Patents by Inventor John E. Welch

John E. Welch 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: 8072547
    Abstract: A comb filter system that utilizes host memory is disclosed. The comb filter system that utilizes host memory may include a comb filter. The comb filter system that utilizes host memory may include an allocated host memory. The comb filter system that utilizes host memory may include an interface in signal communication with the comb filter and allocated host memory.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: December 6, 2011
    Assignee: Conexant Systems, Inc.
    Inventors: John E. Welch, Michael A. Eskin, Lauren E. Linstad, Torry Steed
  • Patent number: 7750976
    Abstract: An automatic Video Detector (“AVD”) for detecting the transmission format of a received video signal is disclosed. The AVD may include a video detector array module and a state machine. The video detector array module may include a video line detector and a sub-carrier frequency detection module in signal communication with the video line detector.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: July 6, 2010
    Assignee: Conexant Systems, Inc.
    Inventors: Harvard L. Scott, John E. Welch, Peter M. Murdock, Chris J. Delgrande
  • Patent number: 7474357
    Abstract: Provided are decoding methods and decoders for separating luminance and chrominance components of a video signal. In one aspect, a reference subcarrier of a first line of the video signal is used for subsequent lines by applying an appropriate rotation to the reference subcarrier of the first line for each subsequent line. In another aspect, comb filtering is adaptively controlled based on determining whether 90 or 180 degrees relationship is maintained from line to line. In a further aspect, both complimentary and non-complimentary comb filtering are implemented. In yet another aspect, SECAM bell filtering is achieved by rotating the video signal to obtain a baseband signal, low-pass filtering and modulating the baseband signal, and subtracting the modulated low-pass filtered baseband signal from the video signal to notch the chroma component from the luma component.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: January 6, 2009
    Assignee: Conexant Systems, Inc.
    Inventors: Peter M. Murdock, John E. Welch
  • Patent number: 7227585
    Abstract: Provided are decoding methods and decoders for separating luminance and chrominance components of a video signal. In one aspect, a reference subcarrier of a first line of the video signal is used for subsequent lines by applying an appropriate rotation to the reference subcarrier of the first line for each subsequent line. In another aspect, comb filtering is adaptively controlled based on determining whether 90 or 180 degrees relationship is maintained from line to line. In a further aspect, both complimentary and non-complimentary comb filtering are implemented. In yet another aspect, SECAM bell filtering is achieved by rotating the video signal to obtain a baseband signal, low-pass filtering and modulating the baseband signal, and subtracting the modulated low-pass filtered baseband signal from the video signal to notch the chroma component from the luma component.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: June 5, 2007
    Assignee: Conexant Systems, Inc.
    Inventors: Peter M. Murdock, John E. Welch
  • Patent number: 7167213
    Abstract: Provided are decoding methods and decoders for calculating comb filter error and performing comb filter calculation used for decoding video signals. In one aspect, a method of calculating comb filter error used for decoding a video signal comprises storing a plurality of consecutive video lines of the video signal, the plurality of consecutive video lines including a first video line, a second video line appearing immediately before the first video line, and a third video line appearing immediately before the second video line; receiving a current video line of the video signal, wherein the current video line appears immediately after the first video line; obtaining a first difference between the current video line and the second video line; obtaining a second difference between the first video line and the third video line; and filtering the video signal for separating components in the video signal, based on the differences.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: January 23, 2007
    Assignee: Conexant Systems, Inc.
    Inventors: Peter M. Murdock, John E. Welch
  • Patent number: 6175389
    Abstract: An adaptive signal separation system and method for quadrature amplitude modulated signals that is particularly well-suited for YC separation of a composite television signal. An adaptive approach for separating overlapping signals wherein the adaptive approach selects between notch or equivalent filtering and a comb filtering system, wherein the chrominance is first demodulated to the IQ domain prior to comb filtering. The demodulated comb filtered IQ data streams are then re-modulated to reconstruct the luminance portion of the signal.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: January 16, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Benjamin E. Felts, III, John E. Welch
  • Patent number: 6055024
    Abstract: An adaptive method and system for processing luma and chroma signals from lines of a video signal. The invention includes an adaptive comb filtering algorithm that determines whether to average lines of video data based on the signal content. If two lines are dissimilar, a simple notch/bandpass system is used. The invention provides improved adaptive comb filtering performance at vertical transitions between high-luminance-detail areas and between other areas such as solid colors or flat gray or white fields by dynamically determining whether to average the chrominance information of the current video line with the chrominance information of the previous line, next line, both of such lines, or neither of such lines.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: April 25, 2000
    Assignee: Rockwell Semiconductor Systems, Inc.
    Inventors: Matthew J. DiMeo, Benjamin E. Felts, III, John E. Welch