Patents Assigned to Tektronix, Inc.
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Patent number: 5442387Abstract: A triggerable ink transfer system that simultaneously transfers ink from a plurality of ink preload chambers to corresponding load chambers and ink reservoirs is disclosed. The delivery system permits an untrained operator to safely load ink without inadvertently interchanging different types (e.g. colors) of ink, and without inadvertently overfilling any of the ink reservoirs. A processing unit that coordinates ink delivery system monitoring and control features is in communication with an operator interface unit that provides ink loading instructions to the operator.Type: GrantFiled: June 23, 1993Date of Patent: August 15, 1995Assignee: Tektronix, Inc.Inventors: Donald I. Loofbourow, Richard G. Chambers
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Patent number: 5440201Abstract: A plasma addressing structure (52) having an ionizable gas captured within each of multiple parallel channels (62a) extending across a display screen (54) includes an arrangement (132a) of anodes (112a) and cathodes (114a) for selectively ionizing the gas to address data elements. The anode in each channel has an extended width (130a) in a direction transverse to the length of the channel, thereby to provide the channel with a relatively large conductive surface area that facilitates the ionization of the gas contained in the channel. The large conductive surface provided by the extended width of the anode allows each channel to be formed with a shallow depth (118a) that enhances the viewing angle characteristics of the display screen and simplifies the manufacture of the addressing structure.Type: GrantFiled: August 3, 1994Date of Patent: August 8, 1995Assignee: Tektronix, Inc.Inventors: Paul C. Martin, Thomas S. Buzak
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Patent number: 5440329Abstract: A system and method for printing a predetermined image onto a substrate includes steps or structure for obtaining pixel data which renders a portion of the predetermined image and relates to whether a colorant is to be deposited in a predetermined area comprising at least one subject pixel and at least one adjacent pixel; determining whether a colorant is specified for any of the predetermined area; and depositing an image-enhancing coating over the subject pixel on the substrate if the above determining step determines that a colorant is so specified, whereby a portion of the image-enhancing coating receiving area is successively determined "on-the-fly" using a minimal physical memory space without sacrificing the system performance. A second aspect of the disclosure involves an efficient method and structure for converting a pixel data relating to the deposition of the image-enhancing coating material format into a compact data format which is acceptable by a printer.Type: GrantFiled: December 22, 1992Date of Patent: August 8, 1995Assignee: Tektronix, Inc.Inventors: Adam E. Meggitt, Thomas J. Brandt, Stephen A. Zimmerman
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Patent number: 5440676Abstract: An analog input signal to a digital oscilloscope is sampled and digitized to form a representative waveform data sequence. A waveform is then displayed on a screen of the oscilloscope to represent the magnitude of the waveform as a function of time as indicated by the waveform data sequence. The waveform is formed by a set of vectors, each vector comprising a straight line between two points on the screen at elevations representing magnitudes of two successive input signal samples, and at horizontal positions representing timing of the two samples. The screen provides a display organized into an array of pixels, each of which may be illuminated with variable intensity, and each vector is represented by illuminating pixels having center points bounding the trajectory of the vector on the screen. The intensity of each such illuminated pixel is modulated in accordance with the distance between the pixel and the vector trajectory.Type: GrantFiled: January 29, 1988Date of Patent: August 8, 1995Assignee: Tektronix, Inc.Inventors: Kuriappan P. Alappat, Edward E. Ayerill, James G. Larsen
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Patent number: 5438531Abstract: A zero dead time acquisition system for a digital storage oscilloscope (DSO) has an input buffer that stores an initial value from an acquisition memory for each sample interval of an input analog signal. The input analog signal is oversampled and digitized so that there are multiple digitized samples of the analog signal for each sample interval. At the beginning of a sample interval the initial value from the input buffer is transferred to an accumulation register, the output of which is compared with the multiple samples of the analog signal during the sample interval. If any of the multiple samples falls outside the limit determined by the value in the accumulation register, in a save on delta mode a latch is set to generate an error signal that terminates further acquisition cycles. In an envelope mode the comparison result causes the value in the accumulation register to be replaced with the sample value that fell outside the limit to establish a new limit, either maximum or minimum.Type: GrantFiled: July 2, 1993Date of Patent: August 1, 1995Assignee: Tektronix, Inc.Inventor: Gordon W. Shank
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Patent number: 5438638Abstract: An M.times.N mechanical optical switch has opposing input and output optical fiber bundles disposed within offset ferrules. Each ferrule 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. Offsetting the axes of rotation of the opposing optical fiber bundles and mounting the bundles in a three-point kinematically correct holder produces a mechanical optical switch having superior cycle-to-cycle repeatability, long term repeatability, and absolute alignment using loosely toleranced components.Type: GrantFiled: April 5, 1994Date of Patent: August 1, 1995Assignee: Tektronix, Inc.Inventor: Duwayne R. Anderson
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Patent number: 5438423Abstract: Time warping for video viewing is achieved by providing a random access dynamic buffer for a video signal from a selected video channel. The video signal is continuously written into the dynamic buffer in a recirculating fashion, and may be read out on a random access basis so that the viewer may control the realtime video viewing in the same manner as controlling a video cassette recorder up to the duration of the video signal stored in the dynamic buffer. In addition the viewer may view the video at various speeds and skip to any point in the stored information. Portions of the video signal in the dynamic buffer may be stored in a static buffer or transferred permanently to a video cassette recorder for subsequent manipulation by the viewer. To expand the capacity of the dynamic buffer a compression circuit may be provided for compressing the video signal before being written into the dynamic buffer.Type: GrantFiled: May 11, 1994Date of Patent: August 1, 1995Assignee: Tektronix, Inc.Inventors: Eugene F. Lynch, Guy W. Cherry, Mayer D. Schwartz
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Patent number: 5436553Abstract: An optical power conversion circuit converts an optical energy signal from an optical source, such as a laser diode, to a regulated D.C. electrical voltage using a single photodetector. A buck-boost circuit uses electrical current from the photodetector in response to the optical energy signal to store energy in an inductor during one polarity of a control signal, and transfers the energy from the inductor to an output capacitor during the other polarity of the control signal. The duty cycle of the control signal determines the regulated D.C. electrical voltage. A switch drive circuit generates the control signal as a pulse width modulated signal from the regulated D.C. electrical voltage and a reference voltage. The control signal is A.C. coupled to a pair of FET switches in the buck-boost circuit to alternately energize and charge the inductor and capacitor respectively.Type: GrantFiled: September 24, 1993Date of Patent: July 25, 1995Assignee: Tektronix, Inc.Inventors: Steven H. Pepper, John T. Ebner
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Patent number: 5430660Abstract: A digital architecture for a pulse generator includes a triggerable voltage controlled oscillator (VCO) with two alternative sources of frequency control voltage, an internal DAC or a phase frequency comparison with an external timebase. In a top octave of operation, the output of the triggerable VCO is used to produce output pulses whose edge locations are then adjusted by small digital increments or "slivers" and very small analog increments or "verniers". In lower octaves of operation, the contents of a pattern RAM serve to frequency divide the triggerable VCO output frequency by powers of two. The RAM contents are converted to a serial bit stream that imposes the coarse pulse width and period as an integral number of top octave periods, or quanta. The edge locations are then adjusted with slivers and verniers, as in the top octave. Automatic calibration facilities are included.Type: GrantFiled: June 1, 1993Date of Patent: July 4, 1995Assignee: Tektronix, Inc.Inventors: Jonathan Lueker, John Hengeveld, Brad Needham, Burt Price, Jim Schlegel, Mehrab Sedeh
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Patent number: 5428626Abstract: A timing analyzer for embedded testing of printed circuit boards, integrated circuits or multi-chip modules is in the form of an integrated circuit that may be included as part of the printed circuit board, integrated circuit or multi-chip module being tested. Each channel of a data path to be tested has a timing analyzer circuit that may be coupled into the path when enabled for testing. The timing analyzer circuit has instruction memories that are loaded with time event commands via a suitable program bus, such as a boundary scan interface. Each event command has a clock portion, an interpolation portion and a drive output portion. A counter counts down the clock portion using a system clock from the board/circuit/module to produce a terminate pulse. The terminate pulse is delayed by an increment less than one period of the system clock by a delay interpolator, the amount of delay being determined by the interpolation portion, to generate a trigger signal.Type: GrantFiled: October 18, 1993Date of Patent: June 27, 1995Assignee: Tektronix, Inc.Inventors: Arnold M. Frisch, Thomas A. Almy
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Patent number: 5424767Abstract: A multiple-orifice phase-change ink-jet print head (28, 44) is heated by a composite laminate heater (29, 58) having multiple heating zones (31-31K, Z1-Z28) spanning the X- and Y-directions of the print head. The print head has multiple rows of ink-jet orifices (34, 46) spread across its face in the Y-direction with the ink in each orifice in each row requiring substantially the same temperature to ensure a uniform jetting velocity from every orifice. In one embodiment, the print head is in fluid communication with a thermally massive multicolor ink reservoir (52) that conducts heat through a region of contact (92) with the print head. A rotating drum (32), spaced across a gap (90) from the print head, draws air through the gap thereby cooling the print head differentially in the Y-direction. Radiation and convection are further thermal transfer mechanisms that contribute to a nonuniform temperature throughout the print heads.Type: GrantFiled: March 2, 1993Date of Patent: June 13, 1995Assignee: Tektronix, Inc.Inventors: Nasser Alavizadeh, Douglas M. Stanley, Bryan F. Johnson
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Patent number: 5422659Abstract: A printer having a paper printing mode and a transparency printing mode detects a leading edge portion of an image-receiving sheet. Based on detection of an opaque leading edge portion of a transparent sheet, the paper printing mode is disabled and a sheet size having boundaries is selected. The printer deposits ink on the transparent sheet within the boundaries of the selected sheet size.Type: GrantFiled: May 20, 1993Date of Patent: June 6, 1995Assignee: Tektronix, Inc.Inventors: Donald R. Titterington, Bruce D. Radke, James D. Rise
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Patent number: 5418470Abstract: A programmable analog multi-channel probe system is embedded within a device under test for coupling test points to external measurement points of the device under test. Programmable input buffer amplifiers are coupled to the test points to couple the data at those points to their outputs when enabled. The data from the input buffer amplifiers are input to respective routers to provide a plurality of outputs. Each common output from the routers is coupled as an input to an output buffer amplifier that provides the data as an output when enabled. The data at the output of the output buffer amplifiers is converted to a differential signal for transmission to the external measurement point by differential input/output amplifiers that have a reference level, selected from a plurality of reference levels including an internal reference level, as an input for comparison with the data from the output buffer amplifiers.Type: GrantFiled: October 22, 1993Date of Patent: May 23, 1995Assignee: Tektronix, Inc.Inventors: Thomas P. Dagostino, Arnold M. Frisch
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Patent number: 5418533Abstract: A method and circuit for conditioning a received analog signal for input to an analog-to-digital converter circuit ("ADC"). For each clock period in which a conversion is triggered, a first analog value is provided during a first predetermined period and a second analog value is provided during a second predetermined period. The first analog value is representative of the received analog signal's instantaneous value at the moment selected for conversion. The second analog value is predetermined, typically being a null value. The signal conditioning circuit includes a hold circuit to hold the received analog signal's instantaneous value; a generating circuit that generates the second analog value; and an output circuit that selectively outputs the instantaneous value or the predetermined value to the ADC.Type: GrantFiled: November 19, 1993Date of Patent: May 23, 1995Assignee: Tektronix, Inc.Inventor: Daniel G. Knierim
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Patent number: 5416484Abstract: A fully differential comparator includes a differential signal input, a differential reference input, and a differential signal output. Identical first and second gain stages are used in the differential comparator that each have a first single-ended input, a second single-ended input, and a differential output. The first single-ended inputs from the first and second gain stages form the differential signal input of the differential comparator. The second single-ended inputs from the first and second gain stages form the differential reference input of the differential comparator. The differential outputs of the first and second gain stages are cross-coupled to form the differential signal output of the differential comparator. The differential comparator can be used in conjunction with a conventional resistor string found in the front end of a flash ADC, but in a novel manner that prevents undesirable loading effects, as well as other problems associated with prior art single-ended comparators.Type: GrantFiled: April 15, 1993Date of Patent: May 16, 1995Assignee: Tektronix, Inc.Inventor: Keith H. Lofstrom
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Patent number: 5414440Abstract: A plasma addressed liquid crystal display (10) uses a liquid crystal material (18) having a low .DELTA..epsilon., .epsilon..sub..perp., and .DELTA.n, resulting in reduced sensitivity to cross talk, reduced operating voltage, and improved resistance to the deleterious electrochemical effects of direct current biases. Liquid crystal layers of low .DELTA..epsilon., .epsilon..sub..perp., and .DELTA.n materials exhibit lower capacitance, which increases the threshold voltage and reduces the saturation voltage to achieve reduced sensitivity to crosstalk and a lower operating voltage.Type: GrantFiled: June 21, 1994Date of Patent: May 9, 1995Assignee: Tektronix, Inc.Inventors: Kevin J. Ilcisin, Thomas S. Buzak, Paul C. Martin
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Patent number: 5412579Abstract: The invention is a method for accumulating and displaying digital waveform data, representing the behavior over time of an electrical signal that includes the steps of: repeatedly acquiring and digitizing (10) waveform data during a first set of time intervals, repeatedly acquiring and digitizing (10) waveform data during a second set of time intervals, the second set of time intervals alternating with the first set of time intervals, during each one of the time intervals in the first set of time intervals, ORing (83) each acquired and digitized waveform together to produce first composite waveforms, during each one of the time intervals in the second set of time intervals, ORing (86) each acquired and digitized waveform together to produce second composite waveforms, displaying (81,84) each first composite waveform during a next occurring time interval in the second set of time intervals, and displaying (81,84) each second composite waveform during a next occurring time interval in the first set of time inteType: GrantFiled: April 5, 1993Date of Patent: May 2, 1995Assignee: Tektronix, Inc.Inventors: R. David Meadows, David H. Price, Joseph H. Hubert
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Patent number: 5412330Abstract: An optical module for an optically based measurement system, such as an electro-optic system (10) for measuring electrical characteristics of a device under test (14), has a probe arm (26), a layer of electro-optic material (27), and a first optical system for delivering a measurement beam (44) to the layer and for producing therefrom an information-carrying beam having optical characteristics indicative of the electric characteristics. The first optical system includes a first lens (128), and (optional) polarization bias adjustment (130), a dichroic beamsplitter (112), and a second lens (114). The module also has a second optical system for delivering an observation beam (66) through the layer and onto a portion (68) of the device and for forming from rays (69) stemming from the observation beam a light pattern (70) indicative of the portion. The information-carrying beam is analyzed in a polarization analysis module into component beams (136, 138) in respective linearly independent polarization states.Type: GrantFiled: June 16, 1993Date of Patent: May 2, 1995Assignee: Tektronix, Inc.Inventors: Mihir K. Ravel, Michael D. Jones, Steven H. Pepper
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Patent number: 5410422Abstract: A gray scale LCD cell device (116) combines a liquid crystal cell (80) having a symmetrical director field (82, 82') with a negative birefringence compensator plate (110) and interposes them between a pair of linear polarizers (112, 114). The symmetrical director field produces a symmetrical but nonuniform gray scale or color viewing circle curve (100) from the liquid crystal cell. The negative birefringence plate restores the gray scale or color viewing angle uniformity. When graphed on a polar plot, the measured light transmission percentage curves (120, 122, 124) characterizing the LCD are substantially concentric circles surrounding the optical axis (18) for all azimuthal angles (28) and viewing angles (24) up to 30 degrees. Adding colored filters (152) to a color cell triad (150) provides a basis for a multi-color display having uniformly perceived colors over a wide range of azimuthal and viewing angles.Type: GrantFiled: March 3, 1993Date of Patent: April 25, 1995Assignee: Tektronix, Inc.Inventor: Philip J. Bos
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Patent number: D361288Type: GrantFiled: March 18, 1994Date of Patent: August 15, 1995Assignee: Tektronix, Inc.Inventors: Paul H. Chandwick, Scott R. Ketterer, Thor R. Culverhouse, Robert C. Proebstel