Patents by Inventor Sean C. Chang

Sean C. 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).

  • Publication number: 20220059018
    Abstract: A light emitting diode (LED) display can calculate a common voltage charge of a line of pixels in the LED display, the common voltage charge comprising a difference between a first line of pixels and a second line of pixels. If the calculated common voltage charge exceeds a predetermined threshold, a toggle matrix can be generated for the line of pixels. The toggle matrix can include a matrix of charge values generated by calculating a difference in charge values for each subpixel a first line of subpixels with each subpixel a second line of subpixels. The LED display can identify one or more regions of subpixels exhibiting the predetermined toggle pattern in the toggle matrix. The LED display can generate a voltage correction charge to apply to affected regions of the display. Alternatively, the subpixels or pixels could be swapped with adjacent pixels to reduce toggling or settling error.
    Type: Application
    Filed: August 18, 2021
    Publication date: February 24, 2022
    Inventors: Shatam Agarwal, Sean C. Chang, Hao-Lin Chiu, Fenghua Zheng, Pierre-Yves Emelie, Yao Chen, Marc Albrecht, Mingxia Gu, Jun Qi, Wei Chen
  • Patent number: 11120747
    Abstract: A display may have an active area that includes display pixels. The display may include an inactive notch region that extends into the active area. Data lines may provide image data from display driver circuitry to the display pixels. The image data may include data signals that correspond to portions of the display that do not include pixels, such as the inactive notch region. The null data signals may cause nonuniformities in the displayed image. The null data signals may be adjusted to minimize the nonuniformities. Null data signals corresponding to the inactive notch region may be adjusted to have gray levels that gradually decrease with distance from the border between the inactive notch and the active area. All of the data signals corresponding to the inactive notch may be set to a uniform gray level.
    Type: Grant
    Filed: February 27, 2020
    Date of Patent: September 14, 2021
    Assignee: Apple Inc.
    Inventors: Koorosh Aflatooni, Warren S. Rieutort-Louis, Jean-Pierre S. Guillou, Pierre-Yves Emelie, Myung-Je Cho, Marc Albrecht, Graeme M. Williams, Sean C. Chang, Zhao Wang
  • Patent number: 10964275
    Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: March 30, 2021
    Assignee: Apple Inc.
    Inventors: Duane M. Petrovich, Sean C. Chang, Tobias Jung, Pierre-Yves Emelie, Marc Albrecht, Chen Zheng, Andrei E. Toma, Kevin W. Sliech, Mingxia Gu, Wei H. Yao
  • Publication number: 20200335047
    Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.
    Type: Application
    Filed: May 21, 2019
    Publication date: October 22, 2020
    Inventors: Duane M. Petrovich, Sean C. Chang, Tobias Jung, Pierre-Yves Emelie, Marc Albrecht, Chen Zheng, Andrei E. Toma, Kevin W. Sliech, Mingxia Gu, Wei H. Yao
  • Publication number: 20200202791
    Abstract: A display may have an active area that includes display pixels. The display may include an inactive notch region that extends into the active area. Data lines may provide image data from display driver circuitry to the display pixels. The image data may include data signals that correspond to portions of the display that do not include pixels, such as the inactive notch region. The null data signals may cause nonuniformities in the displayed image. The null data signals may be adjusted to minimize the nonuniformities. Null data signals corresponding to the inactive notch region may be adjusted to have gray levels that gradually decrease with distance from the border between the inactive notch and the active area. All of the data signals corresponding to the inactive notch may be set to a uniform gray level.
    Type: Application
    Filed: February 27, 2020
    Publication date: June 25, 2020
    Inventors: Koorosh Aflatooni, Warren S. Rieutort-Louis, Jean-Pierre S. Guillou, Pierre-Yves Emelie, Myung-Je Cho, Marc Albrecht, Graeme M. Williams, Sean C. Chang, Zhao Wang
  • 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
  • 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: 10643549
    Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.
    Type: Grant
    Filed: November 5, 2019
    Date of Patent: May 5, 2020
    Assignee: Apple Inc.
    Inventors: Tobias Jung, Marc Albrecht, Duane M. Petrovich, Sean C. Chang, David S. Zalatimo, Pierre-Yves Emelie, Manev Luthra, Chengrui Le, Lingyu Hong, Wei H. Yao
  • Patent number: 10607549
    Abstract: A display may have an active area that includes display pixels. The display may include an inactive notch region that extends into the active area. Data lines may provide image data from display driver circuitry to the display pixels. The image data may include data signals that correspond to portions of the display that do not include pixels, such as the inactive notch region. The null data signals may cause nonuniformities in the displayed image. The null data signals may be adjusted to minimize the nonuniformities. Null data signals corresponding to the inactive notch region may be adjusted to have gray levels that gradually decrease with distance from the border between the inactive notch and the active area. All of the data signals corresponding to the inactive notch may be set to a uniform gray level.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: March 31, 2020
    Assignee: Apple Inc.
    Inventors: Koorosh Aflatooni, Warren S. Rieutort-Louis, Jean-Pierre S. Guillou, Pierre-Yves Emelie, Myung-Je Cho, Marc Albrecht, Graeme M. Williams, Sean C. Chang, Zhao Wang
  • Patent number: 10571744
    Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.
    Type: Grant
    Filed: April 18, 2019
    Date of Patent: February 25, 2020
    Assignee: Apple Inc.
    Inventors: Sean C. Chang, Tobias Jung, Marc Albrecht, Abdeslam Hafidi, Jun Qi, Duane M. Petrovich, Mingxia Gu, Xiang Fang, Pierre-Yves Emelie, Wei H Yao
  • Patent number: 10504487
    Abstract: Systems, methods, and computer readable media to improve the operation of display systems are described herein. In general, techniques are disclosed for ambient and content adaptive local tone mapping operations that improve display readability under bright ambient light conditions. More particularly, techniques disclosed herein improve contrast and brightness of dark image content while preserving bright areas. The disclosed architecture and operational methodologies generate high contrast images (e.g., amplifying dark regions while preserving bright content), preserve uniform backgrounds (e.g., static background pixels), are stabile in the face of local and global histogram changes (e.g., background not affected by small moving objects such as a mouse pointer), and provide near seamless fade-in and fad-out transitions.
    Type: Grant
    Filed: October 13, 2017
    Date of Patent: December 10, 2019
    Assignee: Apple Inc.
    Inventors: Tobias Jung, Marc Albrecht, Sean C. Chang
  • Patent number: 10504453
    Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.
    Type: Grant
    Filed: April 18, 2019
    Date of Patent: December 10, 2019
    Assignee: Apple Inc.
    Inventors: Tobias Jung, Marc Albrecht, Duane M. Petrovich, Sean C. Chang, David S. Zalatimo, Pierre-Yves Emelie, Manev Luthra, Chengrui Le, Lingyu Hong, Wei H. Yao
  • Publication number: 20190325816
    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: Application
    Filed: April 3, 2019
    Publication date: October 24, 2019
    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
  • Publication number: 20190237001
    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: Application
    Filed: September 14, 2018
    Publication date: August 1, 2019
    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: 20190073962
    Abstract: A display may have an active area that includes display pixels. The display may include an inactive notch region that extends into the active area. Data lines may provide image data from display driver circuitry to the display pixels. The image data may include data signals that correspond to portions of the display that do not include pixels, such as the inactive notch region. The null data signals may cause nonuniformities in the displayed image. The null data signals may be adjusted to minimize the nonuniformities. Null data signals corresponding to the inactive notch region may be adjusted to have gray levels that gradually decrease with distance from the border between the inactive notch and the active area. All of the data signals corresponding to the inactive notch may be set to a uniform gray level.
    Type: Application
    Filed: May 24, 2018
    Publication date: March 7, 2019
    Inventors: Koorosh Aflatooni, Warren S. Rieutort-Louis, Jean-Pierre S. Guillou, Pierre-Yves Emelie, Myung-Je Cho, Marc Albrecht, Graeme M. Williams, Sean C. Chang, Zhao Wang
  • Publication number: 20180108327
    Abstract: Systems, methods, and computer readable media to improve the operation of display systems are described herein. In general, techniques are disclosed for ambient and content adaptive local tone mapping operations that improve display readability under bright ambient light conditions. More particularly, techniques disclosed herein improve contrast and brightness of dark image content while preserving bright areas. The disclosed architecture and operational methodologies generate high contrast images (e.g., amplifying dark regions while preserving bright content), preserve uniform backgrounds (e.g., static background pixels), are stabile in the face of local and global histogram changes (e.g., background not affected by small moving objects such as a mouse pointer), and provide near seamless fade-in and fad-out transitions.
    Type: Application
    Filed: October 13, 2017
    Publication date: April 19, 2018
    Inventors: Tobias Jung, Marc Albrecht, Sean C. Chang