Abstract: Apparatus for and method of providing single bit error correction and double bit error detection using through checking parity bits. A coding scheme is implemented which uses through checking parity bits appended to each byte as check bits. The remaining check bits are generated such that the combination of through checking parity bits and remaining check bits together provide single bit error correction and double bit error detection.

Abstract: An apparatus for and a method of providing an amplified, directable laser light beam is disclosed. The apparatus includes two optical cavities sharing a common mirror. The first cavity is resonant and contains a laser rod intermediate a high reflectivity reflecting mirror of 100% reflectivity and a low reflectivity transmitting mirror of 10-90% reflectivity. The second cavity is antiresonant and contains a Faraday effect diffraction grating intermediate the low reflectivity mirror and a 100% reflectivity mirror. The laser light beam that passes through the transmitting mirror is directed normally incident to the surface of and passes through the Faraday effect diffraction grating. On the far side of the diffraction grating is a mirror of 100% reflectivity, which reflects the laser light beam back through the diffraction grating forming a pair of diffracted congruent 1'st order light beams and a single undiffracted 0'th order light beam.

Abstract: A system for compensating misalignment between information represented by transitions in a data bearing medium and a played back signal, the played back signal having consecutive opposite-polarity peaks corresponding to said data transitions, which system comprises a low-pass filter, which receives a signal from a non-linear element, preferably a pulse forming circuit, into which has been introduced the misaligned played back signal, and circuitry for converting the filtered signal to a series of pulses representative of the data transitions, which pulses have reduced misalignment with respect to the data transitions.

Abstract: An apparatus for and a method of measuring the difference in intensity between two coplanar magnetic field vector components at two different points in space. The device is comprised of two interconnected, relatively large, loop patterns of opposite, flux cancelling, winding sense. One or both loops include a trimming element that is itself formed of two interconnected, relatively small, loop patterns of opposite, flux cancelling, winding sense. The device is analyzed for imbalance between the two large loops and is then balanced by placing a balancing superconducting disk of the proper characteristic in or near one of the two small loops of the trimming element. The so-trimmed apparatus forms a gradiometer of substantially improved mensuration.

Abstract: The output signal of a voltage-controlled oscillator of a phase-locked loop has its phase compared with the phase of incoming data in a phase detector producing a first signal. This first signal is then passed through a non-inverting amplifier to produce an amplified signal of the same polarity. The first signal is also passed through an inverting amplifier otherwise similar to the non-inverting amplifier to produce an amplified signal of opposite polarity. The inverted and non-inverted amplified signals are then filtered in respective low pass filter circuits and combined differentially in an amplifier which produces an error voltage for the voltage-controlled oscillator. Differential combining of the inverted and non-inverted amplified signals eliminates undesired D.C. voltage components caused by temperature drifts and the like by mutually cancelling such components while effectively doubling the amplitude of the desired error voltage.

Abstract: An apparatus for spreading a coherent light beam produced by a laser or lasers into a selected pattern. The selected pattern of coherent light, generally a ribbon-like shape, can be used to place a desired amount of electromagnetic energy at a selected frequency for a selected time period on a generally flat surface. The projected coherent light pattern can be used to cure or dry inks without scorching the underlying paper. The control of the intensity of the coherent light allows drying operations at higher speeds than currently feasible.

Abstract: A bi-directional printed circuit motor is coupled to drive at least a pair of one way clutches which selectively actuate one or more utilization devices dependent on the direction of the motor. The utilization devices may, for example, include a print hammer assembly, an inked ribbon and paper driver of a high speed printer in a computer system.

Abstract: An electrostatic copying machine includes a reservoir for liquid developer made up of toner particles in a dispersant. A photoconductive drum, adapted after receiving a latent electrostatic image thereon to pass through the liquid developer in the reservoir and to have an electrostatic image developed on the drum. A metering roller for removing excess dispersant is positioned between the reservoir and an air knife which projects a sharp thin jet of pressurized air at about a 45 degree angle with respect to the surface of the drum. The air pressure produced by the air knife drives any remaining spent dispersant on the surface of the drum back to the reservoir by way of the metering roller and the latent image on the drum is subsequently transferred to paper.

Abstract: This invention includes timer means in combination with switching means disposed in a copying machine for cyclically and automatically activating a pump which circulates liquid developer through the copying machine for a predetermined period of time thereby periodically mixing the toner particles and dispersant in the liquid developer while also rotating the copier drum through an incremental angle thereby periodically immersing each section of the drum surface in the liquid developer reservoir.

Abstract: The invention provides data processing duplication and internal error checking within an integrated circuit chip at intermediate points along the logic chain. In one aspect of the invention, duplicate functional logic within the chip is utilized together with multiple fault detectors to provide error checking of the primary logic chain, mechanical interconnection failures, and power and clock pulse checking. The detectable failures are both transient and hard failures. Other problems are in addition resolvable by utilization of duplicate complementary logic in place of duplicate functional logic, such other problems including chip contamination during manufacture, mask problems and functional design problems. The multiple fault detectors provide a multiplicity of error signals which are multiplexed within the chip to produce encoded output error signals each of which designates the fault which has been detected within the chip.

Abstract: In a magnetic recording system having a medium for storing information in the form of encoded digital data, an improvement in the recording head control circuit including means and a method for determining the temporal occurrence of a major write transition of the encoded digital data and producing a minor write pre-transition and a minor write post-transition each having a lower amplitude and an opposite direction to that of the major write transition thereby providing a readout pulse corresponding to the combined write transitions having a narrower pulse width and improved symmetry which enhances the accuracy in reading out the recorded digital data and increases the packing density in the storage medium of the recording system.

Abstract: A data source is connected through a gating circuit to all stages of an asynchronous shift register. The gating circuit senses the full or empty status of each stage of the shift register and enters an incoming bit of data into that stage of the shift register which is the empty stage nearest the output, and has no stage preceding it which is full. The arrangement decreases the delay time normally encountered by data as it is shifted through the shift register, the decrease in delay time being related to the number of empty stages in the register at the time a bit of data is entered.

Abstract: A vehicle barricade including a barrier plate which can be raised or lowe and a counterweighted sector mounted near the side of the barrier plate. The counterweight is mounted on the sector so that the barrier plate will remain in the raised or lowered position without independent mechanical aid. The barricade is so constructed and secured that it is able to withstand impact from either heavy or light vehicles. The barricade may also be reenforced by placing auxiliary pillars adjacent to the barrier plate and which pillars cooperate with the barrier plate to further secure it when raised.

Abstract: The present device is a means for printing multi-lines of characters simultaneously on a continuously moving print receiving medium or form and in a manner eliminating the need for indexing the form line by line and column by column. Multiple type fonts are arranged in helical paths around a continuously rotating drum, the axis of which is positioned at an angle to the path of movement of the form whereby each font is effective to print an individual line of character on the form as it progresses along its path of movement.

Abstract: A magnetic read/record head having a layer of uniaxially anisotropic magnetic material as the pole faces, which increases the ratio of magnetic reluctance between the pole faces to the magnetic reluctance along the fringing flux path through the recording medium. Two embodiments of the invention are disclosed, one embodiment providing a layer of anisotropic magnetic material in a continuous layer around a complete loop from one pole face to the other pole face, and the other embodiment providing a layer of anisotropic magnetic material confined to each of the pole regions.

Abstract: Apparatus including means for fluidically supporting and guiding a moving, cylindrically formed thin metal belt used in the transport of magnetic particles. Magnet pole pieces disposed adjacent the surface of the belt accommodate formation thereon of a non-translating, rotating bead of dry magnetic ink particles in the application of a uniform ink coating over the belt suitable for printing. The belt is held in substantially fluid tight relation along its opposed edges on bearing means affording rotation of the belt about a fixed, axially extending mandrel including fluid supply cavities and a magnet support cavity. The fluid supply cavities terminate in radially presented recessed orifices for discharging a fluid into a relatively close space provided between the mandrel and the belt, to the side of the latter opposite the surface on which the ink bead is formed by a magnet disposed within the magnet cavity.

Abstract: A toroidal accelerometer including a toroidal shaped housing having first and second oppositely disposed arcuate shaped electrodes and a third electrode which is a common electrode, all three electrodes being partially immersed in an electrolytic fluid and subject to differential wetting in accordance with the angle of tilt about a horizontal axis of rotation or axis of symmetry of the toroid. A fourth electrode positioned between the first and second electrodes, equi-distant from the third electrode is at all times completely immersed in the electrolytic fluid.

Abstract: A sequence of short pulses are produced from a single input pulse of longer duration by use of a plurality of step recovery diodes connected in shunt across a transmission line. The number of individual pulses produced in response to each applied longer pulse is determined by the number of step recovery diodes shunting the transmission line and the distance between adjacent pulses in the sequence is determined by the spacing between the diodes producing the adjacent pulses.

Abstract: A detector which is subject to temperature variations and power supply drift including a tunnel diode circuit having first and second stable states and a variable threshold that is sensitive to noise and input signals within a useful frequency band and produces output signals when the amplitude of the noise or the input signals exceeds the instantaneous value of the variable threshold to cause the tunnel diode to switch from its first low voltage stable state to its second high voltage stable state. A control circuit coupled to the tunnel diode produces a square range-gate pulse having a pulse width which determines the interval during which the detector is sensitized and produces a reset pulse in response to the leading edge of the square range-gate pulse which sets the tunnel diode in its first stable state.

Abstract: A floating bearing having a stationary member and an axially translating member including a pair of O-rings which in combination with surfaces of the movable member and the stationary member define a contained space which is further subdivided by an extension of a surface of either the translating member or the stationary member to form two chambers substantially enclosed but connected through a restricted space formed by the extremity of the extension and a proximate opposing surface of the other member. The chambers are substantially filled with a viscous fluid which provides damping of axial displacements of said movable member relative to said stationary member produced in vibratory environments.