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).

  • 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
  • Publication number: 20180081234
    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: Application
    Filed: August 15, 2017
    Publication date: March 22, 2018
    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
  • Publication number: 20180082638
    Abstract: A display device may include a plurality of pixels that display image data on a display, a digital-to-analog converter that outputs a voltage that corresponds to a luminance value to be depicted on a first pixel, and a circuit that amplifies the voltage and outputs an amplified voltage to the first pixel. The circuit may include a capacitor that receives the voltage via the digital-to-analog converter and an amplifier coupled to the capacitor. The amplifier generates the amplified voltage based on the voltage stored the capacitor. The circuit also include switches that couple a first terminal of the capacitor to an output of the amplifier during a first amount of time and couples a second terminal of the capacitor to the output of the amplifier after the first amount of time expires.
    Type: Application
    Filed: September 6, 2017
    Publication date: March 22, 2018
    Inventors: Derek K. Shaeffer, Jesse A. Richmond, Kenichi Ueno, Kingsuk Brahma, Mohammad B. Vahid Far, Shingo Hatanaka, Yafei Bi
  • Publication number: 20180082635
    Abstract: An electronic device includes a display panel. The display panel includes a plurality of pixels, each of which includes a driving thin-film-transistor (TFT) configured to receive driving data related to the operation of a respective pixel and a light-emitting diode configured to emit light based on the driving data provided to the TFT. The display panel also includes compensation circuitry configured to generate offset data from compressed offset data and apply the offset data to the pixel data to generate the driving data.
    Type: Application
    Filed: September 12, 2017
    Publication date: March 22, 2018
    Inventors: Jesse Aaron Richmond, Mohammad B. Vahid Far, Yafei Bi, Kingsuk Brahma
  • Publication number: 20180082620
    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: Application
    Filed: September 6, 2017
    Publication date: March 22, 2018
    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
  • Publication number: 20180083648
    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: Application
    Filed: September 6, 2017
    Publication date: March 22, 2018
    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
  • Publication number: 20180082621
    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: September 7, 2017
    Publication date: March 22, 2018
    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
  • Publication number: 20180075798
    Abstract: A mobile electronic device includes a display having a pixel and processing circuitry separate from but communicatively coupled to the display. The processing circuitry prepares image data to send to the pixel and adjusts the image data to compensate for operational variations of the display based on feedback received from the display that describes a present operational behavior of the pixel. The mobile electronic device also includes additional electronic components that affect the present operational behavior of the pixel depending on present operational behavior of the additional electronic components.
    Type: Application
    Filed: July 27, 2017
    Publication date: March 15, 2018
    Inventors: Hyunwoo Nho, Hung Sheng Lin, Jie Won Ryu, Junhua Tan, Sun-Il Chang, Shengkui Gao, Rui Zhang, Injae Hwang, Kingsuk Brahma, Jesse Aaron Richmond, Shiping Shen, Hyunsoo Kim, Sebastian Knitter, Lu Zhang, Nicolas P. Bonnier, Chih-Wei Yeh, Chaohao Wang, Paolo Sacchetto, Chin-Wei Lin, Mohammad B Vahid Far, Shinya Ono, Yafei Bi, Majid Gharghi, Kavinaath Murugan, Yun Wang, Derek K. Shaeffer, Baris Cagdaser, Tobias Jung, Marc Albrecht, Myung-Je Cho
  • Publication number: 20180075801
    Abstract: Aspects of the subject technology relate to electronic devices with displays. A display may include an array of display pixels each having a drive transistor and an organic light-emitting diode. A pulse-width-modulated current may be provided to the organic light-emitting diode during each display frame to compensate for an on-bias compensation applied to the drive transistor between display frames. The pulse-width-modulated current may be provided with a pulse-width-modulation ratio that decreases over the course of each display frame. The decrease of the pulse-width-modulation ratio for each display frame may be determined based on a peak luminance for that display frame. The reduction in flicker provided by the pulse-width-modulated current may facilitate operation of the display with a reduced refresh rate, thereby reducing power consumption by the display.
    Type: Application
    Filed: January 11, 2017
    Publication date: March 15, 2018
    Inventors: Chengrui LE, Chaohao Wang, Kingsuk Brahma, Jie Won Ryu, Chin-Wei Lin, Rui Zhang
  • Patent number: 9910533
    Abstract: Various timing schemes can be used to synchronizing display functions with touch and/or stylus sensing functions for devices including a variable refresh rate (VRR) display. In a continuous-touch mode, for example, extended blanking can result in frame judder due to mismatch or latency between reporting of sensing data and the display. To minimize these issues, sensing operations can reset to re-synchronize with the display operation, and unreported data from sensing scans can be discarded or ignored. In some examples, a display frame can be divided into two sub-frames, and a system can be configured to perform a touch sensing scan during the first sub-frame of a display frame. At the conclusion of extended blanking, the sensing operations can reset to re-synchronize with the display. The touch sensing scan can be completed in one intra-frame pause and can begin at the start of the display frame.
    Type: Grant
    Filed: September 25, 2015
    Date of Patent: March 6, 2018
    Assignee: Apple Inc.
    Inventors: Manu Agarwal, Hopil Bae, Kingsuk Brahma
  • Publication number: 20180061305
    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: Application
    Filed: December 1, 2016
    Publication date: March 1, 2018
    Inventors: Haifeng LI, Kingsuk BRAHMA, Yafei BI
  • Publication number: 20180059868
    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: Application
    Filed: July 14, 2017
    Publication date: March 1, 2018
    Inventors: Kingsuk BRAHMA, Jie Won RYU, Hopil BAE, Yafei BI
  • Publication number: 20180062508
    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: Application
    Filed: October 30, 2017
    Publication date: March 1, 2018
    Inventors: Weijun YAO, David A. STRONKS, Hopil BAE, Kingsuk BRAHMA, Wei Hsin YAO, Yafei BI, Yingxuan LI
  • Publication number: 20180005579
    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: Application
    Filed: September 24, 2016
    Publication date: January 4, 2018
    Inventors: Kingsuk Brahma, Mohammad B. Vahid Far
  • Publication number: 20170351368
    Abstract: A sensing device can be included in a display of an electronic device. Various techniques can be used to reduce display noise in the signals output from the sensing device. The techniques include the use of a filtering layer in a display stack, the use of a non-uniform sampling scheme, averaging together noise signal samples sampled over multiple display frames, and inverting a phase of the sampling of the noise signal over multiple display frames.
    Type: Application
    Filed: August 4, 2017
    Publication date: December 7, 2017
    Inventors: Manu Agarwal, Erno H. Klaassen, Hopil Bae, Kingsuk Brahma
  • Patent number: 9806608
    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: February 12, 2016
    Date of Patent: October 31, 2017
    Assignee: Apple Inc.
    Inventors: Weijun Yao, David A. Stronks, Hopil Bae, Kingsuk Brahma, Wei Hsin Yao, Yafei Bi, Yingxuan Li
  • Publication number: 20170243548
    Abstract: Systems and methods are provided for improving displayed image quality of an electronic display that includes a display pixel. The electronic display displays a first image frame directly after a second image frame by applying an analog electrical signal to the display pixel. To facilitate display of the first image frame, circuitry receives image data corresponding to the image frame, in which the image data includes a grayscale value that indicates target luminance of the display pixel; determines expected refresh rate of the first image frame based at least in part on actual refresh rate of the second image frame; determines a pixel response correction offset based at least in part on the expected refresh rate of the first image frame; and determines processed image data by applying the pixel response correction offset to the grayscale value, in which the processed image data indicates magnitude of the analog electrical signal.
    Type: Application
    Filed: September 24, 2016
    Publication date: August 24, 2017
    Inventors: Chaohao Wang, Lu Zhang, Zhibing Ge, Shih-Chyuan Fan Jiang, Ilie Garbacea, Marc Albrecht, Kingsuk Brahma, Hopil Bae, Paolo Sacchetto, Jie Won Ryu, Sandro H. Pintz, Chengrui Le
  • Patent number: 9734783
    Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The display may be provided with intra-frame pausing (IFP) capabilities, where touch or other operations may be performed during one or more intra-frame blanking intervals. In one suitable arrangement, a gate driver may be operable in a high impedance mode, where the output of the gate driver is left floating during touch or IFP intervals. In another suitable arrangement, the gate driver may be operable in an IFP reduced stress mode, where a digital pass gate in the gate driver is deactivated during IFP intervals. In yet another suitable arrangement, the gate driver may be operable in an all-gate-high (AGH) power-down mode, where the output of each gate driver in the driver circuitry is driven high in parallel when the displayed is being powered off. These arrangements may be implemented in any suitable combination.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: August 15, 2017
    Assignee: Apple Inc.
    Inventors: Cheng-Ho Yu, Keitaro Yamashita, Ting-Kuo Chang, Yun Wang, Hopil Bae, Kingsuk Brahma
  • Patent number: 9726922
    Abstract: A sensing device can be included in a display of an electronic device. Various techniques can be used to reduce display noise in the signals output from the sensing device. The techniques include the use of a filtering layer in a display stack, the use of a non-uniform sampling scheme, averaging together noise signal samples sampled over multiple display frames, and inverting a phase of the sampling of the noise signal over multiple display frames.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: August 8, 2017
    Assignee: Apple Inc.
    Inventors: Manu Agarwal, Erno H. Klaassen, Hopil Bae, Kingsuk Brahma
  • Publication number: 20170090612
    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: Application
    Filed: September 30, 2015
    Publication date: March 30, 2017
    Inventors: Taif A. Syed, Kingsuk Brahma, Christoph H. Krah