Patents by Inventor Changhun Cho

Changhun Cho 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: 11176879
    Abstract: A foldable display comprises a flexible display panel including a first screen, a second screen, and a foldable boundary region positioned between the first screen and the second screen; a first drive IC connected to data lines of the first screen and connected to data lines of a first boundary region to drive pixels of the first screen and the first boundary region; and a second drive IC connected to data lines of the second screen and connected to data lines of a second boundary region to drive pixels of the second screen and the second boundary region, wherein channels of the first drive IC and channels of the second drive IC are driven and shutdown in accordance with status on whether the first and second screens are driven.
    Type: Grant
    Filed: December 20, 2019
    Date of Patent: November 16, 2021
    Assignee: LG DISPLAY CO., LTD.
    Inventor: Changhun Cho
  • Publication number: 20200202774
    Abstract: A foldable display comprises a flexible display panel including a first screen, a second screen, and a foldable boundary region positioned between the first screen and the second screen; a first drive IC connected to data lines of the first screen and connected to data lines of a first boundary region to drive pixels of the first screen and the first boundary region; and a second drive IC connected to data lines of the second screen and connected to data lines of a second boundary region to drive pixels of the second screen and the second boundary region, wherein channels of the first drive IC and channels of the second drive IC are driven and shutdown in accordance with status on whether the first and second screens are driven.
    Type: Application
    Filed: December 20, 2019
    Publication date: June 25, 2020
    Applicant: LG Display Co., Ltd.
    Inventor: Changhun Cho
  • Patent number: 9343033
    Abstract: A method of controlling polarity of a data voltage and a liquid crystal display using the same, the method including calculating a direct current DC value of the data from each group which data to be output through I-channels adjacent to each other in a source drive IC belong; accumulating the DC value; comparing an absolute value of the accumulation DC value of the n-th group obtained by adding the accumulation DC value of the n?1-th group accumulated up to the n?1-th group to the DC value of the n-th group (n is positive integer) with a predetermined threshold value; and changing a group polarity data when the absolute value of the accumulation DC value of the n-th group exceeds the threshold value.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: May 17, 2016
    Assignee: LG DISPLAY CO., LTD.
    Inventor: Changhun Cho
  • Publication number: 20150170594
    Abstract: A data driver of a display panel includes a gamma voltage generating unit generating a gamma grayscale voltage for converting the digital data signal into an analog data signal; and a digital-to-analog conversion unit converting the digital data signal into an analog data signal in response to the gamma grayscale voltage. The gamma voltage generating unit generates the gamma grayscale voltage based on one of an external reference voltage and an internal reference voltage in response to a control signal.
    Type: Application
    Filed: May 28, 2014
    Publication date: June 18, 2015
    Applicant: LG Display Co., Ltd.
    Inventor: Changhun Cho
  • Publication number: 20140184580
    Abstract: Discussed herein is a method of controlling polarity of a data voltage and a liquid crystal display using the same, the method including calculating a direct current DC value of the data from each group which data to be output through I-channels adjacent to each other in a source drive IC belong; accumulating the DC value; comparing an absolute value of the accumulation DC value of the n-th group obtained by adding the accumulation DC value of the n?1-th group accumulated up to the n?1-th group to the DC value of the n-th group (n is positive integer) with a predetermined threshold value; and changing a group polarity data when the absolute value of the accumulation DC value of the n-th group exceeds the threshold value.
    Type: Application
    Filed: December 20, 2013
    Publication date: July 3, 2014
    Applicant: LG DISPLAY CO., LTD.
    Inventor: Changhun CHO
  • Patent number: 8390554
    Abstract: A liquid crystal display device and a method of driving the same are disclosed. The liquid crystal display device includes a liquid crystal display panel including data lines, gate lines crossing the data lines, and liquid crystal cells arranged in a matrix format at each of crossings of the data lines and the gate lines; a data drive circuit that converts digital video data into a positive/negative data voltage using gamma reference voltages to supply the positive/negative data voltage to the data lines; and a gamma voltage adjusting unit that increases a potential of each of the gamma reference voltages during a blanking period when a polarity of the positive/negative data voltage is inverted.
    Type: Grant
    Filed: October 16, 2009
    Date of Patent: March 5, 2013
    Assignee: LG Display Co., Ltd.
    Inventors: Changhun Cho, Jinsung Kim, Hyunchul Kim
  • Patent number: 8212803
    Abstract: A liquid crystal display and a method of driving the same are provided. The liquid crystal display includes a first source drive IC group outputting a first feedback lock signal in response to one of a power voltage input through a first lock signal input terminal and a lock signal from the timing controller, a second source drive IC group outputting a second feedback lock signal in response to one of the power voltage input through a second lock signal input terminal, the lock signal from the timing controller, and a lock signal transferred from the first source drive IC group, and a comparator that compares the first feedback lock signal with the second feedback lock signal and supplies a comparison result to the timing controller.
    Type: Grant
    Filed: September 4, 2009
    Date of Patent: July 3, 2012
    Assignee: LG Display Co., Ltd.
    Inventors: Jincheol Hong, Seungcheol Oh, Changhun Cho
  • Patent number: 7948465
    Abstract: A liquid crystal display and a method of driving the same are disclosed. The liquid crystal display includes a timing controller, N source drive integrated circuits (ICs), where N is an integer equal to or greater than 2, N pairs of data bus lines, each of which connects the timing controller to each of the N source drive ICs in a point-to-point manner, a lock check line that connects a first source drive IC of the N source drive ICs to the timing controller and cascade-connects the N source drive ICs to one another, and a feedback lock check line connecting a last source drive IC of the N source drive ICs to the timing controller. A swing width of an output voltage of the timing controller increases in proportion to a distance between the timing controller and the N source drive ICs.
    Type: Grant
    Filed: August 7, 2009
    Date of Patent: May 24, 2011
    Assignee: LG Display Co., Ltd.
    Inventors: Soondong Cho, Pilsung Kang, Mangyu Park, Jeongho Kang, Yangseok Jeong, Geunwoo Koh, Changhun Cho, Hyunchul Kim
  • Publication number: 20100277494
    Abstract: A liquid crystal display device and a method of driving the same are disclosed. The liquid crystal display device includes a liquid crystal display panel including data lines, gate lines crossing the data lines, and liquid crystal cells arranged in a matrix format at each of crossings of the data lines and the gate lines; a data drive circuit that converts digital video data into a positive/negative data voltage using gamma reference voltages to supply the positive/negative data voltage to the data lines; and a gamma voltage adjusting unit that increases a potential of each of the gamma reference voltages during a blanking period when a polarity of the positive/negative data voltage is inverted.
    Type: Application
    Filed: October 16, 2009
    Publication date: November 4, 2010
    Inventors: Changhun CHO, Jinsung Kim, Hyunchul Kim
  • Publication number: 20100156885
    Abstract: A liquid crystal display and a method of driving the same are disclosed. The liquid crystal display includes a timing controller, N source drive integrated circuits (ICs), where N is an integer equal to or greater than 2, N pairs of data bus lines, each of which connects the timing controller to each of the N source drive ICs in a point-to-point manner, a lock check line that connects a first source drive IC of the N source drive ICs to the timing controller and cascade-connects the N source drive ICs to one another, and a feedback lock check line connecting a last source drive IC of the N source drive ICs to the timing controller. A swing width of an output voltage of the timing controller increases in proportion to a distance between the timing controller and the N source drive ICs.
    Type: Application
    Filed: August 7, 2009
    Publication date: June 24, 2010
    Inventors: Soondong CHO, Pilsung Kang, Mangyu Park, Jeongho Kang, Yangseok Jeong, Geunwoo Koh, Changhun Cho, Hyunchul Kim
  • Publication number: 20100156879
    Abstract: A liquid crystal display and a method of driving the same are provided. The liquid crystal display includes a first source drive IC group outputting a first feedback lock signal in response to one of a power voltage input through a first lock signal input terminal and a lock signal from the timing controller, a second source drive IC group outputting a second feedback lock signal in response to one of the power voltage input through a second lock signal input terminal, the lock signal from the timing controller, and a lock signal transferred from the first source drive IC group, and a comparator that compares the first feedback lock signal with the second feedback lock signal and supplies a comparison result to the timing controller.
    Type: Application
    Filed: September 4, 2009
    Publication date: June 24, 2010
    Inventors: Jincheol Hong, Seungcheol Oh, Changhun Cho