Patents by Inventor Douglas G. Keithley

Douglas G. Keithley 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: 7943896
    Abstract: A mechanical galvanometer tilt control system includes two beam detection sensors that detect vertical displacement caused by the horizontal rotation of a galvanometer and the vertical rotation of a photoconductive drum. The galvanometer may be in communication with a mirror holder that holds a mirror. The mirror holder may be operable to horizontally rotate the mirror as the mirror reflects a light beam onto a photosensitive image forming surface of the photoconductive drum. The two beam detection sensors receive the reflected light beam as the galvanometer generates one or more forward-going and one or more reverse-going scanlines on the photosensitive image forming surface. The mechanical galvanometer tilt control system may further determine an amount of vertical correction required to correct for the vertical displacement caused by the rotation of the galvanometer and the rotation of the photoconductive drum.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: May 17, 2011
    Assignee: Marvell International Ltd.
    Inventor: Douglas G. Keithley
  • Patent number: 7925912
    Abstract: A device for adjusting the timing of at least one edge of an output pulse created in response to a reference pulse is disclosed. Such a device may include a first memory circuit having two or more first memory cells and a second memory circuit also having two or more second memory cells. The first memory circuit may be configured to periodically sample the reference pulse at the rising edges of a first sample clock while the second memory circuit may be configured to periodically sample the reference pulse at the falling edges of the first sample clock. A combinatorial logic circuit may also be included to produce the output pulse having at least one adjusted edge based on a set of timing instructions and timing information provided by the first and/or second memory circuits.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: April 12, 2011
    Assignee: Marvell International Ltd.
    Inventors: Roy G. Moss, Douglas G. Keithley, Richard N. Woolley
  • Patent number: 7904614
    Abstract: A direct memory access controller is set forth. The direct memory access controller includes first and second registers storing various values that are used to set the parameters of DMA transfers that take place during a single data transaction. The first register stores a start address location value used to define a start address at which direct memory access transfers for the transaction are to begin. The second register stores a value used to end data transfers of the data transaction. The DMA controller also includes transfer control circuitry for executing the data transaction. The transfer control circuitry is adapted to automatically execute multiple, consecutive data transactions using the values stored in the first and second registers.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: March 8, 2011
    Assignee: Marvell International Ltd.
    Inventors: John D. Marshall, Douglas G. Keithley, William R. Schmidt
  • Publication number: 20100321734
    Abstract: A scanning apparatus and method for entering a user input into the apparatus uses a non-electrical control device having a target undersurface, which can be manually manipulated to a particular setting. The particular setting of the non-electrical control device is determined by processing an image of at least a portion of the target undersurface captured by a scan sensor of the scanning apparatus.
    Type: Application
    Filed: August 30, 2010
    Publication date: December 23, 2010
    Applicant: Marvell International Technology Ltd.
    Inventors: James A. Hall, JR., Douglas G. Keithley
  • Patent number: 7839424
    Abstract: A system is provided for scaling image data comprising a Direct Memory Access (DMA) engine adapted to read the image data from a horizontal pixel strip in a column-by-column format, a scaling block adapted to scale the image data read by the read DMA engine into scaled column output data, and a buffer memory for storing the scaled column output data for the horizontal pixel strip. A method is also provided for scaling an image comprising reading pixel values from a pixel strip in a column-by-column manner across the pixel strip and scaling the pixel values for each column to produce scaled column output data. The scaled column output data for a plurality of columns is then read and the scaled column output data is scaled from the plurality of columns to produce scaled row output data for a row of pixels.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: November 23, 2010
    Assignee: Marvell International Ltd.
    Inventors: Gordon R. Clark, Douglas G. Keithley
  • Patent number: 7798407
    Abstract: A scanning apparatus and method for entering a user input into the apparatus uses a non-electrical control device having a target undersurface, which can be manually manipulated to a particular setting. The particular setting of the non-electrical control device is determined by processing an image of at least a portion of the target undersurface captured by a scan sensor of the scanning apparatus.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: September 21, 2010
    Assignee: Marvell International Technology Ltd.
    Inventors: James A. Hall, Jr., Douglas G. Keithley
  • Publication number: 20100177985
    Abstract: Methods and systems for scaling an input image.
    Type: Application
    Filed: March 24, 2010
    Publication date: July 15, 2010
    Applicant: Marvell International Technology LTD.
    Inventors: Douglas G. Keithley, David A. Bartle
  • Patent number: 7755659
    Abstract: A laser printer for Braille that obviates the need for embossing mechanisms and specialized paper. A laser printer for Braille according to the present teachings increases an amount of a toner that adheres to an area of a paper that corresponds to the Braille element. The increased amount of toner yields a printed Braille element that may be read by touch.
    Type: Grant
    Filed: November 19, 2007
    Date of Patent: July 13, 2010
    Assignee: Marvell International Technology Ltd.
    Inventors: James R. Emmert, Charles Evans, Michael A. Rencher, Douglas G. Keithley
  • Publication number: 20100165404
    Abstract: A laser print apparatus includes a memory for storing a multi-bit image including a plurality of pixels. Each pixel is represented by an N-bit value, wherein N is greater than one. A modulation code generator analyzes three adjacent pixels. The three adjacent pixels include a left pixel, a center pixel, and a right pixel. The modulation code generator is configured to generate a pulse width value based on the value of the center pixel, and a justification value based on the values of the left pixel and the right pixel. A laser print engine forms an output pixel on media based on the pulse width value and the justification value.
    Type: Application
    Filed: September 22, 2009
    Publication date: July 1, 2010
    Applicant: MARVELL INTERNATIONAL TECHNOLOGY LTD.
    Inventors: John D. Marshall, Douglas G. Keithley
  • Patent number: 7725680
    Abstract: An application specific integrated circuit (ASIC) comprises a first bus that communicates with inputs and outputs of N processing modules, where N is an integer greater than 1. A control module communicates with the first bus and a second bus that is different than the first bus, and that generates first control signals. A routing module communicates with the first bus, receives data via the second bus from a first memory, selectively routes the data to a first of the inputs, and selectively routes one of the outputs to a second of the inputs. The routing module selects the first and second of the inputs based on the first control signals.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: May 25, 2010
    Assignee: Marvell International Ltd.
    Inventors: William R. Schmidt, Douglas G. Keithley
  • Patent number: 7719558
    Abstract: Systems and methods are disclosed for determining and generating horizontal synchronization signals for a laser printer having a multi-facet rotating mirror. Each horizontal synchronization signal is determined based on measurements of the facets. The measurements are reflective of the configuration of the mirror and may be acquired using one horizontal synchronization sensor. Respective pseudo horizontal synchronization signals may be generated for multiple emitters based on the measurements obtained with the single horizontal synchronization sensor.
    Type: Grant
    Filed: July 15, 2008
    Date of Patent: May 18, 2010
    Assignee: Marvell International Ltd.
    Inventors: Gregory Lee Unruh, Douglas G. Keithley
  • Patent number: 7710777
    Abstract: Semi-volatile NAND flash memory systems, apparatuses, and methods for use are described herein. According to various embodiments, a semi-volatile NAND flash memory may be partitioned into various retention regions. Other embodiments may be described and claimed.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: May 4, 2010
    Assignee: Marvell International Ltd.
    Inventors: Mark D. Montierth, Randall D. Briggs, Douglas G. Keithley
  • Patent number: 7706635
    Abstract: Methods and systems for scaling an input image.
    Type: Grant
    Filed: October 20, 2005
    Date of Patent: April 27, 2010
    Assignee: Marvell International Technology Ltd.
    Inventors: Douglas G. Keithley, David A. Bartle
  • Patent number: 7707349
    Abstract: A system, method, and processor executable instructions to isochronously communicate in standard USB mode laser printer scan data from a host computer to a laser printer. The host computer transmits a data stream that includes data packets having laser printer scan data, error detection information, and correction packets such as parity packets for use to reconstruct packets having an error. The laser printer receives the data stream, processes the error detection information, data packets and parity packets, and provides a continuous stream of laser printer scan data for printing.
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: April 27, 2010
    Assignee: Marvell International Ltd.
    Inventor: Douglas G. Keithley
  • Patent number: 7707324
    Abstract: A direct memory access controller comprises a plurality of registers defining parameters for multiple direct memory access transactions and transfer control circuitry responsive to data in the plurality of registers. The transfer control circuitry is adapted to automatically execute multiple, consecutive data transactions using the parameters of the plurality of registers. At least two consecutive data transactions are executed with respect to non-contiguous system locations.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: April 27, 2010
    Assignee: Marvell International Ltd.
    Inventors: William R. Schmidt, Douglas G. Keithley
  • Patent number: 7701477
    Abstract: A scanning system is adapted to scan an image beam across a photoconductive surface. The scanning system includes an oscillating mirror and is operable to generate an image beam and to reflect the image beam off the oscillating mirror to bidirectionally scan the image beam across the photoconductive surface and thereby discharge regions on the surface. The system is further operable to dynamically scale an intensity of the image beam as a function of a position of the image beam on the photoconductive surface.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: April 20, 2010
    Assignee: Marvell International Technology Ltd.
    Inventor: Douglas G. Keithley
  • Publication number: 20100047001
    Abstract: Embodiments of the present invention provide a multi-function device including a housing, a printing assembly disposed within the housing, the printing assembly being configured to print a document, and a copying assembly comprising a complementary metal-oxide-semiconductor (CMOS) image sensor and an illumination source disposed within the housing, the copying assembly further including a substantially flat transparent surface disposed in an optical path of the CMOS image sensor, the substantially flat transparent surface to support an object for image capture by the CMOS image sensor, wherein the illumination source is configured to provide illumination during image capture. Other embodiments may be described and/or claimed.
    Type: Application
    Filed: August 18, 2009
    Publication date: February 25, 2010
    Inventors: Mark D. Montierth, Douglas G. Keithley, Richard D. Taylor
  • Publication number: 20090303539
    Abstract: An image forming apparatus includes a scanning region and a user interface region adjacent to the scanning region. In the user interface, a first illuminated indicator corresponds to a function of the image forming apparatus. A light source is operable to illuminate an object in the scanning region. A first light conveying member is coupled to the illuminated indicator and operable to receive light from the light source.
    Type: Application
    Filed: August 14, 2009
    Publication date: December 10, 2009
    Inventors: James A. Hall, JR., Douglas G. Keithley
  • Patent number: 7609409
    Abstract: A laser print apparatus includes a memory for storing a multi-bit image including a plurality of pixels. Each pixel is represented by an N-bit value, wherein N is greater than one. A modulation code generator analyzes three adjacent pixels. The three adjacent pixels include a left pixel, a center pixel, and a right pixel. The modulation code generator is configured to generate a pulse width value based on the value of the center pixel, and a justification value based on the values of the left pixel and the right pixel. A laser print engine forms an output pixel on media based on the pulse width value and the justification value.
    Type: Grant
    Filed: October 8, 2007
    Date of Patent: October 27, 2009
    Assignee: Marvell International Technology Ltd.
    Inventors: John D. Marshall, Douglas G. Keithley
  • Publication number: 20090015882
    Abstract: Systems, apparatuses, and methods for pre-rendering image data for a plurality of scanning paths are described here. The method includes receiving image data including a plurality of scan lines for a top portion of an image page, pre-rendering the data for a first scanning path to generate a first data set, pre-rendering the data for a second scanning path to generate a second data set, determining an initial scanning direction, and selecting the first data set or the second data set responsive to said determining. Other embodiments may be described and claimed.
    Type: Application
    Filed: July 11, 2008
    Publication date: January 15, 2009
    Inventor: Douglas G. Keithley