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).

  • Patent number: 10943541
    Abstract: Current-voltage shift determination circuitry of a processing core complex coupled to the electronic display determines total current-voltage shift values at a pixel. The current-voltage shift determination circuitry then determines temperature-based current-voltage shift values at the pixel. The current-voltage shift determination circuitry extracts the temperature-based current-voltage shift values from the total current-voltage shift values to determine age-based voltage degradation values. Display compensation circuitry of the processing core complex adjusts display of image data by the pixel based on the age-based voltage degradation values. In this manner, voltage degradation due to pixel aging may be determined separately from current-voltage shift due to temperature, and, as such, be more accurately compensated for, resulting in better display of image data.
    Type: Grant
    Filed: August 29, 2019
    Date of Patent: March 9, 2021
    Assignee: Apple Inc.
    Inventors: Junhua Tan, Hsin-Ying Chiu, Sun-Il Chang, Yunhui Hou, Jie Won Ryu, Hyunwoo Nho, Weichuan Yao, Shiping Shen, Injae Hwang, Hyunsoo Kim, Myungjoon Choi, Shengkui Gao, Chaohao Wang, Kingsuk Brahma, Jesse Aaron Richmond, Myung-Je Cho, Changki Min, Wei H. Yao
  • Patent number: 10936120
    Abstract: A self-capacitance touch screen. In some examples, the touch screen comprises a plurality of display pixels, a first display pixel of the plurality of display pixels including a first touch electrode of a plurality of touch electrodes, and a gate line coupled to the first display pixel, wherein the gate line is configured such that a voltage at the gate line substantially follows a voltage at the first touch electrode. In some examples, the gate line is coupled to a resistor, the resistor being configured to decouple the gate line from ground. In some examples, the gate line is coupled to an AC voltage source.
    Type: Grant
    Filed: May 22, 2014
    Date of Patent: March 2, 2021
    Assignee: Apple Inc.
    Inventors: Weijun Yao, Ahmad Al-Dahle, Hyunwoo Nho, Taif A. Syed, Wei Hsin Yao, Yingxuan Li
  • Publication number: 20210056930
    Abstract: An electronic device may include an electronic display having multiple display pixels. The display pixels may illuminate at a target luminance based at least in part on a first analog voltage signal. The electronic device may also include an electrical bus configured to generate multiple analog voltage signals including the first analog voltage signal, which is output on an output of the electrical bus. The electrical bus may include a digital to analog converter to generate at least some of the analog voltage signals and multiple output buffers to buffer the analog voltage signals. The outputs may be buffered by an output buffer of the output buffers.
    Type: Application
    Filed: July 14, 2020
    Publication date: February 25, 2021
    Inventors: Jaeyoung Kang, Jesse Aaron Richmond, Mahdi Farrokh Baroughi, Hopil Bae, John T. Wetherell, Kingsuk Brahma, Yuichi Okuda, Shingo Hatanaka, Baris Cagdaser, Myungjoon Choi, Jie Won Ryu, Hyunwoo Nho, Yafei Bi, Wei H. Yao, Henry C. Jen, Derek Keith Shaeffer
  • Publication number: 20210049962
    Abstract: An apparatus receives current image frame data and data relating to at least one previous image frame for an electronic display. One or more parameters related to hysteresis of transistors in the electronic display are sensed. A correlation device, such as a look-up table, receives the sensed parameter or parameters and the data relating to one or more image frames, and uses this information, at least in part, to output an appropriate compensation signal for the current image frame data. The compensated current image frame data may then be supplied to the electronic display to reduce or eliminate the effects of hysteresis on the displayed image.
    Type: Application
    Filed: November 3, 2020
    Publication date: February 18, 2021
    Inventors: Chaohao Wang, Chih-Wei Yeh, Chin-Wei Lin, Hung Sheng Lin, Hyunwoo Nho, Injae Hwang, Jie Won Ryu, Junhua Tan, Paolo Sacchetto, Rui Zhang, Shengkui Gao, Sun-Il Chang, Wei H. Yao, Howard H. Tang
  • Publication number: 20210012712
    Abstract: A display may include an array of organic light-emitting diode display pixels having transistors characterized by threshold voltages subject to transistor variations. Compensation circuitry may be used to sense a current from selected display pixels. A display pixel may include a drive transistor, a gate setting transistor for driving a reference voltage onto the gate terminal of the drive transistor, a data loading and current sensing transistor for connecting the drive transistor to a data/current-sensing line, a light-emitting diode, an emission control transistor coupled between the drive transistor and the diode, and an anode resetting transistor for selectively resetting the anode terminal of the diode. During in-frame current sensing operations, the emission control transistor may be turned off to decouple the drive transistor from the diode, thereby blocking off any residue current and lateral leakage current that may be present at the diode.
    Type: Application
    Filed: September 28, 2018
    Publication date: January 14, 2021
    Inventors: Chin-Wei Lin, Fan Gui, Hung Sheng Lin, Hyunwoo Nho, Jie Won Ryu, Junhua Tan, Kingsuk Brahma, Majid Gharghi, Mohammad Reza Esmaeili Rad, Shinya Ono, Yun Wang, Zino Lee
  • Patent number: 10878747
    Abstract: Methods and systems for compensating a display of an electronic device using internal sensing and external compensation. The external compensation uses a generated compensation map that then is used to compensate for variations that occur outside of display circuitry. The internal sensing compensation is used to compensate for internally sensed parameters (e.g., aging) of the display.
    Type: Grant
    Filed: July 9, 2019
    Date of Patent: December 29, 2020
    Assignee: Apple Inc.
    Inventors: Shengkui Gao, Chaohao Wang, Hung Sheng Lin, Hyunsoo Kim, Hyunwoo Nho, Injae Hwang, Jesse Aaron Richmond, Jie Won Ryu, Junhua Tan, Kingsuk Brahma, Myung-Je Cho, Myungjoon Choi, Shiping Shen, Sun-Il Chang, Wei H. Yao, Yi Qiao
  • Publication number: 20200388215
    Abstract: An electronic device includes an electronic display having an active area comprising a pixel. The electronic device also includes processing circuitry configured to receive image data and predict a change in threshold voltage associated with a transistor of the pixel based at least in part on the image data. Furthermore, the processing circuitry is configured to adjust the image data to generate adjusted image data based at least in part on the predicted change in threshold voltage.
    Type: Application
    Filed: May 7, 2020
    Publication date: December 10, 2020
    Inventors: Hei Kam, Junhua Tan, Wei H. Yao, Shihchang Chang, Derek K. Shaeffer, Chaohao Wang, Hyunwoo Nho, Yun Wang, Baris Cagdaser, Majid Gharghi, Yongjun Li, Aida Raquel Colon-Berrios, Mohammad Reza Esmaeili Rad, Hyunsoo Kim, Alex H. Pai, Hsin-Ying Chiu, Jiun-Jye Chang, Ching-Sang Chuang, Xin Lin
  • Publication number: 20200388225
    Abstract: Systems and methods are presently disclosed that compensate for temperature-based parasitic capacitance variation of a pixel of a display by causing a driver transistor of the pixel to enter an ohmic or linear region. A lookup table is generated based on temperatures at the pixel, diode voltages, and target diode currents or luminances at a diode of the pixel. A correction voltage is determined based on a target diode current or luminance, a temperature at the pixel, and the lookup table. A data voltage is applied corresponding to the target diode current or luminance and the correction voltage to the driver transistor.
    Type: Application
    Filed: June 9, 2020
    Publication date: December 10, 2020
    Inventors: Hyunsoo Kim, Injae Hwang, Jesun Kim, Jesse A. Richmond, Junhua Tan, Jie Won Ryu, Hyunwoo Nho, Kingsuk Brahma, Chaohao Wang, Shiping Shen, Myungjoon Choi, Myung-Je Cho, Rebecca Park, Sun-Il Chang
  • Publication number: 20200365082
    Abstract: A current-voltage (IV) relationship of a pixel having a diode is initially determined. A first voltage is determined that does not cause the diode to emit light, and a first current across the diode is sensed by applying the first voltage. A predetermined current is determined based on the first voltage and the IV relationship. A ratio is determined based on the first current, a target current, and the predetermined current. A ratio voltage is determined by applying the ratio to a predetermined target voltage. If the first current is less than the predetermined current, then the ratio voltage is applied to supply a target current to the diode. If the first current is greater than the predetermined current, then a second voltage is determined by averaging the first test voltage and the ratio voltage, and the second voltage is applied to supply the target current to the diode.
    Type: Application
    Filed: April 15, 2020
    Publication date: November 19, 2020
    Inventors: Injae Hwang, Jesun Kim, Hyunwoo Nho, Jie Won Ryu, Hyunsoo Kim, Junhua Tan, Myungjoon Choi, Rebecca Park, Shiping Shen, Sun-Il Chang, Shengkui Gao, Kingsuk Brahma, Jesse Aaron Richmond, Changki Min, Yifan Zhang, Jiye Lee, Chaohao Wang
  • Patent number: 10839738
    Abstract: An electronic device that includes processing circuitry configured to generate a frame of image data that has a frame duration is provided. The electronic device includes a display that has a plurality of pixels. Each of the plurality of pixels displays image data from the frame of image data for a pixel emission period that is less than the frame duration. A first pixel of a column of pixels of the plurality of pixels begins displaying the image data from the frame of image data at a first time for a first duration. A second pixel of the column of pixels that is adjacent to the first pixel begins displaying the image data from the frame of image data at a second time for a second duration. The first and second durations are equal to the pixel emission period. The second time begins after the first duration of time.
    Type: Grant
    Filed: April 3, 2018
    Date of Patent: November 17, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Paolo Sacchetto, Yingying Tang, Hyunwoo Nho, Sebastian Knitter, Chaohao Wang, Sheng Zhang
  • Patent number: 10825385
    Abstract: An apparatus receives current image frame data and data relating to at least one previous image frame for an electronic display. One or more parameters related to hysteresis of transistors in the electronic display are sensed. A correlation device, such as a look-up table, receives the sensed parameter or parameters and the data relating to one or more image frames, and uses this information, at least in part, to output an appropriate compensation signal for the current image frame data. The compensated current image frame data may then be supplied to the electronic display to reduce or eliminate the effects of hysteresis on the displayed image.
    Type: Grant
    Filed: September 11, 2017
    Date of Patent: November 3, 2020
    Assignee: Apple Inc.
    Inventors: Chaohao Wang, Chih-Wei Yeh, Chin-Wei Lin, Hung Sheng Lin, Hyunwoo Nho, Injae Hwang, Jie Won Ryu, Junhua Tan, Paolo Sacchetto, Rui Zhang, Shengkui Gao, Sun-Il Chang, Wei H. Yao, Howard H. Tang
  • Publication number: 20200335046
    Abstract: Techniques for implementing and/or operating an electronic device, which includes a display pixel that emits light to facilitate displaying an image during an emission period and a data driver coupled to the display pixel via a data line. The data driver generates a data line voltage signal based on image data that indicates target luminance of the display pixel in the image and supplies the data line voltage signal to the data line during a non-emission period preceding the emission period to facilitate writing the image to the display pixel. Additionally, the data driver supplies an intermediate voltage greater than a ground voltage to the data line during the emission period in which the image is displayed to facilitate reducing luminance variation in the image resulting from a leakage current flowing between an internal node of the display pixel and the data line during the emission period.
    Type: Application
    Filed: April 16, 2020
    Publication date: October 22, 2020
    Inventors: Jie Won Ryu, Myungjoon Choi, Hyunsoo Kim, Hyunwoo Nho, Chin-Wei Lin, Shiping Shen, Kingsuk Brahma, Chaohao Wang, Shinya Ono, Alex H. Pai, Hassan Edrees
  • Publication number: 20200335040
    Abstract: An electronic device includes a display having multiple regions of pixels. Each pixel includes a diode that emits light based on an amount of current through the diode and a transistor that controls the amount of current flowing through the diode. The electronic device includes driver-integrated circuitry that reduces hysteresis in a first transistor of a first pixel of a region of pixels, settles a threshold voltage of the first transistor, applies a test voltage to the first transistor, and senses a current across the first transistor. The electronic device includes processing circuitry that determines a predetermined voltage based on the current and a predetermined current-voltage relationship determined at an initial temperature, determines a voltage difference between the test voltage and the predetermined voltage, and applies the predetermined voltage and the voltage difference to a second transistor of a second pixel of the region of pixels.
    Type: Application
    Filed: February 26, 2020
    Publication date: October 22, 2020
    Inventors: Hyunwoo Nho, Myungjoon Choi, Hyunsoo Kim, Mohammad Ali Jangda, Jie Won Ryu, Shiping Shen, Kingsuk Brahma, Chaohao Wang, Wei H. Yao, Alex H. Pai
  • Publication number: 20200302856
    Abstract: A system includes an electronic display panel that has a plurality of pixels configured to depict frames of image data. The electronic display also includes display driver circuitry configured to, for a first frame of image data representing first image content, modify a gate-to-source voltage of a transistor of a first pixel of the plurality of pixels to a content-dependent first gate-to-source voltage. Additionally, after modifying the gate-to-source voltage to the first gate-to-source voltage, the display driver circuitry is configured to program the first pixel by modifying the gate-to-source voltage to a gate-to-source programming voltage that differs from the first gate-to-source voltage and is based on image data associated with the pixel from the first frame of the image data. Furthermore, the display driver circuitry is configured to cause the plurality of pixels to emit light.
    Type: Application
    Filed: January 17, 2020
    Publication date: September 24, 2020
    Inventors: Xin Lin, Yun Wang, Chin-Wei Lin, Majid Gharghi, Fan Gui, Chen-Ming Chen, Jie Won Ryu, Hyunwoo Nho, Alex H. Pai, Kingsuk Brahma, Junhua Tan, Szu Heng Tseng
  • Patent number: 10777106
    Abstract: An electronic device includes a display having a number of pixels, source driving circuitry that drives data to the pixels, and data lines that communicatively couple the source driving circuitry with the pixels. The electronic device also includes quality monitoring and calibration circuitry that identifies degradation in the source driving circuitry, one or more of the data lines, or both. The electronic device may be controlled based at least in part upon identification of the degradation.
    Type: Grant
    Filed: September 27, 2017
    Date of Patent: September 15, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Jie Won Ryu, Kingsuk Brahma, Hyunwoo Nho, Baris Cagdaser, Junhua Tan, Sun-Il Chang, Luigi Panseri, Injae Hwang, Jesse A. Richmond, Toshiaki Sawada, Hyuck-Jae Lee
  • Patent number: 10755618
    Abstract: Systems and methods are provided for differential sensing (DS), difference-differential sensing (DDS), correlated double sampling (CDS), correlated-correlated double sampling (CDS-CDS) and/or programmable capacitor matching to reduce display panel sensing noise. An electronic device may include one or more processors that generate image data according to sensing operations. The one or more processors may reference a sensing pattern as part of sensing operations. Applying test sensing signals based on the sensing pattern may help reduce error associated with sensing operations.
    Type: Grant
    Filed: April 19, 2019
    Date of Patent: August 25, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Shengkui Gao, Hyunwoo Nho, Chin-Wei Lin, Mohammad B. Vahid Far, Jie Won Ryu, Kingsuk Brahma, Junhua Tan, Sun-Il Chang, Shinya Ono, Jesse Aaron Richmond, Yafei Bi, Derek K. Shaeffer, Myungjoon Choi, Shiping Shen
  • Patent number: 10672320
    Abstract: A display device may include a processor that may receive image data, such that the image data may include gray level data and display brightness value (DBV) data for a first pixel of a display. The processor may then determine a gain compensation factor associated with the first pixel based on a correction spatial map, a brightness adaptation lookup table (LUT), the gray level data, and the DBV data. The processor may then determine an offset compensation factor associated with the first pixel based on the correction spatial map, the brightness adaptation lookup table (LUT), the gray level data, and the DBV data. The processor may generate compensated gray level data by applying the gain compensation factor and the offset compensation factor to the gray level data and transmit the compensated gray level data to pixel driving circuitry associated with the first pixel.
    Type: Grant
    Filed: September 14, 2018
    Date of Patent: June 2, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Soojin Park, Bhadrinarayana L. Visweswaran, Chieh-Wei Chen, Anshi Liang, Marc Albrecht, Pierre-Yves Emelie, Sean C. Chang, Hyunwoo Nho, Mohammad Hajirostam, Myung-Je Cho, Shengkui Gao, Wei H. Yao, Yafei Bi
  • Publication number: 20200166644
    Abstract: A method for operating an electronic display includes receiving, using a controller, sensor data related to operational parameters of the electronic display based at least in part on illuminating a sense pixel of at least one row of pixels of the electronic display, wherein a first set of pixels below the at least one row of pixels renders a portion of a first image frame and a second set of pixels above the at least one row of pixels renders a portion of a second image frame. The method also includes adjusting, using the controller, image display on the electronic display based at least in part on the sensor data.
    Type: Application
    Filed: January 28, 2020
    Publication date: May 28, 2020
    Inventors: Hung Sheng Lin, Hyunwoo Nho, Jie Won Ryu, Junhua Tan, Sun-Il Chang
  • Patent number: 10665157
    Abstract: Systems and methods reduce likelihood of hysteresis that reduces perceived image quality of a subsequent image frame by toggling the display pixels to relax the display pixels by overwriting previous image frame data. During non-emission periods of the pixels, the pixels may be pre-toggled or exercised to improve response time and accuracy of the pixel. Data for pixels being programmed may also be used to pre-toggle other pixels reducing overhead but increasing cross-talk. Since the amount of cross-talk is related to content of the pixels being pre-toggled, a line buffer may be used to store image data for the pixels being pre-toggled. This stored image data may be used to determine how much pre-compensation is to be applied to data for the pixels being programmed. In other words, an amount of compensation applied is based at least in part on the content (e.g., greyscale levels) of the image data.
    Type: Grant
    Filed: April 3, 2019
    Date of Patent: May 26, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Shengkui Gao, Yingying Tang, Sean C. Chang, Mohammad B. Vahid Far, Kasra M. Omid-Zohoor, Chumin Zhao, Jingyu Huang, Mohammad Ali Jangda, Hyunwoo Nho, Chaohao Wang, Marc J. DeVincentis, Marc Albrecht, Warren S. Rieutort-Louis
  • Patent number: 10642083
    Abstract: Electronic devices and methods for compensating for temperature-dependent fluctuations in a display include receiving a temperature index may be received from a sensor and/or calculations that indicates a temperature of the system, a pixel, a panel, a grid of a panel, or a combination thereof. The temperature is used to predict a voltage change across an emissive element (VHILO), such as an organic light emitting diode (OLED). This predicted voltage change is then compensated for before emission.
    Type: Grant
    Filed: June 14, 2018
    Date of Patent: May 5, 2020
    Assignee: Apple Inc.
    Inventors: Injae Hwang, Rui Zhang, Hung Sheng Lin, Hyunsoo Kim, Hyunwoo Nho, Jesse A. Richmond, Jie Won Ryu, Junhua Tan, Kingsuk Brahma, Shengkui Gao, Shiping Shen, Sun-Il Chang