Patents by Inventor Fenghua Zheng

Fenghua Zheng 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: 10380937
    Abstract: The disclosure relates to systems and methods for reducing VCOM settling periods. A number of pixels is sub-divided into a plurality of regions. The pixels are configured to transmit light. A common voltage (VCOM) driving circuit is configured to drive a common electrode of the pixels. Moreover, each of a number of VCOM driving circuits includes a variable resistor configured to be driven to a resistance level based at least in part on which region of the plurality of regions includes an active pixel within the region. Furthermore, a resistance level is set and based at least in part on where the active pixel is located.
    Type: Grant
    Filed: August 25, 2016
    Date of Patent: August 13, 2019
    Assignee: Apple Inc.
    Inventors: Howard H. Tang, Paolo Sacchetto, Chaohao Wang, Szu-Hsien Lee, Patrick Bennett, Fenghua Zheng
  • Patent number: 10311822
    Abstract: Systems and methods are provided for improving displayed image quality of an electronic display with reduced power consumption. In some embodiments, a display pixel in the electronic display includes a pixel electrode and a common electrode. A pixel electrode driver electrically coupled to the first display pixel writes the display pixel by supplying a pixel voltage signal to the pixel electrode. A common electrode driver electrically coupled to the common electrode includes a power amplifier that supplies a common voltage signal to the common electrode to predictively offset net charge accumulation expected in the common electrode; a first power supply rail selectively connectable to the power amplifier based on a target voltage of the common voltage signal; and a second power supply rail selectively connectable to the power amplifier based on the target voltage, in which the first and second power supply rails supply different voltages when connected.
    Type: Grant
    Filed: August 2, 2017
    Date of Patent: June 4, 2019
    Assignee: APPLE INC.
    Inventors: Fenghua Zheng, Howard H. Tang, Sandro H. Pintz
  • Publication number: 20190005897
    Abstract: Aspects of the subject technology relate to electronic devices with displays. A display may include an array of display pixels and control circuitry for operating the display. The control circuitry may determine, based on pixel values for a row of display pixels, that a current in common supply voltage circuitry for the display pixels will exceed a threshold, if the row of display pixels is operated using the pixel values. The control circuitry may modify the pixel values for the row of display pixels to reduce the current in the common supply voltage circuitry and/or prevent the current in the common supply voltage circuitry from exceeding the threshold.
    Type: Application
    Filed: February 9, 2018
    Publication date: January 3, 2019
    Inventors: Manev LUTHRA, Joseph P. MANCA, Fenghua ZHENG, David S. ZALATIMO
  • Patent number: 10163385
    Abstract: A display may have an array of pixels controlled by display driver circuitry. Gate driver circuitry supplies gate line signals to rows of the pixels. The gate driver circuitry may include gate driver integrated circuits. Each gate driver integrated circuit may have a shift register that supplies the gate line signals to the rows of pixels. The display driver circuitry supplies a clock signal to the gate driver integrated circuits. Each gate driver integrated circuit may have one or more clock trees that are selectively enable and disabled. Each gate driver integrated circuit may have a controller and a buffer that is controlled by a control signal from the controller. The buffer may be adjusted to supply or to not supply the clock signal to an associated clock tree in that gate driver integrated circuit.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: December 25, 2018
    Assignee: Apple Inc.
    Inventors: Fenghua Zheng, Christopher P. Tann, David S. Zalatimo, James E. C. Brown, Sandro H. Pintz
  • Publication number: 20180350313
    Abstract: The disclosure describes procedures for dynamically employing a variable refresh rate at an LCD display of a consumer electronic device, such as a laptop computer, a tablet computer, a mobile phone, or a music player device. In some configurations, the consumer electronic device can include a host system portion, having one or more processors and a display system portion, having a timing controller, a buffer circuit, a display driver, and a display panel. The display system can receive image data and image control data from a GPU of the host system, evaluate the received image control data to determine a reduced refresh rate (RRR) for employing at the display panel, and then transition to the RRR, whenever practicable, to conserve power. In some scenarios, the transition to the RRR can be a transition from a LRR of 50 hertz or above to a RRR of 40 hertz or below.
    Type: Application
    Filed: August 14, 2018
    Publication date: December 6, 2018
    Inventors: Prasanna NAMBI, Jason N. GOMEZ, Fenghua ZHENG, Paolo SACCHETTO, Sandro H. PINTZ, Taesung KIM, Christopher P. TANN, Marc ALBRECHT, David W. LUM
  • Patent number: 10121410
    Abstract: This application relates to systems, methods, and apparatus for reducing the power consumption of a display panel. Specifically, the embodiments discussed herein relate to a panel pixel charge scheme that allows the current output of a display driver to be modified based on the content to be displayed at the display panel. The display driver can compare current and upcoming display content in order to determine how the line voltage for one or more output lines will change over time. If, based on the comparison, the voltage for an output line is not going to vary substantially over time, the bias current output from the display driver can be modified in order to save power. The modification to the bias current can depend on the amount of change the line voltage will undergo in subsequent executions of the content data.
    Type: Grant
    Filed: September 15, 2014
    Date of Patent: November 6, 2018
    Assignee: Apple Inc.
    Inventors: Fenghua Zheng, Sandro H. Pintz
  • Patent number: 10056050
    Abstract: The disclosure describes procedures for dynamically employing a variable refresh rate at an LCD display of a consumer electronic device, such as a laptop computer, a tablet computer, a mobile phone, or a music player device. In some configurations, the consumer electronic device can include a host system portion, having one or more processors and a display system portion, having a timing controller, a buffer circuit, a display driver, and a display panel. The display system can receive image data and image control data from a GPU of the host system, evaluate the received image control data to determine a reduced refresh rate (RRR) for employing at the display panel, and then transition to the RRR, whenever practicable, to conserve power. In some scenarios, the transition to the RRR can be a transition from a LRR of 50 hertz or above to a RRR of 40 hertz or below.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: August 21, 2018
    Assignee: Apple Inc.
    Inventors: Prasanna Nambi, Jason N. Gomez, Fenghua Zheng, Paolo Sacchetto, Sandro H. Pintz, Taesung Kim, Christopher P. Tann, Marc Albrecht, David W. Lum
  • Patent number: 9984608
    Abstract: System and method for improving displayed image quality of an electronic display that displays a first image frame by applying a first voltage to a display pixel and a second image frame directly before the first image frame by applying a second voltage to the display pixel. A display pipeline is communicatively coupled to the electronic display and receives first image data corresponding with the first image frame, where the image data includes a first grayscale value corresponding with the display pixel. Additionally the display pipeline determines an inversion balancing grayscale offset based at least in part on the first grayscale value when polarity of the first voltage and polarity of the second voltage are the same and determines magnitude of the first voltage by applying the inversion balancing grayscale offset to the first grayscale value to reduce likelihood of a perceivable luminance spike when displaying the first image frame.
    Type: Grant
    Filed: December 31, 2015
    Date of Patent: May 29, 2018
    Assignee: APPLE INC.
    Inventors: Paolo Sacchetto, Christopher P. Tann, Taesung Kim, Sandro H. Pintz, Marc Albrecht, Chaohao Wang, David S. Zalatimo, Fenghua Zheng, Zhibing Ge
  • Patent number: 9946101
    Abstract: A method for operating a gate driver that is driving pixel transistors of a display panel, is described. An internal start pulse is produced in response to an external start pulse and in accordance with a system clock, wherein the internal start pulse is input to a first cell of a gate driver shift register whose outputs are coupled to level shifting output stages that are driving the rows of pixel transistors of the display panel. The produced internal start pulse was qualified by an output of a last cell of the gate driver shift register. Other embodiments are also described and claimed.
    Type: Grant
    Filed: August 25, 2015
    Date of Patent: April 17, 2018
    Assignee: APPLE INC.
    Inventors: James E. C. Brown, Fenghua Zheng, Sandro H. Pintz
  • Publication number: 20180090084
    Abstract: Devices and methods for useful in providing localized synchronized and/or dynamic in-band internal gamma code adjustment per frame period are provided. By way of example, a display panel includes a data driver, which includes a first DAC configured to provide an internal gamma voltage signal to cause a first adjustment to an image data signal. The first adjustment is configured to selectively adjust the image data signal based at least in part on a refresh rate or a frame rate of the display panel. The data driver includes a second DAC coupled to the first DAC and configured to provide an external gamma voltage signal configured to provide a second adjustment to the image data signal, and an output buffer configured to supply the image data signal to pixels of the display panel, wherein the image data signal comprises the first adjustment and the second adjustment.
    Type: Application
    Filed: September 7, 2017
    Publication date: March 29, 2018
    Inventors: Fenghua Zheng, Christopher P. Tann, Sandro H. Pintz, David S. Zalatimo, Jun Qi, Zhibing Ge
  • Patent number: 9916787
    Abstract: This application sets forth systems, methods, and apparatus for improving charge settling times for lines and pixels of a display panel. The charge settling times are improved by providing an over drive signal and a bias current to a line and/or pixel of the display panel based a comparison of content data to be output by the display panel. In this way, by initially charging the line and/or pixel with the over drive signal, the line and/or pixel can be fully charged more quickly in display panels that operate at higher refresh rates.
    Type: Grant
    Filed: March 3, 2016
    Date of Patent: March 13, 2018
    Assignee: APPLE INC.
    Inventors: Fenghua Zheng, Paolo Sacchetto
  • Publication number: 20180068624
    Abstract: Methods and systems for compensating for VCOM variations include determining a voltage change in pixels between frames to be displayed on an electronic display. Based on the determined voltage change, VCOM variation is calculated based on coupling the VCOM to one or more data lines of the electronic display. VCOM compensation is determined and applied to offset for the VCOM variation. Using the VCOM offset, subsequent pixel content for the one or more pixels is written using the compensated VCOM.
    Type: Application
    Filed: September 11, 2017
    Publication date: March 8, 2018
    Inventors: Fenghua Zheng, Howard H. Tang, James C. Aamold, Sandro H. Pintz, Chaohao Wang, Paolo Sacchetto
  • Publication number: 20180061355
    Abstract: Systems and methods are provided for improving displayed image quality of an electronic display with reduced power consumption. In some embodiments, a display pixel in the electronic display includes a pixel electrode and a common electrode. A pixel electrode driver electrically coupled to the first display pixel writes the display pixel by supplying a pixel voltage signal to the pixel electrode. A common electrode driver electrically coupled to the common electrode includes a power amplifier that supplies a common voltage signal to the common electrode to predictively offset net charge accumulation expected in the common electrode; a first power supply rail selectively connectable to the power amplifier based on a target voltage of the common voltage signal; and a second power supply rail selectively connectable to the power amplifier based on the target voltage, in which the first and second power supply rails supply different voltages when connected.
    Type: Application
    Filed: August 2, 2017
    Publication date: March 1, 2018
    Inventors: Fenghua Zheng, Howard H. Tang, Sandro H. Pintz
  • Publication number: 20180025689
    Abstract: This application relates to systems, methods, and apparatus for reducing the power consumption of a display panel. Specifically, the embodiments discussed herein relate to a panel pixel charge scheme that allows the current output of a display driver to be modified based on the content to be displayed at the display panel. The display driver can compare current and upcoming display content in order to determine how the line voltage for one or more output lines will change over time. If, based on the comparison, the voltage for an output line is not going to vary substantially over time, the bias current output from the display driver can be modified in order to save power. The modification to the bias current can depend on the amount of change the line voltage will undergo in subsequent executions of the content data.
    Type: Application
    Filed: October 2, 2017
    Publication date: January 25, 2018
    Inventors: James AAMOLD, Fenghua ZHENG, Sandro H. PINTZ
  • Patent number: 9761188
    Abstract: Methods and systems for compensating for VCOM variations include determining a voltage change in pixels between frames to be displayed on an electronic display. Based on the determined voltage change, VCOM variation is calculated based on coupling the VCOM to one or more data lines of the electronic display. VCOM compensation is determined and applied to offset for the VCOM variation. Using the VCOM offset, subsequent pixel content for the one or more pixels is written using the compensated VCOM.
    Type: Grant
    Filed: March 6, 2015
    Date of Patent: September 12, 2017
    Assignee: APPLE INC.
    Inventors: Fenghua Zheng, Howard H. Tang, James C. Aamold, Sandro H. Pintz, Chaohao Wang, Paolo Sacchetto
  • Patent number: 9678916
    Abstract: A method for simplifying the host-to-display subsystem communications and consolidating the non-volatile memory requirements into a PMIC (power management integrated circuit) is disclosed. Hardware and software resource reduction in both the client devices (located in the display subsystem) and the host System on a Chip (SOC) can be realized with a novel PMIC design. The novel PMIC design achieves the resource reduction by providing for the following features: (1) Single-point communication, (2) Single-point notification, (3) Client device status storage, (4) Client device initialization from PMIC non-volatile memory, and (5) Subsystem calibration retrieval from PMIC non-volatile memory.
    Type: Grant
    Filed: September 29, 2014
    Date of Patent: June 13, 2017
    Assignee: Apple Inc.
    Inventors: David W. Lum, Thomas J. Wilson, Paolo Sacchetto, Sandro H. Pintz, Fenghua Zheng
  • Publication number: 20170061864
    Abstract: The disclosure relates to systems and methods for reducing VCOM settling periods. A number of pixels is sub-divided into a plurality of regions. The pixels are configured to transmit light. A common voltage (VCOM) driving circuit is configured to drive a common electrode of the pixels. Moreover, each of a number of VCOM driving circuits includes a variable resistor configured to be driven to a resistance level based at least in part on which region of the plurality of regions includes an active pixel within the region. Furthermore, a resistance level is set and based at least in part on where the active pixel is located.
    Type: Application
    Filed: August 25, 2016
    Publication date: March 2, 2017
    Inventors: Howard H. Tang, Paolo Sacchetto, Chaohao Wang, Szu-Hsien Lee, Patrick Bennett, Fenghua Zheng
  • Publication number: 20170047027
    Abstract: The disclosure describes procedures for dynamically employing a variable refresh rate at an LCD display of a consumer electronic device, such as a laptop computer, a tablet computer, a mobile phone, or a music player device. In some configurations, the consumer electronic device can include a host system portion, having one or more processors and a display system portion, having a timing controller, a buffer circuit, a display driver, and a display panel. The display system can receive image data and image control data from a GPU of the host system, evaluate the received image control data to determine a reduced refresh rate (RRR) for employing at the display panel, and then transition to the RRR, whenever practicable, to conserve power. In some scenarios, the transition to the RRR can be a transition from a LRR of 50 hertz or above to a RRR of 40 hertz or below.
    Type: Application
    Filed: October 28, 2016
    Publication date: February 16, 2017
    Inventors: Prasanna NAMBI, Jason N. GOMEZ, Fenghua ZHENG, Paolo SACCHETTO, Sandro H. PINTZ, Taesung KIM, Christopher P. TANN, Marc ALBRECHT, David W. LUM
  • Publication number: 20160365042
    Abstract: Gate driver circuitry in a display may supply gate line signals to rows of pixels on gate lines. Data line driver circuitry may supply data line signals to columns of pixels on data lines. The gate driver circuitry may have registers that are coupled to form a shift register that supplies the gate line signals to the gate lines. To compensate for data line signal propagation delays, the registers of the shift register may be clocked with increasingly delayed clocks as a function of increasing distance away from the display driver circuitry. To compensate for gate line signal propagation delays, the data line driver circuitry may impose increasing delays on the data line signals carried on the data lines as a function of increasing distance of the data lines away from the gate driver circuitry.
    Type: Application
    Filed: June 15, 2015
    Publication date: December 15, 2016
    Inventors: Fenghua Zheng, Sandro H. Pintz
  • Patent number: 9501993
    Abstract: The disclosure describes procedures for dynamically employing a variable refresh rate at an LCD display of a consumer electronic device, such as a laptop computer, a tablet computer, a mobile phone, or a music player device. In some configurations, the consumer electronic device can include a host system portion, having one or more processors and a display system portion, having a timing controller, a buffer circuit, a display driver, and a display panel. The display system can receive image data and image control data from a GPU of the host system, evaluate the received image control data to determine a reduced refresh rate (RRR) for employing at the display panel, and then transition to the RRR, whenever practicable, to conserve power. In some scenarios, the transition to the RRR can be a transition from a LRR of 50 hertz or above to a RRR of 40 hertz or below.
    Type: Grant
    Filed: January 14, 2014
    Date of Patent: November 22, 2016
    Assignee: Apple Inc.
    Inventors: Prasanna Nambi, Jason N. Gomez, Fenghua Zheng, Paolo Sacchetto, Sandro H. Pintz, Taesung Kim, Christopher P. Tann, Marc Albrecht, David W. Lum