Patents by Inventor Chul Sang Jang
Chul Sang Jang 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).
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Patent number: 8362935Abstract: The present invention relates to device and method for controlling a reference voltage of a digital-to-analog converter for minimizing variation of output voltages among LED driving chips which drive an LED (Light Emitting Diode) backlight.Type: GrantFiled: July 21, 2011Date of Patent: January 29, 2013Assignee: LG Display Co., Ltd.Inventors: Sun-Kyung Shin, Chul-Sang Jang
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Publication number: 20120146826Abstract: The present invention relates to device and method for controlling a reference voltage of a digital-to-analog converter for minimizing variation of output voltages among LED driving chips which drive an LED (Light Emitting Diode) backlight.Type: ApplicationFiled: July 21, 2011Publication date: June 14, 2012Inventors: Sun-Kyung SHIN, Chul-Sang JANG
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Patent number: 8179347Abstract: An apparatus and a method of driving a liquid crystal display device include receiving gamma-treated data, performing a reverse gamma correction of the data, the reverse-gamma-corrected data having a first linear characteristic, performing a signal processing of the reverse-gamma-corrected data having the first linear characteristic, performing a gamma correction of the processed data, and generating data signals based on the gamma-corrected data using analog voltage values, the data signals having a second linear characteristic.Type: GrantFiled: June 29, 2004Date of Patent: May 15, 2012Assignee: LG Display Co., Ltd.Inventors: Eui Yeol Oh, Ki Duk Kim, Chul Sang Jang
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Patent number: 8031156Abstract: A data driving circuit of a liquid crystal display for selectively switching and multiplexing voltages in accordance with a bit order of input data is disclosed. The data driver circuit includes: a voltage distributor that selects one of a first voltage and a second voltages as first output voltage in accordance with the most significant bit of input data including a plurality of n data bits, that multiplexes the first voltage and the second voltage to be output as one of more multiplexed output voltage is one of the first voltage and the second voltage selected in accordance with bits of the input data lower in significance than the most significant bit, and that outputs the first voltage as a final output voltage; and an output buffer that is driven by the first output voltage, the one or more multiplexed output voltages, and the final output voltage.Type: GrantFiled: June 29, 2007Date of Patent: October 4, 2011Assignee: LG Display Co., Ltd.Inventors: Chul Sang Jang, Jin Chul Choi
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Patent number: 7986288Abstract: An LCD with reduced power consumption is described. The LCD includes a liquid crystal panel having a plurality of gate lines and data lines, a data driver supplying a data voltage to the plurality of data lines, a controller generating a current control signal to control an output terminal of the data driver so that the output terminal operates during a first period in which data is outputted from the data driver, and the output terminal does not operate during a second period in which data is not outputted from the data driver, and a gate driver that supplies a scan signal to the plurality of the gate lines.Type: GrantFiled: July 27, 2006Date of Patent: July 26, 2011Assignee: LG Display Co., Ltd.Inventors: Chul Sang Jang, Jin Chul Choi
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Patent number: 7928998Abstract: A method and apparatus for driving a liquid crystal display improves a picture quality displayed by a liquid crystal display. A brightness adjuster adjusts a brightness component of input video data and a brightness controller returns the adjusted brightness component to the brightness adjuster when the a value of the adjusted brightness component is outside a predetermined brightness reference range until the brightness adjuster produces a brightness component that is within the predetermined brightness reference range.Type: GrantFiled: June 28, 2004Date of Patent: April 19, 2011Assignee: LG Display Co., Ltd.Inventor: Chul Sang Jang
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Patent number: 7876300Abstract: A driving method and apparatus for a liquid crystal display uses a comparison between the previous frame and the current frame to expand the contrast ratio and reduce the manufacturing cost. A limited amount of data from the current image may be used: either using a limited area of the image or merely the amount of green in the overall image or the limited area. In the apparatus, an image signal modulator expands the contrast of the input data when the previous image is analogous to the current image to thereby generate output data. A timing controller re-arranges the output data to apply the output data to a data driver.Type: GrantFiled: March 10, 2010Date of Patent: January 25, 2011Assignee: LG Display Co., Ltd.Inventors: Seong Ho Baik, Chul Sang Jang
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Patent number: 7839395Abstract: A flat panel display device may improve picture quality by compensating a panel defect by use of a circuit and a picture quality controlling method. A flat panel display device includes a display panel. A memory stores a location information and a compensation value for a panel defect location on the display panel. A first converter calculates a brightness and color difference signals from red, green, blue video signals to be displayed in the display panel. The first converter expands the number of data bits of the brightness signal to generate the expanded brightness signal. A compensating part generates a compensated brightness signal by increasing or decreasing the expanded brightness signal of the video signal to be displayed in the panel defect location. A second converter calculates the red, green, blue signals from the color difference signal and the compensated brightness signal, and generates the compensated video signal by reducing the number of bits of the calculated red, green, blue signals.Type: GrantFiled: June 29, 2006Date of Patent: November 23, 2010Assignee: LG. Display Co., Ltd.Inventors: In Jae Chung, Chul Sang Jang, Young Woo Choi, Jong Hee Hwang
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Patent number: 7834836Abstract: A flat panel display device includes a display panel, a memory storing a compensation value that corresponds to a panel defect location, the panel defect location being where any one of a brightness and a color difference exists compared to other part of the display panel, a compensating unit to adjust image data to be displayed in the panel defect location using the compensation value, and a driver to apply the adjusted image data from the compensating unit to the display panel.Type: GrantFiled: June 30, 2006Date of Patent: November 16, 2010Assignee: LG Display Co., Ltd.Inventors: In Jae Chung, Chul Sang Jang, Sung Hak Jo, Deuk Su Lee, Jong Hoon Kim, Jong Hee Hwang
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Publication number: 20100165010Abstract: A driving method and apparatus for a liquid crystal display uses a comparison between the previous frame and the current frame to expand the contrast ratio and reduce the manufacturing cost. A limited amount of data from the current image may be used: either using a limited area of the image or merely the amount of green in the overall image or the limited area. In the apparatus, an image signal modulator expands the contrast of the input data when the previous image is analogous to the current image to thereby generate output data. A timing controller re-arranges the output data to apply the output data to a data driver.Type: ApplicationFiled: March 10, 2010Publication date: July 1, 2010Applicant: LG Display Co., Ltd.Inventors: Seong Ho Baik, Chul Sang Jang
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Patent number: 7746334Abstract: A driving apparatus of a liquid crystal display device includes a liquid crystal display panel display a video signal by use of a liquid crystal cell of a matrix shape. A plurality of data drive circuits generate a polarity pattern of the video signal in accordance with a polarity signal and supply the polarity pattern to the liquid crystal cell through a plurality of output channels. A polarity controller controls the polarity signal and supplies the polarity signal to the data drive circuits on the basis of a first selection signal corresponding to the number of the output channels of one drive circuit and a second selection signal corresponding to a repetition period of the polarity pattern.Type: GrantFiled: May 27, 2005Date of Patent: June 29, 2010Assignee: LG. Display Co., Ltd.Inventors: Dong Hoon Lee, Juhn Suk Yoo, Chul Sang Jang, Oh Kyong Kwon
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Patent number: 7724230Abstract: A driving circuit of a display device includes a timing controller for combining p first digital data signals (p being a positive integer greater than 1) corresponding to colors for displaying images to generate q second digital data signals and for supplying the q second digital data signals to first to qth data transmission lines (q being a positive integer smaller than p), and a plurality of data driver integrated circuits for processing the q second digital data signals from the timing controller to restore the p first digital data signals, converting the p restored digital data signals into analog data signals, and supplying the analog data signals to a display panel.Type: GrantFiled: March 15, 2006Date of Patent: May 25, 2010Assignee: LG Display Co., Ltd.Inventors: Sun Young Kim, Chul Sang Jang, Jong Hoon Kim
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Patent number: 7705814Abstract: A driving method and apparatus for a liquid crystal display uses a comparison between the previous frame and the current frame to expand the contrast ratio and reduce the manufacturing cost. A limited amount of data from the current image may be used: either using a limited area of the image or merely the amount of green in the overall image or the limited area. In the apparatus, an image signal modulator expands the contrast of the input data when the previous image is analogous to the current image to thereby generate output data. A timing controller re-arranges the output data to apply the output data to a data driver.Type: GrantFiled: June 28, 2004Date of Patent: April 27, 2010Assignee: LG. Display Co., Ltd.Inventors: Seong Ho Baik, Chul Sang Jang
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Patent number: 7688301Abstract: A driving apparatus of a liquid crystal display device according to an embodiment of the present invention includes a liquid crystal display panel having a liquid crystal cell of a matrix shape to display a video signal; N (where N is a positive integer) number of data drive circuits that generate a polarity pattern of the video signal and supply it to the liquid crystal cell through a plurality of output channels; and a polarity controller that controls the polarity signal and supplies it to the N number of the data drive circuits on the basis of a first selection signal corresponding to the number of the output channels and a second selection signal corresponding to a repetition period of the polarity pattern.Type: GrantFiled: March 30, 2005Date of Patent: March 30, 2010Assignee: LG Display Co., Ltd.Inventors: Dong Hoon Lee, Juhn Suk Yoo, Chul Sang Jang, Oh Kyong Kwon
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Patent number: 7663588Abstract: A circuit for driving a liquid crystal display device, as embodied, includes: a gray level voltage generator for generating a plurality of gray level voltages; and an intermediate gray level voltage generator for receiving a first gray level voltage and a second gray level voltage among the plurality of gray level voltages and for selectively outputting one of the first gray level voltage and a third gray level voltage through a plurality of capacitors, a value of the third gray level voltage being between the first and second gray level voltage and set by the plurality of capacitors, the intermediate gray level voltage generator including: an operational amplifier for pre-charging the plurality of capacitors using a current outputted from the operational amplifier and for selectively outputting one of the first gray level voltage and the third gray level voltage.Type: GrantFiled: June 29, 2006Date of Patent: February 16, 2010Assignee: LG Display Co., Ltd.Inventors: Chul Sang Jang, Jin Chul Choi
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Patent number: 7629956Abstract: An apparatus and method for driving an image display device is disclosed, in which data signals are transmitted in a multilevel to reduce transmission frequencies, power consumption and transmission lines. The apparatus for driving an image display device includes a display panel including an image display unit for displaying images, a plurality of data driver integrated circuits supplying image signals to the image display unit, and a timing controller converting externally supplied i bit digital source data (i is a positive number) to a plurality of voltage levels to supply the converted voltage levels to the respective data driver integrated circuits and controlling the data driver integrated circuits.Type: GrantFiled: December 13, 2005Date of Patent: December 8, 2009Assignee: LG. Display Co., Ltd.Inventors: Chul Sang Jang, Jong Hoon Kim
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Publication number: 20080278427Abstract: An LCD with reduced power consumption is described. The LCD includes a liquid crystal panel having a plurality of gate lines and data lines, a data driver supplying a data voltage to the plurality of data lines, a controller generating a current control signal to control an output terminal of the data driver so that the output terminal operates during a first period in which data is outputted from the data driver, and the output terminal does not operate during a second period in which data is not outputted from the data driver, and a gate driver that supplies a scan signal to the plurality of the gate lines.Type: ApplicationFiled: July 27, 2006Publication date: November 13, 2008Inventors: Chul Sang Jang, Jin Chul Choi
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Publication number: 20080001149Abstract: A data driving circuit of a liquid crystal display for selectively switching and multiplexing voltages in accordance with a bit order of input data is disclosed. The data driver circuit includes: a voltage distributor that selects between outputting a first voltage and a second voltage as first output voltage in accordance with the most significant bit of input data including a plurality of n data bits, that multiplexes the first voltage and the second voltage to be output as one or more multiplexed output voltages wherein each of the one or more multiplexed output voltage is one of the first voltage and the second voltage selected in accordance with bits of the input data lower in significance than the most significant bit, and that outputs the first voltage as a final output voltage; and an output buffer that is driven by the first output voltage, the multiplexed output voltage, and the final output voltage.Type: ApplicationFiled: June 29, 2007Publication date: January 3, 2008Inventors: Chul Sang Jang, Jin Chul Choi
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Patent number: 6597395Abstract: The black level calibration apparatus includes a black level clamp circuit which generates a black level clamp signal based on a calibrated reference voltage. A correlated double sampling/automatic gain control (CDS/AGS) circuit performs sample/hold and automatic gain control operations on an analog image signal based on the black level clamping signals. An analog-to-digital converter converts the analog image output from the CDS/AGS circuit into a digital image signal. A control signal setting circuit compares the black level value of the digital image signal with a black level calibration value, and sets a digital control signal based on the comparison. A reference voltage calibration circuit generates the calibrated reference voltage in accordance with the digital control signal.Type: GrantFiled: February 16, 1999Date of Patent: July 22, 2003Assignee: Hyundai Electronics Industries Co., Ltd.Inventors: Min Gyu Kim, Chul Sang Jang
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Patent number: 5946270Abstract: An over power supply voltage cut-off circuit includes: a power supply voltage supplying path switching part for switching a supplying path of the power supply voltage provided to the power consumption type of load from the power supply voltage generating part in accordance with a driving control signal; a voltage sensing part for sensing an abnormal voltage, in case where a level of the power supply voltage generated from the power supply voltage generating part is over a predetermined set voltage level; and a control signal converting part for converting the driving control signal supplied to the power supply voltage supplying path switching part from the voltage sensing part into a transmission cut-off control signal in accordance with a sensing signal outputted from the voltage sensing part.Type: GrantFiled: April 15, 1997Date of Patent: August 31, 1999Assignee: LG Semicon Co., Ltd.Inventor: Chul-Sang Jang