Patents by Inventor Sun-Il Chang

Sun-Il Chang 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: 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: 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: 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
  • 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
  • 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: 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
  • Patent number: 10643511
    Abstract: An electronic device may have a flexible display such as an organic light-emitting diode display. A strain sensing resistor may be formed on a bent tail portion of the flexible display to gather strain measurements. Resistance measurement circuitry in a display driver integrated circuit may make resistance measurements on the strain sensing resistor and a temperature compensation resistor to measure strain. A crack detection line may be formed from an elongated pair of traces that are coupled at their ends to form a loop. The crack detection line may run along a peripheral edge of the flexible display. Crack detection circuitry may monitor the resistance of the crack detection line to detect cracks. The crack detection circuitry may include switches that adjust the length of the crack detection line and thereby allow resistances to be measured for different segments of the line.
    Type: Grant
    Filed: September 23, 2016
    Date of Patent: May 5, 2020
    Assignee: Apple Inc.
    Inventors: Rui Zhang, Mohammad Hajirostam, Hung Sheng Lin, Mohammad B. Vahid Far, Sang Y. Youn, Zhen Zhang, Prashant Mandlik, Sun-Il Chang, Jie Won Ryu, Shengkui Gao, Hyunwoo Nho, Wei H. Yao, Yafei Bi, Yun Wang
  • Publication number: 20200118486
    Abstract: An electronic device comprises an electronic display having an active area having a pixel. The electronic device also comprises processing circuitry configured to receive image data to send to the pixel and adjust the image data to generate corrected image data based at least in part on a stored correction value for the pixel. The processing circuitry also is configured to generate a test data to send to the pixel subsequent to sending corrected image data to the pixel, wherein the test data is selected based upon a comparison of at least one aspect of the corrected image data with a threshold value.
    Type: Application
    Filed: March 27, 2018
    Publication date: April 16, 2020
    Inventors: Hung Sheng Lin, Hyunwoo Nho, Sun-Il Chang, Junhua Tan, Jie Won Ryu, Shengkui Gao, Rui Zhang, Injae Hwang, Kingsuk Brahma, Jesse Aaron Richmond, Shiping Shen, Hyunsoo Kim
  • Patent number: 10573211
    Abstract: Systems and methods are provided for differential sensing (DS), difference-differential sensing (DDS), correlated double sampling (CDS), and/or programmable capacitor matching to reduce display panel sensing noise. An electronic device may include one or more processors and an electronic display. The one or more processors may generate image data and adjust the image data based at least in part on display sensing feedback. The electronic display may employ sensing circuitry that obtains the display sensing feedback at least in part by applying test data to a pixel of a column of an active area of the display and differentially senses an electrical value of the pixel in comparison to a reference signal from a different column. This reference signal may provide a common mode noise reference, which is removed by the differential sensing and thereby enhances a quality of the sensed electrical value of the pixel.
    Type: Grant
    Filed: March 21, 2019
    Date of Patent: February 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 A. Richmond, Yafei Bi, Derek K. Shaeffer
  • Patent number: 10573234
    Abstract: A method for operating an electronic display includes displaying image frames and receiving operational parameters of the electronic display based on illuminating a sense pixel of at least one row of pixels of the electronic display when displaying the image frames. 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 image display of a third image frame on the electronic display based on the operational parameters.
    Type: Grant
    Filed: July 30, 2018
    Date of Patent: February 25, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Hyunwoo Nho, Chaohao Wang, Jie Won Ryu, Kingsuk Brahma, Shiping Shen, Shengkui Gao, Hyunsoo Kim, Sun-Il Chang, Junhua Tan, Injae Hwang, Myungjoon Choi
  • Patent number: 10565923
    Abstract: Electronic devices and methods for compensating for noise in a display that includes sensing a current in a sensing channel of the display. Compensating for the noise also includes sensing an observation current from noise in an observation channel of the display and scaling the observation current to generate a scaled observation current. The scaled observation current is subtracted from the sense current to generate a compensated output. The compensated output is used to drive compensation operations of the display based at least in part on the compensated output to reduce effects of the noise.
    Type: Grant
    Filed: September 11, 2017
    Date of Patent: February 18, 2020
    Assignee: Apple Inc.
    Inventors: Shiping Shen, Derek K. Shaeffer, Baris Cagdaser, Hyunwoo Nho, Kingsuk Brahma, Hung Sheng Lin, Injae Hwang, Jie Won Ryu, Hyunsoo Kim, Junhua Tan, Rui Zhang, Shengkui Gao, Mohammad B Vahid Far, Jesse A. Richmond, Sun-Il Chang
  • Patent number: 10564774
    Abstract: Methods for mitigation of sensing error effects in display panels are disclosed. Display panels, such as pixel-based panels, may have circuitry to sense the luminance values, compare measurements with target luminance values, and provide corrections. Sensing errors, such as ones caused by sensor hysteresis and thermal fluctuations, may lead to overcorrections and visible artifacts. Mitigations schemes discussed herein include filtering of sensed signal with low pass filters, partial correction strategies, and feedforward sensing schemes. Circuitry that implements these schemes are also discussed.
    Type: Grant
    Filed: June 14, 2018
    Date of Patent: February 18, 2020
    Assignee: Apple Inc.
    Inventors: Sun-Il Chang, Myung-Je Cho, Kingsuk Brahma, Jesse A. Richmond, Hyunsoo Kim, Shiping Shen, Injae Hwang, Rui Zhang, Shengkui Gao, Hung Sheng Lin, Jie Won Ryu, Junhua Tan, Hyunwoo Nho
  • Patent number: 10545242
    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: Grant
    Filed: August 7, 2017
    Date of Patent: January 28, 2020
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Hyunwoo Nho, Jie Won Ryu, Junhua Tan, Sun-Il Chang
  • Publication number: 20200005716
    Abstract: The present disclosure relates generally to systems and methods that may reduce a reduction in visual artifacts related to hysteresis of a light emitting diode (LED) electronic display. In one example, an electronic device may include a controller. The controller is may provide a signal to a pixel of a display of the electronic device while at least a portion of the display is turned off. The signal may include a first current and a second current. The first current may be designed to increase an ambient temperature corresponding to the pixel. The second current may be generated as part of an active panel conditioning operation. By applying the first current and the second current, hysteresis settling times from the pixel may improve, therefore improving speeds of sensing and compensation operations of the electronic device.
    Type: Application
    Filed: September 11, 2019
    Publication date: January 2, 2020
    Inventors: Junhua Tan, Kingsuk Brahma, Jie Won Ryu, Shengkui Gao, Shiping Shen, Majid Gharghi, Hyunwoo Nho, Injae Hwang, Kavinaath Murugan, Sun-Il Chang, Chin Wei Lin, Hyunsoo Kim, Rui Zhang, Jesse Aaron Richmond, Yun Wang, Hung Sheng Lin, Alex H. Pai, Chaohao Wang, Wei H. Yao
  • Patent number: 10497767
    Abstract: Electronic devices, storage medium containing instructions, and methods pertain to scanning a display during a sensing phase for the display. One or more parameters pertaining to operation or conditions around the display are obtained. Using the obtained one or more parameters, scanning mode parameters used for sensing are set based at least in part on the obtained one or more parameters. Using the scanning mode parameters, the display is scanned during a sensing phase of the display while reducing the likelihood of visible artifacts.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: December 3, 2019
    Assignee: APPLE INC.
    Inventors: Junhua Tan, Sun-Il Chang, Sebastian Knitter, Jie Won Ryu, Hyunwoo Nho, Lu Zhang, Nicolas P. Bonnier, Hung Sheng Lin, Rui Zhang
  • Patent number: 10453432
    Abstract: An electronic device includes an electronic display, whereby the electronic display includes an active area that includes a pixel having a display behavior that varies with temperature. The electronic display also includes processing circuitry. The processing circuitry may, when in operation, generate image data to send to the pixel and adjust the image data to generate corrected image data based at least in part on a stored correction value for the pixel, wherein the stored correction value corresponds to an effect of temperature on the pixel.
    Type: Grant
    Filed: September 8, 2017
    Date of Patent: October 22, 2019
    Assignee: Apple Inc.
    Inventors: Hung Sheng Lin, Sun-Il Chang, Hyunwoo Nho, Jie Won Ryu, Junhua Tan
  • Patent number: 10388201
    Abstract: Electronic devices and methods pertain to reducing artifacts resulting from a thermal profile preexisting a boot up of an electronic device are disclosed. Scanning driving circuitry of the electronic device scans at least a portion of one or more pixels of an active area of a display using a boot up scan before a boot up sequence of at least a portion of an electronic device completes. The results of the boot up scan are stored in local buffers and transferred to one or more processors upon connection to the one or more processors. The results of the boot up scan cause the one or more processors to modify image data to reduce or eliminate artifacts that may result during boot up due to thermal profiles or other parameters that may cause artifacts.
    Type: Grant
    Filed: September 6, 2017
    Date of Patent: August 20, 2019
    Assignee: Apple Inc.
    Inventors: Sun-Il Chang, Hyunwoo Nho, Hung Sheng Lin, Junhua Tan, Jie Won Ryu, Kingsuk Brahma, Jesse A. Richmond, Mohammad B. Vahid Far, Yafei Bi
  • Patent number: 10269278
    Abstract: Electronic displays, systems, and methods that perform display panel sensing are provided. An electronic device may include processing circuitry that generates image data based at least in part on display panel sensing feedback and an electronic display. The electronic display may display the image data on pixels coupled to one of several sense lines. There may be an odd number of sense lines with common electrical characteristics. The electronic display may obtain display panel sense feedback at least in part by differentially sensing each one of the sense lines with sense lines with common electrical characteristics with another one of the sense lines the common electrical characteristics.
    Type: Grant
    Filed: September 1, 2017
    Date of Patent: April 23, 2019
    Assignee: APPLE INC.
    Inventors: Hung Sheng Lin, Hyunwoo Nho, Shengkui Gao, Jesse A. Richmond, Jie Won Ryu, Junhua Tan, Kingsuk Brahma, Mohammad B. Vahid Far, Sun-Il Chang, Yafei Bi