Abstract: A magnetoresistive head achieves maximum signal output with minimal electromigration by use of two increased direct currents with different polarities which are directed periodically through a magnetoresistive element in opposite directions, with minimal long term directional diffusion for minimizing electromigration and for increasing the signal output. The magnetoresistive element defines two magnetic centers MC.sup.+ and MC.sup.- that correspond to the polarities of the two currents, and the magnetic centers are positioned at optimal magnetic locations.

Abstract: The present invention describes a new digital video tape recorder apparatus and method in which video channels are simultaneously recorded in a recording mode, and in which any of the recorded video channels is reproduced when in a reproducing mode. The apparatus includes a first selector unit for generating signals for identifying one or more channels containing video signals to be recorded. A receiver sends the channel identifying signals to a transmitter, which, in turn, uses the channel identifying signals to selectively identify the channels to be transmitted to the receiver. The transmitter compresses and multiplexes the video signals of the channels selected by the receiver. The receiver receives the compressed and multiplexed signals, and records and stores the received signals. A demultiplexer selectively demultiplexes the channels transmitted to the receiver, and a memory records or stores the signals in the demultiplexed channels.

Abstract: A low noise inductive magnetic head used for writing and reading magnetic signals onto and from a magnetic recording medium includes two magnetic poles P1, P2 that are formed on a substrate which define a transducing gap therebetween. Each of the poles P1, P2 includes an outer magnetic layer formed remotely from the gap and an inner magnetic layer formed adjacent to the gap. The inner and outer magnetic layers have magnetostrictions (.lambda..sub.s) of approximately equal but opposite values, such that each of the magnetic poles P1, P2 exhibits a net magnetostriction of zero or is biased within a predefined range, regardless of the individual magnetostriction values of its layers.

Abstract: An optical data storage medium transmissive to a laser beam and formed of a light transmissive substrate that provides mechanical support, and a light transmissive data substrate formed on the substrate. The data substrate is patterned to form block regions that block the laser beam from passing through, and pass regions that allow the laser beam to pass through, such that the blockage or passage of light through the optical storage medium reflects the type of data bits to be stored on the optical medium. In another embodiment a magneto-optical data storage medium which is also transmissive (or partly transmissive) to a laser beam includes a data magneto-optical data substrate formed on a substrate. The data substrate is recordable by patterning a magnetic domain with magnetic fields of opposite directions, such that each magnetic direction reflects the type of data bits to be stored on the optical medium.

Abstract: An optical data storage system for use with a stationary data storage medium includes a stationary optical head for steering an incident laser beam holographically and/or by means of an acousto-optical method along the X and Y direction across the data storage medium. The incident laser beam is selectively reflected by the data storage medium to indicate the type of data bits recorded on the storage medium. In a preferred embodiment the optical head includes a laser source for emiting a collimated laser beam, a beam steering element for steering the laser beam; a beam splitter for deflecting the reflected laser beam; and a photo-detector for detecting the relative intensity of the reflected laser beam for determining the type of recorded data bits. In one embodiment the beam splitting element includes an elasto-optical crystal that causes the impinging laser beam to be deflected in the X and Y directions.

Abstract: A program delivery system using a compression apparatus capable of compressing incoming video and non-video signals, such as audio and data signals. The system includes a frequency modulator which modulates the incoming audio, data or other non-video signals, unto selected video frequencies. A Fourier transformer generates a set of sinusoidal transform components corresponding to the incoming video, audio, data or other non-video signals, and a selector chooses the most desirable Fourier sinusoidal transforms. A multiplexer multiplexes only the selected Fourier transform components for further processing.

Abstract: The present invention describes a new pump which can be used as a mechanical heart, as a body fluid, as a drug infusion pump, and in similar or related applications for the circulation of body fluids including but not limited to blood and oxygenated air. The pump includes a scroll type pump that has been modified for medical applications. The pump includes two scroll involute spiral elements that are maintained at an angular and radial offset so that both spiral elements interfit to make a plurality of line contacts between their spiral curved surfaces to thereby seal off and define at least one pair of fluid pockets. The relative orbital motion of the two spiral elements shifts the line contact along the spiral curved surfaces thus causing the fluid pockets to change in volume. Since the volume of the fluid pockets increases or decreases, depending on the direction of the orbital motion, the scroll type pump is capable of either compressing, expanding or pumping the body fluids.

Abstract: Video receiving method and apparatus, are responsive to requests from a selector unit (240), for identifying channels (1 through n), in a transmitter system (204), containing video signals to be sent from the transmitter system (204) to one or more receiver systems (202). The receiving method includes steps of having the receiver system (202) select (94) one or more channels. The receiver system generates (90) signals identificative of the selected channels, and sends (29) the channel identifying signals to the transmitter system (204). The transmitter system uses the channel identifying signals to selectively identify the channels to be transmitted to the receiver system (202). The transmitter system compresses (17, 19, 21) and multiplexes (25) the signals of the channels selected by the receiver system (202). The receiver system (202) receives (75) the compressed and multiplexed signals, and stores (35, 37, 39) the received signals.