Patents by Inventor Douglas A. Webb

Douglas A. Webb 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: 7405389
    Abstract: The present disclosure describes an optical displacement sensor having a dense multi-axis array of photosensitive elements. Generally, the sensor includes a two dimensional array of multiple photosensitive elements. In one embodiment, the array includes multiple linear arrays of photosensitive elements arranged along three or more axes in a space-filling, close-packed multi-axis array. The photosensitive elements are connected to each other in such a way that motion is determinable along each of the axes by measuring differential photocurrents between photosensitive elements along each of the axes. The inventive architecture advantageously increases signal redundancy, and reduces signal drop-out or low signals due to random fluctuations in the incident or absorbed light or in the signals from the photosensitive elements.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: July 29, 2008
    Assignee: Silicon Light Machines Corporation
    Inventors: Michael J. Dueweke, Douglas A. Webb
  • Patent number: 7250893
    Abstract: A signal processing circuit and processing method are provided for measuring an analog signal from a photo-detector. Generally, the method includes steps of: (i) sampling and storing a characteristic of the signal at a first predetermined time following a reset of the circuit; (ii) sampling the characteristic of the signal at a second predetermined time following a reset or initialization of the circuit; (iii) determining a difference between the stored characteristic of the signal sampled at the first predetermined time and the characteristic of the signal sampled at the second predetermined time; and (iv) converting the determined difference to a digital value and determining a slope of the signal from the digital value and the difference between the first and second predetermined times. Thus, the measurement of the slope is independent of and substantially unaffected by absolute values of the characteristics measured at the first and second predetermined times.
    Type: Grant
    Filed: November 12, 2005
    Date of Patent: July 31, 2007
    Assignee: Silicon Light Machines Corporation
    Inventors: Brian D. Todoroff, Douglas A. Webb
  • Patent number: 7247832
    Abstract: A signal processor and processing method are provided for measuring current received from a photo-detector. Generally, the processor includes a transimpedance amplifier (TIA) to integrate a current received from a photo-detector in the optical navigation system to generate a voltage signal having a slope that is proportional to the received current, and a comparator having a first input coupled to an output of the TIA to receive the voltage signal, and a second, inverting, input coupled to a threshold voltage. The comparator is configured to compare the voltage signal to the threshold voltage and to generate an output pulse having a predetermined voltage and a duration or width that is a function of the received current.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: July 24, 2007
    Assignee: Silicon Light Machines Corporation
    Inventor: Douglas A. Webb
  • Patent number: 7218336
    Abstract: A method of providing drive signals to an illuminator module having a plurality of channels in a printing application. Binary image data including image bits is provided from a data source to the illuminator module. Each image bit is converted to a multi-bit amplitude value within the illuminator module, wherein the conversion of each image bit to the multi-bit amplitude value depends at least on a value of the image bit and which channel is associated with the image bit. Pulse width modulation (PWM) may be applied to the drive signals using programmable transition delays. Apparatus for performing the aforementioned method are also disclosed.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: May 15, 2007
    Assignee: Silicon Light Machines Corporation
    Inventors: David T. Amm, Douglas A. Webb, Gregory A. Myatt
  • Patent number: 7161518
    Abstract: In one embodiment, a micro electromechanical system (MEMS) driver circuit receives a pulse-width modulated (PWM) signal and uses it to control a voltage at a MEMS cell. The driver circuit further includes a current source, a capacitor, and a reset circuit that can discharge the capacitor. The voltage at the MEMS cell can be controlled in proportion to the pulse width of the PWM signal. In another embodiment disclosed, a MEMS driver circuit receives a first PWM signal and a second PWM signal. Each PWM signal is coupled to a current source. One current source can provide a course current control and the other current source can provide fine current control. The driver circuit can further include a capacitor and a reset circuit for discharging the capacitor. The voltage at the MEMS cell can be controlled in proportion to a summation of the first and second current sources. According to another aspect of the embodiments, a method of controlling a voltage at a MEMS cell is disclosed.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: January 9, 2007
    Assignee: Silicon Light Machines Corporation
    Inventors: Douglas A. Webb, Stephen Gaalema
  • Patent number: 7053930
    Abstract: One embodiment disclosed relates to a method for bi-directional progressive scanning in a display system. The method includes receiving image data for an image to be displayed, forward scanning the image data in a first direction using a linear array of controllable light elements, and reverse scanning the image data in a second direction opposite to the first direction using the linear array. Another embodiment disclosed relates to an apparatus for bi-directional progressive scanning. The apparatus includes a linear array of controllable light elements, and a scanner driver that drives a scanner apparatus using a drive signal that is applied to drive both forward and reverse optical scanning of an image by the linear array.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: May 30, 2006
    Assignee: Silicon Light Machines Corporation
    Inventors: Douglas A. Webb, David T. Amm, Paul A. Alioshin, David A. LeHoty, Mark A. Koenig
  • Patent number: 6967758
    Abstract: In one embodiment, a delay circuit is configured to delay pixel information from an image source, such as a frame buffer. The delay circuit may be configured to delay the pixel information by an amount of time that would move a pixel projected on a surface by a distance less than a dimension of the pixel. A light modulator may modulate a light beam onto a surface, such as a display screen, based on the delayed pixel information. This advantageously allows for sub-pixel electronic alignment.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: November 22, 2005
    Assignee: Silicon Light Machines Corporation
    Inventors: David T. Amm, Douglas A. Webb
  • Patent number: 6967718
    Abstract: An apparatus for measuring wavelength composition and power of a dispersed spectrum of light comprises a diffractive light modulator and a detector. The diffractive light modulator comprises an array of light modulating pixels operable in a first mode and a second mode. In operation, the dispersed spectrum of light illuminates the diffractive light modulator along the array of light modulating pixels, which selectively directs a subset of the dispersed spectrum of light into the first mode while directing a remainder of the dispersed spectrum of light into the second mode. The detector is optically coupled to the diffractive light modulator. In operation, the detector detects the subset of the dispersed spectrum of light while not detecting the remainder of the dispersed spectrum of light. Each of the light modulating pixels is controlled by signals sent from a controller. The signals comprise a time division multiplex modulation, a code division multiplex modulation, or a combination thereof.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: November 22, 2005
    Assignee: Silicon Light Machines Corportion
    Inventors: Clinton B. Carlisle, Jahja I. Trisnadi, Douglas A. Webb, David Lehoty, Kais Almarzouk, Akira Tomita
  • Patent number: 6936869
    Abstract: Semiconductor devices, e.g., heterojunction field effect transistors, fabricated with silicon-germnanium buffer layer and silicon-carbon channel layer structures. The invention provides a method of reducing threading defect density via reducing germanium content in a SiGe relaxed buffer layer on which a strained silicon channel layer is formed, by forming the strained silicon channel layer of a silicon-carbon alloy, e.g., containing less than about 1.5 atomic % C substitutionally incorporated in the Si lattice of the alloy.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: August 30, 2005
    Assignee: International Rectifier Corporation
    Inventors: Douglas A. Webb, Michael G. Ward
  • Publication number: 20040183882
    Abstract: In one embodiment, a delay circuit is configured to delay pixel information from an image source, such as a frame buffer. The delay circuit may be configured to delay the pixel information by an amount of time that would move a pixel projected on a surface by a distance less than a dimension of the pixel. A light modulator may modulate a light beam onto a surface, such as a display screen, based on the delayed pixel information. This advantageously allows for sub-pixel electronic alignment.
    Type: Application
    Filed: January 30, 2004
    Publication date: September 23, 2004
    Inventors: David T. Amm, Douglas A. Webb
  • Publication number: 20040165069
    Abstract: One embodiment disclosed relates to a method for bi-directional progressive scanning in a display system. The method includes receiving image data for an image to be displayed, forward scanning the image data in a first direction using a linear array of controllable light elements, and reverse scanning the image data in a second direction opposite to the first direction using the linear array. Another embodiment disclosed relates to an apparatus for bi-directional progressive scanning. The apparatus includes a linear array of controllable light elements, and a scanner driver that drives a scanner apparatus using a drive signal that is applied to drive both forward and reverse optical scanning of an image by the linear array.
    Type: Application
    Filed: June 27, 2002
    Publication date: August 26, 2004
    Inventors: Douglas A. Webb, David T. Amm, Paul A. Alioshin, David A. LeHoty, Mark A. Koenig
  • Patent number: 6781739
    Abstract: One embodiment disclosed relates to a method for driving a micro electromechanical (MEM) device. The method includes generating a high-frequency AC drive signal that is substantially greater in frequency than a resonance frequency of a movable feature in the MEM device, and modulating the amplitude of the high-frequency AC drive signal. A DC-like displacement of the movable feature in the MEM device is achieved by driving the movable feature using the amplitude modulated high-frequency AC drive signal.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: August 24, 2004
    Assignee: Silicon Light Machines, Inc.
    Inventors: David T. Amm, Douglas A. Webb
  • Publication number: 20040007715
    Abstract: Semiconductor devices, e.g., heterojunction field effect transistors, fabricated with silicon-germnanium buffer layer and silicon-carbon channel layer structures. The invention provides a method of reducing threading defect density via reducing germanium content in a SiGe relaxed buffer layer on which a strained silicon channel layer is formed, by forming the strained silicon channel layer of a silicon-carbon alloy, e.g., containing less than about 1.5 atomic % C substitutionally incorporated in the Si lattice of the alloy.
    Type: Application
    Filed: July 9, 2002
    Publication date: January 15, 2004
    Inventors: Douglas A. Webb, Michael G. Ward
  • Patent number: 6271121
    Abstract: A process for chemical vapor deposition of blanket tungsten thin films on titanium nitride proceeds by hydrogen reduction of tungsten hexafluoride at temperatures between 200° C. and 500° C. Tungsten film nucleation is preferably facilitated by a hydrogen plasma treatment of the titanium nitride surface of the substrate. The plasma treatment may be carried out in a separate etch chamber and transferred to a tungsten CVD chamber without intervening exposure to air, or, preferably, is carried out with a low energy etch performed with the substrate mounted on a susceptor in the chamber of the tungsten CVD reactor at which the tungsten film is to be applied.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: August 7, 2001
    Assignee: Tokyo Electron Limited
    Inventor: Douglas A. Webb
  • Patent number: 6093645
    Abstract: An effective barrier layer to chemical attack of fluorine during chemical vapor deposition of tungsten from a tungsten fluoride source gas is fabricated by the present invention. A titanium nitride conformal barrier film can be formed by in-situ nitridation of a thin titanium film. The substrate is placed in a module wherein the pressure is reduced and the temperature raised to 350.degree. C. to about 700.degree. C. A titanium film is then deposited by plasma-enhanced chemical vapor deposition of titanium tetrahalide and hydrogen. This is followed by formation of titanium nitride on the titanium film by subjecting the titanium film to an nitrogen containing plasma such as an ammonia, an N.sub.2 or an NH.sub.3 /N.sub.2 based plasma. Tungsten is then deposited on the film of titanium nitride by plasma-enhanced chemical vapor deposition.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: July 25, 2000
    Assignee: Tokyo Electron Limited
    Inventors: Michael S. Ameen, Joseph T. Hillman, Douglas A. Webb
  • Patent number: 5906866
    Abstract: A process for chemical vapor deposition of blanket tungsten thin films on titanium nitride proceeds by hydrogen reduction of tungsten hexafluoride at temperatures of 200 to 500.degree. C. Tungsten film nucleation is preferably facilitated by partial removal of the oxidized surface of titanium nitride or titanium nitride coated substrates by a sputter cleaning process prior to the tungsten CVD. The process differs in part from other processes in that deposition proceeds rapidly on titanium nitride without a significant nucleation period without the addition of other chemical compounds such as silane. The sputter cleaning process preferably takes place in an inert vacuum environment that protects the substrate from atmosphere and oxygen until the tungsten CVD step occurs.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: May 25, 1999
    Assignee: Tokyo Electron Limited
    Inventor: Douglas A. Webb
  • Patent number: 5768007
    Abstract: A method of resetting the mirrors (11, 21) of the mirror elements of a digital micro-mechanical device (DMD) (10, 20). A bias voltage is applied to the mirror elements and the surface upon which they land, but is removed after the address voltage has been switched. (FIG. 4). Immediately before the bias is removed, a reset voltage is added to the bias voltage. The reset voltage signal is comprised of a number of pulses at a frequency that matches the resonant frequency of the mirrors. The magnitude of the reset voltage results in a total applied voltage that permits vibrational energy to build but that is insufficient to cause the mirrors to become unstuck until the end of the reset signal. In other words, the magnitude of the reset voltage is small relative to that of the bias voltage.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: June 16, 1998
    Assignee: Texas Instruments Incorporated
    Inventors: Richard Knipe, Rabah Mezenner, Douglas A. Webb
  • Patent number: 5739941
    Abstract: A non-linear torsion hinge (12, 22) for a micro-mechanical device (10, 20) having a hinged movable element (11, 21). Each hinge (22) is comprised of two hinge strips (22a) spaced apart in the same plane, such that the axis of rotation of at least one of the hinge strips (22a) is different from the axis of rotation of the movable element (21). As a result, the hinge strip (22a) must elongate as it twists, thereby providing a greater restoring torque.
    Type: Grant
    Filed: July 20, 1995
    Date of Patent: April 14, 1998
    Assignee: Texas Instruments Incorporated
    Inventors: Richard L. Knipe, Douglas A. Webb
  • Patent number: 5610438
    Abstract: The present invention relates to micro-mechanical devices including actuators, motors and sensors with improved operating characteristics. A micro-mechanical device (10) comprising a DMD-type spatial light modulator with a getter (100) located within the package (52). The getter (100) is preferably specific to water, larger organic molecules, various gases, or other high surface energy substances. The getter is a non-evaporable getter (NEG) to permit the use of active metal getter systems without their evaporation on package surfaces.
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: March 11, 1997
    Assignee: Texas Instruments Incorporated
    Inventors: Robert M. Wallace, Douglas A. Webb
  • Patent number: 5523878
    Abstract: A method of forming of a monomolecular coating (19) for surfaces of contacting elements (11, 17) of micro-mechanical devices (10), specifically, devices that have moving elements that contact other elements and that tend to stick as a result of the contact. The method uses liquid deposition, with the device being placed in a solution that contains a precursor to the formation of the coating. The precursor is chosen based on coordination chemistry between the precursor and the surface to be coated.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: June 4, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Robert M. Wallace, Douglas A. Webb, Bruce E. Gnade