic transducer having a magnetic circuit having nickel-iron layers which encloses a portion of first and second windings. The portions of each winding traversing the nickel-iron layers have conductor segments equal in number and separated from each other in parallel planes. The conductor segments of each winding have a center-to-center spacing different from the remaining winding selected to avoid contact with the transition regions of the nickel-iron layers and which results in a common inductance for each winding. The windings are joined at one end to form a center tapped winding.

Abstract: A magnetoresistive (MR) read transducer assembly in which the thin film MR layer is longitudinally biased only in the end regions by exchange bias developed by a thin film of antiferromagnetic material that is deposited in direct contact only in the end regions of the MR layer and a thin film of soft magnetic material which extends across the transducer assembly. The longitudinal bias is developed by exchange coupling between the thin film of antiferromagnetic material and both the MR layer and the thin film of soft magnetic material in the end regions. However, the thin film of soft magnetic material is separated from the MR layer in the central region only of the MR layer by a decoupling layer which interrupts the exchange coupling so that transverse bias is produced only in the central region upon connection of a bias source to conductor leads which are connected to the MR layer within the end region.

Abstract: An ink jet drop-on-demand print head comprises a plurality of tubular piezoelectric transducers each having two electrodes formed by an electrically conducting coating. A housing member holds the transducers in a position which includes at least one row of transducers. A substrate includes a plurality of electrical conductors, and the substrate is positioned so that each electrical conductor is adjacent one of the electrodes. A resilient connector means is provided which is not conductive along its length but is conductive across its width, and the connector means is positioned to make contact with a selected one of the electrical conductors and only one of the electrodes of one of the transducers. In a specific embodiment, the substrate comprises a flat conductor cable, and in a second embodiment the substrate comprises a printed circuit board.

Abstract: An electroplating cell having a cathode assembly which is vertically mounted and which holds a plurality of wafers to be plated, and an anode which is vertically mounted adjacent to the cathode assembly. The anode and cathode are spaced apart and form opposite walls of a channel through which the plating bath flows. The plating bath is introduced through an isostatic chamber which produces, at its output, a substantially equal flow across the width of the channel so that a substantially vertical laminar flow is produced through the channel and the plated deposits are of uniform thickness within a wafer, from wafer to wafer and from batch to batch.

Abstract: A method for determining the position of a lapped edge of a substrate during lapping of a row of thin film magnetic transducer elements. First and second electrical lapping guide structures are formed on each side of the row of transducer elements. The lapping guide structures include a series of switching junctions, each switching junction paralleled by a resistor. A lapping resistor which provides a change in resistance proportional to the lapping of the row is measured and compared with the position of the lapping plane as determined from each switching junction change of state. Calibration of the resistor versus lapping plane position is effected to permit an accurate determination of the lapped surface from subsequent resistance measurements of the lapping resistor.

Abstract: Method and apparatus for controlling the throat height of batch fabricated thin film magnetic transducers. During deposition of the transducer elements on a substrate, a resistive electrical lapping guide is deposited on at least one end of the array of transducer elements. The electrical lapping guide includes a plurality of switching junctions formed between a section of electrically resistive material and conductors. At least one switching junction is deposited on the substrate having a known switching plane position. During lapping of the transducer pole tip ends to a final height, the switching junction will change state to provide an accurate indication of the lapped throat height. The throat height, as determined from measured resistance of the lapping guide, is compared to the switching junction position at the time said switching junction changes state. Subsequent resistance measurements are calibrated in light of this comparison.

Abstract: An electrical lapping guide resistor for measuring the lapping distance in a process for manufacturing thin film magnetic transducers. Final throat height is measured with an electrical lapping guide resistor which provides a linear change in resistance versus lapping distance. The lapping guide resistor is configured in a shape such that the effective length of the resistors increases as the effective width decreases. In a preferred embodiment of the invention, the resistor includes first and second converging edges which extend from a rearward edge parallel to the final throat height toward the lapping surface. Conductors are disposed along the converging edges. Measurements of the change in lapping distance are effected by measuring the distance between the conductors.

Abstract: A magnetoresistive (MR) read transducer assembly in which the thin film MR layer is longitudinally biased only in the end regions by exchange bias developed by a thin film of antiferromagnetic material that is deposited in direct contact with the MR layer in the end regions. The longitudinal bias is of a level sufficient to maintain the end regions of the MR layer in a single domain state and thereby induce a single domain state in the central region of the MR layer. Transverse bias is produced within the central region of the MR layer of a level sufficient to maintain that region of the MR layer in a linear response mode. Spaced conductive elements are connected to the MR layer within the central region to define a detection region so that signal output means connected to the conductive elements can determine the resistance changes in the detection region of the MR layer as a function of the fields which are intercepted by the MR layer.