Patents Assigned to Tektronix, Inc.
  • Patent number: 4691174
    Abstract: An amplifier includes first and second transistors having emitters connected to a first current source, feedback from the second transistor collector to its base being supplied through a base-emitter path of a first Darlington pair in series with a first diode. A second current source is connected to the first Darlington pair emitter. Third and fourth transistors have emitters connected to a third current source with feedback supplied from the fourth transistor collector to its base through a second Darlington pair and a second diode. The second Darlington pair emitter is connected to a fourth current source and resistively coupled to the first Darlington pair emitter.
    Type: Grant
    Filed: September 19, 1986
    Date of Patent: September 1, 1987
    Assignee: Tektronix, Inc.
    Inventors: Theodore G. Nelson, Calvin D. Diller
  • Patent number: 4691121
    Abstract: A digital free-running clock oscillator comprises a circuit synchronizing the operation of the oscillator with an asynchronous timing signal from an external source, and is provided with a protection circuit for preventing a logic race condition in the synchronizing circuit during a period of coincident transition of the oscillator output and the external timing signal.
    Type: Grant
    Filed: November 29, 1985
    Date of Patent: September 1, 1987
    Assignee: Tektronix, Inc.
    Inventor: John G. Theus
  • Patent number: 4689674
    Abstract: A horizontal position control for a television waveform monitor includes a potentiometer that has a substantially linear input position/output voltage transfer function, and a circuit for reducing the sensitivity of the horizontal position control over a predetermined range of input positions of the potentiometer. The reduced sensitivity is preferably provided over a band approximately at the center of the range of horizontal positions covered by the horizontal position control.
    Type: Grant
    Filed: September 26, 1985
    Date of Patent: August 25, 1987
    Assignee: Tektronix, Inc.
    Inventors: Davorin Fundak, Larry R. Adams
  • Patent number: 4688148
    Abstract: Packaging for an electrical instrument wherein the electrical field is to be contained in a metal card cage and the card cage enveloped in a plastic shell. Fastening towers or stems are molded in the base portion of the plastic shell and key slotted windows in the card cage drop over the tower and slid under a ledge of the tower to secure the card cage to the base. Main interface circuit boards having keyslots are adapted to interfit the protruded end of the fastening towers. Biased locking lugs enter the slots in the "seated" or "home" positions of both the card cage and circuit board to interlock the three components all without separate fasteners and with a minimum of time and effort.
    Type: Grant
    Filed: June 6, 1986
    Date of Patent: August 18, 1987
    Assignee: Tektronix, Inc.
    Inventors: Robert L. Mallory, Alfred H. Schamel, Stephen M. Sekel
  • Patent number: 4688253
    Abstract: An L+R separation system separates the L+R component of a composite stereo signal, such as a BTSC signal or an FM broadcast stereo signal, from the L-R suppressed subcarrier component by sampling the composite stereo signal at a rate which is twice the frequency of the L-R component subcarrier frequency. The sampling signal, which is derived from the composite stereo signal, is synchronized with the subcarrier frequency such that the sampling occurs at the zero crossings of the subcarrier frequency, eliminating the L-R component from the sampled output. A simple lowpass filter recovers the L+R component.
    Type: Grant
    Filed: July 28, 1986
    Date of Patent: August 18, 1987
    Assignee: Tektronix, Inc.
    Inventor: Linley F. Gumm
  • Patent number: 4687552
    Abstract: A process for two layer gold integrated circuit metallization is disclosed. The process includes electrodeposition of a first metal layer, preferably of gold, atop a barrier layer, followed by electrodeposition of a second metal layer or cap, atop the gold to form a first metallization layer. The cap is corrosion-resistant metal having a rigidity at annealing temperature greater than that of gold. Following annealing, a dielectric interlayer is deposited so as to fill the regions adjacent sidewalls of the first metallization layer. Vias are formed in the interlayer dielectric, a second barrier layer is deposited and photoresist is applied and patterned for electrodeposition of a second, gold metallization layer. During annealing, the rhodium cap retains the as-deposited shape of the gold in the first metallization layer to facilitate insulative spacing between the first and second metallizations and to insure complete filling of interlayer dielectric on the lower edges of the first metallization.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: August 18, 1987
    Assignee: Tektronix, Inc.
    Inventors: Stephen R. Early, Daniel Grogan
  • Patent number: 4686489
    Abstract: A voltage controlled triggered oscillator includes a NAND gate and a set of series connected triggerable delay circuits, the output of the NAND gate being fed back to one of its inputs through the delay circuits. A trigger signal is applied to another input of the NAND gate and to triggering inputs of the delay circuits. When the trigger signal is asserted, each delay circuit produces an output signal of state which tracks the state of its input signal but with a predetermined delay so that the NAND gate output oscillates with a frequency determined by the delay times of the delay circuits and the propagation time of the NAND gate. When the trigger signal is deasserted the NAND gate output is terminated and each delay circuit drives its output signal high regardless of the state of its input signal so that the oscillator may be rapidly retriggered.
    Type: Grant
    Filed: June 16, 1986
    Date of Patent: August 11, 1987
    Assignee: Tektronix, Inc.
    Inventor: George J. Caspell
  • Patent number: 4686492
    Abstract: A bond wire connection between two semiconductor devices alleviates the problem of inductive loading at high frequencies by providing a capacitive effect which compensates for inductive reactance. The capacitive effect is provided by utilizing multiple parallel layers of bond wires at a common electrical connection point. As more layers are added the net impedance can be controlled so as to match the impedance driving the downstream semiconductor.
    Type: Grant
    Filed: March 4, 1985
    Date of Patent: August 11, 1987
    Assignee: Tektronix, Inc.
    Inventors: H. Erwin Grellmann, Leonard A. Roland
  • Patent number: 4686523
    Abstract: A cursor generator for an oscilloscope presents a cursor line or lines in juxtaposition with waveforms on an oscilloscope display, wherein the cursor is formed of a plurality of discrete points or dots. The deflection signal for generating the cursor is preferably supplied from the oscilloscope's character generator, while the analog positioning voltages for the cursor are also used in sweep delay comparison portion of the oscilloscope for initiating the oscilloscope's delayed sweep.
    Type: Grant
    Filed: January 31, 1984
    Date of Patent: August 11, 1987
    Assignee: Tektronix, Inc.
    Inventor: L. Rodney Bristol
  • Patent number: 4685185
    Abstract: An aperture plate for an ink jet head is formed by micro electrical discharge machining one surface of the plate to form a dimple-like recess with a relatively wide flat base. An aperture is then formed through the plate in the region of the dimple, as by micro electrical discharge machining. In one method of the invention, recesses are formed in two plates which are then mounted to the body of an ink jet head. A third plate with a formed third aperture is then mounted to the body such that the first, second and third plates overly one another and the third aperture is aligned with the recesses. Apertures of a smaller cross-section than the third aperture are then formed in the first two plates by drilling through the third aperture. The aperture through the first plate is then enlarged.
    Type: Grant
    Filed: August 29, 1986
    Date of Patent: August 11, 1987
    Assignee: Tektronix, Inc.
    Inventors: Brian Boso, Gerhard J. Beenen, Bruce Murdock
  • Patent number: 4686390
    Abstract: A digital peak-hold detector for determining the peak value of an input analog voltage to be displayed on a multiple-element display device detects when the value of the input analog voltage exceeds the value of a ramp-like waveform generated from a counter which repetitively counts down from a number equal to the total number of display elements to zero to generate a compare signal. A control circuit strobes the count corresponding to the peak value into a storage register when the value of the input analog voltage exceeds the current peak value in the storage register. A digital comparator compares the current peak value from the storage register with the repetitive count from the counter and outputs an update signal when the value of the count is greater than the current peak value. The update signal is combined with the compare signal by the control circuit to make the determination whether to update the current peak value.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: August 11, 1987
    Assignee: Tektronix, Inc.
    Inventors: Edward J. Cleary, Jr., Mike R. Coleman
  • Patent number: 4684881
    Abstract: A switched attenuator circuit providing three selectable voltage-divider ratios including one which passes substantially 100 percent of the input signal. The circuit places constant load resistance on its source in all positions when driving a high-resistance load. The circuit is inexpensive to construct, comprising three attenuation resistors, two input resistance compensating resistors, and two single-pole double-throw switching elements for changing the series/parallel configuration of the attenuation resistors and switching the compensating resistors into the circuit. The circuit places all parasitic capacitance associated with the switches on the input side of the circuit, thereby providing uniformly low output capacitance for all voltage-divider ratios.
    Type: Grant
    Filed: September 17, 1986
    Date of Patent: August 4, 1987
    Assignee: Tektronix, Inc.
    Inventors: Calvin D. Diller, Michael J. Burke
  • Patent number: 4683415
    Abstract: A line-frequency switching power supply for producing a regulated D.C. output voltage includes a pass element disposed between a rectifier circuit and an output terminal to which a filter is connected. The pass element is enabled when a zero-crossing of line voltage is detected, and switched on when the line voltage exceeds the voltage on the filter capacitor plus the operational drop across the pass element. The pass element is switched off when the output reaches a preselected D.C. output level, tripping a switch. Since the pass element is switched on for only a portion of a cycle of line voltage, power dissipation is minimized and efficiency is kept high. Regulators of type described herein suitably may be stacked on a single secondary winding to produce multiple output voltages, or may suitably function as preregulators for following linear regulators to produce very stable and constant D.C. output voltages with minimum power dissipation.
    Type: Grant
    Filed: September 15, 1986
    Date of Patent: July 28, 1987
    Assignee: Tektronix, Inc.
    Inventor: Matt J. Zimmerman
  • Patent number: 4682304
    Abstract: A communications interface for controlling asynchronous data transmission between a host computer and an input/output device achieves very high data transfer rates and reduces I/O bottlenecks. The interface includes a microprocessor and a memory addressable thereby. The microprocessor controls data transfer from the host computer into an output buffer maintained within the memory and controls subsequent data transfer from the output buffer to an output device, independently of the operation of the host computer. Data received from the host computer is stored directly into an appropriate output buffer storage location without any time-consuming reading and writing of the data by the microprocessor. This is accomplished by providing a hardware register for storing data received from the host computer. At the appropriate time data transfer from the microprocessor to the memory is disabled, and data transfer from the register to the memory is enabled.
    Type: Grant
    Filed: May 23, 1986
    Date of Patent: July 21, 1987
    Assignee: Tektronix, Inc.
    Inventor: Lannie J. Tierney
  • Patent number: 4680620
    Abstract: Apparatus for indicating the timing relationship between a reference point of a repetitive input signal, e.g. the horizontal sync point of a video signal, and a signal element that repeats at a higher frequency than the input signal, e.g. an element of the color burst, comprises a phase-locked oscillator for generating a continuous wave signal that is in phase with the signal element. The continuous wave signal is used to generate a train of pulses having a repetition frequency that is equal to the repetition frequency of the signal element and is selectively variable in phase relative to the continuous wave signal, and this train of pulses is used to modulate a display of the repetitive input signal in a dimension other than one that is used in a normal waveform display, e.g. intensity.
    Type: Grant
    Filed: March 6, 1986
    Date of Patent: July 14, 1987
    Assignee: Tektronix, Inc.
    Inventors: Daniel G. Baker, Kenneth M. Ainsworth
  • Patent number: 4680780
    Abstract: A digital phase-locked loop circuit for recovering an external clock signal from an input serial data stream includes an up/down counter responsive to both the serial data stream and to the clock pulse output of a variable divider driven by an external clock. The up/down counter counts in a direction which depends upon whether the input data stream leads or lags the variable divider's clock pulse output. The output of the up/down counter drives an n-bit memory and a comparator such that the n-bit memory stores the n most significant bits of the up/down counter for a predetermined period of time and then provides them to the comparator for comparison with the present value of the up/down counter. A binary code is provided to the variable divider to determine its divisor depending upon whether the memory count is greater than, equal to, or less than the present count of the up/down counter. This enables an external clock to be synchronized to the input data stream while removing random noise.
    Type: Grant
    Filed: May 1, 1986
    Date of Patent: July 14, 1987
    Assignee: Tektronix, Inc.
    Inventors: Agoston Agoston, Robert G. Sparkes
  • Patent number: 4680557
    Abstract: A microstrip transmission line comprises a plurality of signal-carrying lines disposed along a dielectric ribbon and separated by a predetermined spacing. Ground-plane conductors are disposed on the opposite side of the ribbon in staggered relation to the signal-carrying lines such that the ground-plane conductors occupy spaces corresponding to the gaps between adjacent signal-carrying lines. This arrangement lowers the capacitance and raises the impedance of the transmission line while maintaining high signal line density.
    Type: Grant
    Filed: April 22, 1985
    Date of Patent: July 14, 1987
    Assignee: Tektronix, Inc.
    Inventor: Peter M. Compton
  • Patent number: 4680621
    Abstract: A periodic output signal is generated at a variable phase relative to a periodic input signal by comparing the input signal with a third periodic signal that has a frequency which is less than the frequency of the input signal and that has a duty cycle which is equal to one-half of the ratio of the frequency of the third periodic signal to the frequency of the input signal. The phase difference is detected between the input signal and a frequency component of the third periodic signal which has the same frequency as the input signal. The output signal is generated at a frequency to maintain a predetermined phase relationship between the periodic input signal and the frequency component of the third periodic signal, and the phase of the output signal relative to the third periodic signal is varied.
    Type: Grant
    Filed: September 16, 1985
    Date of Patent: July 14, 1987
    Assignee: Tektronix, Inc.
    Inventors: Daniel G. Baker, Magaret A. Feisel
  • Patent number: 4680429
    Abstract: A touch panel has panel scanning signals selectively applied to the four sides of a touch sensing surface of the panel so as to establish alternating current voltage gradients in desired directions across the touch sensing surface. When the panel is touched, touch currents result and are utilized by a touch location circuit in determining the location of touch. The impedance touch current resulting from a user's touch may also be determined and used. The touch panel circuit automatically compensates for changes in impedance touch current, such as results when users touch the panel with ungloved and gloved fingers.
    Type: Grant
    Filed: January 15, 1986
    Date of Patent: July 14, 1987
    Assignee: Tektronix, Inc.
    Inventors: Bruce Murdock, Daniel G. Teichmer
  • Patent number: 4680577
    Abstract: A multipurpose keyswitch for controlling cursor movement on a CRT display and for character entry includes a key cap that moves laterally to provide cursor control and that moves vertically for character entry. Sensors are coupled to the key cap for sensing the lateral movement of the key cap. Forward and backward movement of the key cap selects upward and downward movement of the cursor on the CRT display. Left and right movement of the key cap selects left and right movement of the cursor. Vertical movement of the key cap selects the entry of a character. The multipurpose keyswitch is advantageously positioned as one of the home keys of the keyboard.
    Type: Grant
    Filed: April 18, 1986
    Date of Patent: July 14, 1987
    Assignee: Tektronix, Inc.
    Inventors: David H. Straayer, Patrick J. Franz, Eugene F. Lynch