61
Clark P Foley: Dual-ranked time-interval conversion circuit. Tektronix, William A Birdwell, April 20, 1993: US05204678 (13 worldwide citation)

A dual-ranked time-interval conversion circuit. Two time trap circuits are employed to convert the time interval between a logic level transition of a first signal and a logic level transition of a second signal to an analog or digital signal representative of that time interval. Each time trap circ ...


62
Colin T Farrell, Jon D Herron Jr: Reduced noise sensitivity method and apparatus for converting an interferogram phase map to a surface profile map. Veeco Instruments, William A Birdwell, Durando Birdwell & Janke, May 18, 2004: US06738511 (13 worldwide citation)

In the process of converting an interferogram phase map to a surface profile, in the absence of tilt, a histogram of occurrences of phase values is created from phase data. Useful data are identified in bins with contents that exceed a threshold value. Where useful data wrap around the end of the hi ...


63
Richard C Cabot: Hybrid form digital filter. Audio Precision, William A Birdwell, February 18, 1992: US05089981 (12 worldwide citation)

A hybrid form digital filter. A digital filter is provided wherein the zeros of its transfer function are provided by a direct form digital filter portion and the poles of the transfer function are provided by a normal form digital filter portion. The hybrid filter provides truncation noise and stab ...


64
Richard C Cabot: Method and apparatus for recognizing a test signal and determining signal transfer characteristics therefrom. Audio Precision, William A Birdwell & Associates, May 5, 1998: US05749047 (12 worldwide citation)

A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input o ...


65
Theodore G Nelson, Calvin D Diller, Robert D Meadows: Method and circuit for triggering an electronic instrument only once during a period of a signal. Tektronix, Boulden G Griffith, William A Birdwell, June 29, 1993: US05223784 (12 worldwide citation)

A method and circuit for triggering an electronic instrument only once during a period of an input signal having multiple triggering events during that period. A signal applied to an electronic instrument, such as an oscilloscope, is acquired. Qualified triggering events occurring on the acquired si ...


66
Roy I Siegel, John A Hengeveld: Graded display of digitally compressed waveforms. Tektronix, William A Birdwell, Boulden G Griffith, August 27, 1996: US05550963 (12 worldwide citation)

A visually graded display of digitally compressed waveforms for a digital storage oscilloscope. A histogram is formed by sampling or otherwise resolving a data set of values corresponding to an independent variable to produce a quantized set of values over a selected compression interval of the inde ...


67
Mark W Rohde, George T Kirkwood, Dick G Schalk: Illuminated elastomeric rocker switch assembly. Rodgers Instrument Corporation, William A Birdwell, February 11, 1992: US05087798 (11 worldwide citation)

A rocker switch, particularly for selecting voices in an electronic organ. A translucent tab is pivotally mounted at its center on a printed circuit board such that when the tab is pressed at either end, it actuates a respective elastomeric electric switch also mounted on the printed circuit board. ...


68
Richard A Booman, Stephen F Blazo: Optical waveguide photocathode. Tektronix, William A Birdwell, September 19, 1989: US04868380 (10 worldwide citation)

An optical waveguide photocathode for converting optical signals to electrical signals has an optical waveguide, a semiconductor covering the end of the optical waveguide, a first transparent electrode disposed between the end of the waveguide and the semiconductor, and a second electrode disposed a ...


69
Michael D Jones: Method and apparatus for carrying out optical time domain reflectometry using weighing techniques. Tektronix, John D Winkelman, Francis I Gray, William A Birdwell, October 4, 1994: US05353110 (10 worldwide citation)

An optical time domain reflectometry method and apparatus that employs Hadamard transforms to increase the signal-to-noise ratio. A sequence of N pulses of light corresponding to a Hadamard derived code are launched down a fiber optic cable for each of N such codes. Selected combinations of pulses o ...


70
Charles L Saxe: Address computation system for updating starting addresses of data arrays in an array processor within an instruction cycle. Tektronix, William A Birdwell, George T Noe, November 3, 1987: US04704680 (10 worldwide citation)

An address computation system for updating starting addresses of data arrays in an array processor within an instruction cycle. A first set of registers is provided for storing starting addresses for each array. A second set of registers is provided for storing current addresses for each array. Logi ...