Abstract: A pre-distortion shaping network employing a field effect transistor as one leg of a resistive voltage divider for shaping the modulating signal of a voltage controlled oscillator is described.

Abstract: Apparatus is provided in which a colleting and spindle assembly for lifting and rotating a substrate mounting chassis within a high vacuum sputtering chamber is mounted. Lifting and clamping action is accomplished utilizing rolling contact between surfaces produced by rotating a minor shaft with an eccentrically mounted bearing within and relative to a major shaft. A pneumatically-actuated piston mounted on one end of the major shaft drives an internally mounted high helix screw which is prevented from rotating relative to the major shaft thereby producing linear motion of the helix screw in a helix nut resulting in rotational motion of the helix nut relative to the major shaft. The rotational motion of the helix nut is coupled to the minor shaft causing it to rotate relative to the major shaft. Once the spindle assembly has been coupled to the substrate mounting chassis, the major shaft couples rotational motion to the substrate mounting chassis from outside the chamber to inside the chamber.

Abstract: An apparatus and method is disclosed to facilitate the dispensing of powders, particularly toner in a photocopy machine, which must be vibrated to prevent clumping. A powder container is shown with a unique neck baffle, and sloping sides so that the flow of powder is substantially regular when the vibration is turned on and the flow will stop when the vibration is turned off. A method and apparatus for adjusting the natural frequency of the container system is shown so that the amplitude of vibration does not significantly increase as the dispenser is emptied and the flow of powder is thereby maintained at a relatively constant rate.

Abstract: Apparatus to provide calibrated frequency modulation (FM) of frequencies generated in a phase-locked loop is disclosed. A phase-locked loop (PLL) includes a voltage-controlled oscillator (VCO) which is locked to a loop frequence signal frequency. A modulo-10 divider is included which adds integral multiples of two pi radians of phase to the output signal of the VCO whenever the modulus of the divider is reduced by an integer. This forces the PLL to step change the loop frequency by an integral multiple of the reference frequency. A sampling circuit senses and measures the change in the VCO control voltage resulting from the step change in the loop frequency. The change in the control voltage is a measure of the VCO gain at that frequency. The change in the control voltage is converted to a digital number which is loaded into a multiplying digital-to-analog converter (DAC) to adjust the gain of the DAC.

Abstract: Cleaning and priming of ink-ejecting nozzles is achieved by engaging the nozzles with an elastomeric suction cup as the printhead moves to the beginning or ending of a print line. The suction cup contains an inner cup of foam which wipes off any residual ink droplets. The cup assembly is connected to a vacuum pump for drawing ink out of the nozzles. The assembly is mounted on a four-bar linkage which, as it rotates, lifts the cup assembly to engage the nozzles in the printhead.

Abstract: Apparatus comprising a test chamber, an electric solenoid and a pressure detector is provided to measure the partial pressure of oxygen contained in a mixture of gases. As a result of the paramagnetic properties of oxygen, an acoustic wave is produced in the gas mixture by the application of a pulsed magnetic field. The magnitude of the dynamic acoustic wave is dependent on the amount of oxygen present in the gas mixture. The solenoid generates a pulsating magnetic field in response to an electric signal provided by a signal source. The pressure detector measures the magnitude of the resulting acoustic wave and provides a signal whose amplitude is directly proportional to the amount of oxygen present in the sample gas.

Abstract: A thin film transducer is provided for inductively recording and magnetoresistively reading magnetic information. The thin film magnetoresistive (MR) element is mounted on a bottom yoke member and is provided with means, which may be a pair of legs of the MR material extending in the same direction, so as to define a single magnetic domain in the MR element. The read conductor is provided in the form of a "barber pole" so that the angled transducer gap thereof overlies the magnetic domain in the MR element. The bottom yoke is a planar surface essentially dimensionless with respect to the other elements of the transducer head while the top yoke is specifically shaped so as to have a tail portion which overlies the write conductor and is parallel to the transducer gap in the read conductor.

Abstract: A cable drive system is provided in which a fixedly mounted reversible motor imparts translational motion to a plurality of pairs of elements such as the right and left pairs of paper moving tractors in a high-speed printer. By means of a continuous cable loop routed around passive rotational elements, each element of a pair of elements, each of which is rigidly attached to the cable, can be translated the same distance in the same direction as the other while the relative alignment of one element with respect to the other element is maintained. Means for selectively translating one pair of elements independently or a plurality of pairs of elements simultaneously while maintaining the distance between the pairs are provided.

Abstract: In a standard residue class analog-to-digital converter, pseudo-random noise is introduced at first or subsequent approximations of an analog input signal by the local digital-to-analog converter.

Abstract: In a dot matrix printer, a single main shift register is loaded in the non-printing time during which a transversely shuttling print bar is changing direction with the complete dot row to be printed on the next printing pass of the print bar. A custom VLSI integrated circuit comprising a serial loaded 2772-bit main shift register and a parallel loaded 132-bit bidirectional parallel-to-serial output shift register is provided. The main shift register has one storage cell for each dot that can be printed across the dot row during a single pass of the print bar. Parallel output taps physically placed along the main shift register provide simultaneous serial output of the storage cells between each tap. The number of bits stored between each output tap is the number of dots each individual print hammer can print on a single pass of the print bar. The 132-bit output shift register is utilized to limit the number of package pins and to compensate for the direction of motion of the print bar.

Abstract: Apparatus is provided to frequency modulate (FM) RF carrier frequencies generated in a phase-locked loop (PLL). FM outside the loop bandwidth is AC coupled to the loop. FM within the loop bandwidth is DC coupled via an integrating OP-AMP to provide phase modulation. Whenever the output of the integrator exceeds a preset threshold, a prescaler removes or adds two pi (or integral multiples of two pi) radians of phase change from the input to the loop divide-by-N circuit. At the same time, a current source pumps charge into the integrator to exactly compensate for the amount of phase removed or added resetting the integrator. DC feedback around the integrating OP-AMP and a feedback signal proportional to the exact amount of phase added or removed provides a true synthesized loop center frequency with no drift. When the feedback path is interrupted, DC FM is provided.

Abstract: Method and apparatus for starting and driving a brushless DC motor and compensating variations in motor speed by producing sequential drive currents through the motor coils, selectively interrupting such currents to allow the rotor to catch up with the rotating stator field during startup, and stabilizing motor speed by controlling motor coil current in inverse proportion to the rate of change of phase lag of the rotor behind the rotating stator field.

Abstract: An apparatus amplifies a signal in two different modes. The apparatus amplifies the signal in a linear mode when the voltage of the signal is much less than the voltage of the power source, and in a switching mode when the signal is at other voltages.