Patents Assigned to Tektronix, Inc.
  • Phase change ink additive for improved electronic level sensing reliability and type encoding
    Patent number: 6001160
    Abstract: Phase change ink additives are disclosed which comprise quaternary ammonium salts that are extremely useful in producing phase change inks with increased specific conductance. Higher specific conductance is necessary for reliable functioning of electronic type ink level sensing systems used in phase change ink jet printers. Phase change inks may also be encoded for type by virtue of their specific conductance.
    Type: Grant
    Filed: September 4, 1998
    Date of Patent: December 14, 1999
    Assignee: Tektronix, Inc.
    Inventors: C. Wayne Jaeger, Susan Schoening-Federici, Clifford R. King
  • Instrument with strengthened hollow handle
    Patent number: 6000097
    Abstract: An elongated bail handle for an electronic instrument housing with opposed ends providing handle mounts. The handle has an elongated intermediate portion extending the width of the instrument, and a pair terminal arm portions each connected to the intermediate portion and having a free end for connection to a respective end surface of the housing. The intermediate portion defines an elongated bore, and a reinforcing bar laterally spans the bore to connect opposed walls of the intermediate portion. The arm and bore may have an oblong cross section, with the bar spanning the short span. The bar may define a passage, and an overmolded handle grip encompassing the reinforcing bar may have material filling the passage to secure it to the handle.
    Type: Grant
    Filed: June 18, 1998
    Date of Patent: December 14, 1999
    Assignee: Tektronix, Inc.
    Inventor: Brian G. Russell
  • Digital oscilloscope with high live time recording of signal anomalies and method
    Patent number: 5999163
    Abstract: A method of analyzing and displaying waveforms by acquiring an electrical signal, converting it into a stream of digital data points, and sequentially storing each data point to a memory device. Then, analyzing each of the data points to detect whether the data point is an anomalous data point outside of a preselected range. Until an anomalous data point is detected, the steps of acquiring, converting, storing, and analyzing data are repeated. Shortly after the anomalous data point is detected, storage of the data points to the memory device is stopped, so that the anomalous data point and adjacent data points are preserved in memory. Then, the anomalous data point is displayed, preferably along with the immediately preceding and succeeding data points.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: December 7, 1999
    Assignee: Tektronix, Inc.
    Inventors: Kevin T. Ivers, Eric P. Etheridge, Roy I. Siegel
  • Bit rate control mechanism for digital image and video data compression
    Patent number: 5995151
    Abstract: A bit rate control mechanism for a digital image or video compression system estimates a complexity parameter for a current picture, or block of samples, of a video signal as a function of parameters for a prior picture of the video signal, which parameters include a bit rate. From the complexity parameter a quality factor for the current picture is determined and applied to a quantizer to compress the current picture. A complexity pre-processor may also be used to detect scene changes in the video signal prior to estimating the complexity parameter. If there is a scene change detected, then the rate control mechanism is reset prior to estimating the complexity parameter for the first picture in the new scene. Also a video buffer verifier is controlled so that the buffer occupancy at the end of a specified image sequence is at a target value so that looping and editing applications are facilitated.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: November 30, 1999
    Assignee: Tektronix, Inc.
    Inventors: Thumpudi Naveen, Ali Tabatabai, Robert O. Eifrig
  • Rasterization control method
    Patent number: 5995117
    Abstract: One or more recently acquired waveform data sets are maintained in memory after they are initially rasterized. During repeated waveform acquisitions, when the trigger and new waveform acquisition rates become so low that rasterizer time is being wasted, one or more of the most recent previously acquired waveforms are re-rasterized and displayed again to maintain the display until another newly acquired waveform becomes available. The rasterizer's readiness to re-rasterize a previously rasterized waveform data set can be qualified with a pre-determined or programmable time delay, thereby providing more flexibility for external circuitry and controllers to optimize utilization of the rasterizer's behavior. The method of this invention works especially well with rasterizers that produce some form of randomization in their outputs.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: November 30, 1999
    Assignee: Tektronix, Inc.
    Inventors: Kenneth P. Dobyns, Robert A. Nishida, George S. Walker
  • Phase change ink formulation containing a combination of a urethane resin, a mixed urethane/urea resin, a mono-amide and a polyethylene wax
    Patent number: 5994453
    Abstract: Phase change carrier compositions made from the combination of at least one urethane resin; at least one urethane/urea resin; at least one mono-amide; and at least one polyethylene wax are disclosed. The order of addition of the reactants to form the reactant product urethane resin and urethane/urea resin permits the tailoring or design engineering of desired properties.
    Type: Grant
    Filed: January 26, 1998
    Date of Patent: November 30, 1999
    Assignee: Tektronix, Inc.
    Inventors: Jeffrey H. Banning, Donald R. Titterington, Clifford R. King, Michael B. Meinhardt
  • Intermediate transfer surface supply system
    Patent number: 5988808
    Abstract: A supply system for supplying liquid to an applicator assembly in an imaging apparatus is provided. The supply system includes a liquid retaining reservoir that is in fluid communication with an applicator assembly. The reservoir utilizes a collapsible bellows construction to contain maximum volume in minimal space. A moveable contact surface selectively contacts and squeezes the reservoir to speed flow of the liquid to the applicator assembly.
    Type: Grant
    Filed: April 24, 1997
    Date of Patent: November 23, 1999
    Assignee: Tektronix, Inc.
    Inventor: Brent R. Jones
  • Electrode structures for plasma addressed liquid crystal display devices
    Patent number: 5990619
    Abstract: A plasma addressed liquid crystal display system (10) includes improved electrode structures (90, 100, 130) that are nonuniform parallel to their surfaces and may also be nonuniform perpendicular to their major surfaces. The nonuniformities include surface nonuniformities (92, 94), bulk nonuniformities (108, 110, 112, 112), and geometric nonuniformities (132, 134). Electrodes having such nonuniformities provide localized sites of preferential and nonpreferential surface and bulk properties of the electrodes, which, in turn, provide improved and locally tailored plasma discharge characteristics. PALC displays having the nonuniform electrodes have improved quality because of reduced firing voltages in one plasma channel region compared to another, reduced sputtering damage, reduced total current between electrodes, decreased discharge initiation time, and decreased ionized gas decay time.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: November 23, 1999
    Assignee: Tektronix, Inc.
    Inventors: Kevin J. Ilcisin, Paul C. Martin, Thomas S. Buzak
  • Chiral shaped ink sticks
    Patent number: 5988805
    Abstract: An ink stick shape for use in a printer ink stick feed chute is disclosed wherein the opposing sides of the ink stick are tapered or angled from the horizontal so that at least one area intermediate the top and the bottom of the ink stick is a greater distance from the horizontal than the junction of the side walls and the bottom of the ink stick. The ink stick shape or geometry may be keyed to a particular color.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: November 23, 1999
    Assignee: Tektronix, Inc
    Inventor: Michael B. Meinhardt
  • Electrophotographic duplex printing media system
    Patent number: 5991564
    Abstract: A method and system media sheet handling in an electrophotographic color desktop printer are disclosed wherein a media sheet is imaged with toner on both sides of the media sheet without smudging or remelting the images. The temperature of the fusing roller and the pressure roller are controlled to keep the pressure roller temperature below the toner cold offset temperature.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: November 23, 1999
    Assignee: Tektronix, Inc.
    Inventor: Beta Y. Ni
  • Digital oscilloscope architecture for signal monitoring with enhanced duty cycle
    Patent number: 5986637
    Abstract: To increase the percentage of time that an input signal is actively monitored, a digital oscilloscope has an acquisition system (100) that includes an analog-to-digital converter (15), an acquisition memory (40), an acquisition rasterizer (50), and a raster acquisition memory (60). The rasterizer contains circuitry (52) for concurrently rasterizing and combining the results of several acquisitions together and with a stored composite raster image to produce a new composite raster image, while additional acquisition records are being created and stored in the acquisition memory. A display system 200 takes the composite raster images after they contain the results of many acquisitions and overlays these single-bit raster images on a multi-bit raster image that is then decremented to produce a simulated persistence effect.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: November 16, 1999
    Assignee: Tektronix, Inc.
    Inventors: Eric P. Etheridge, Gordon W. Shank, Daniel G. Knierim
  • Forwarding multicast frames on an ethernet bridge
    Patent number: 5982775
    Abstract: Forwarding of multicast data frames over an Ethernet bridged network infrastructure is performed by storing in a bridge forwarding table the multicast destination address when the hosts are polled via the bridge by a router. Then when a multicast data frame is received by the bridge, the forwarding table is searched and the frame is forwarded to each port of the bridge that corresponds to a host that subscribed to the particular multicast session indicated by the multicast destination address.
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: November 9, 1999
    Assignee: Tektronix, Inc.
    Inventors: Theodore O. Brunner, Dennis B. Thomas
  • Reduced crosstalk microstrip transmission-line
    Patent number: 5982249
    Abstract: A reduced crosstalk microstrip transmission-line has a plurality of microstrips sandwiched between a lower base dielectric layer of flexible circuit material and an upper coverlay with higher permittivity and of different flexible circuit material than the base dielectric layer. With the higher permittivity of the coverlay, the thickness of the coverlay is selected such that the microstrip transmission-line retains practical flexibility and far-end crosstalk to a first neighboring microstrip from a driving channel is zero.
    Type: Grant
    Filed: March 18, 1998
    Date of Patent: November 9, 1999
    Assignee: Tektronix, Inc.
    Inventor: Michael W. Bruns
  • Method and apparatus for measuring time intervals between electrical signals
    Patent number: 5982712
    Abstract: A method and apparatus for measuring time intervals between electrical signals. A coincidence detection circuit is adapted to detect coincidence or near coincidence of two signals and to provide for selection from a plurality of predetermined delays to remove the coincidence. If the two input signals are periodic and have the same frequency, the apparatus also provides a signal from which both the time delay between the signals and the period of the signals may be determined at substantially the same point in time.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: November 9, 1999
    Assignee: Tektronix, Inc.
    Inventor: Patrick A. Smith
  • Solid ink stick supply system
    Patent number: 5975690
    Abstract: A solid ink stick supply system and related method for delivering solid ink sticks to an ink jet print head reservoir is disclosed. The supply system includes a housing with a keyed plate that guides the ink sticks into the proper loading position in a supply channel. A pusher rod in the supply channel transfers an ink stick onto an endless belt for delivery to the print head reservoir. A push device on the endless belt engages and delivers the ink stick to the print head reservoir. A second ink stick is transferred from the supply channel to the endless belt and is retained on the belt by a stop device. A method for efficiently loading ink sticks into the supply system is also provided.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: November 2, 1999
    Assignee: Tektronix, Inc.
    Inventors: H. Erwin Grellmann, John B. Gilbert, Robert C. Tidrick, Perry E. Wingfield
  • Method of operating a plasma addressed liquid crystal display panel to extend useful life of the panel
    Patent number: 5978052
    Abstract: A display device for displaying an image represented by an incoming raster scan video signal comprises a PALC display panel having a rectangular array of addressable panel elements. A frame buffer stores a frame of video and a comparator compares the incoming video signal with the frame stored in the frame buffer on a line-by-line basis. In the event that a line of the incoming video signal is different from the corresponding line of the stored frame, the line of the incoming video signal is supplied to the display panel and is used to update the corresponding line of the frame buffer. Otherwise, the line of the incoming video signal is not supplied to the display panel.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: November 2, 1999
    Assignee: Tektronix, Inc.
    Inventors: Kevin J. Ilcisin, Thomas S. Buzak, Paul C. Martin
  • Method and apparatus for digital sampling of electrical waveforms
    Patent number: 5978742
    Abstract: A method and apparatus for digitally sampling electrical waveforms. A sampling circuit for sampling an electrical signal, a digitizing circuit for digitizing the samples produced by the sampling circuit and an acquisition memory for storing the samples are employed, the acquisition memory being partitioned into a plurality of frames. Each frame is triggered to store samples associated with a respective triggering event. After substantially all of the frames have been triggered, the contents of the acquisition memory are retrieved from the acquisition memory, filtered in an equalization filter and stored in a waveform memory for ultimate display as an ET record under software control. A plurality of digitizing circuits associated with respective inputs of a multi-channel digital sampling oscilloscope are interleaved to increase the sampling rate.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: November 2, 1999
    Assignee: Tektronix, Inc.
    Inventor: John J. Pickerd
  • Duplex printing media handling system
    Patent number: 5974298
    Abstract: A media sheet handling system and a method of duplex printing are disclosed wherein a media sheet is imaged with a phase change ink on both sides of the media sheet without smudging or remelting the images and the media sheet is partially exited from the printer into a media output tray and then is drawn back into the printer along a duplex path of travel that automatically reverses the media sheet so that the trailing edge becomes the leading edge during the imaging of the second side of the media sheet. The stiffness of the media sheet facilitates the media sheet moving above and beyond a stationary media path diverter prior to reversing its direction of travel along and passing along the duplex path of travel back to the imaging station.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: October 26, 1999
    Assignee: Tektronix, Inc.
    Inventors: Carl T. Urban, Barry G. Mannie
  • Method to improve solid ink output resolution
    Patent number: 5966150
    Abstract: A method of printing with phase change ink on an ink jet printer that contains multiple levels of black gray scale ink and a clear or slightly tinted wax ink base and which is applied to the roughened surface of an adhesion promoting coating applied to a transparent substrate is disclosed. The adhesion promoting coating has a surface roughness of greater than about 0.5 micrometers and contains a binder and an inorganic particulate material.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: October 12, 1999
    Assignee: Tektronix, Inc.
    Inventors: Audrey A. Lester, Steven V. Korol, Stephen M. Kroon, C. Wayne Jaeger
  • Solid ink stick for a color printer
    Patent number: D416936
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: November 23, 1999
    Assignee: Tektronix, Inc.
    Inventors: Henry Y. Chin, Penelope C. Yao, David L. Brown