Patents by Inventor Kingsuk Brahma

Kingsuk Brahma 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: 10388223
    Abstract: An electronic device includes display circuitry with a source amplifier and a data line that drives signals provided by the source amplifier. Additionally, the display circuitry includes pixels, where each pixel includes a diode, and a scan thin-film-transistor (TFT) that selectively couples the pixels with the data line, based upon a scan control signal. Sensing circuitry of the electronic device includes a capacitor that is electrically coupled to the data line, wherein the capacitor is pre-charged by the source amplifier when the scan TFT is OFF and a sensing amplifier electrically coupled to the data line, providing a sensing output of both a diode voltage of the one or more pixels and a driving current of the one or more pixels, depending on the current operation of the sensing circuitry. Further, conversion circuitry converts the sensing output from an analog domain to a digital domain.
    Type: Grant
    Filed: September 24, 2016
    Date of Patent: August 20, 2019
    Assignee: Apple Inc.
    Inventors: Kingsuk Brahma, Mohammad B. Vahid Far
  • Publication number: 20190244555
    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: Application
    Filed: April 19, 2019
    Publication date: August 8, 2019
    Inventors: Hung Sheng Lin, Shengkui Gao, Hyunwoo Nho, Chin-Wei Lin, Mohammad B. Vahid Far, Jie Won Ryu, Kingsuk Brahma, Junhua Tan, Sun-II Chang, Shinya Ono, Jesse Aaron Richmond, Yafei Bi, Derek K. Shaeffer, Myungjoon Choi, Shiping Shen
  • Patent number: 10359885
    Abstract: Touch induced flicker for variable refresh rate (VRR) displays can be reduced by adjusting one or more voltages. Synchronization of touch sensing operations after an immediate exit can introduce flicker issues into the VRR display. In some examples, the touched induced flicker can be reduced or eliminated by tuning the voltage on a common electrode (Vcom) to a tuning point that reduces a maximum error below a threshold, irrespective of refresh rate. In some examples, touch induced flicker can be reduced or eliminated by monitoring average Vcom, and when the change in average Vcom exceeds a threshold, Vcom can be adjusted to counteract the change in average Vcom due to the variable refresh rate and/or immediate exit. In some examples, touch induced flicker can be reduced or eliminated by applying a direct current (DC) pedestal to pixel gate lines during touch sensing scans.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: July 23, 2019
    Assignee: Apple Inc.
    Inventors: Kingsuk Brahma, Jie Won Ryu, Hopil Bae, Yafei Bi
  • Publication number: 20190221146
    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: Application
    Filed: March 21, 2019
    Publication date: July 18, 2019
    Inventors: Hung Sheng Lin, Shengkui Gao, Hyunwoo Nho, Chin-Wei Lin, Mohammad B. Vahid Far, Jie Won Ryu, Kingsuk Brahma, Junhua Tan, Sun-II Chang, Shinya Ono, Jesse A. Richmond, Yafei Bi, Derek K. Shaeffer
  • Patent number: 10277119
    Abstract: A charge pump that can be configured to operate in a first mode and a second mode is disclosed. The charge pump can comprise a charging capacitor coupled to a first node and configured to transfer a first DC voltage to the first node. The charge pump can also comprise a first output node and a second output node coupled to the first node. During the first mode, the first output node can be configured to output a second DC voltage based on the first DC voltage, and the second output node can be configured to output a third DC voltage based on the first DC voltage. During the second mode, the first output node can be configured to output the second DC voltage, and the second output node can be configured to output an AC voltage, the AC voltage being offset by the third DC voltage.
    Type: Grant
    Filed: October 30, 2017
    Date of Patent: April 30, 2019
    Assignee: Apple Inc.
    Inventors: Weijun Yao, David A. Stronks, Hopil Bae, Kingsuk Brahma, Wei Hsin Yao, Yafei Bi, Yingxuan Li
  • 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
  • Publication number: 20190102599
    Abstract: An electronic device may include a display and a biometric image sensor configured for biometric image sensing. The electronic device may also include a display driver coupled to the display. The display driver may include first and second memories and a processor configured to alternatingly read respective illumination pattern data from the first and second memories to drive the display during biometric image sensing.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 4, 2019
    Inventors: Mohammad Yeke Yazdandoost, Yafei Bi, Kingsuk Brahma, Giovanni Gozzini, Mohammad Jangda
  • Publication number: 20190096300
    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: Application
    Filed: September 27, 2017
    Publication date: March 28, 2019
    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
  • Publication number: 20190088207
    Abstract: A display may have rows and columns of pixels. Gate lines may be used to supply gate signals to rows of the pixels. Data lines may be used to supply data signals to columns of the pixels. The data lines may include alternating even and odd data lines. Data lines may be organized in pairs each of which includes one of the odd data lines and an adjacent one of the even data lines. Demultiplexer circuitry may be configured dynamically during data loading and pixel sensing operations. During data loading, data from display driver circuitry may be supplied, alternately to odd pairs of the data lines and even pairs of the data lines. During sensing, the demultiplexer circuitry may couple a pair of the even data lines to sensing circuitry in the display driver circuitry and then may couple a pair of the odd data lines to the sensing circuitry.
    Type: Application
    Filed: September 18, 2018
    Publication date: March 21, 2019
    Inventors: Chin-Wei Lin, Majid Gharghi, Mohammad Reza Esmaeili Rad, Yun Wang, Jie Won Ryu, Kingsuk Brahma, Shingo Hatanaka, Shinya Ono, Ting-Kuo Chang
  • Patent number: 10235927
    Abstract: Aspects of the subject technology relate to electronic devices with displays. A display may include display control circuitry including an internal oscillator and one or more counters. The counters may be used to calibrate a display line time to a system line time to ensure that each displayed frame is synchronized with received display data frames from system circuitry for the electronic device. The counters may include a first counter that maintains a current-row count during operation of a current row of display pixels during a current display frame and a second counter that maintains a current-frame count that indicates a number of counts accumulated during the current display frame. The current-row count and the current-frame count may be referenced to the system line time during operation of each pixel row to remove any errors accumulated during operation of the previous pixel rows.
    Type: Grant
    Filed: December 1, 2016
    Date of Patent: March 19, 2019
    Assignee: Apple Inc.
    Inventors: Haifeng Li, Kingsuk Brahma, Yafei Bi
  • Patent number: 10209551
    Abstract: Devices, storage media, and methods for compensating for aging and temperature variations using dual-loop compensation are provided. The compensating for temperature and aging variations of one or more pixels of the display using a coarse scan loop updated at a faster rate. Compensation also includes compensating for aging variations of the one or more pixels of the display using a fine scan loop updated at a slower rate.
    Type: Grant
    Filed: August 15, 2017
    Date of Patent: February 19, 2019
    Assignee: APPLE INC.
    Inventors: Hung Sheng Lin, Jesse A. Richmond, Mohammad B. Vahid Far, Tobias Jung, Jie Won Ryu, Hyunwoo Nho, Kingsuk Brahma, Sun-Il Chang, Junhua Tan, Marc Albrecht, Chih-Wei Yeh, Chaohao Wang
  • Patent number: 10200059
    Abstract: A device includes a resistor string that includes a plurality resistors with voltage taps disposed therebetween. The device may select one particular voltage tap of the plurality of voltage taps based on received gray level data for a pixel of a display. The device also includes a first amplifier that may be coupled to a first terminal end of the resistor string. The device additionally includes a second amplifier that may be coupled to a second terminal end of the resistor string, wherein the plurality of voltage taps may each supply a tap voltage derived from a voltage between the first amplifier and the second amplifier, wherein any tap amplifier of the device coupled to a voltage tap of the plurality of voltage taps provides a reference voltage thereto.
    Type: Grant
    Filed: September 6, 2017
    Date of Patent: February 5, 2019
    Assignee: APPLE INC.
    Inventors: Baris Cagdaser, Derek K. Shaeffer, Hopil Bae, Jesse Aaron Richmond, Jie Won Ryu, Kingsuk Brahma, Mohammad B. Vahid Far, Shingo Hatanaka, Yafei Bi, Yuichi Okuda
  • Patent number: 10175830
    Abstract: A method for pre-charging a display panel may include simultaneously charging the display panel that displays image data and receives one or more touch inputs via a first voltage source and a capacitor that provides a first voltage to the display panel via a second voltage source. The first voltage is associated with receiving the one or more touch inputs, and the display panel and the capacitor are simultaneously charged for a first amount of time. The method may then include charging the display panel via the capacitor after the first amount of time for a second amount of time and charging the display panel via the second voltage source after the second amount of time for a third amount of time.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: January 8, 2019
    Assignee: Apple Inc.
    Inventors: Taif A. Syed, Kingsuk Brahma, Christoph H. Krah
  • Publication number: 20180342193
    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: Application
    Filed: September 11, 2017
    Publication date: November 29, 2018
    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
  • Publication number: 20180336823
    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: Application
    Filed: July 30, 2018
    Publication date: November 22, 2018
    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: 10008172
    Abstract: Devices and methods for reducing or eliminating image artifacts are provided. By way of example, a display panel includes a pixels including pixel electrodes configured to receive an image data signal, and common electrodes (VCOMs) configured to receive a common voltage signal. The display panel includes a source driver, which includes a first digital to analog converter (DAC) configured to generate a gamma voltage signal to provide a first adjustment to the image data signal, and a second DAC configured to generate an error correction voltage signal to provide a second adjustment to the image data signal. The second adjustment is configured to adjust the image data signal to compensate for an operational characteristic difference between row pixels and column pixels of the display panel. The source driver includes an output buffer to supply the image data signal to the pixel electrodes.
    Type: Grant
    Filed: May 13, 2014
    Date of Patent: June 26, 2018
    Assignee: APPLE INC.
    Inventors: Yingxuan Li, Weijun Yao, Wei H. Yao, Kingsuk Brahma, Hyunwoo Nho
  • Patent number: 9952264
    Abstract: A display may have a substrate layer to which a display driver integrated circuit and flexible printed circuit are bonded. The display driver integrated circuit may be provided with switches and control circuitry for controlling the operation of the switches during bond resistance measurements. Test equipment may apply currents to pads in the display driver integrated circuit through contacts in the flexible printed circuit while controlling the switching circuitry. Based on these measurements and the measurement of trace resistances in a dummy flexible printed circuit, the test equipment may determine bond resistances for bonds between the display driver integrated circuit and the display substrate and between the flexible printed circuit and the display substrate. Displays may have master and slave display driver integrated circuits that share coarse reference voltages produced by the master from raw power supply voltages.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: April 24, 2018
    Assignee: Apple Inc.
    Inventors: Kingsuk Brahma, David A. Stronks, Hopil Bae, Wei H. Yao
  • Patent number: 9952265
    Abstract: A display may have a substrate layer to which a display driver integrated circuit and flexible printed circuit are bonded. The display driver integrated circuit may be provided with switches and control circuitry for controlling the operation of the switches during bond resistance measurements. Test equipment may apply currents to pads in the display driver integrated circuit through contacts in the flexible printed circuit while controlling the switching circuitry. Based on these measurements and the measurement of trace resistances in a dummy flexible printed circuit, the test equipment may determine bond resistances for bonds between the display driver integrated circuit and the display substrate and between the flexible printed circuit and the display substrate. Displays may have master and slave display driver integrated circuits that share coarse reference voltages produced by the master from raw power supply voltages.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: April 24, 2018
    Assignee: Apple Inc.
    Inventors: Kingsuk Brahma, David A. Stronks, Hopil Bae, Wei H. Yao
  • Patent number: 9933879
    Abstract: A touch sensor panel configured to switch between a mutual capacitance touch sensing architecture and a self-capacitance touch sensing architecture is provided. The touch sensor panel includes circuitry that can switch the configuration of touch electrodes to act as either drive lines in a mutual capacitance configuration or as sense electrodes in a self-capacitance configuration. The touch sensor panel also includes circuitry that can switch the configuration of touch electrodes to act as either sense lines in a mutual capacitance configuration or as sense electrode in a self-capacitance configuration. By splitting a self-capacitance touch mode into a drive line self-capacitive mode and sense line self-capacitive mode, the touch sensor panel is able to reuse components thus requiring less space, weight and power.
    Type: Grant
    Filed: November 25, 2013
    Date of Patent: April 3, 2018
    Assignee: Apple Inc.
    Inventors: Weijun Yao, Kingsuk Brahma, Taif A. Syed
  • Publication number: 20180090042
    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: Application
    Filed: September 1, 2017
    Publication date: March 29, 2018
    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