Patents by Inventor Ronald T. Fulks

Ronald T. Fulks has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6245602
    Abstract: A top gate, self-aligned polysilicon (poly-Si) thin film transistor (TFT) is formed using a single laser anneal to crystallize the active silicon and to activate the source-drain region. The poly-Si TFT includes a substrate, dummy gate, a barrier oxide layer, a polysilicon pattern having a source region and a drain region, a gate oxide, and a gate.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: June 12, 2001
    Assignee: Xerox Corporation
    Inventors: Jackson Ho, Ronald T. Fulks
  • Patent number: 6201633
    Abstract: A micro-electromechanical bistable shutter display device is provided capable of being implemented for both small screen, high resolution devices and for large billboard-type displays. The micro-electromechanical shutter assembly has bi-stability characteristics which allow the use of only a holding voltage to maintain an image. The micro-electromechanical shutter assembly includes a shutter having petal-like shutter segments covering reflective or transmittive films. To expose the film in a particular shutter assembly, its shutter segments are moved from the horizontal to a vertical position using electrostatic attraction forces to “collapse” the torsionally-hinged shutter segments. The shutter assembly can have a number of segments, as long as the resulting shutter assembly shape can be stacked to form a dense 2D array.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: March 13, 2001
    Assignee: Xerox Corporation
    Inventors: Eric Peeters, Jackson Ho, Feixia Pan, Raj B. Apte, Joel A. Kubby, Ronald T. Fulks, Decai Sun, Patrick Y. Maeda, David Fork, Robert Thornton, Ross Bringans, G. A. Neville Connell, Philip Don Floyd, Tuan Anh Vo, Koenraad Van Schuylenbergh
  • Patent number: 5959312
    Abstract: A sensor device includes a sensing element and a thin film transistor (TFT), and the TFT's channel leads include semiconductor channel leads formed in a layer of microcrystalline silicon (.mu.c-Si). The sensing element is formed in a semiconductor layer that includes silicon-based material and is over the .mu.c-Si layer. Each of the semiconductor channel leads has a structure that prevents formation of bubbles at the lower and upper sides of the .mu.c-Si layer during production of the sensing element. The TFT's channel can be formed in a layer of intrinsic silicon-based material under the .mu.c-Si layer and the .mu.c-Si layer can be a deposited doped layer; or the TFT's channel can be formed in an intrinsic .mu.c-Si layer in which the leads are formed by implanting a dopant. The .mu.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: September 28, 1999
    Assignee: Xerox Corporation
    Inventors: Chuang-Chuang Tsai, William W. Yao, Ronald T. Fulks
  • Patent number: 5867242
    Abstract: The present invention is a novel pixel structure, and method for making the same, that reduces wasteful voltage drop associated with other pixel structures that cover their pixel elements with a final passivation layer. The presently claimed pixel structure is a combination of a thin film transistor (TFT), an associated pixel element, and a passivation layer. The TFT is first deposited atop a suitable substrate and patterned. Then, the passivation layer is deposited on top of the thin film transistor. Contact cuts are made into the passivation layer where the pixel element is to contact the TFT. Finally, the pixel element is deposited--lying atop the passivation layer and contacting with the underlying TFT where the contact cuts were made in the passivation layer.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: February 2, 1999
    Assignee: Xerox Corporation
    Inventors: William W. Yao, Ronald T. Fulks
  • Patent number: 5814530
    Abstract: In producing a sensor device with a sensing element and a thin film transistor, a semiconductor layer with microcrystalline silicon (.mu.c-Si) is produced in which semiconductor channel leads are formed. The .mu.c-Si has a structure that prevents formation of bubbles at the sides of the semiconductor layer during subsequent production of a sensing element in a silicon-based layer. The semiconductor layer can be a deposited doped layer of .mu.c-Si, or a layer of intrinsic .mu.c-Si can be doped. The .mu.c-Si layer can be deposited with a sufficiently small amount of hydrogen to prevent formation of bubbles; it can be deposited with crystalline grain structures permitting hydrogen to dissipate at a sufficient rate to prevent formation of bubbles; or its interfaces can be formed with sufficiently stability to prevent formation of bubbles.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: September 29, 1998
    Assignee: Xerox Corporation
    Inventors: Chuang-Chuang Tsai, William W. Yao, Ronald T. Fulks
  • Patent number: 5682211
    Abstract: The invention provides an integrated dark matrix for an active matrix liquid crystal display. A plurality of pixel electrodes overlap at least one of a plurality of gate lines and a plurality of data lines. A perimeter of the pixel electrodes overlaps the gate lines and/or data lines by twice the distance that the pixel electrode is above the gate and data lines, respectively to obtain a viewing angle of over 60 degrees.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: October 28, 1997
    Assignee: Xerox Corporation
    Inventors: William Yao, Ronald T. Fulks, Jackson Ho
  • Patent number: 5621556
    Abstract: The invention provides a method for manufacturing an active matrix liquid crystal displaying device having a plurality of thin film transistors using five masks. A plurality of gate electrodes are formed using a first mask. A plurality of etch stoppers are formed over the gate electrodes using a second mask. A plurality of chain electrodes and a plurality of source electrodes are formed using a third mask. A passivation layer including via holes is formed using a fourth mask. A plurality of pixel electrodes are formed using a fifth mask.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: April 15, 1997
    Assignee: Xerox Corporation
    Inventors: Ronald T. Fulks, William Yao, Chuang C. Tsai
  • Patent number: 5518805
    Abstract: The present invention is a novel multilayered structure comprising alternating layers of a base metal and a metal selected from a group of barrier metals. The base metal, in any given layer, is deposited to a thickness less than its critical thickness--a thickness beyond which hillocks are more likely to form for a given temperature. Between each such layer of base metal, a layer of barrier metal is interposed. The intervening layer of barrier metal acts to suppress the formation of hillocks in the base metal.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: May 21, 1996
    Assignee: Xerox Corporation
    Inventors: Jackson H. Ho, Ronald T. Fulks, Tzu-Chin Chuang
  • Patent number: 5491347
    Abstract: A thin-film structure on an insulating substrate includes an array of binary control units with an area of at least 90 cm.sup.2 and a density of at least 60 binary control units per cm. One implementation has an area of approximately 510 cm.sup.2, a diagonal of approximately 33 cm, and a total of approximately 6.3 million binary control units. Each binary control unit has a lead for receiving a unit drive signal, to which it responds by causing presentation of a segment of images presented by the array. Each binary control unit can present a segment with either a first color having a maximum intensity or a second color having a minimum intensity. Each binary control unit's unit drive signal causes the binary control unit to present its first and second colors. The substrate can be glass. Each binary control unit can include an amorphous silicon thin-film transistor (TFT) and a storage capacitor. Each binary control unit can be square.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: February 13, 1996
    Assignee: Xerox Corporation
    Inventors: Robert R. Allen, deceased, Richard H. Bruce, Tzu-Chin Chuang, Thomas G. Fiske, Ronald T. Fulks, Michael Hack, Jackson H. Ho, Alan G. Lewis, Russel A. Martin, Louis D. Silverstein, Hugo L. Steemers, Susan M. Stuber, Malcolm J. Thompson, William D. Turner, William W. Yao
  • Patent number: 5486939
    Abstract: A thin-film structure includes conductive lines that cross in a crossover region. A first insulating layer covers the lower conductive line. A second insulating layer is sufficiently thick to isolate signals in the lines and to prevent coupling. Each of the lower conductive line and the second insulating layer can have an edge. A smoothing layer is formed over the edges so that the upper conductive line forms continuously, providing an electrical connection between two points on opposite sides of the edges. The insulating layers can be nitride, separated by an undoped layer of amorphous silicon, so that the same layer sequence can be used as in a thin-film transistor. The smoothing layer can be n+ doped amorphous silicon. The conductive lines can be scan and data lines in an AMLCD or other array.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: January 23, 1996
    Assignee: Xerox Corporation
    Inventor: Ronald T. Fulks
  • Patent number: 4522845
    Abstract: Multichromatic radiation is applied rapidly to silicon or polysilicon placed in contact with a silicide-forming metal to form metal silicide having low resistivity without deleterious later diffusion of dopants in adjacent single crystal or polysilicon. The radiation is applied to a metal deposited on silicon or to a metal codeposited with or to silicide deposited from a metal-Si composite target. The temperatures preferably rise to between 600.degree. C. and 1200.degree. C. and the total heating periods are less than about one minute, with 10 to 30 seconds being typical.
    Type: Grant
    Filed: June 20, 1983
    Date of Patent: June 11, 1985
    Assignee: Varian Associates, Inc.
    Inventors: Ronald A. Powell, Ronald T. Fulks