Patents by Inventor Hopil Bae

Hopil Bae 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: 20190279553
    Abstract: A display device may include pixels that display image data. The display device may also include a circuit that receives pixel data having a gray level for at least one pixel, such that the pixel data corresponds to a frame of the image data and the frame includes sub-frames. The pixel data causes the circuit to provide at least one current pulse to the at least one pixel according to a first order of the sub-frames. The circuit may also receive a second order of the sub-frames, such that the second order is mapped with respect to the first order, and at least one current pulse is provided to the at least one pixel according to the second order. As such, visual artifacts depicted on the display are reduced.
    Type: Application
    Filed: September 13, 2017
    Publication date: September 12, 2019
    Inventors: Mohammad B. Vahid Far, Tore Nauta, Hopil Bae, Mahdi Farrokh Baroughi, Jun Li
  • Publication number: 20190279552
    Abstract: A display device may include a plurality of pixels that may display image data on a display. The display device may also include a circuit that may receive pixel data including a gray level for at least one pixel of the plurality of pixels. The circuit may then receive an emission clock signal using a clock circuit based on the pixel data, such that the emission clock signal may cause the at least one pixel to receive a current for an amount of time based on the gray level. The circuit may then gate off the clock circuit after the amount of time.
    Type: Application
    Filed: September 20, 2017
    Publication date: September 12, 2019
    Inventors: Derek K. Shaeffer, Hopil Bae, Yafei Bi, Wei H. Yao, Xiaofeng Wang
  • Patent number: 10394359
    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: August 4, 2017
    Date of Patent: August 27, 2019
    Assignee: Apple Inc.
    Inventors: Manu Agarwal, Erno H. Klaassen, Hopil Bae, Kingsuk Brahma
  • Patent number: 10360826
    Abstract: An electronic device includes one or more unit pixels with a first node, a second node, and a third node. The device includes light-emitting-diode (LED) voltage (Vled) sensing circuitry, that senses Vled of the one or more unit pixels, by: sampling a charge of a capacitor of the one or more unit pixels, transitioning from the sampling, and reading out the Vled based upon a change in the charge of the capacitor, such that an operation of the unit pixel may be modified based upon the Vled.
    Type: Grant
    Filed: September 22, 2016
    Date of Patent: July 23, 2019
    Assignee: Apple Inc.
    Inventors: Yafei Bi, Xiaofeng Wang, Haifeng Li, Mohammad B. Vahid Far, Hopil Bae, Hung Shen Lin, Hyunwoo Nho, Wei H. Yao
  • 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
  • Patent number: 10360827
    Abstract: An electronic device includes one or more unit pixels and threshold voltage (Vth) sensing circuitry. The threshold voltage sensing circuitry senses Vth of the one or more unit pixels, by: sampling a charge of a capacitor of the one or more unit pixels, transitioning from the sampling, and reading out the threshold voltage based upon a change in the charge of the capacitor, such that an operation of the one or more unit pixels may be modified based upon the threshold voltage.
    Type: Grant
    Filed: September 22, 2016
    Date of Patent: July 23, 2019
    Assignee: Apple Inc.
    Inventors: Yafei Bi, Xiaofeng Wang, Haifeng Li, Mohammad B. Vahid Far, Hopil Bae, Hung Shen Lin, Hyunwoo Nho, Wei H. Yao
  • Patent number: 10283037
    Abstract: Systems and apparatuses provide a digital architecture with merged non-linear emission clocks for a display panel. In one embodiment, a display driver hardware circuit includes decoder logic to store a mapping between a plurality of non-linear gray scale clock signals and a merged non-linear gray scale clock signal that represents a combination of the plurality of non-linear gray scale clock signals including first and second non-linear gray scale clock signals. In one example, the first non-linear gray scale clock signal is associated with at least one display element of a first color and the second non-linear gray scale clock signal is associated with at least one display element of a second color. A driver circuitry is coupled to the decoder logic.
    Type: Grant
    Filed: August 26, 2016
    Date of Patent: May 7, 2019
    Assignee: Apple Inc.
    Inventors: Mohammad B. Vahid Far, Hopil Bae, Hyunwoo Nho, Xiang Lu
  • 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
  • Publication number: 20190088199
    Abstract: An electronic device includes a display having a reference array that includes a first pixel. The display also includes a first emission power supply coupled to the first pixel. The display further includes an active array having a second pixel. The display also includes a second emission power supply coupled to the second pixel.
    Type: Application
    Filed: September 14, 2018
    Publication date: March 21, 2019
    Inventors: Sheng Zhang, Chengrui Le, Hopil Bae, Mahdi Farrokh Baroughi, David W. Lum, Adam Adjiwibawa, Chaohao Wang, Paolo Sacchetto, Wei H. Yao, Enkhamgalan Dorjgotov, Michael Slootsky, Giovanni Carbone, Derek K. Shaeffer, Henry C. Jen, Shingo Hatanaka, Hasan Akyol
  • Publication number: 20190088204
    Abstract: A mobile electronic device includes a display having an active array and a reference array. The active array includes a pixel and the reference array includes a reference pixel. The mobile electronic device also includes processing circuitry communicatively coupled to the display. The processing circuitry is configured to instruct the active array to drive the pixel based at least in part on a current-voltage relationship of the pixel and a reference current-voltage relationship of the reference pixel.
    Type: Application
    Filed: September 14, 2018
    Publication date: March 21, 2019
    Inventors: Sheng Zhang, Chih-Wei Yeh, Yunhui Hou, Chaohao Wang, Wei H. Yao, Paolo Sacchetto, Derek K. Shaeffer, Henry C. Jen, Shingo Hatanaka, Hasan Akyol, Mahdi Farrokh Baroughi, Hopil Bae
  • Patent number: 10217402
    Abstract: Methods and devices useful in compensating for VDD and VTH variations in a micro light-emitting diode (micro-LED) display are provided. By way of example, an LED driver includes a first transistor having a first source coupled to an upper voltage rail (VDD), a first gate, and a first drain. The LED driver includes a second transistor having a second source coupled to the first drain of the first transistor, a second gate, and a second drain coupled to the LED. The second transistor is configured to receive the drive current signal from the first transistor and supply the drive current signal to the LED. The LED driver includes compensation circuitry configured to adjust the drive current signal such that the drive current signal is independent of the upper voltage rail (VDD) and a threshold voltage (VTH) of the first transistor or the second transistor.
    Type: Grant
    Filed: August 25, 2016
    Date of Patent: February 26, 2019
    Assignee: Apple Inc.
    Inventors: Mohammad B. Vahid Far, Yafei Bi, Shinya Ono, Hopil Bae, Chieh-Chien Lin, Hasan Akyol, Xiaofeng 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
  • Publication number: 20180337687
    Abstract: A display device may include rows of pixels that displays image data on a display, data lines coupled to the rows of pixels, and a digital-to-analog converter (DAC) that outputs a ramp voltage signal including a data voltage to be depicted on a first pixel of the rows of pixels. The display device may also include a capacitor that receives the ramp voltage signal via the DAC and a circuit that sends a control signal to a circuit component that causes the DAC to couple to the capacitor via one of the data lines for a duration of time that comprises a first time when the ramp voltage signal is below the data voltage and a second time when the ramp voltage signal is approximately equal to the data voltage. The capacitor is coupled to the DAC when the ramp voltage signal is greater than zero.
    Type: Application
    Filed: May 19, 2017
    Publication date: November 22, 2018
    Inventors: Adam Adjiwibawa, David W. Lum, Wonjae Choi, Hynwoo Nho, Hopil Bae, Injae Hwang, Bryce T. Bradford, Jie Won Ryu, Hung Sheng Lin
  • Publication number: 20180286300
    Abstract: An electronic display includes an active area including multiple pixels. The electronic display also includes a first row driver set including a first column of row drivers and a second column of row drivers. A first active row driver in the first column of row drivers drives a first portion of the multiple pixels, and a first spare row driver in the second column of row drivers is in an inactive state. The electronic display also includes a second row driver set including a third column of row drivers and a fourth column of row drivers. A third active row driver in the third column of row drivers drives a second portion of the multiple pixels, and a second spare row driver in the fourth column of row drivers is inactive.
    Type: Application
    Filed: September 20, 2016
    Publication date: October 4, 2018
    Inventors: Mohammad B Vahid Far, Hopil Bae, Mahid Farrokh Baroughi, Xiaofeng Wang
  • Publication number: 20180247586
    Abstract: Systems and apparatuses for hybrid micro-driver architectures having time multiplexing for driving displays are described. In one embodiment, a display (e.g., hybrid display architecture) includes a backplane and a micro-driver circuitry that is coupled to the backplane. The backplane includes circuitry (e.g., sample and hold circuitry) for sampling and holding analog data and for time multiplexing analog data. The micro-driver circuitry includes at least a capacitor of a ramp generator for generating a ramp voltage based on the analog data of the backplane and drive circuitry to cause at least one emission pulse for emitting a display element.
    Type: Application
    Filed: September 21, 2016
    Publication date: August 30, 2018
    Inventors: Mohammad B. Vahid Far, Yafei Bi, Kapil V. Sakariya, Hopil Bae, Shinya Ono, Thomas Charisoulis, Chin-Wei Lin
  • Publication number: 20180211582
    Abstract: Display panel redundancy schemes and methods of operation are described. In an embodiment, and display panel includes an array of drivers (e.g. microdrivers), each of which including multiple portions to independently receive control and pixel bits. In an embodiment, each driver portion is to control a group of redundant emission elements.
    Type: Application
    Filed: May 27, 2016
    Publication date: July 26, 2018
    Applicant: Apple Inc.
    Inventors: Kapil V. SAKARIYA, Tore NAUTA, Hopil BAE, Henry C. JEN, James E. PEDDER, Sunggu KANG, Shingo HATANAKA, Xiang LU, Mahdi Farrokh BAROUGHI, Hasan AKYOL, Saif CHOUDHARY, Ion BITA
  • Publication number: 20180182279
    Abstract: Methods and apparatuses relating to controlling an emission of a display panel. In one embodiment, a display driver hardware circuit includes row selection logic to select a number of rows in an emission group of a display panel, wherein the number of rows is adjustable from a single row to a full panel of the display panel, column selection logic to select a number of columns in the emission group of the display panel, wherein the number of columns is adjustable from a single column to the full panel of the display panel, and emission logic to select a number of pulses per data frame to be displayed, wherein the number of pulses per data frame is adjustable from one to a plurality and a pulse length is adjustable from a continuous duty cycle to a non-continuous duty cycle.
    Type: Application
    Filed: May 27, 2016
    Publication date: June 28, 2018
    Inventors: Kapil V. SAKARIYA, Tore NAUTA, Hopil BAE, Henry C. JEN
  • 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: 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
  • Publication number: 20180090059
    Abstract: Methods and systems for testing a display having an array of microdrivers arranged in multiple of rows and columns including setting a testing mode of a microdriver of the array of microdrivers using multiple pins of the microdriver that are used in scanning or operation modes of the microdriver. The microdriver is configured to light one or more connected micro light emitting diode pixels coupled to the microdriver during the testing mode. Testing also includes operating the microdriver in the testing mode and determining functionality of the one or more connected micro light emitting diode pixels or the microdriver based on the testing mode.
    Type: Application
    Filed: September 22, 2017
    Publication date: March 29, 2018
    Inventors: Mahdi Farrokh Baroughi, Bo Yang, Xiang Lu, Hopil Bae