Patents by Inventor Hyunwoo Nho

Hyunwoo Nho 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: 20170103703
    Abstract: An electronic device includes one or more unit pixels and threshold voltage (Vth) sensing circuitry. The threshold voltage sensing circuitry senses Vth of the one or more unit pixels, by: sampling a charge of a capacitor of the one or more unit pixels, transitioning from the sampling, and reading out the threshold voltage based upon a change in the charge of the capacitor, such that an operation of the one or more unit pixels may be modified based upon the threshold voltage.
    Type: Application
    Filed: September 22, 2016
    Publication date: April 13, 2017
    Inventors: Yafei Bi, Xiaofeng Wang, Haifeng Li, Mohammad B. Vahid Far, Hopil Bae, Hung Shen Lin, Hyunwoo Nho, Wei H. Yao
  • Publication number: 20170103702
    Abstract: An electronic device includes a display panel with pixels arranged in at least one row and at least one column. The electronic device also includes a sensing channel coupled to the at least one column. The sensing channel indirectly calculates a threshold voltage of the plurality of pixels based on an application of a first current level and a second current level to a data line of a first column of the at least one column of the pixels.
    Type: Application
    Filed: September 22, 2016
    Publication date: April 13, 2017
    Inventors: Yafei Bi, Xiaofeng Wang, Haifeng Li, Mohammad B. Vahid Far, Hopil Bae, Hung Shen Lin, Hyunwoo Nho, Wei H. Yao
  • Publication number: 20170103688
    Abstract: An electronic device includes one or more unit pixels with a first node, a second node, and a third node. The device includes light-emitting-diode (LED) voltage (Vled) sensing circuitry, that senses Vled of the one or more unit pixels, by: sampling a charge of a capacitor of the one or more unit pixels, transitioning from the sampling, and reading out the Vled based upon a change in the charge of the capacitor, such that an operation of the unit pixel may be modified based upon the Vled.
    Type: Application
    Filed: September 22, 2016
    Publication date: April 13, 2017
    Inventors: Yafei Bi, Xiaofeng Wang, Haifeng Li, Mohammad B. Vahid Far, Hopil Bae, Hung Shen Lin, Hyunwoo Nho, Wei H. Yao
  • Publication number: 20170092192
    Abstract: An electronic device includes a display and a controller. The controller is configured to receive one or more operational characteristics of the display. The controller is also configured to calculate a blank time voltage level for a data line of the display based on the one or more operational characteristics, wherein the blank time voltage level corresponds to a voltage transmitted along the data line of the display immediately subsequent to image data being transmitted along the data line.
    Type: Application
    Filed: February 1, 2016
    Publication date: March 30, 2017
    Inventors: Hung Sheng Lin, Mohammad Ali Jangda, Chin-Wei Lin, Hyunwoo Nho, Vasudha Gupta
  • Publication number: 20170084243
    Abstract: Methods and devices useful in discharging an aberrant charge on the VCOM of an electronic display and harvesting energy from the VCOM of the electronic display are provided. By way of example, a method may include supplying an activation signal to an active switching device of an electronic display. The active switching device is configured to discharge an aberrant charge on a common electrode of the electronic display. The method further includes discharging the aberrant charge by way of the active switching device. Discharging the aberrant charge comprises preventing a possible occurrence of image artifacts from becoming apparent on the electronic display.
    Type: Application
    Filed: January 26, 2016
    Publication date: March 23, 2017
    Inventors: Kasra M. Ohmid Zohoor, Hyunwoo Nho, Keitaro Yamashita, Majid Gharghi, Sarath Chandrasekhar Venkatesh Kumar, Ting-Kuo Chang, Abbas Jamshidi Roudbari
  • Publication number: 20170032742
    Abstract: In order to reduce non-uniform luminance and/or chrominance, a display panel can determine, on a pixel-by-pixel basis in at least a row of pixels, a correction for voltage drops in the display panel. The voltage drop can be estimated based on a state of pixels in the display panel corresponding to at least a portion of a current frame of image data and at least a portion of a previous frame of image data. Moreover, based on the correction, the display plane can modify on the pixel-by-pixel basis in at least the row: a supply voltage applied to the display panel; a digital representation of the image data in the current frame that correspond to the pixels; and pixel drive signals corresponding to the image data in the current frame. Furthermore, the correction may be based on a predefined calibration constant and/or may be dynamically calculated.
    Type: Application
    Filed: September 12, 2016
    Publication date: February 2, 2017
    Inventors: Johan L. PIPER, James C. AAMOLD, Shengkui GAO, Hung Sheng LIN, Hyunwoo NHO
  • Publication number: 20170024043
    Abstract: Systems and methods for improving display image quality on electronic displays are provided. One embodiment of an electronic display includes display pixels that share a common electrode. Each of the display pixels includes a first conductive path electrically coupled between a pixel electrode and a data line, in which the first conductive path only enables the data line to charge the pixel electrode; and a second conductive path electrically coupled between the pixel electrode and the data line in parallel with the first conductive path, in which the second conductive path enables the data line to discharge the pixel electrode such that discharge rate of the pixel electrode is approximately equal to charge rate of the pixel electrode. Additionally, the embodiment includes a touch pixel that detects occurrence and position of a touch on a screen of the electronic display using the first common electrode.
    Type: Application
    Filed: July 24, 2015
    Publication date: January 26, 2017
    Inventors: Kasra Omid-Zohoor, Jie Won Ryu, Jiayi Jin, Hyunwoo Nho
  • Patent number: 9553578
    Abstract: Systems, methods, and devices to control a transistor to maintain one or more substantially constant characteristics while activated or deactivated are provided. One such system includes a transistor that receives an activation signal on a gate terminal to become activated during a first period and receives a deactivation signal on the gate terminal to become deactivated during a second period. The transistor receives an input signal on an input terminal during the first period and the second period. The input signal varies during the first period and during the second period. The transistor may have improved reliability (e.g., substantially constant on resistance RON) because a first difference between the input signal and the activation signal substantially does not vary during the first period and a second difference between the input signal and the deactivation signal substantially does not vary during the second period.
    Type: Grant
    Filed: September 30, 2014
    Date of Patent: January 24, 2017
    Assignee: APPLE INC.
    Inventors: Ahmad Al-Dahle, Hyunwoo Nho, Marduke Yousefpor, Weijun Yao, Yingxuan Li
  • Patent number: 9524676
    Abstract: A display may receive image data to be displayed for a user of an electronic device. Display driver circuitry in the display may analyze the data to detect static data. The image data may contain static frames of data or static portions of a frame of data. In response to detection of static data, the display driver circuitry can take actions to avoid display damage due to burn-in effects. The display driver circuitry may reduce a peak luminance value associated with a peak luminance control algorithm, may reduce display brightness, may map image data to reduced brightness levels, or may take other actions to ensure that display pixels in the display are not damaged. Temperature information may be used in determining how to classify information as static data and in determining how significantly to reduce display pixel drive currents in response to the detection of static image data.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: December 20, 2016
    Assignee: Apple Inc.
    Inventors: Yafei Bi, Wei H. Yao, Ahmad Al-Dahle, Jean-Pierre S. Guillou, Hyunwoo Nho, Koorosh Aflatooni
  • Publication number: 20160247456
    Abstract: This application sets forth a circuit configuration for a light emitting diode (LED) or organic light emitting diode (OLED) display. The circuit configuration allows for the pulse-width modulation (PWM) of each emission signal sent to each line of the display. The PWM of each emission signal is accomplished using a gate-in-panel (GIP) controller of the display. The GIP controller uses an arrangement of shift register outputs and a programmable clock input to control an output of an inverter that provides the emission signal. The programmable clock input can be programmed according to a desired timing or duty cycle for the emission signal. In this way, by limiting the duty cycle of the emission signal, dimming and other display features can be exhibited by the LED or OLED display.
    Type: Application
    Filed: January 5, 2016
    Publication date: August 25, 2016
    Inventors: Hung Sheng Lin, Chin-Wei Lin, Tsung-Ting Tsai, Sang Y. Youn, Hyunwoo Nho
  • Publication number: 20160196802
    Abstract: An electronic device may have a variable refresh rate display. Static content may be displayed on the display at a lower refresh rate than moving content to conserve power. The display may include an array of pixels. Display driver circuitry in the display may load image data into rows of the pixels. The display driver circuitry may have digital-to-analog converter circuitry that supplies data signals to the array. The display driver circuitry may respond to a variable refresh rate control signal that is asserted and deasserted depending on whether static or moving image content is to be displayed. The display driver circuitry may use the digital-to-analog converter circuitry to apply a time-varying scaling factor to the image data. The magnitude of the scaling factor may be adjusted during transitions between refresh rates to help suppress luminance variations that might otherwise result in flickering on the display.
    Type: Application
    Filed: January 7, 2015
    Publication date: July 7, 2016
    Inventors: Hyunwoo Nho, Wei Chen, Wei Yao, Yafei Bi
  • Publication number: 20160094219
    Abstract: Systems, methods, and devices to control a transistor to maintain one or more substantially constant characteristics while activated or deactivated are provided. One such system includes a transistor that receives an activation signal on a gate terminal to become activated during a first period and receives a deactivation signal on the gate terminal to become deactivated during a second period. The transistor receives an input signal on an input terminal during the first period and the second period. The input signal varies during the first period and during the second period. The transistor may have improved reliability (e.g., substantially constant on resistance RON) because a first difference between the input signal and the activation signal substantially does not vary during the first period and a second difference between the input signal and the deactivation signal substantially does not vary during the second period.
    Type: Application
    Filed: September 30, 2014
    Publication date: March 31, 2016
    Inventors: Ahmad Al-Dahle, Hyunwoo Nho, Marduke Yousefpor, Weijun Yao, Yingxuan Li
  • Publication number: 20160071452
    Abstract: Devices and methods for reducing or eliminating image artifacts are provided. By way of example, a method of preventing an occurrence of an image artifact on a display panel may include generating a first gate signal to be supplied to a first gate of a first transistor, generating a second gate signal to be supplied to a second gate of a second transistor, and adjusting a falling edge rate of the first gate signal or a rising edge rate of the second gate signal to reduce a voltage drop associated with row pixels of the display panel. Adjusting the falling edge rate of the first gate signal or the rising edge rate of the second gate signal include decreasing the falling edge rate of the first gate signal or the rising edge rate of the second gate signal during a period of time in which the first gate signal falls.
    Type: Application
    Filed: July 8, 2015
    Publication date: March 10, 2016
    Inventors: Hyunwoo Nho, Hopil Bae, Wei H. Yao
  • Publication number: 20160063659
    Abstract: An electronic device may be provided with a housing such as a metal housing in which a display is mounted. Control circuitry in the electronic device such as a system-on-chip integrated circuit may produce image data. A display driver integrated circuit may receive the image data from the system-on-chip integrated circuit and may display the image data on the display. In the absence of electrostatic discharge, the display driver integrated circuit may operate normally and may generate a heartbeat signal. When disrupted due to electrostatic discharge, the display driver circuitry may cease production of the heartbeat signal. The system-on-chip integrated circuit can implement a watchdog timer. If the watchdog timer times out because the heartbeat signal is not received within a timeout period, the system-on-chip integrated circuit may reset the display.
    Type: Application
    Filed: August 31, 2015
    Publication date: March 3, 2016
    Inventors: Mohammad Ali Jangda, Sang Y. Youn, Wei H. Yao, Hyunwoo Nho, Arthur L. Spence, Viswa B. Pilla, Axel B. Schumacher, Ramachandran Chundru
  • Publication number: 20150332638
    Abstract: Devices and methods for reducing or eliminating image artifacts are provided. By way of example, a display panel includes a pixels including pixel electrodes configured to receive an image data signal, and common electrodes (VCOMs) configured to receive a common voltage signal. The display panel includes a source driver, which includes a first digital to analog converter (DAC) configured to generate a gamma voltage signal to provide a first adjustment to the image data signal, and a second DAC configured to generate an error correction voltage signal to provide a second adjustment to the image data signal. The second adjustment is configured to adjust the image data signal to compensate for an operational characteristic difference between row pixels and column pixels of the display panel. The source driver includes an output buffer to supply the image data signal to the pixel electrodes.
    Type: Application
    Filed: May 13, 2014
    Publication date: November 19, 2015
    Applicant: APPLE INC.
    Inventors: Yingxuan Li, Weijun Yao, Wei H. Yao, Kingsuk Brahma, Hyunwoo Nho
  • Patent number: 9137848
    Abstract: A mobile terminal and controlling method thereof are disclosed, by which an operable time of the mobile terminal can be increased in a manner of raising CPU power efficiency of the mobile terminal. The present invention includes a plurality of cores, a multicore adjuster configured to obtain a frequency of an active core of the plurality of cores, determine whether the obtained frequency exceeds a first threshold value for N consecutive times, wherein N is a positive integer, and activate at least one inactive core of the plurality of cores when the obtained frequency exceeds the first threshold value for N consecutive times, and a frequency adjuster configured to determine a workload of the active core, and adjust the obtained frequency of the active core according to the determined workload.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: September 15, 2015
    Assignee: LG ELECTRONICS INC.
    Inventor: Hyunwoo Nho
  • Publication number: 20140375704
    Abstract: A display may receive image data to be displayed for a user of an electronic device. Display driver circuitry in the display may analyze the data to detect static data. The image data may contain static frames of data or static portions of a frame of data. In response to detection of static data, the display driver circuitry can take actions to avoid display damage due to burn-in effects. The display driver circuitry may reduce a peak luminance value associated with a peak luminance control algorithm, may reduce display brightness, may map image data to reduced brightness levels, or may take other actions to ensure that display pixels in the display are not damaged. Temperature information may be used in determining how to classify information as static data and in determining how significantly to reduce display pixel drive currents in response to the detection of static image data.
    Type: Application
    Filed: April 28, 2014
    Publication date: December 25, 2014
    Applicant: Apple Inc.
    Inventors: Yafei Bi, Wei H. Yao, Ahmad Al-Dahle, Jean-Pierre S. Guillou, Hyunwoo Nho, Koorosh Aflatooni
  • Patent number: 8451670
    Abstract: Adaptive and dynamic stability enhancement for memories is described. In one example, the enhancement includes a plurality of sensors each located near a plurality of memory cells to provide a sensor voltage, a controller to receive the sensor voltage and provide a control signal based thereon, and a read/write assist circuit coupled to the controller to adjust a parameter applied to reading from and writing to a memory cell of the plurality of memory cells in response to the control signal.
    Type: Grant
    Filed: September 23, 2010
    Date of Patent: May 28, 2013
    Assignee: Intel Corporation
    Inventors: Pramod Kolar, Fatih Hamzaoglu, Yih Wang, Eric A Karl, Yong-Gee Ng, Uddalak Bhattacharya, Kevin X. Zhang, Hyunwoo Nho
  • Publication number: 20120075938
    Abstract: Adaptive and dynamic stability enhancement for memories is described. In one example, the enhancement includes a plurality of sensors each located near a plurality of memory cells to provide a sensor voltage, a controller to receive the sensor voltage and provide a control signal based thereon, and a read/write assist circuit coupled to the controller to adjust a parameter applied to reading from and writing to a memory cell of the plurality of memory cells in response to the control signal.
    Type: Application
    Filed: September 23, 2010
    Publication date: March 29, 2012
    Inventors: Pramod Kolar, Fatih Hamzaoglu, Yih Wang, Eric A. Karl, Yong-Gee NG, Uddalak Bhattacharya, Kevin X. Zhang, Hyunwoo Nho
  • Patent number: 7979832
    Abstract: Methods and systems for designing process variation tolerant memory are disclosed. A memory circuit is divided into functional blocks. A statistical distribution is calculated for each of the functional blocks. Then, the distributions of each block are combined to verify a credibility of the circuit. The credibility is verified if the circuit meets a predetermined yield.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: July 12, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Seong-Ook Jung, Sei Seung Yoon, Hyunwoo Nho