Patents by Inventor Randall Sprague

Randall Sprague 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).

  • Publication number: 20050280879
    Abstract: A resonant MEMS scanning system operates a MEMS scanner at its resonant frequency to maximize scan angle and minimize power consumption. A controller includes a phase locked loop, an amplitude servo control loop, and a resonant frequency servo control loop. A microprocessor controls the loops and provides override during conditions such as start-up. Resonant frequency is dynamically thermally trimmed, allowing the device to be operated at higher Q. The phase lock loop operates in a pre-lock condition to allow faster start-up. Resonant frequency is controlled open loop during idle and start-up. Drive voltage is set high during start-up to achieve a rapid rise in scan angle.
    Type: Application
    Filed: November 12, 2004
    Publication date: December 22, 2005
    Inventors: Gregory Gibson, Wyatt Davis, Dean Brown, Randall Sprague
  • Publication number: 20050264502
    Abstract: A scanned light display system includes a light source operable to emit light and a curved mirror positioned to receive at least a portion of the light. The curved mirror is configured to substantially collimate the received light. The substantially collimated light is scanned to form an image by moving at least one of the light source and the curved mirror relative to each other. Alternatively, the scanned light display system includes a light source operable to emit light, a curved mirror positioned to receive some of the light, and an optical element positioned to receive light reflected from the curved mirror. The optical element is configured to substantially collimate the reflected light. The substantially collimated light is scanned to form an image by moving at least one of the light source, the curved mirror, and the optical element. Scanning mirror assemblies and methods of making are also disclosed.
    Type: Application
    Filed: March 9, 2005
    Publication date: December 1, 2005
    Inventors: Randall Sprague, Hakan Urey, Dean Brown, Margaret Brown, John Lewis, Mathew Watson, Thomas Montague, Stephen Willey
  • Publication number: 20050253055
    Abstract: A MEMS oscillator, such as a MEMS scanner, has an improved and simplified drive scheme and structure. Drive impulses may be transmitted to an oscillating mass via torque through the support arms. For multi-axis oscillators drive signals for two or more axes may be superimposed by a driver circuit and transmitted to the MEMS oscillator. The oscillator responds in each axis according to its resonance frequency in that axis. The oscillator may be driven resonantly in some or all axes. Improved load distribution results in reduced deformation. A simplified structure offers multi-axis oscillation using a single moving body. Another structure directly drives a plurality of moving bodies. Another structure eliminates actuators from one or more moving bodies, those bodies being driven by their support arms.
    Type: Application
    Filed: November 9, 2004
    Publication date: November 17, 2005
    Inventors: Randall Sprague, Jun Yan, Jason Tauscher, Wyatt Davis, John Lewis, Dean Brown, Thomas Montague, Chancellor Brown
  • Publication number: 20050179976
    Abstract: A high performance MEMS scanner is disclosed. In some embodiments, scanner mirror has a wide and short aspect ratio that is similar to rotating polygon facets. Long torsion arms allow large rotation angles including 20° zero-to-peak mechanical and greater. Suspensions couple the scan mirror to torsion arms, reducing dynamic mirror deformation by spreading the torque load. “leverage members” at the distal ends of the torsion arms help reduce stress concentrations. Elimination of a mounting frame increases device yield. Heater leads allow for precise trimming of the scanner resonant frequency. A compressive mount holds mounting pads against mounting structures.
    Type: Application
    Filed: November 12, 2004
    Publication date: August 18, 2005
    Inventors: Wyatt Davis, Dean Brown, Thomas Montague, Randall Sprague
  • Publication number: 20050173770
    Abstract: Devices are formed on a semiconductor wafer in an interdigitated relationship and are released by deep reactive ion etching. MEMS scanners are formed without a surrounding frame. Mounting pads extend outward from torsion arms. Neighboring MEMS scanners are formed with their mounting pads interdigitated such that a regular polygon cannot be formed around a device without also intersecting a portion of one or more neighboring devices. MEMS scanners may be held in their outlines by a metal layer, by small semiconductor bridges, or a combination.
    Type: Application
    Filed: November 12, 2004
    Publication date: August 11, 2005
    Inventors: Kelly Linden, Mark Helsel, Dean Brown, Randall Sprague, Wyatt Davis
  • Publication number: 20050018958
    Abstract: Methods of calibrating and operating optical switches as well as optical switches in which the orientations of mirrors are measured and controlled using control light beams and position sensing detectors are described. The present invention may provide high resolution control of a plurality of mirrors in an optical switch and thus allow the optical switch to cross-connect a large number of input and output ports with a low insertion loss.
    Type: Application
    Filed: August 26, 2004
    Publication date: January 27, 2005
    Inventors: Cheng-Chung Huang, Steven Saeed Nasiri, Randall Sprague, Alex Harwit, Dmitry Vasily Bakin, Janusz Bryzek
  • Publication number: 20050006564
    Abstract: An apparatus for detecting a centroid of a spot produced by electromagnetic radiation, e.g., optic radiation, using an array of PIN photodiodes serving as photodetectors and being organized in columns and in rows. Vertical connections are used to interconnect the PIN photodiodes in the columns in accordance with a first pattern that interconnects two or more adjacent columns. Horizontal connections are used to interconnect PIN photodiodes in the rows in accordance with a second pattern that interconnects two or more adjacent rows. The first and second patterns of interconnections can include just two adjacent columns and two adjacent rows, respectively and form a checkerboard interconnect pattern. The interconnections are made such that there are no anode connections between the PIN photodiodes in the rows and columns.
    Type: Application
    Filed: August 5, 2004
    Publication date: January 13, 2005
    Inventors: David Skurnik, Randall Sprague, Geoffrey Jones, Eric Abbott, Waisiu Law