Patents by Inventor Changhee Kim

Changhee Kim 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: 20180061913
    Abstract: A display and degradation sensing method, includes a display panel having a plurality of pixels that each comprise an Organic Light Emitting Diode (OLED) and Thin Film Transistor (TFT). The pixels are divided into multiple pixel groups of two or more pixels, each connected to different data lines but to the same gate and sensing lines. A gate driving circuit supplies a scan control signal to the gate line. A data driving circuit selectively supplies turn-on driving data voltage and turn-off data voltage to the data lines in sync with the scan control signal; a sensing circuit outputs (i) a first sensing value based upon an OLED threshold voltage of a sensing pixel, and (ii) a second sensing value based upon a kickback current. A sensing value correction circuit determines a final sensing value for the OLED threshold voltage based on the first sensing value and the second sensing value.
    Type: Application
    Filed: August 24, 2017
    Publication date: March 1, 2018
    Inventors: Changhee KIM, Hyemin PARK
  • Patent number: 9449560
    Abstract: An organic light emitting display includes a display panel including a plurality of pixels, each of the plurality of pixels including an organic light emitting diode (OLED) and a driving thin film transistor (TFT) to control an emission amount of the OLED, the plurality of pixels connected to respective sensing lines; and at least one sensing unit connected to a corresponding one of the pixels through the respective sensing line, the at least one sensing unit configured to sense an amount of carriers accumulated in a parasitic capacitor of the OLED of the corresponding one of the pixels when a driving current flows in the OLED, the at least one sensing unit thereby sensing a degradation of the OLED.
    Type: Grant
    Filed: December 29, 2014
    Date of Patent: September 20, 2016
    Assignee: LG Display Co., Ltd.
    Inventors: Hyemi Oh, Hunki Shin, Changhee Kim
  • Patent number: 9396675
    Abstract: A method for sensing degradation of an organic light emitting display includes an initialization step for applying a sensing data voltage to a gate node of a driving TFT and applying an initialization voltage to a source node of the driving TFT, a boosting step for floating the gate node and the source node of the driving TFT and applying a drain-to-source current of the driving TFT to an organic element, a sensing step for again applying the initialization voltage to the source node of the driving TFT, setting a gate-to-source voltage of the driving TFT depending on a degradation degree of the organic element, and storing the drain-to-source current of the driving TFT determined by the set gate-to-source voltage in a line capacitor, and a sampling step for outputting a voltage stored in the line capacitor as a sensing voltage.
    Type: Grant
    Filed: December 29, 2014
    Date of Patent: July 19, 2016
    Assignee: LG DISPLAY CO., LTD.
    Inventors: Changhee Kim, Kilhwan Oh, Hunki Shin
  • Publication number: 20160071445
    Abstract: A method for sensing degradation of an organic light emitting display includes an initialization step for applying a sensing data voltage to a gate node of a driving TFT and applying an initialization voltage to a source node of the driving TFT, a boosting step for floating the gate node and the source node of the driving TFT and applying a drain-to-source current of the driving TFT to an organic element, a sensing step for again applying the initialization voltage to the source node of the driving TFT, setting a gate-to-source voltage of the driving TFT depending on a degradation degree of the organic element, and storing the drain-to-source current of the driving TFT determined by the set gate-to-source voltage in a line capacitor, and a sampling step for outputting a voltage stored in the line capacitor as a sensing voltage.
    Type: Application
    Filed: December 29, 2014
    Publication date: March 10, 2016
    Inventors: Changhee KIM, Kilhwan OH, Hunki SHIN
  • Publication number: 20160012798
    Abstract: An organic light emitting display includes a display panel including a plurality of pixels, each of the plurality of pixels including an organic light emitting diode (OLED) and a driving thin film transistor (TFT) to control an emission amount of the OLED, the plurality of pixels connected to respective sensing lines; and at least one sensing unit connected to a corresponding one of the pixels through the respective sensing line, the at least one sensing unit configured to sense an amount of carriers accumulated in a parasitic capacitor of the OLED of the corresponding one of the pixels when a driving current flows in the OLED, the at least one sensing unit thereby sensing a degradation of the OLED.
    Type: Application
    Filed: December 29, 2014
    Publication date: January 14, 2016
    Applicant: LG Display Co., Ltd.
    Inventors: Hyemi OH, Hunki SHIN, Changhee KIM
  • Patent number: 7619187
    Abstract: Disclosed herein is a porous ceramic heating element wherein 0.08 to 1.00 wt % of a foaming agent is added in 99.00 to 99.92 wt % of a mixture of an inorganic material, a binder, a conductive material, a hardener, a bonding agent and a dispersion medium and mixed with the mixture. The bonding strength of porous foam formed in the ceramic heating element is increased, thereby providing an effect that the entire structure is hardened.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: November 17, 2009
    Inventors: Changhee Kim, Taehee Kim
  • Publication number: 20070003750
    Abstract: The present invention provides a porous ceramic heating element wherein 0.08 to 1.00 wt % of a foaming agent is added in 99.00 to 99.92 wt % of a mixture of an inorganic material, a binder, a conductive material, a hardener, a bonding agent and a dispersion medium and mixed with the mixture. According to the porous ceramic heating element, the bonding strength of porous foam formed in the ceramic heating element becomes strong, thereby providing an effect that the entire structure is hardened.
    Type: Application
    Filed: September 24, 2004
    Publication date: January 4, 2007
    Inventors: Changhee Kim, Taehee Kim