Patents Assigned to Tektronix, Inc.
  • Patent number: 5689291
    Abstract: An ink jet (10, 200) provides high-resolution gray scale printing or switchable resolution printing by providing PZT drive waveforms (100, 110, 120, 360, 370), each having a spectral energy distribution that excites a modal resonance of ink in an ink jet print head orifice (14, 208). By selecting the particular drive waveform with selectable energy inputs that concentrates spectral energy at frequencies associated with a desired oscillation mode and that suppresses energy at the other oscillation modes, an ink drop (170, 180, 190, 210) is ejected that has a diameter proportional to a center excursion size of the selected meniscus surface oscillation mode. The center excursion size of high order oscillation modes is substantially smaller than the orifice diameter, thereby causing ejection of ink drops smaller than the orifice diameter. Conventional orifice manufacturing techniques may be used because a specific orifice diameter is not required.
    Type: Grant
    Filed: January 11, 1995
    Date of Patent: November 18, 1997
    Assignee: Tektronix, Inc.
    Inventors: David A. Tence, Sharon S. Berger, Ronald F. Burr
  • Patent number: 5689288
    Abstract: A flexible bar connected to an actuator is suspended within an ink reservoir. The bar is preferably mounted in a cantilever or free-standing mode and vibrates in response to signals from the actuator. When the actuator signals are discontinued the bar continues to vibrate and causes the actuator to generate signals that are analyzed to determine the level of ink in the reservoir.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: November 18, 1997
    Assignee: Tektronix, Inc.
    Inventors: Guenther W. Wimmer, Richard S. Meissner, David L. Knierim
  • Patent number: 5686998
    Abstract: A method of printing an image onto a substrate includes the steps of determining a difference in intended color intensity between a first pixel and a second pixel; adjusting the intended color intensity of the first pixel based on the determined difference; and depositing a colorant onto the substrate at the first pixel at the adjusted intended intensity, so as to enhance the appearance of the image on the substrate. The current system has particular utility in enhancing the appearance of fine images such as one pixel wide, vertical and diagonal lines in a printing system which utilizes printhead heating elements that are larger in the vertical direction than in the horizontal direction.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: November 11, 1997
    Assignee: Tektronix, Inc.
    Inventors: Jeffery J. Clark, Brian G. Crosby, Bo Lewendal, Gregory P. Thornton
  • Patent number: 5682209
    Abstract: Motion estimation using limited-time early exit with prequalification matrices and a predicted search center reduces computational time for a video compression encoder. The partial absolute error obtained for a given location within a search area is compared periodically with a prior absolute error obtained for a prior position within the search area to determine whether the partial absolute error is greater than such prior absolute error. If the partial absolute error is greater, then the processing for that position may be terminated and the search moved to the next location within the search area. Using the triangle inequality a series of prequalification matrices are generated for the reference image and for the current image being searched. Comparing the prequalification matrices using early exit further reduces the computational time.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: October 28, 1997
    Assignee: Tektronix, Inc.
    Inventor: Peter A. Borgwardt
  • Patent number: 5677647
    Abstract: A high power pulse waveform generator for amplifying an input pulse signal has an a.c. coupled amplifier with d.c. negative feedback. An output stage of the a.c. coupled amplifier has a pair of opposite polarity, high power transistors coupled in series between a high power voltage source and a reference power rail, such as ground, with the junction between the transistors being an output terminal. An input stage receives the input pulse signal and provides a bias during a quiescent state of the input pulse signal to the output stage so that the output terminal is clamped to the reference power rail regardless of any d.c. offset in the input pulse signal. The input stage a.c. couples the pulse of the input pulse signal to the output stage to provide the high power pulse waveform at the output terminal. The output terminal is d.c. coupled to the input terminal to provide negative feedback so that the shape of the high power pulse waveform follows the shape of the input pulse signal.
    Type: Grant
    Filed: October 20, 1995
    Date of Patent: October 14, 1997
    Assignee: Tektronix, Inc.
    Inventor: David L. Knierim
  • Patent number: 5677718
    Abstract: A compact ink jet print head has cross-sectionally tapered ink manifolds (16) for supplying ink to ink supply channels (18) leading to the acoustically driven ink pressure chambers (22). An array of closely spaced nozzles (14) which are supplied with ink from the densely packed ink pressure chambers by way of offset channels (71). The tapered manifolds, ink supply channels, pressure chambers, and offset channels are designed to provide uniform operating characteristics among the ink jet nozzles of the array. To enhance the packing density of the pressure chambers, the ink supply channels leading to the pressure chambers and offset channels are positioned in planes between the pressure chambers and nozzles. The tapered ink supply manifolds enhance purging of contaminants or bubbles from the print head by providing uniform ink flow rates (97, 97') along the entire length of the manifolds.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: October 14, 1997
    Assignee: Tektronix, Inc.
    Inventors: Clark W. Crawford, Ronald F. Burr
  • Patent number: 5673273
    Abstract: An embedded electronic system includes a clock controller embedded in the same matrix material as a subsystem under test and the measurement devices needed to test it. This embedded clock controller controls the distribution and gating of a system clock that runs continuously, but is only supplied to the subsystem under test during normal operation or during pre-programmed intervals of testing operations. A test data bus supplies test data and a path for the return of test results. The test data supplied to the clock controller includes information to control time relationships between its trigger and gated clock outputs. Different versions of the clock controller are described, one for use with a serial test data bus and another for use with a parallel test data bus. The clock controller can also be configured to produce trigger signals with timing appropriate to operating either edge-sensitive or level-sensitive measurement devices.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: September 30, 1997
    Assignee: Tektronix, Inc.
    Inventor: Thomas A. Almy
  • Patent number: 5668609
    Abstract: A motion detector and improved key signal interpolator using the same inputs a video signal to both a frame and a field based interpolator to produce both frame and field interpolated signals. The frame and field interpolated signals are input to a mixer. The frame interpolated signal also is input to a frame delay circuit, the output of which is subtracted from input to produce a motion signal. The motion signal is converted by an absolute value/lookup table into a mix signal that is also input to the mixer. The mix signal determines which interpolated signal at the input is passed to the output, the field interpolated signal being passed when motion is detected and the frame interpolation signal being passed when motion is not detected.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: September 16, 1997
    Assignee: Tektronix, Inc.
    Inventors: Brion L. Dunbar, Daniel J. Chaplin
  • Patent number: 5664033
    Abstract: An remote fiber test system includes a non-blocking N.times.N optical switch having N input ports and N output ports with one of the input ports coupled to a measurement test instrument for examining any of the optical fibers coupled to the output ports. The non-blocking switch includes a plurality of N input mechanical optical switches and an plurality of N output mechanical optical switches with each of the input mechanical optical switches having an input optical transmission path representing one of the input ports and each of the output mechanical optical switches having an output optical transmission path representing one of the output ports. Each input mechanical optical switch has N output optical transmission paths which each optical transmission path being coupled to one of the input optical transmission paths of each of the output mechanical optical switches.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: September 2, 1997
    Assignee: Tektronix, Inc.
    Inventors: Friedrich Scheu, Duwayne R. Anderson, William K. Bucher, Steve U. Reinhold, Lorimer L. Twigg, Mark D. Marineau
  • Patent number: 5661527
    Abstract: An automatic video signal identification system uses zero-mean normalized reference signals that are cross-correlated with an input video signal. The input video signal is stored in an acquisition memory and then cross-correlated with a plurality of reference signal templates, each template representing a particular video signal to be identified. The cross-correlation process provides a corresponding plurality of maximum correlation outputs. The largest maximum correlation output is determined, and the corresponding template identified. If not already normalized, the largest maximum correlation .output is normalized to produce a correlation coefficient. Based upon the identified template the correlation coefficient is tested to determine the validity of the match, i.e., whether the video signal is identified or whether the video signal is unknown.
    Type: Grant
    Filed: July 7, 1995
    Date of Patent: August 26, 1997
    Assignee: Tektronix, Inc.
    Inventor: Kevin M. Ferguson
  • Patent number: 5659587
    Abstract: A phase-locked loop circuit comprises a VCO and a ramp generator. The ramp generator has an output connected to a control terminal of the VCO. A center frequency control loop is connected between a signal output terminal of the VCO and a first ramp control input of the ramp generator and a spread spectrum control loop is connected between the signal output terminal of the VCO and a second ramp control input of the ramp generator. The signals applied to the ramp control inputs of the ramp generator by the two control loops control respective characteristics of a periodic voltage ramp signal that is generated by the ramp generator at its signal output terminal.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: August 19, 1997
    Assignee: Tektronix, Inc.
    Inventor: David L. Knierim
  • Patent number: 5654762
    Abstract: Block matching for picture motion estimation uses Gray codes, and preferably a new Hamming-2 Gray code where the bit pattern changes by only one bit for each step in the Gray code count sequence with the additional condition that all other codes are at least two bits different if not adjacent in the count sequence. The pixels for a reference block from a first picture frame and the pixels for a corresponding block within a search area of the next picture frame are each quantized and then converted to an appropriate Gray code. The Gray codes for corresponding pixels are compared to determine whether they are equal or adjacent to each other. If there is adjacency or equality a match signal is generated for that pixel which is tallied. The total tally for each reference block position within the search area is determined, with the maximum tally indicating a match between blocks from which picture motion estimation may be determined.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: August 5, 1997
    Assignee: Tektronix, Inc.
    Inventors: Keith R. Slavin, Shane Ching-Feng Hu
  • Patent number: 5649036
    Abstract: An remote fiber test system includes at least one mechanical optical switch has opposing input and output optical fiber bundles disposed within offset ferrules with at least one input fiber coupled to a measurement test instrument and each of the output fiber coupled to an optical fiber link via wavelength division multiplexers. Each ferrule of the optical switch is mounted in three-point kinematically correct V-groove holder allowing the optical fibers in each optical fiber bundle to traverse on a closed curve path during the rotation of the respective ferrules. The closed curve paths of each optical fiber in one of the optical fiber bundles intersect at least one of the closed curve paths of the optical fiber in the opposing optical fiber bundles. The intersection points of two opposing closed curve paths establish the optimum positioning locations for two opposing fibers.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: July 15, 1997
    Assignee: Tektronix, Inc.
    Inventors: Duwayne R. Anderson, Steve U. Reinhold, Lorimer L. Twigg, Mark D. Marineau
  • Patent number: 5646742
    Abstract: A system for printing an image onto a substrate includes a print controller that determines a difference in intended color intensity between a first pixel and a second pixel; adjusts the intended color intensity of the first pixel based on the determined difference; and deposits a colorant onto the substrate at the first pixel at the adjusted intended intensity, so as to enhance the appearance of the image on the substrate. The current system has particular utility in enhancing the appearance of fine images such as one pixel wide, vertical and diagonal lines in a printing system which utilizes printhead heating elements that are larger in the vertical direction than in the horizontal direction.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: July 8, 1997
    Assignee: Tektronix, Inc.
    Inventors: Jeffery J. Clark, Brian G. Crosby, Bo Lewendal, Gregory P. Thornton
  • Patent number: 5645888
    Abstract: Reactive ink compositions of the present invention utilize at least two reactive components, a base ink component and a curing component, that are applied to a receiving substrate separately. The base ink component includes an ink carrier, a compatible colorant, and a cross-linkable constituent, and the curing component is a cross-linking agent. Upon exposure of the base ink component to the curing component, at least a portion of the ink is cross-linked to provide a printed image that is durable and abrasion-resistant.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: July 8, 1997
    Assignee: Tektronix, Inc.
    Inventors: Donald R. Titterington, Loc V. Bui, Linda M. Hirschy, C. Wayne Jaeger
  • Patent number: 5644261
    Abstract: An adjustable precision delay circuit includes a series of inverter gates and a multiplexer for selecting any of their outputs or the input to the series. The polarity of the signal input to this circuit is controlled so that any selected output always has the same predetermined polarity, thereby eliminating timing errors arising from factors that vary with the polarity of the output.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: July 1, 1997
    Assignee: Tektronix, Inc.
    Inventors: Arnold M. Frisch, Thomas A. Almy
  • Patent number: 5642497
    Abstract: An application programming interface for a digital disk recorder uses a port to link resources together to form a multimedia recorder that emulates a tape recorder while retaining the flexibility of the digital disk recorder. The port is a matrix of timelines for each resource, with each track in the port representing a media stream associated with a different one of the resources. A dynamic subsystem controls recording and playing back multimedia between the resources and a disk file system of the digital disk recorder using the port. A static subsystem maintains on the disk file system a database of movies recorded by the digital disk recorder from the resources according to the port, with each movie being a collection of media files for each resource that are independently accessible.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: June 24, 1997
    Assignee: Tektronix, Inc.
    Inventors: Errol C. Crary, Richard W. Stallkamp, Laurence J. Morandi, Douglas C. Stevens, Alexandru Mitaru
  • Patent number: D380771
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: July 8, 1997
    Assignee: Tektronix, Inc.
    Inventor: Brent R. Jones
  • Patent number: D383153
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: September 2, 1997
    Assignee: Tektronix, Inc.
    Inventors: Brent R. Jones, Clark W. Crawford
  • Patent number: D383154
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: September 2, 1997
    Assignee: Tektronix, Inc.
    Inventors: Brent R. Jones, Clark W. Crawford, John A. Wright