Patents by Inventor Ho-Hak Rho

Ho-Hak Rho 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: 20170004799
    Abstract: An output buffer circuit is provided. The output buffer circuit includes a fast slew rate (FSR) controller that detects a transition duration of an input voltage, to adjust a magnitude of a detection current generated in the detected transition duration based on information on a slew slope, and to generate a slew rate control signal as the adjustment result, and an output buffer that outputs the input voltage as a source drive signal having a slew rate or a slew slope, which is selected, in response to the slew rate control signal.
    Type: Application
    Filed: June 27, 2016
    Publication date: January 5, 2017
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Gyu-Sung PARK, Seungjung LEE, Ho Hak RHO, Junkwan PARK
  • Publication number: 20150325200
    Abstract: Provided are a source driver configured to drive a display panel and a display device including the same. A source driver configured to drive a source line of a display panel includes a digital circuit configured to receive and store digital pixel data, and an analog circuit configured to convert the stored digital pixel data into an analog-signal-type gradation voltage and output the analog-signal-type gradation voltage. A static current of the analog circuit is reduced in response to a value of a timing signal corresponding to a non-driving section of the display panel.
    Type: Application
    Filed: May 7, 2015
    Publication date: November 12, 2015
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Ho-hak RHO, Gyu-sung PARK, Seung-jung LEE, Jun-kwan PARK
  • Patent number: 8872859
    Abstract: Provided are a method of driving a liquid crystal panel which prevents unintended digital image data from being displayed on a liquid crystal panel when power is provided or interrupted, and a source driver and a liquid crystal display apparatus. The source driver includes output buffers; output pads; and a switching unit which is disposed between the output buffers and the output pads and controls an electrical connection state of the output pads. If a level up or a level down of a power voltage occurs, the switching unit prevents output signals of the output buffers from being transmitted to the liquid crystal panel via corresponding output pads and performs at least one of a charge sharing operation for connecting the output pads to each other and a discharging operation for providing a discharge path from the output pads to a ground terminal, in a preset period.
    Type: Grant
    Filed: February 9, 2011
    Date of Patent: October 28, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-hong Ko, Do-youn Kim, Ho-hak Rho, Kee-moon Chun, Jae-suk Yu
  • Patent number: 8817500
    Abstract: A power supply apparatus and a power supply method are disclosed. The power supply apparatus may include an internal power supply including a first voltage generator configured to generate a first voltage based on a pulse width modulation control signal, a charge pump configured to receive the first voltage and generate a second voltage, and an inrush current controller configured to be connected between the charge pump and the internal power supply and configured to generate the pulse width modulation control signal based on a target signal and a selection reference voltage.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: August 26, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Seung Jung Lee, Hun Lim, Ho Hak Rho, Gyu-Sung Park
  • Publication number: 20140111501
    Abstract: A power-off discharge circuit comprises a power voltage detection unit that detects whether a first power voltage for driving a source driver circuit is blocked and generates a discharge control signal, and a discharge unit that discharges a load circuit in a display panel based on the discharge control signal.
    Type: Application
    Filed: December 24, 2013
    Publication date: April 24, 2014
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jae-hong KO, Ho-hak RHO, Do-Yoon KIM
  • Patent number: 8619069
    Abstract: A power-off discharge circuit comprises a power voltage detection unit that detects whether a first power voltage for driving a source driver circuit is blocked and generates a discharge control signal, and a discharge unit that discharges a load circuit in a display panel based on the discharge control signal.
    Type: Grant
    Filed: June 29, 2010
    Date of Patent: December 31, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Hong Ko, Ho-Hak Rho, Do-Yoon Kim
  • Patent number: 8264260
    Abstract: Provided are a delay locked loop (DLL) having a pulse width detection circuit and a method of driving the DLL. The DLL includes a pulse width detection circuit and a delay circuit. The pulse width detection circuit receives a reference clock signal, detects a pulse width of the reference clock signal, and outputs the detection result as a pulse width detection result signal. The delay circuit receives and delays the reference clock signal, and outputs the delayed reference clock signal as an output clock signal. The delay circuit receives the pulse width detection result signal from the pulse width detection circuit, and controls a time delay in the reference clock signal in response to the pulse width detection result signal.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: September 11, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-hong Ko, Ho-Hak Rho, Paul Kim
  • Publication number: 20120212201
    Abstract: A power supply apparatus and a power supply method are disclosed. The power supply apparatus may include an internal power supply including a first voltage generator configured to generate a first voltage based on a pulse width modulation control signal, a charge pump configured to receive the first voltage and generate a second voltage, and an inrush current controller configured to be connected between the charge pump and the internal power supply and configured to generate the pulse width modulation control signal based on a target signal and a selection reference voltage.
    Type: Application
    Filed: February 2, 2012
    Publication date: August 23, 2012
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Seung Jung Lee, Hun Lim, Ho Hak Rho, Gyu-Sung Park
  • Publication number: 20110199397
    Abstract: Provided are a method of driving a liquid crystal panel which prevents unintended digital image data from being displayed on a liquid crystal panel when power is provided or interrupted, and a source driver and a liquid crystal display apparatus. The source driver includes output buffers; output pads; and a switching unit which is disposed between the output buffers and the output pads and controls an electrical connection state of the output pads. If a level up or a level down of a power voltage occurs, the switching unit prevents output signals of the output buffers from being transmitted to the liquid crystal panel via corresponding output pads and performs at least one of a charge sharing operation for connecting the output pads to each other and a discharging operation for providing a discharge path from the output pads to a ground terminal, in a preset period.
    Type: Application
    Filed: February 9, 2011
    Publication date: August 18, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jae-hong KO, Do-youn KIM, Ho-hak RHO, Kee-moon CHUN, Jae-suk YU
  • Publication number: 20110012888
    Abstract: A power-off discharge circuit comprises a power voltage detection unit that detects whether a first power voltage for driving a source driver circuit is blocked and generates a discharge control signal, and a discharge unit that discharges a load circuit in a display panel based on the discharge control signal.
    Type: Application
    Filed: June 29, 2010
    Publication date: January 20, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jae-Hong KO, Ho-Hak RHO, Do-Yoon KIM
  • Publication number: 20100264968
    Abstract: Provided are a delay locked loop (DLL) having a pulse width detection circuit and a method of driving the DLL. The DLL includes a pulse width detection circuit and a delay circuit. The pulse width detection circuit receives a reference clock signal, detects a pulse width of the reference clock signal, and outputs the detection result as a pulse width detection result signal. The delay circuit receives and delays the reference clock signal, and outputs the delayed reference clock signal as an output clock signal. The delay circuit receives the pulse width detection result signal from the pulse width detection circuit, and controls a time delay in the reference clock signal in response to the pulse width detection result signal.
    Type: Application
    Filed: March 12, 2010
    Publication date: October 21, 2010
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jae-hong Ko, Ho-hak Rho, Paul Kim