Patents by Inventor Shankar Krishnan

Shankar Krishnan 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: 20140262194
    Abstract: A heat sink comprising a base, fins attached to the base and a flow diverter in contact with the base or at least one of the fins. The flow diverter has a rectangular cross-sectional profile in a plane that is coplanar with and elevated above a plane of the base and spanning the entire separation distance, and, a segment of the flow diverter is angled towards the base to direct the fluid flow towards the base.
    Type: Application
    Filed: March 27, 2014
    Publication date: September 18, 2014
    Applicant: Alcatel-Lucent USA Inc.
    Inventors: Domhnaill Hernon, Marc Hodes, Alan Lyons, Alan O'Loughlin, Shankar Krishnan
  • Patent number: 8797534
    Abstract: An apparatus to calibrate a polarizer in a polarized optical system at any angle of incidence. The apparatus decouples the polarization effect of the system from the polarization effect of the sample. The apparatus includes a substrate with a polarizer disposed on the surface. An indicator on the substrate indicates the polarization orientation of the polarizer, which is in a predetermined orientation with respect to the substrate.
    Type: Grant
    Filed: September 24, 2013
    Date of Patent: August 5, 2014
    Assignee: KLA-Tencor Corporation
    Inventors: Johannes D. de Veer, Leonid Poslavsky, G. Vera Zhuang, Shankar Krishnan
  • Patent number: 8737735
    Abstract: A method includes generating a first principle bilateral filtered image component from a source image. The first principle bilateral filtered image component corresponds to a second pixel value of a set, the second pixel value greater than or equal to a first pixel value. The method includes selectively updating a result pixel of a result image based on the first principle bilateral filtered image component and deallocating the first principle bilateral filtered image component. After deallocating the first principle bilateral filtered image component, a second principle bilateral filtered image component is generated from the source image. The second principle bilateral filtered image component corresponds to a third pixel value. The third pixel value is greater than the second pixel value. The third pixel value is less than or equal to a fourth pixel value. The result pixel is selectively updated based on the second principle bilateral filtered image component.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: May 27, 2014
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Chao Tian, Shankar Krishnan
  • Publication number: 20140043608
    Abstract: An apparatus to calibrate a polarizer in a polarized optical system at any angle of incidence. The apparatus decouples the polarization effect of the system from the polarization effect of the sample. The apparatus includes a substrate with a polarizer disposed on the surface. An indicator on the substrate indicates the polarization orientation of the polarizer, which is in a predetermined orientation with respect to the substrate.
    Type: Application
    Filed: September 24, 2013
    Publication date: February 13, 2014
    Applicant: KLA-Tencor Corporation
    Inventors: Johannes D. de Veer, Leonid Poslavsky, G. Vera Zhuang, Shankar Krishnan
  • Publication number: 20130342629
    Abstract: A method that incorporates teachings of the subject disclosure may include, for example, utilizing a system including at least one processor for determining a video modification plan for a received video stream of a video call session according to the at least one party associated with the video call session, modifying, by the system, a plurality of background images of the received video stream according to the video modification plan to generate a plurality of modified background images, and generating, by the system, a modified video stream according to the plurality of modified background images. Other embodiments are disclosed.
    Type: Application
    Filed: June 20, 2012
    Publication date: December 26, 2013
    Applicant: AT&T Intellectual Property I, LP
    Inventors: Stephen C. North, John F. Murray, Christopher W. Rice, Shankar Krishnan
  • Publication number: 20130336585
    Abstract: A method includes generating a first principle bilateral filtered image component from a source image. The first principle bilateral filtered image component corresponds to a second pixel value of a set, the second pixel value greater than or equal to a first pixel value. The method includes selectively updating a result pixel of a result image based on the first principle bilateral filtered image component and deallocating the first principle bilateral filtered image component. After deallocating the first principle bilateral filtered image component, a second principle bilateral filtered image component is generated from the source image. The second principle bilateral filtered image component corresponds to a third pixel value. The third pixel value is greater than the second pixel value. The third pixel value is less than or equal to a fourth pixel value. The result pixel is selectively updated based on the second principle bilateral filtered image component.
    Type: Application
    Filed: June 15, 2012
    Publication date: December 19, 2013
    Applicant: AT&T Intellectual Property I, L.P.
    Inventors: Chao Tian, Shankar Krishnan
  • Publication number: 20130321810
    Abstract: Methods and systems for small angle CD metrology with a small spot size are introduced to increase measurement sensitivity while maintaining adequate throughput necessary for modern semiconductor manufacture. A small angle CD metrology system includes a small angle spectroscopic ellipsometry (SE) subsystem combined with a small angle spectroscopic reflectometry system, both operated at small angles of incidence. The small angle SE subsystem is configured to operate in a complete Mueller Matrix mode to further improve measurement sensitivity. The small angle CD metrology system includes an objective having all reflective surfaces in the light path. In some embodiments, the all-reflective objective is a Schwartzschild objective having an axicon mirror element to further reduce measurement spot size. In some embodiments, the small angle CD metrology system includes a dynamic aperture subsystem to isolate specific ranges of angles of incidence and azimuth for improved measurement sensitivity.
    Type: Application
    Filed: May 28, 2013
    Publication date: December 5, 2013
    Inventors: Haiming Wang, Shankar Krishnan
  • Publication number: 20130299148
    Abstract: A heat sink includes a base and a heat exchange element coupled to the base. The heat exchange element includes a foam structure that is coupled to the base.
    Type: Application
    Filed: July 12, 2013
    Publication date: November 14, 2013
    Inventors: Domhnaill Hernon, Alan Lyons, Shankar Krishnan, Marc Hodes, Alan O'Loughlin
  • Patent number: 8570514
    Abstract: A method to calibrate a polarizer in polarized optical system at any angle of incidence, by decoupling the calibration from a polarization effect of the system, by providing a calibration apparatus that includes a substrate having a polarizer disposed on a surface thereof, with an indicator on the substrate for indicating a polarization orientation of the polarizer, loading the calibration apparatus in the polarized optical system with the indicator in a desired position, determining an initial angle between the polarization orientation and a reference of the polarized optical system, acquiring spectra using the polarized optical system at a plurality of known angles between the polarization orientation and the reference of the polarized optical system, using the spectra to plot a curve indicating an angle of the polarizer in the polarized optical system, and when the angle of the polarizer is outside of a desired range, adjusting the angle of the polarizer, and repeating the steps of acquiring the spectra, a
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: October 29, 2013
    Assignee: KLA-Tencor Corporation
    Inventors: Johannes D. de Veer, Leonid Poslavsky, Guorong V. Zhuang, Shankar Krishnan
  • Patent number: 8571309
    Abstract: A method includes receiving an image having a first resolution and generating an upsampled image having a second resolution based on the image. A multi-dimensional data structure corresponding to a multi-dimensional image space is generated from the upsampled image. Each node of the data structure is determined based on a weighted sum of values of one or more pixels in the upsampled image. Each of the one or more pixels corresponds to a pixel in the received image and is located within a region of the image space having a vertex defined by the node. A filter modifies the values of the nodes and a second upsampled image is generated based on the modified values. Each pixel of the second upsampled image not corresponding to a pixel in the received image is determined based on a weighted sum of the modified values of one or more nodes.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: October 29, 2013
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Shankar Krishnan, James Klosowski
  • Patent number: 8538138
    Abstract: A method for registering multiple 3D point sets by determining optimal relative positions and orientations of the 3D point sets. Initial values are determined for the rotation matrices corresponding to the relative orientations of reference frames of the 3D point sets. A registration error cost function is optimized on a product manifold of all of the rotation matrices to determine optimal values of the rotation matrices. The optimal values of the rotation matrices are used to determine optimal values for translation vectors corresponding to the relative positions of the reference frames of the 3D point sets. The 3D point sets are registered on a common reference frame using the optimal rotation matrices and the optimal translation vectors.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: September 17, 2013
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Shankar Krishnan, Pei Yean Lee, John Barrett Moore, Suresh Venkatasubramanian
  • Patent number: 8456639
    Abstract: A spectroscopic instrument for conducting multi-wavelength, multi-azimuth, multi-angle-of-incidence readings on a substrate, the instrument having a broadband light source for producing an illumination beam, an objective for directing the illumination onto the substrate at multiple azimuth angles and multiple angels-of-incidence simultaneously, thereby producing a reflection beam, an aperture plate having an illumination aperture and a plurality of collection apertures formed therein for selectively passing portions of the reflection beam having desired discreet combinations of azimuth angle and angle-of-incident, a detector for receiving the discreet combinations of azimuth angle and angle-of-incident and producing readings, and a processor for interpreting the readings.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: June 4, 2013
    Assignee: KLA-Tencor Corporation
    Inventors: Shankar Krishnan, Haiming Wang
  • Patent number: 8446584
    Abstract: A Mueller ellipsometer of the type having a first rotating element on an incident beam side of a sample and a second rotating element on a reflected beam side of the sample and a detector having an integration time, having a controller for selectively and separately adjusting (1) a first angular frequency of the first rotating element and (2) a second angular frequency of the second rotating element.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: May 21, 2013
    Assignee: KLA-Tencor Corporation
    Inventors: Shankar Krishnan, Haiming Wang
  • Publication number: 20130121568
    Abstract: A method includes receiving an image having a first resolution and generating an upsampled image having a second resolution based on the image. A multi-dimensional data structure corresponding to a multi-dimensional image space is generated from the upsampled image. Each node of the data structure is determined based on a weighted sum of values of one or more pixels in the upsampled image. Each of the one or more pixels corresponds to a pixel in the received image and is located within a region of the image space having a vertex defined by the node. A filter modifies the values of the nodes and a second upsampled image is generated based on the modified values of the nodes. Each pixel of the second upsampled image not corresponding to a pixel in the received image is determined based on a weighted sum of the modified values of one or more nodes.
    Type: Application
    Filed: November 15, 2011
    Publication date: May 16, 2013
    Applicant: AT&T Intellectual Property I, L.P.
    Inventors: Shankar Krishnan, James Klosowski
  • Publication number: 20130033704
    Abstract: The present invention may include loading a diagnostic sample onto a sample stage, focusing light from an illumination source disposed on a multi-axis stage onto the diagnostic sample, collecting a portion of light reflected from a surface of the diagnostic sample utilizing a detector, wherein the illumination source and the detector are optically direct-coupled via an optical system, acquiring a set of diagnostic parameters indicative of illumination source position drift from the diagnostic sample, determining a magnitude of the illumination source position drift by comparing the acquired set of diagnostic parameters to an initial set of parameters obtained from the diagnostic sample at a previously measured alignment condition, determining a direction of the illumination source position drift; and providing illumination source position adjustment parameters configured to correct the determined magnitude and direction of the illumination source position drift to the multi-axis actuation control system of th
    Type: Application
    Filed: October 31, 2011
    Publication date: February 7, 2013
    Applicant: KLA-TENCOR CORPORATION
    Inventors: Guorong V. Zhuang, Shankar Krishnan, Johannes D. de Veer, Klaus Flock, David Y. Wang, Lawrence D. Rotter
  • Publication number: 20130025192
    Abstract: A solar thermochemical processing system is disclosed. The system includes a first unit operation for receiving concentrated solar energy. Heat from the solar energy is used to drive the first unit operation. The first unit operation also receives a first set of reactants and produces a first set of products. A second unit operation receives the first set of products from the first unit operation and produces a second set of products. A third unit operation receives heat from the second unit operation to produce a portion of the first set of reactants.
    Type: Application
    Filed: July 26, 2012
    Publication date: January 31, 2013
    Applicant: BATTELLE MEMORIAL INSTITUTE
    Inventors: Robert S. Wegeng, Paul H. Humble, Shankar Krishnan, Steven D. Leith, Daniel R. Palo
  • Publication number: 20130003068
    Abstract: A spectroscopic instrument for conducting multi-wavelength, multi-azimuth, multi-angle-of-incidence readings on a substrate, the instrument having a broadband light source for producing an illumination beam, an objective for directing the illumination onto the substrate at multiple azimuth angles and multiple angels-of-incidence simultaneously, thereby producing a reflection beam, an aperture plate having an illumination aperture and a plurality of collection apertures formed therein for selectively passing portions of the reflection beam having desired discreet combinations of azimuth angle and angle-of-incident, a detector for receiving the discreet combinations of azimuth angle and angle-of-incident and producing readings, and a processor for interpreting the readings.
    Type: Application
    Filed: July 1, 2011
    Publication date: January 3, 2013
    Applicant: KLA-TENCOR CORPORATION
    Inventors: Shankar Krishnan, Haiming Wang
  • Publication number: 20120320377
    Abstract: A method to calibrate a polarizer in polarized optical system at any angle of incidence, by decoupling the calibration from a polarization effect of the system, by providing a calibration apparatus that includes a substrate having a polarizer disposed on a surface thereof, with an indicator on the substrate for indicating a polarization orientation of the polarizer, loading the calibration apparatus in the polarized optical system with the indicator in a desired position, determining an initial angle between the polarization orientation and a reference of the polarized optical system, acquiring spectra using the polarized optical system at a plurality of known angles between the polarization orientation and the reference of the polarized optical system, using the spectra to plot a curve indicating an angle of the polarizer in the polarized optical system, and when the angle of the polarizer is outside of a desired range, adjusting the angle of the polarizer, and repeating the steps of acquiring the spectra, a
    Type: Application
    Filed: June 20, 2011
    Publication date: December 20, 2012
    Applicant: KLA-TENCOR CORPORATION
    Inventors: Johannes D. de Veer, Leonid Poslavsky, G. Vera Zhuang, Shankar Krishnan
  • Publication number: 20120287433
    Abstract: A Mueller ellipsometer of the type having a first rotating element on an incident beam side of a sample and a second rotating element on a reflected beam side of the sample and a detector having an integration time, having a controller for selectively and separately adjusting (1) a first angular frequency of the first rotating element and (2) a second angular frequency of the second rotating element.
    Type: Application
    Filed: May 13, 2011
    Publication date: November 15, 2012
    Applicant: KLA-TENCOR CORPORATION
    Inventors: Shankar Krishnan, Haiming Wang
  • Patent number: 8040511
    Abstract: Methods and apparatus for measuring an optical azimuth angle ?O of a substrate relative to a plane of detection in scatterometry tools are disclosed. A grating target on a stage of a scatterometry tool may be illuminated and positions of the resulting diffraction orders may be observed. The optical azimuth angle may be determined from the positions of the diffraction orders. Alternatively, polarization-dependent signals of radiation scattered from a line grating may be measured for equal and opposite polarization angles +A and ?A. A combination signal may be computed from the polarization-dependent signals obtained at +A and ?A and a property of the combination signal may be calculated for several mechanical Azimuth angles ?M. A relationship between the optical azimuth angle ?O and the mechanical azimuth angle ?M may be determined from a behavior of the property as a function of mechanical azimuth angle ?M.
    Type: Grant
    Filed: January 21, 2009
    Date of Patent: October 18, 2011
    Assignee: KLA-Tencor Corporation
    Inventors: Shankar Krishnan, Haixing Zhou, Haiming Wang, David Lidsky, Walter Dean Mieher