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: 11955076
    Abstract: An example method includes estimating, based on content to be displayed at a display of a mobile computing device at a future time, an amount of power to be used by the display at the future time; selecting, based on the estimated power level, a power converter of a plurality of power converters of the mobile computing device, each of the plurality of power converters optimized for a different output power range; and causing electrical power from the selected power converter to be supplied to the display at the future time.
    Type: Grant
    Filed: July 10, 2020
    Date of Patent: April 9, 2024
    Assignee: Google LLC
    Inventors: Ji Hoon Lee, Sun-il Chang, Sang Young Youn
  • Patent number: 11948520
    Abstract: PWM-frame rate misalignment is mitigated through implementation of a discrete variable refresh rate (VRR) scheme. A target frame rate is limited to a frame rate selected from only those frame rates that facilitate alignment of each frame period to a specified edge of a PWM cycle of a brightness control signal of a display panel. This alignment results in each frame period at the selected frame rate starting at a same point in a corresponding PWM cycle and ending at a same point in a corresponding PWM cycle to help ensure a constant effective duty cycle across each successive frame period, which in turn mitigates perception of flicker that otherwise would arise. Further, the discrete VRR scheme can employ a compensation mode for compensating for the delay in rendering or otherwise obtaining a frame for display so as to maintain a consistent duty cycle in the brightness control signal.
    Type: Grant
    Filed: March 31, 2020
    Date of Patent: April 2, 2024
    Assignee: GOOGLE LLC
    Inventors: Sang Young Youn, Sun-il Chang, Wonjae Choi, Sangmoo Choi
  • Patent number: 11929018
    Abstract: A frame generation subsystem renders a sequence of frames and a display control subsystem provides a brightness control signal configured to control a brightness of frames displayed at a display panel via pulse width modulation (PWM) of the brightness control signal and determines a deviation in a duty cycle of a first PWM period of the brightness control signal from a default duty cycle resulting from a delayed rendering of a frame. The display control subsystem adjusts a duty cycle of at least a second PWM period to compensate for the deviation in the duty cycle of the first PWM period. The resulting average duty cycle of the brightness control signal over the two frame periods is approximately equal to a default duty cycle and thereby mitigates viewable flicker resulting from the duty cycle change caused by the delayed rendering.
    Type: Grant
    Filed: May 19, 2020
    Date of Patent: March 12, 2024
    Assignee: GOOGLE LLC
    Inventors: Sang Young Youn, Sun-il Chang, Wonjae Choi, Hyunchul Kim
  • Patent number: 11893933
    Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for compensating an image to be shown on a display including an array of light-emitting pixels and a sensor arranged to receive light transmitted by adjacent light-emitting pixels. A method includes collecting, from the sensor, a luminance of light received by the sensor during an emission-on period, and a luminance of light received by the sensor during an emission-off period. The method includes calculating, by comparing the luminance during the emission-on period to the luminance during the emission-off period, a luminance of light internally reflected from the adjacent pixels and received by the sensor during the emission-on period. The method includes determining that an error between the luminance of light internally reflected and a reference luminance equals or exceeds a threshold error, and adjusting a driving voltage for driving the pixels to reduce the error.
    Type: Grant
    Filed: January 24, 2020
    Date of Patent: February 6, 2024
    Assignee: Google LLC
    Inventors: Sun-il Chang, Hyunchul Kim
  • Publication number: 20240021164
    Abstract: A display device includes subpixels of a first, second, and third colors, scan lines, and column lines. The subpixels are arranged in an array of rows and columns, with each subpixel in a column being electrically connected to a same column line. Each subpixels in a column is configured for receiving electronic scan signals that control a light output from an emissive element of the subpixel from a scan line and from the column line connected to the subpixel. One or more line drivers provide the electronic scan signals, during a time period for rendering a frame, to subpixels in a first set of columns first to subpixels of the first color and then to the subpixels of the third color and to subpixels in a second set of columns first to subpixels of the third color and then to the subpixels of the first color.
    Type: Application
    Filed: May 11, 2021
    Publication date: January 18, 2024
    Inventors: Sangmoo CHOI, Sun-il CHANG
  • Patent number: 11842674
    Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for a display with discrete gate-in-panel circuitry. In some implementations, a display includes an array of emissive pixels arranged in rows and columns, where the array includes a first continuous area having a first pixel density and a second continuous area having a second pixel density less than the first pixel density, and consecutive rows of the emissive pixels extending between the first and second continuous areas. The display also includes gate in panel (GIP) circuits in the second continuous area, a data lines connected to the array of emissive pixels, and signal lines connected to the array of emissive pixels.
    Type: Grant
    Filed: November 8, 2019
    Date of Patent: December 12, 2023
    Assignee: Google LLC
    Inventors: Sun-il Chang, Sangmoo Choi
  • Publication number: 20230341908
    Abstract: A device includes: an array of light emitting elements extending in a first plane, each light emitting element being arranged to emit light; an array of pixel driver elements extending in a second plane beneath the array of pixels, in which each pixel driver element is configured to drive a corresponding light emitting element of the array of light emitting elements; a hole positioned within the array of light emitting elements and the array of pixel driver elements, in which the hole extends from the first plane through the second plane, a first multiple of light emitting elements from the array of light emitting elements in a first region adjacent the hole are arranged to provide a first resolution, and a second multiple of light emitting elements from the array of elements in a second region away from the hole are arranged to provide a second resolution.
    Type: Application
    Filed: May 26, 2023
    Publication date: October 26, 2023
    Inventors: Sun-il Chang, Sangmoo Choi
  • Patent number: 11783752
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for gamma lookup table compression. In one aspect, a method includes obtaining a gamma value for a pixel of an image to be shown on a display, determining a base gamma value based on a base lookup table that corresponds to a base display condition, determining a delta gamma value based on a delta lookup table that corresponds to a current display condition for the pixel, determining a remapped gamma value for the pixel based on a combination of the base gamma value and the delta gamma value, and providing the remapped gamma value to be shown on the display.
    Type: Grant
    Filed: December 17, 2019
    Date of Patent: October 10, 2023
    Assignee: Google LLC
    Inventors: Hyunchul Kim, Sun-il Chang, Wonjae Choi, Sang Young Youn
  • Patent number: 11770962
    Abstract: A display configuration to extend the light emitting and touch sensitive portion of a display panel into areas normally reserved for other light devices is disclosed. In the configuration, light devices and the display panel are configured to operate together. The display panel may include an aperture through the display panel to provide an unobstructed light path to a light device. The display panel may also include a routing area to provide space for data lines feeding pixels to be rerouted around the aperture. The routing area is partially obstructed by data lines but otherwise transparent. Accordingly, some display devices may be positioned behind the routing area and still operate.
    Type: Grant
    Filed: August 31, 2021
    Date of Patent: September 26, 2023
    Assignee: Google LLC
    Inventors: Sangmoo Choi, Sun-il Chang, Jyothi Karri, Ion Bita
  • Publication number: 20230236698
    Abstract: A computing device can receive a first measured touch value, the first measured touch value indicating first touch input at a first location near a camera included in the computing device, receive a second measured touch value, the second measured touch value indicating second touch input at a second location farther from the camera than the first location, a density of touch sensors in the second location being greater than a density of touch sensors in the first location, generate a first compensated touch value based on the first measured touch value and a first scaling value, generate a second compensated touch value based on the second measured touch value and a second scaling value, the second scaling value being less than the first scaling value, and process the first touch input and the second touch input based on the first compensated touch value and the second compensated touch value.
    Type: Application
    Filed: June 3, 2020
    Publication date: July 27, 2023
    Inventors: Young Seok Oh, Sun-il Chang
  • Patent number: 11687126
    Abstract: A device includes: an array of light emitting elements extending in a first plane, each light emitting element being arranged to emit light; an array of pixel driver elements extending in a second plane beneath the array of pixels, in which each pixel driver element is configured to drive a corresponding light emitting element of the array of light emitting elements; a hole positioned within the array of light emitting elements and the array of pixel driver elements, in which the hole extends from the first plane through the second plane, a first multiple of light emitting elements from the array of light emitting elements in a first region adjacent the hole are arranged to provide a first resolution, and a second multiple of light emitting elements from the array of elements in a second region away from the hole are arranged to provide a second resolution.
    Type: Grant
    Filed: February 17, 2021
    Date of Patent: June 27, 2023
    Assignee: Google LLC
    Inventors: Sun-il Chang, Sangmoo Choi
  • Publication number: 20230196524
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for remapping for mixed dynamic range content. In one aspect, a method for remapping for mixed dynamic range content, the method includes obtaining an image to be displayed that includes both first dynamic range content and second dynamic range content, determining that the image includes first dynamic range content at a first pixel, determining a first remapped value for the first pixel based on a lookup table for first dynamic range content and an initial value for the first pixel, providing the first remapped value for the first pixel for display, determining that the image includes second dynamic range content at a second pixel, determining a second remapped value for the second pixel based on a second initial value for the second pixel, and providing the second remapped value for the second pixel for display.
    Type: Application
    Filed: December 4, 2019
    Publication date: June 22, 2023
    Inventors: Hyunchul Kim, Wonjae Choi, Sang Young Youn, Sun-il Chang
  • Patent number: 11663973
    Abstract: External compensation of display panels may employ measurement or sensing circuitry configured to measure the output of a pixel and compensate for variations. Due to effects from the sensing circuitry, a mismatch between a target current and the actual current in the pixel may occur. Systems and methods that compensate for the effects from sensing circuitry and reduce or mitigate the mismatch are described. Systems and methods described herein include compensation circuitry that is capable of employing correction factors to compensate for the effects due to the presence of sensing circuitry. Methods for determining the correction factor are also described.
    Type: Grant
    Filed: May 10, 2019
    Date of Patent: May 30, 2023
    Assignee: Apple Inc.
    Inventors: Junhua Tan, Shengkui Gao, Myungjoon Choi, Injae Hwang, Chaohao Wang, Myung-Je Cho, Hyunwoo Nho, Sun-Il Chang, Jesse A. Richmond, Kingsuk Brahma, Jie Won Ryu, Shiping Shen, Yunhui Hou
  • Publication number: 20230030201
    Abstract: PWM-frame rate misalignment is mitigated through implementation of a discrete variable refresh rate (VRR) scheme. A target frame rate is limited to a frame rate selected from only those frame rates that facilitate alignment of each frame period to a specified edge of a PWM cycle of a brightness control signal of a display panel. This alignment results in each frame period at the selected frame rate starting at a same point in a corresponding PWM cycle and ending at a same point in a corresponding PWM cycle to help ensure a constant effective duty cycle across each successive frame period, which in turn mitigates perception of flicker that otherwise would arise. Further, the discrete VRR scheme can employ a compensation mode for compensating for the delay in rendering or otherwise obtaining a frame for display so as to maintain a consistent duty cycle in the brightness control signal.
    Type: Application
    Filed: March 31, 2020
    Publication date: February 2, 2023
    Inventors: Sang Young Youn, Sun-il Chang, Wonjae Choi, Sangmoo Choi
  • Publication number: 20220415256
    Abstract: An example method includes estimating, based on content to be displayed at a display of a mobile computing device at a future time, an amount of power to be used by the display at the future time; selecting, based on the estimated power level, a power converter of a plurality of power converters of the mobile computing device, each of the plurality of power converters optimized for a different output power range; and causing electrical power from the selected power converter to be supplied to the display at the future time.
    Type: Application
    Filed: July 10, 2020
    Publication date: December 29, 2022
    Inventors: Ji Hoon Lee, Sun-il Chang, Sang Young Youn
  • Publication number: 20220406854
    Abstract: A display device includes a plurality of subpixel emissive areas of a first color, a second color, and a third color arranged in an array having a plurality of rows and columns. Rows of the array include subpixel emissive areas arranged in a repeating pattern of a first color subpixel emissive area, a second color subpixel emissive area, a third color subpixel emissive area, and a second color subpixel emissive area. Alternating columns of the array include subpixel emissive areas: (a) arranged in a repeating pattern of a subpixel emissive area of the first color and a subpixel emissive areas of the third color, and (b) including only subpixel emissive areas of the second color. The display device further includes a plurality of scan lines, a plurality of column lines, and a plurality of electronic subpixel circuits arranged in the array.
    Type: Application
    Filed: February 7, 2020
    Publication date: December 22, 2022
    Inventors: Sangmoo Choi, Sun-il Chang
  • Publication number: 20220375385
    Abstract: A display panel includes a first set of pixels that each include a respective red sub-pixel and a respective green sub-pixel and a second set of pixels that each include a respective blue sub-pixel and a respective green sub-pixel, where the first set of pixels and the second set of pixels are arranged on the display panel such that at least one side of each of the pixels in the first set of pixels is adjacent to at least one of the pixels in the second set of pixels, at least one side of each of the pixels in the first set of pixels is not adjacent to any pixel, and the green sub-pixels are arranged on the display panel such that the green sub-pixels are evenly distributed in the display panel.
    Type: Application
    Filed: August 3, 2022
    Publication date: November 24, 2022
    Inventors: David Morris Hoffman, Sangmoo Choi, Sun-il Chang, Ion Bita
  • Publication number: 20220366829
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dual color management for a multi-pixel density display. In one aspect, the method includes obtaining an image to be shown on a display, where the display includes both a first area that has a first pixel density and a second area that has a second pixel density that is less than the first pixel density, determining that a pixel with an initial value in the image will be displayed in the first area of the display (120), in response to determining that a pixel with the initial value in the image will be displayed in the first area of the display, determining a remapped value for the pixel in the image based on the initial value and a lookup table for the first area (130), and providing the remapped value for output on the display (150).
    Type: Application
    Filed: December 5, 2019
    Publication date: November 17, 2022
    Inventors: Hyunchul Kim, Wonjae Choi, Sun-il Chang
  • Publication number: 20220366846
    Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for compensating an image to be shown on a display including an array of light-emitting pixels and a sensor arranged to receive light transmitted by adjacent light-emitting pixels. A method includes collecting, from the sensor, a luminance of light received by the sensor during an emission-on period, and a luminance of light received by the sensor during an emission-off period. The method includes calculating, by comparing the luminance during the emission-on period to the luminance during the emission-off period, a luminance of light internally reflected from the adjacent pixels and received by the sensor during the emission-on period. The method includes determining that an error between the luminance of light internally reflected and a reference luminance equals or exceeds a threshold error, and adjusting a driving voltage for driving the pixels to reduce the error.
    Type: Application
    Filed: January 24, 2020
    Publication date: November 17, 2022
    Inventors: Sun-il Chang, Hyunchul Kim
  • Patent number: 11488529
    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: Grant
    Filed: April 15, 2020
    Date of Patent: November 1, 2022
    Assignee: Apple Inc.
    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