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).

  • Patent number: 9384698
    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: Grant
    Filed: April 24, 2013
    Date of Patent: July 5, 2016
    Assignee: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Publication number: 20160180755
    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: March 2, 2016
    Publication date: June 23, 2016
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Publication number: 20160140222
    Abstract: Item classification rules are created based on examples selected by a user, such as by selecting a subset of emails, and the rule is used across a larger set of items to obtain automatic classification of similar items according to the rule. Based on an analysis, a candidate classification rule is generated identifying text-based features shared among the items of the subset. The user can review the candidate rule as well as a resultant subset of items generated by the rule, and either accept the candidate rule or make an adjustment to the examples and then perform one or more iterations of the analysis to refine the rule. Adjustments can be made by removing items incorrectly included in a resultant subset and/or adding items incorrectly excluded from a resultant subset, and using the adjusted subset in a next iteration.
    Type: Application
    Filed: November 17, 2014
    Publication date: May 19, 2016
    Inventors: Ashish V. Thapliyal, Anne Marie Lock, Elizabeth Thapliyal, Ryan W. Kasper, Stefan Alexander von Imhof
  • Publication number: 20160142359
    Abstract: A method of operating a computerized device to indicate importance of messages to a user includes calculating importance scores for the messages based on importance features of the messages, the importance scores calculated as weighted sums of respective feature scores for the messages, and selecting messages for including in a subset of messages based on the importance scores. Message data and respective importance indicators for the subset of messages are displayed to the user, the importance indicators drawn from a set of distinct importance indicators corresponding to the set of importance features. An importance indicator is displayed for a given importance feature of a message when a feature score for the importance feature is above a threshold.
    Type: Application
    Filed: November 17, 2014
    Publication date: May 19, 2016
    Inventors: Anne Marie Lock, Elizabeth Thapliyal, Ryan W. Kasper, Ashish V. Thapliyal, Nikolay Avrionov, Ankit Mandhani, Yogeshwar Narayana Shenoy, Stefan Alexander von Imhof
  • Publication number: 20160104411
    Abstract: A method and system for programming, calibrating and driving a light emitting device display, and for operating a display at a constant luminance even as some of the pixels in the display are degraded over time. The system may include extracting a time dependent parameter of a pixel for calibration. 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: August 3, 2015
    Publication date: April 14, 2016
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander, Peyman Servati, Richard I-Heng Huang, Corbin Church
  • Patent number: 9311859
    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: Grant
    Filed: May 9, 2013
    Date of Patent: April 12, 2016
    Assignee: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Publication number: 20160005350
    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: July 13, 2015
    Publication date: January 7, 2016
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Abbas Hormati, Tong Liu, Stefan Alexander, Arokia Nathan
  • Publication number: 20150378164
    Abstract: Systems, devices, and methods for transparent displays that are well-suited for use in wearable heads-up displays are described. Such transparent displays include a register of light-emitting diodes that sequentially generates pixels or other discrete portions of an image. Respective sets of light signals corresponding to the respective portions (e.g., rows) of the image are sequentially directed into the user's field of view by a combination of a dynamic reflector and a set of static light-redirection elements. The dynamic reflector is an elongated reflective strip (including, for example, one or more MEMS-based digital micromirror(s)) mounted outside of the field of view of the user and the set of static light-redirection elements are substantially transparent and mounted directly in a field of view of the user. Successive portions of the image are generated in rapid succession until the entire image is displayed to the user.
    Type: Application
    Filed: June 24, 2015
    Publication date: December 31, 2015
    Inventors: Matthew Bailey, Stefan Alexander
  • Publication number: 20150378162
    Abstract: Systems, devices, and methods for transparent displays that are well-suited for use in wearable heads-up displays are described. Such transparent displays include one or more scanning projector(s) that is/are mounted on or proximate the lens portion(s) thereof, directly in the field of view of the user. Each scanning projector includes a respective light source that sequentially generates pixels or other discrete portions of an image and a respective dynamic optical beam-steerer that controllably steers the modulated light directly towards select regions of the eye of the user. Successive portions of the image are generated in rapid succession until the entire image is displayed to the user by projection directly onto the eye of the user from one or more point(s) within the user's field of view.
    Type: Application
    Filed: June 24, 2015
    Publication date: December 31, 2015
    Inventors: Matthew Bailey, Stefan Alexander
  • Publication number: 20150378161
    Abstract: Systems, devices, and methods for transparent displays that are well-suited for use in wearable heads-up displays are described. Such transparent displays include a light source that sequentially generates pixels or other discrete portions of an image. Respective modulated light signals corresponding to the respective pixels/portions are sequentially directed towards at least one dynamic reflector positioned on a lens of the transparent display within the user's field of view. The dynamic reflector (such as a MEMS-based digital micromirror) scans the modulated light signals directly over the user's eye and into the user's field of view. Successive portions of the image are generated in rapid succession until the entire image is displayed to the user.
    Type: Application
    Filed: June 24, 2015
    Publication date: December 31, 2015
    Inventors: Matthew Bailey, Stefan Alexander
  • Publication number: 20150339977
    Abstract: A method and system for programming, calibrating and driving a light emitting device display, and for operating a display at a constant luminance even as some of the pixels in the display are degraded over time. The system may include extracting a time dependent parameter of a pixel for calibration. 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: June 12, 2015
    Publication date: November 26, 2015
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander, Peyman Servati, Richard I-Heng Huang, Corbin Church
  • Publication number: 20150325202
    Abstract: Systems, devices, and methods for wearable computer systems are described. A wearable heads-up display (“WHUD”) is implemented as a peripheral to a wearable electronic band worn on a limb of the user. The majority (or all) of the application storage and processing is performed on the band instead of on the WHUD, and therefore the WHUD does not include all of the hardware infrastructure necessary for application storage and processing. This significantly reduces the bulk of the WHUD and enables more aesthetically pleasing WHUD designs. Graphics processing is also performed on the band instead of on the WHUD. In some implementations, rasterized display data is wirelessly transmitted from the band to the WHUD using an ultra-wideband wireless communication scheme. Gesture-based control of content displayed by the WHUD is enabled by sensors on-board the band itself or by a third wearable component in communication with the band.
    Type: Application
    Filed: May 5, 2015
    Publication date: November 12, 2015
    Inventors: Stephen Lake, Stefan Alexander, Thomas Mahon
  • Patent number: 9117400
    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: Grant
    Filed: June 16, 2010
    Date of Patent: August 25, 2015
    Assignee: Ignis Innovation Inc.
    Inventors: G. Reza Chaji, Joseph Marcel Dionne, Abbas Hormati, Tong Liu, Stefan Alexander, Arokia Nathan
  • Patent number: 9111485
    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: Grant
    Filed: March 16, 2013
    Date of Patent: August 18, 2015
    Assignee: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Abbas Hormati, Tong Liu, Stefan Alexander, Arokia Nathan
  • Patent number: 9040922
    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: Grant
    Filed: June 4, 2010
    Date of Patent: May 26, 2015
    Assignee: KONINKLIJKE PHILIPS N.V.
    Inventors: Jaime Gomez Rivas, Vincenzo Giannini, Audrey Anne-Marie Berrier, Stefan Alexander Maier, Marion Matters-Kammerer, Lorenzo Tripodi
  • Patent number: 8934202
    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: Grant
    Filed: December 15, 2011
    Date of Patent: January 13, 2015
    Assignee: Seagate Technology LLC
    Inventors: Narayanan Ramakrishnan, Stefan Alexander Weissner
  • Publication number: 20150002378
    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: September 18, 2014
    Publication date: January 1, 2015
    Inventors: Arokia Nathan, Gholamreza Chaji, Stefan Alexander, Peyman Servati, Richard I-Heng Huang, Corbin Church
  • Publication number: 20140375701
    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: September 5, 2014
    Publication date: December 25, 2014
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Patent number: 8914246
    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: Grant
    Filed: November 30, 2010
    Date of Patent: December 16, 2014
    Assignee: Ignis Innovation Inc.
    Inventors: Gholamreza Chaji, Joseph Marcel Dionne, Yaser Azizi, Javid Jaffari, Abbas Hormati, Tong Liu, Stefan Alexander
  • Patent number: RE45291
    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: November 26, 2013
    Date of Patent: December 16, 2014
    Assignee: Ignis Innovation Inc.
    Inventors: Arokia Nathan, Richard I-Heng Huang, Stefan Alexander