Patents Assigned to Tektronix, Inc.
  • YIG Bandpass filter interconnected by means of longitudinally split coaxial transmission lines
    Patent number: 4334201
    Abstract: An electronically tunable YIG microwave filter with a two-piece housing is described. The two-piece housing makes possible the fabrication of small holes deep within the filter housing for mounting the filter components. This filter uses the center conductors of its input and output coaxial cables as input and output coupling loops.
    Type: Grant
    Filed: September 21, 1978
    Date of Patent: June 8, 1982
    Assignee: Tektronix, Inc.
    Inventor: David H. Shores
  • Temperature-stabilized logarithmic converter
    Patent number: 4333023
    Abstract: A logarithmic converter circuit comprising an emitter-coupled pair of transistors and a pair of operational amplifiers is provided with a temperature-stabilized environment so that accurate logarithmic conversion is facilitated. One of the pair of transistors is utilized as a temperature sensor to provide a temperature control voltage, which in turn controls the power applied to a heating element disposed adjacent the pair of transistors to maintain a constant semiconductor junction temperature. The heating element may suitably be one or more transistors disposed proximate the pair of transistors on a common substrate. The absolute temperature of the sensor transistor base-to-emitter junction is established by the use of precise gain-setting components, and by adjusting the temperature reference voltage for the correct system gain.
    Type: Grant
    Filed: June 16, 1980
    Date of Patent: June 1, 1982
    Assignee: Tektronix, Inc.
    Inventor: Rush W. Hood, Jr.
  • Sputtering targets with low mobile ion contamination
    Patent number: 4331476
    Abstract: Metallic sputtering targets having minimal mobile ion contamination are produced by forming a compacted slab of particles of the constituent metal(s) in an isostatic pressing operation. The slab is then transferred to a heat resistant support faced with a material, such as alumina, that is inert at high temperatures. Next, the supported slab is placed in a vacuum oven and heated to a temperature sufficient to bond the metal particles together and volatilize mobile ion contaminants. The sintered slab is usable as a cathodic sputtering target with minimal additional treatment. The level of mobile ion contaminants in the completed target may be monitored by fabricating an MOS capacitor using the target, plotting its capacitance versus applied voltage over a suitable range, then measuring the extent to which the plot shifts after a high temperature-positive bias stress treatment.
    Type: Grant
    Filed: January 31, 1980
    Date of Patent: May 25, 1982
    Assignee: Tektronix, Inc.
    Inventors: Earl R. Helderman, Robert R. Zimmerman
  • Cascode feed-forward amplifier
    Patent number: 4322688
    Abstract: The cascode feed forward amplifier is modified to correct alpha-induced error. A pair of resistors are serially disposed between the bases of a pair of common-base amplifiers to generate an error voltage proportional to the input signal. The error voltage is applied to the correction amplifier to provide an appropriate correction current.
    Type: Grant
    Filed: October 11, 1979
    Date of Patent: March 30, 1982
    Assignee: Tektronix, Inc.
    Inventors: Kenneth G. Schlotzhauer, Arthur J. Metz
  • Electromagnetic interference shielding device
    Patent number: 4322572
    Abstract: An electromagnetic interference (EMI) shielding device for use in supporting members that receive enclosure covers of electrical or electronic instruments. The EMI device comprises an L-shaped strip of metal having first contact means which maintain the device in position in a groove in the supporting member and provide electrical contact therewith and spring contact means against which an edge of an enclosure member disposed in the groove engages thereby providing electrical contact therewith and securely maintaining the enclosure member in position.
    Type: Grant
    Filed: October 22, 1979
    Date of Patent: March 30, 1982
    Assignee: Tektronix, Inc.
    Inventor: Delmer E. Snyder
  • Efficient power amplifier with staggered power supply voltages
    Patent number: 4319199
    Abstract: An amplifier which minimizes the power loss in its output stages is described. This is achieved by operating the several output stages from separate power supplies operating at staggered voltage levels. The output stages, which have parallel signal paths, are unity-gain emitter follower circuits connected so that the follower operating from the lowest usable power supply voltage always delivers the load current. Control circuitry shifts the load current from one output stage to another based upon the instantaneous relationship between supply voltages and the output voltage. The shift between output stages introduces very little signal distortion into the output.
    Type: Grant
    Filed: December 20, 1979
    Date of Patent: March 9, 1982
    Assignee: Tektronix, Inc.
    Inventor: Richard A. Sunderland
  • Diagnostic extender test apparatus
    Patent number: 4317199
    Abstract: A diagnostic extender test apparatus for use with a processor-based product under test incorporates analog and digital measurement functions and logic stimulus functions to give a complete diagnostic picture of the product under test. The diagnostic extender test apparatus according to the preferred embodiment has its own microprocessor system and may be operated as a stand-alone instrument as well as an extension of a product under test.
    Type: Grant
    Filed: January 31, 1980
    Date of Patent: February 23, 1982
    Assignee: Tektronix, Inc.
    Inventor: Alan K. Winslow
  • Phase locked loop including phase detector system controlled by enable pulses
    Patent number: 4316150
    Abstract: A second-order phase-locked loop circuit which does not require error voltage amplification is described. The output of a voltage controlled oscillator is accurately phase locked to a reference pulse. The loop phase detector is periodically enabled by a pulse generator and draws current only when enabled. Therefore very little noise may be coupled to the voltage controlled oscillator. The phase detector incorporates a current amplifier which allows very accurate establishment of the instant phase comparison takes place.
    Type: Grant
    Filed: January 9, 1980
    Date of Patent: February 16, 1982
    Assignee: Tektronix, Inc.
    Inventor: Philip S. Crosby
  • Circuit and method for correcting side pincushion distortion and regulating picture width
    Patent number: 4309640
    Abstract: A circuit within a cathode-ray tube electromagnetic deflection system for correcting side pincushion distortion and regulating picture width independent of changes in the video line rate. The circuit employs a predistorted AC reference signal and a second DC reference signal in a closed-loop manner to cause a deflection current to describe precisely an ideal waveform defining simultaneously both pincushion correction and picture width regulation.
    Type: Grant
    Filed: January 25, 1980
    Date of Patent: January 5, 1982
    Assignee: Tektronix, Inc.
    Inventor: Samuel Y. Gordon
  • Apparatus and method for producing an image on a sensitized surface
    Patent number: 4309720
    Abstract: A system and method of same for converting an electrical signal defining a refreshed raster-scan image of n differentiable components, for example, colors, into a permanent hard-copy representation of such image in terms of the cumulative sum of such components. Successive segments of a raster-scan image are scrolled across the display screen of a cathode-ray tube whose target structure comprises n adjacent strips of different phosphor materials so as to successively expose a sensitized medium scrolled at the same rate adjacent the screen to each component of each segment of the image, thereby producing in such medium a copy of such image.
    Type: Grant
    Filed: January 15, 1980
    Date of Patent: January 5, 1982
    Assignee: Tektronix, Inc.
    Inventor: Dan F. Denham
  • Foreshortened coaxial resonators
    Patent number: 4307357
    Abstract: A coaxial-structure filter which utilizes a flat depression machined in the bottom surface of the filter cover as the resonant frequency determining element in a resonant cavity is disclosed. The depression is directly above the cavity resonator post when the cover is installed and provides a lumped capacitance from the post to the cover. The resonator post is machined flush with the resonator's top wall thereby placing the critical mechanical dimensions associated with the frequency determining elements in a more desirable location than prior methods (i.e., in the filter cover).
    Type: Grant
    Filed: March 4, 1980
    Date of Patent: December 22, 1981
    Assignee: Tektronix, Inc.
    Inventor: Robert W. Alm
  • Noise rejection circuitry for a frequency discriminator
    Patent number: 4302738
    Abstract: A noise reducing circuit for a frequency discriminator is disclosed for providing a frequency discriminator with reduced sensitivity to noise. Reducing the sensitivity to noise allows certain distortion measurements, such as the well-known SINAD test for broadcast receivers, to be made in the presence of high noise levels.
    Type: Grant
    Filed: April 11, 1980
    Date of Patent: November 24, 1981
    Assignee: Tektronix, Inc.
    Inventors: Richard C. Cabot, Bruce E. Hofer
  • Color coding of write-through information in direct viewing bistable storage CRT display
    Patent number: 4301388
    Abstract: A color difference between stored and write-through (unstored) information displayed by a direct viewing bistable storage CRT is achieved by admixing the storage phosphor with a second phosphor that emits light of a distinctly different color. The second phosphor is chosen to have a lower relative light output efficiency than the storage phosphor under low voltage, flood gun illumination conditions.
    Type: Grant
    Filed: June 2, 1977
    Date of Patent: November 17, 1981
    Assignee: Tektronix, Inc.
    Inventor: William M. Mason
  • Residual clamp error compensation circuit
    Patent number: 4301474
    Abstract: An apparatus for matching the blanking levels of two television video signals is disclosed. When the vertical interval reference signal or any other signal (e.g., sync) is inserted on a program video signal their blanking levels should be matched. The apparatus described accomplishes this by matching the blanking level of the signal being inserted to that of the program video. The match is produced by sampling the residual clamping error of a slow clamp on the program channel and adding it to the signal being inserted. Therefore, the noise which would have been added to the program video is added to the inserted signal instead and therefore will not be visible in the television picture.
    Type: Grant
    Filed: April 14, 1980
    Date of Patent: November 17, 1981
    Assignee: Tektronix, Inc.
    Inventors: David J. Jurgensen, Roger A. Marin
  • Time interval meter
    Patent number: 4301360
    Abstract: A time interval meter for measuring extremely short time intervals includes a timing circuit operable at a fast predetermined rate over the time interval between first and second events, and operable at a slow predetermined rate which is precisely scaled to the first rate over a time interval between the occurrence of the second event and the upper limit of a predetermined timing window. During the slow ramp period, clock pulses are counted to provide a count which is proportional to that portion of the predetermined timing window occupied by the slow ramp interval. The fast ramp time interval may then be readily attained by subtracting the slow ramp interval from the total time of the timing window. The circuit includes a control circuit, a timing circuit including a capacitor and a pair of selectable constant current sources, and a counter.
    Type: Grant
    Filed: October 25, 1979
    Date of Patent: November 17, 1981
    Assignee: Tektronix, Inc.
    Inventor: Bruce W. Blair
  • Erasure method for memory-type EL display devices
    Patent number: 4301451
    Abstract: An improved method of completely erasing images stored by memory-type electroluminescent display panels. The method comprises interrupting the a.c. sustaining bias signal normally applied to the panel and impressing an erase pulse that is opposite in polarity to the last-preceding sustaining pulse or cycle. The amplitude and duration of the erase pulse are chosen to effect relaxation of the EL layer's internal field. The sustaining bias signal is then restored to place the panel in an erased, ready-to-write condition.
    Type: Grant
    Filed: December 4, 1979
    Date of Patent: November 17, 1981
    Assignee: Tektronix, Inc.
    Inventor: Gary S. Barta
  • Distortion reduction circuit for an inverting feedback amplifier
    Patent number: 4296381
    Abstract: An amplifier is connected between the inverting and non-inverting inputs of an inverting feedback amplifier to substantially reduce distortion caused by inherent physical properties of the semiconductor devices.
    Type: Grant
    Filed: October 1, 1979
    Date of Patent: October 20, 1981
    Assignee: Tektronix, Inc.
    Inventor: Bruce E. Hofer
  • Dual-mode amplifier
    Patent number: 4288738
    Abstract: A circuit, including a dual-mode amplifier, for producing a controlled current through an inductance; in particular, the inductive yoke of a cathode-ray tube electromagnetic deflection system. A diode coupled to a fly-back capacitor operates automatically to connect the capacitor in parallel resonant connection with the yoke whenever the voltage induced in the yoke exceeds a predetermined value, thereby switching the circuit from a linear mode to a non-linear mode. In a repetitive beam-sweeping environment, the circuit operates in the linear mode during forward scan time and in the non-linear mode during reverse retrace time. In the more general case, the circuit switches from linear operation to non-linear operation whenever the rate of change of a single input signal exceeds a predetermined design rate.
    Type: Grant
    Filed: April 3, 1980
    Date of Patent: September 8, 1981
    Assignee: Tektronix, Inc.
    Inventors: Jerrold J. Rogers, John Durecka
  • Passivated thin-film hybrid circuits
    Patent number: 4288776
    Abstract: Thin-film microcircuit structures passivated with silicon nitride are provided in which included electrical components containing nickel, chromium or other nitride-forming metals are encapsulated in an oxide material, preferably silicon oxide. The metal-containing components are thus prevented from reacting with the silicon nitride passivation coating during through-passivation laser trimming of the components.
    Type: Grant
    Filed: January 9, 1980
    Date of Patent: September 8, 1981
    Assignee: Tektronix, Inc.
    Inventor: Robert E. Holmes
  • Process for making bistable storage cathode ray tube
    Patent number: 4284661
    Abstract: A method for making a storage target for use with a cathode ray tube involves forming an insulating material at least around each of an array of collector electrode members which has been formed onto a conductive layer but leaving outer ends of the collector electrode members exposed and fixing a layer of dielectric storage material onto the conductive layer and in engagement with the insulating material around the collector electrode members to prevent luminance around the collector electrode members.
    Type: Grant
    Filed: January 31, 1979
    Date of Patent: August 18, 1981
    Assignee: Tektronix, Inc.
    Inventors: Duane A. Haven, Robert L. Arneson