Patents by Inventor Stefan Alexander

Stefan Alexander 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: 20140361708
    Abstract: A light emitting device display, its pixel circuit and its driving technique is provided. The pixel includes a light emitting device and a plurality of transistors. A bias current and programming voltage data are provided to the pixel circuit in accordance with a driving scheme so that the current through the driving transistor to the light emitting device is adjusted.
    Type: Application
    Filed: August 22, 2014
    Publication date: December 11, 2014
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander
  • Publication number: 20140312330
    Abstract: A system for inspecting at least a portion of a display panel having thin film transistors (TFTs) and light emitting devicxes (OLEDs), during or immediately following fabrication, so that adjustments can be made to the fabrication procedures to avoid defects and non-uniformities. The system provides bonding pads connected to signal lines on at least portions of the display panel, and probe pads along selected edges of the display panel. The probe pads are coupled to the bonding pads through a plurality of multiplexers so that the number of probe pads is smaller than the number of bonding pads.
    Type: Application
    Filed: April 21, 2014
    Publication date: October 23, 2014
    Applicant: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Stefan Alexander
  • Publication number: 20140304556
    Abstract: A method, system and program product for performing automated tests on a system under test. A set of test blocks is provided, with each test block triggering at least one user activity on the system under test. The following is performed iteratively to execute multiple test blocks consecutively: defining a subset of executable test blocks; scoring the executable test blocks based on at least one scoring parameter; selecting a test block to be executed out of the subset of executable test blocks by randomly selecting a test block based on the scores, where the probability of selection of a test block depends on the score; executing the selected test block; updating the data of the status repository based on data of the system under test; and updating the data of the history log by adding data regarding the executed test block and the results of the test block execution.
    Type: Application
    Filed: April 9, 2014
    Publication date: October 9, 2014
    Applicant: International Business Machines Corporation
    Inventors: Stefan Alexander, Frank Lautenbach
  • Patent number: 8793647
    Abstract: Graphic objects generated by a software application executing in a computing environment are evaluated. The computing environment includes a graphical user interface for managing I/O functions, a data storage device for storing computer usable program code and data, and a data processing engine in communication with the graphical user interface and the data storage device The data processing engine receives and processes origin data from the data storage device to produce projected values for data points in the graphic image intended to be displayed. The data processing engine also creates and processes a snapshot of the displayed graphic object to produce actual values of data points in the displayed graphic object, compares the projected values to the actual values, and outputs an indication of the degree of similarity between the intended graphic object and the displayed graphic object.
    Type: Grant
    Filed: February 20, 2012
    Date of Patent: July 29, 2014
    Assignee: International Business Machines Corporation
    Inventors: Stefan Alexander, Rene Pietzsch, Sebastian Schaefer, Andreas Trinks, Henning Wilbert
  • Publication number: 20140111567
    Abstract: A display degradation compensation system and method for adjusting the operating conditions for pixels in an OLED display to compensate for non-uniformity or aging of the display. The system or method sets an initial value for at least one of peak luminance and an operating condition, calculates compensation values for the pixels in the display, determines the number of pixels having compensation values larger than a predetermined threshold compensation value, and if the determined number of pixels having compensation values larger than said predetermined threshold value is greater than a predetermined threshold number, adjusts the set value until said determined number of pixels is less than said predetermined threshold number.
    Type: Application
    Filed: December 20, 2013
    Publication date: April 24, 2014
    Applicant: Ignis Innovation Inc.
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander, Peyman Servati, Richard I-Heng Huang, Corbin Church
  • Publication number: 20140085359
    Abstract: A light emitting device display, its pixel circuit and its driving technique is provided. The pixel includes a light emitting device and a plurality of transistors. A bias current and programming voltage data are provided to the pixel circuit in accordance with a driving scheme so that the current through the driving transistor to the light emitting device is adjusted.
    Type: Application
    Filed: December 2, 2013
    Publication date: March 27, 2014
    Applicant: Ignis Innovation Inc.
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander
  • Patent number: 8614652
    Abstract: A light emitting device display, its pixel circuit and its driving technique is provided. The pixel includes a light emitting device and a plurality of transistors. A bias current and programming voltage data are provided to the pixel circuit in accordance with a driving scheme so that the current through the driving transistor to the light emitting device is adjusted.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: December 24, 2013
    Assignee: Ignis Innovation Inc.
    Inventors: Arokia Nathan, G. Reza Chaji, Stefan Alexander
  • Publication number: 20130286055
    Abstract: A system and method for operating a display at a constant luminance even as some of the pixels in the display are degraded over time. Each pixel in the display is configured to emit light when a voltage is supplied to the pixel's driving circuit, which causes a current to flow through a light emitting element. Degraded pixels are compensated by supplying their respective driving circuits with greater voltages. The display data is scaled by a compression factor less than one to reserve some voltage levels for compensating degraded pixels. As pixels become more degraded, and require additional compensation, the compression factor is decreased to reserve additional voltage levels for use in compensation.
    Type: Application
    Filed: May 21, 2013
    Publication date: October 31, 2013
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander, Peyman Servati, Richard I-Heng Huang, Corbin Church
  • Publication number: 20130265338
    Abstract: A system for maintaining a substantially constant display white point over an extended period of operation of a color display formed by an array of multiple pixels in which each of the pixels includes multiple subpixels having different colors, and each of the subpixels includes a light emissive device. The display is generated by energizing the subpixels of successively selected pixels, and the color of each selected pixel is controlled by the relatives levels of energization of the subpixels in the selected pixel. The degradation behavior of the subpixels in each pixel is determined, and the relative levels of energization of the subpixels in each pixel are adjusted to adjust the brightness shares of the subpixels to compensate for the degradation behavior of the subpixels. The brightness shares are preferably adjusted to maintain a substantially constant display white point.
    Type: Application
    Filed: March 16, 2013
    Publication date: October 10, 2013
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Abbas Hormati, Tong Liu, Stefan Alexander, Arokia Nathan
  • Publication number: 20130257845
    Abstract: A method of voltage-programming a pixel circuit in a display panel to remove, before programming the pixel circuit, effects due to short-term effects such as caused by fast light transitions or effects due to previous pixel circuit measurements such as charge trapping. During a resetting cycle, the pixel circuit is programmed with a reset voltage value corresponding to a maximum or a minimum voltage value. Then, during a calibration cycle, the pixel circuit is programmed with a calibration voltage based on previously extracted data for the pixel circuit, a pixel current of the pixel circuit is measured, and the extracted data for the pixel circuit is updated based on the measured pixel current. Then, the pixel circuit is programmed with a video data that is calibrated with the updated extracted data. The pixel circuit is finally driven according to the programmed video data and emits a commensurate amount of light.
    Type: Application
    Filed: May 9, 2013
    Publication date: October 3, 2013
    Applicant: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Publication number: 20130235023
    Abstract: A voltage-programmed display system allows measurement of effects on pixels in a panel that includes both active pixels and reference pixels coupled to a supply line and a programming line. The reference pixels are controlled so that they are not subject to substantial changes due to aging and operating conditions over time. A readout circuit is coupled to the active pixels and the reference pixels for reading at least one of current, voltage or charge from the pixels when they are supplied with known input signals. The readout circuit is subject to changes due to aging and operating conditions over time, but the readout values from the reference pixels are used to adjust the readout values from the active pixels to compensate for the unwanted effects.
    Type: Application
    Filed: April 24, 2013
    Publication date: September 12, 2013
    Applicant: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Publication number: 20130152695
    Abstract: In certain embodiments, an apparatus includes a first piezoelectric (PZT) element poled in the same direction as a second PZT element. The first and second PZT elements are configured to be driven while simultaneously sensing motion. The apparatus further includes a circuit configured to add outputs of the first and second PZT elements, extract the sensed motion, and detect off-track motion from the extracted sensed motion.
    Type: Application
    Filed: December 15, 2011
    Publication date: June 20, 2013
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Narayanan Ramakrishnan, Stefan Alexander Weissner
  • Publication number: 20120224745
    Abstract: Graphic objects generated by a software application executing in a computing environment are evaluated. The computing environment includes a graphical user interface for managing I/O functions, a data storage device for storing computer usable program code and data, and a data processing engine in communication with the graphical user interface and the data storage device The data processing engine receives and processes origin data from the data storage device to produce projected values for data points in the graphic image intended to be displayed. The data processing engine also creates and processes a snapshot of the displayed graphic object to produce actual values of data points in the displayed graphic object, compares the projected values to the actual values, and outputs an indication of the degree of similarity between the intended graphic object and the displayed graphic object.
    Type: Application
    Filed: February 20, 2012
    Publication date: September 6, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stefan Alexander, René Pietzsch, Sebastian Schaefer, Andreas Trinks, Henning Wilbert
  • Patent number: 8232939
    Abstract: A system and method for driving an AMOLED display is provided. The AMOLED display includes a plurality of pixel circuits. A voltage-programming scheme, a current-programming scheme or a combination thereof is applied to drive the display. Threshold shift information, and/or voltage necessary to obtain hybrid driving circuit may be acquired. A data sampling may be implemented to acquire a current/voltage relationship. A feedback operation may be implemented to correct the brightness of the pixel.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: July 31, 2012
    Assignee: Ignis Innovation, Inc.
    Inventors: Arokia Nathan, Rick Huang, Stefan Alexander
  • Publication number: 20120139894
    Abstract: A system and method for driving an AMOLED display is provided. The AMOLED display includes a plurality of pixel circuits. A voltage-programming scheme, a current-programming scheme or a combination thereof is applied to drive the display. Threshold shift information, and/or voltage necessary to obtain hybrid driving circuit may be acquired. A data sampling may be implemented to acquire a current/voltage relationship. A feedback operation may be implemented to correct the brightness of the pixel.
    Type: Application
    Filed: February 14, 2012
    Publication date: June 7, 2012
    Applicant: Ignis Innovation, Inc.
    Inventors: Arokia Nathan, Rick Huang, Stefan Alexander
  • Publication number: 20120074323
    Abstract: A THz frequency range antenna is provided which comprises: a semiconductor film (3) having a surface adapted to exhibit surface plasmons in the THz frequency range. The surface of the semiconductor film (3) is structured with an antenna structure (4) arranged to support localized surface plasmon resonances in the THz frequency range.
    Type: Application
    Filed: June 4, 2010
    Publication date: March 29, 2012
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Jaime Gomez rivas, Vincenzo Giannini, Audrey Anne-Marie Berrier, Stefan Alexander Maier, Marion Matters-Kammerer, Lorenzo Tripodi
  • Patent number: 8141097
    Abstract: An execution management method includes providing an execution plan, balancing an execution load across a plurality of servers, automatically interpreting the execution plan, and re-driving a failed test to another of the plurality of servers if the test case fails on an originally selected available server. The execution plan includes a plurality of test cases and criteria corresponding to the test cases. More than one of the plurality of test cases may be run on each of the plurality of servers at a same time in parallel. Each of the plurality of servers is run independently.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: March 20, 2012
    Assignee: International Business Machines Corporation
    Inventors: Stefan Alexander, Jason F. Basler, Neeta Garimella, Clemens Kalbfuss, Dale Mark Mock, Frank Albert Mueller
  • Patent number: 8115707
    Abstract: A system and method for driving an AMOLED display is provided. The AMOLED display includes a plurality of pixel circuits. A voltage-programming scheme, a current-programming scheme or a combination thereof is applied to drive the display. Threshold shift information, and/or voltage necessary to obtain hybrid driving circuit may be acquired. A data sampling may be implemented to acquire a current/voltage relationship. A feedback operation may be implemented to correct the brightness of the pixel.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: February 14, 2012
    Assignee: Ignis Innovation Inc.
    Inventors: Arokia Nathan, Rick Huang, Stefan Alexander
  • Publication number: 20110199395
    Abstract: A system and method for operating a display at a constant luminance even as some of the pixels in the display are degraded over time. Each pixel in the display is configured to emit light when a voltage is supplied to the pixel's driving circuit, which causes a current to flow through a light emitting element. Degraded pixels are compensated by supplying their respective driving circuits with greater voltages. The display data is scaled by a compression factor less than one to reserve some voltage levels for compensating degraded pixels. As pixels become more degraded, and require additional compensation, the compression factor is decreased to reserve additional voltage levels for use in compensation.
    Type: Application
    Filed: November 15, 2010
    Publication date: August 18, 2011
    Applicant: Ignis Innovation Inc.
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander, Peyman Servati, Richard I-Heng Huang, Corbin Church
  • Publication number: 20110130981
    Abstract: Methods and systems to provide baseline measurements for aging compensation for a display device are disclosed. An example display system has a plurality of active pixels and a reference pixel. Common input signals are provided to the reference pixel and the plurality of active pixels. The outputs of the reference pixel is measured and compared to the output of the active pixels to determine aging effects. The display system may also be tested applying a first known reference current to a current comparator with a second variable reference current and the output of a device under test such as one of the pixels. The variable reference current is adjusted until the second current and the output of the device under test is equivalent of the first current. The resulting current of the device under test is stored in a look up table for a baseline for aging measurements during the display system operation.
    Type: Application
    Filed: November 30, 2010
    Publication date: June 2, 2011
    Applicant: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander