Abstract: An oscillator circuit which demonstrates stable operation over a wide range of supply voltages and process variations. A latch circuit is controlled utilizing a timing capacitor. A constant current source is applied alternately to opposite sides of the timing capacitor through a series of switching gates which bootstrap the voltage across the timing capacitor, with the switching gates being controlled by the output of the latch circuit.

Abstract: A unique method and apparatus for manufacturing gas-filled tubes utilizes an optically-spread beam of light to seal and cut short segments of tubing from a long tube containing the gas. Neither the laser beam nor the tubing is moved during the cutting and sealing operation. The gas being supplied to the length of tubing during the cutting and sealing operation is maintained at constant pressure so that each cut segment has the same resultant internal gas pressure. In one embodiment, radioactive light sources for illuminating displays and the like are manufactured by indexing a long phosphor-coated glass tube containing radioactive gas maintained at constant pressure, past a laser which generates an optically-spread light beam. The laser is activated in each index position of the tube to seal and cut short segments of the tubing with each segment having the same quantity of radioactive gas to provide the same desired quantity of illumination.

Abstract: An improved fuel cell electrode comprising a graphite felt substrate having a thin vapor deposited graphite film coating the exterior fiber surfaces and a perforated metallic backing plate having one surface coated with a noble material such as platinum.

Abstract: A digital computing system is disclosed having a monolithic microprocessor, a versatile input/output subsystem, a multi-medium capability. In the memory subsystem, a balanced mix of dynamic RAM, P-channel MOS ROM and N-channel MOS ROM are included to minimize cost without sacrificing performance. In the video display subsystem, a monolithic video display processor performs all RAM access functions, in addition to composite video generation. The resultant composite video signal, which may include audio and external video information, can be applied directly to a video monitor or RF modulated for use by a television receiver.

Abstract: A coupler pair provides the communication link between two multiprocessors wherein each multiprocessor comprises a plurality of master and slave devices interconnected by a communication bus. The coupler pair provides a communication path between any master device on one of the communication buses and any slave device on the opposite communication bus. More generally a plurality of coupler pairs provides inter-communication within a polysystem comprised of a plurality of multiprocessors.

Abstract: A method and system for driving a liquid crystal display (LCD) with adjustable drive voltages to match selected ones of a number of different liquid crystal materials utilize variable duty cycle control. Instead of regulating the battery supply voltage to provide desired driving voltage, the driving voltage is disabled for preselected portions of each cycle thereby controlling the root mean square voltage across the LCD segments during both the display-on and display-off states of each display segment to match the liquid crystal material. Two-, three- and four-way multiplexing or any other level of multiplexing may be used in conjunction with this method and system.

Abstract: A charge-coupled device (CCD) imager has an output shift register having a number of bits equal to at least a multiple (N), where N is an integer greater than 1, times the number of columns of pixels in the imager. Appropriately spaced in the output shift register are N groups of N outputs each for non-destructive, simultaneous readout of N.times.N bits. The N.times.N bits are then available for pre-processing or display without the requirement for having previously stored each bit, digitally represented, in a computer memory.

Abstract: A differential reference voltage regulator for I.sup.2 L silicon integrated circuits having temperature compensation means including a temperature reference transistor and a balance resistance, R2, connected in series between a reference resistance, R1, and a current source transistor wherein ##EQU1## where n is the ratio of currents applied to a pair of transistors which form a differential regulator.

Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having internal sleeve and shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle engages an internal sleeve having ports that momentarily align with exhaust ports and then moves past, sealing off the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. By preventing further discharge of air with little or no loss in acoustic output, pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.

Abstract: The specification discloses a method and system wherein an operator interacts with an automatic data processing and display system to classify and sort subsurface reflective surfaces or segments in a multidimensional context. The technique utilizes a properly programmed general purpose digital computer in combination with a plurality of storage tube display screens. Seismic reflection data in the form of computer picked reflection segments, hereinafter referred to as seismic segment data, produced from previous computer processing steps is entered into the computer. Displays of the velocity, amplitude, dip and length of the segments in a space gate are then provided on the display screens. A data responsive surface having a network of conductive wires and a detecting stylus are utilized by the operator to operate upon the displayed segment data to classify primary segments and to define boundaries relative to each of the parameter displays.

Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is controlled by secondary shuttle means for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. This point of closing the exhaust ports before virtually all of the compressed air is discharged differs from prior art air guns. By preventing further discharge of air, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further, by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.

Abstract: A minimum design I.sup.2 L full adder with carry look ahead capabilities has all arithmetic logic unit functions, including OR, AND, XOR and SUM generated within. The full adder is easily extended to an arithmetic logic unit where all logic functions are selected at the output.

Abstract: A charge coupled device having geometries suitable for fabrication in high density packages (64,000 bits per chip-1,000,000 bits per chip) is comprised of a semiconductor substrate having dopant impurity atoms of a first type and a first surface. A charge transfer channel lies in the substrate near the first surface, and it is overlaid by an insulating layer of non-uniform thickness. A plurality of first and second electrodes lie on the insulating layer traversely to the channel. A well region of dopant impurity atoms of a second type opposite to the first type lies under each of the electrodes. The non-uniform insulating layer underlies each of the first electrodes by a first uniform thickness, underlies the second electrodes by a second uniform thickness, and separates the each of the first and second electrodes by approximately the second thickness. The second thickness is 20%-60% greater than the first thickness to greatly reduce inter-electrode shorts in high density packages.

Abstract: A charge coupled device having geometries suitable for fabrication in high density packages (64,000 bits per chip--1,000,000 bits per chip) is comprised of a semiconductor substrate having dopant impurity atoms of a first type and a first surface. A charge transfer channel lies in the substrate near the first surface; and it is overlaid by an insulating layer of non-uniform thickness. A plurality of first and second electrodes lie on the insulating layer traversely to the channel. A barrier region of dopant impurity atoms of the first type lies under each of the electrodes. The non-uniform insulating layer underlies each of the first electrodes by a first uniform thickness, underlies the second electrodes by a second uniform thickness, and separates the each of the first and second electrodes by approximately the second thickness. The second thickness is 20%-60% greater than the first thickness to greatly reduce inter-electrode shorts in high density packages.

Abstract: A switch mode driver for a wire matrix printer employs a single power switch circuit to connect one or more solenoids across a DC source or power and to disconnect those solenoids from that source. Enable signals are provided to select any one or all of the solenoids, such enable signals remaining for a predetermined time during which a slewing period, followed by a chopping period, occur and after which energy remaining in the selected solenoids is returned to the DC power source. The initial ramping of current through the selected solenoids occurs when the power switch circuit is closed for a time period determined by an RC circuit, such time period defining the slewing period. Then the power switch opens and the chopping period begins. The charge on the capacitor of the RC circuit is discharged and at a certain voltage point, the power switch is again closed until the charge on the capacitor of the RC circuit again reaches a predetermined voltage at which time the power switch opens.

Abstract: A self-referencing power converter operates at a high frequency with a low loss, light weight ferrite core transformer. The transformer primary is selectively connected across a DC source of rectified AC power to provide energy storage followed by a predetermined time period of disconnect to provide energy transfer by way of transformer flyback. The energy storage cycle begins when the voltage across the primary winding of the transformer does not exceed a predetermined value and the predetermined time period of disconnect has ended. A current sensing circuit senses the current flowing through the primary winding, permitting such current to flow until a power reference is reached. A comparison circuit in the transformer secondary compares a reference voltage with an operating voltage and returns any error voltage to the primary circuit, the error voltage then being used to set the power reference.

Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is controlled by valve means for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. By preventing further discharge of air, with little or no loss in acoustic output, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.

Abstract: An arithmetic logic unit bit-slice implemented as an integrated circuit is able to perform iterative algorithms such as multiply and divide, using control logic which is also part of the integrated circuit to cause the selected algorithm to be performed. A plurality of the arithmetic logic unit bit-slices may be concatenated to provide the word size desired. The bit-slices are electrically identified as the most significant, least significant, and middle digits, such identification being provided to the control logic so that the control logic is identical on each bit-slice irresepective of its position within a word to enable the control logic to cause performance of the algorithms for any desired word length.

Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is indirectly controlled by a moveable plate for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. In one embodiment, the plate is freely moveable; in a second embodiment, the plate is attached to the shuttle. By preventing further discharge of air, with little or no loss in acoustic output, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.

Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle and external sliding valve control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is controlled by air pressure to move it upward, thereby permitting compressed air in the firing chamber to exhaust through exhaust ports. The external sliding valve had been held in a downward position by air pressure supplied from the firing chamber, compressing a spring. As the firing chamber pressure drops, the compressed spring expands, forcing the sliding valve to move upward, closing the exhaust ports. By preventing further discharge of air, secondary pulses are greatly reduced, with little or no loss in acoustic output, thereby enhancing the operation of the entire system. Further, by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.