Patents by Inventor Cheng-Lung Chiang

Cheng-Lung Chiang 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: 20120007520
    Abstract: A driver for driving a light emitting device includes an output stage and a driving stage. The output stage is for outputting a driving current to the light emitting device according to a driving signal, wherein the light emitting device is coupled between the output stage and a second reference voltage different from the first reference voltage. The driving stage is for generating the driving signal to the output stage, wherein one of the third reference voltage and the fourth reference voltage is within a range between the first reference voltage and the second reference voltage, and the other of the third reference voltage and the fourth reference voltage is outside the range between the first reference voltage and the second reference voltage.
    Type: Application
    Filed: July 6, 2010
    Publication date: January 12, 2012
    Inventor: Cheng-Lung Chiang
  • Patent number: 8054306
    Abstract: A circuit providing a common voltage for a panel of a display includes a first operational amplifier, a second operational amplifier, a third operational amplifier, a capacitor and a switch circuit. The first operational amplifier outputs a first voltage. The second operational amplifier is powered by the first voltage and receives a polarity signal to output a second voltage. The third operational amplifier outputs a third voltage. The capacitor has a first end coupled to an output of the second operational amplifier and a second end coupled to an output of the third operational amplifier. The switch circuit couples the second end of the capacitor to the panel during a normal operation of the display, and couples one of a high constant voltage and a low constant voltage to the panel during a power saving operation of the display.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: November 8, 2011
    Assignee: Himax Technologies Limited
    Inventors: Cheng-Lung Chiang, Chin-Chan Chang
  • Publication number: 20100220084
    Abstract: A source driver with low consumption and the driving method thereof are provided herein. The source driver includes an output buffer with a first input terminal receiving a pixel signal, a second input terminal, and an output terminal coupled to the second input terminal and a display panel. The source driver also includes a pre-charge circuit pre-charges a first terminal of the display panel to a first preset voltage or a second preset voltage for a pre-charge period according to a polarity of a common voltage coupled to the display panel. The second preset voltage is smaller than the first preset voltage. The output buffer is inactivated during the pre-charge period and activated for a preset period after the pre-charge period. Therefore, the present invention reduces power consumption of the source driver.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 2, 2010
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventors: Cheng-Lung Chiang, Way-Guo Tseng, Jui-Lin Chang
  • Publication number: 20100220095
    Abstract: A source driver adapted to drive a display panel and a driving method thereof are provided herein. The source driver includes an output buffer and a first pre-charge circuit. The output buffer has a first input terminal receiving a pixel signal and has both of a second input terminal and an output terminal coupled to the display panel. The first pre-charge circuit charges the output terminal of the output buffer to a preset voltage associated with the pixel signal for a pre-charge period. The output buffer is inactivated during the pre-charge period and is activated for a preset period after the pre-charge period. Therefore, power consumption of the source driver can be reduced.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 2, 2010
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventors: Ming-Cheng Chiu, Cheng-Lung Chiang, Way-Guo Tseng
  • Publication number: 20100134400
    Abstract: A liquid crystal display (LCD) device with reduced power consumption is provided with a plurality of data lines, a plurality of gate lines, and at least one multiplexer. Each multiplexer can comprise a plurality of switches respectively connected to the corresponding data lines and controlled by a plurality of clock signals and configured to receive an image signal, and selectively output the image signal to one of the data lines via the switches. During a driving period, one of the gate lines can be asserted, and the switches can be turned on simultaneously, then only the first one of the switches remains turned on to transmit the image signal to the corresponding data line, and then the first one of the switches are turned off and the other switches are sequentially turned on one at a time to transmit the image signal to the corresponding data lines.
    Type: Application
    Filed: December 1, 2008
    Publication date: June 3, 2010
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventors: Cheng-Lung Chiang, Ming-Cheng Chiu
  • Publication number: 20090122044
    Abstract: A circuit providing a common voltage for a panel of a display includes a first operational amplifier, a second operational amplifier, a third operational amplifier, a capacitor and a switch circuit. The first operational amplifier outputs a first voltage. The second operational amplifier is powered by the first voltage and receives a polarity signal to output a second voltage. The third operational amplifier outputs a third voltage. The capacitor has a first end coupled to an output of the second operational amplifier and a second end coupled to an output of the third operational amplifier. The switch circuit couples the second end of the capacitor to the panel during a normal operation of the display, and couples one of a high constant voltage and a low constant voltage to the panel during a power saving operation of the display.
    Type: Application
    Filed: November 8, 2007
    Publication date: May 14, 2009
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventors: Cheng-Lung CHIANG, Chin-Chan Chang
  • Patent number: 7522081
    Abstract: For reducing device areas required by digital-to-analog converters used in source driving circuits of a liquid crystal display device, a compound circuit structure based on a pre-decoder, a binary decoder, and ROM decoders is set forth to meet the demand for cutting down the device areas. The pre-decoder is configured to decode a first sub-signal of a digital data signal for generating a plurality of control signals. Each of the ROM decoders is configured to select a gamma reference voltage out of one corresponding set of gamma reference voltages based on the control signals and a second sub-signal of the digital data signal. The binary decoder is configured to select one of the gamma reference voltages selected by the ROM decoders based on a third sub-signal of the digital data signal for outputting an output voltage. The number of transistors used by the compound circuit structure is then reduced significantly.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: April 21, 2009
    Assignee: Himax Technologies Limited
    Inventors: Cheng-Lung Chiang, Ming-Cheng Chiu, Ting-Jung Ku
  • Patent number: 7426132
    Abstract: An SRAM device is disclosed, which comprises a plurality of rows of SRAM cells and a line-buffer SRAM cell. Each row of SRAM cells is controlled by a word line. The line-buffer SRAM cell is coupled to the rows of SRAM cells and controlled by a read enable line. The signal on the read enable line is activated after the signal on the word line is activated, and part of the activated signal on the read enable line overlaps with the activated signal on the word line. The power provided to the line-buffer SRAM cell is selectively cut off.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: September 16, 2008
    Assignee: Himax Technologies, Inc.
    Inventors: Cheng-Lung Chiang, Ming-Cheng Chiu
  • Publication number: 20070211518
    Abstract: An SRAM device is disclosed, which comprises a plurality of rows of SRAM cells and a line-buffer SRAM cell. Each row of SRAM cells is controlled by a word line. The line-buffer SRAM cell is coupled to the rows of SRAM cells and controlled by a read enable line. The signal on the read enable line is activated after the signal on the word line is activated, and part of the activated signal on the read enable line overlaps with the activated signal on the word line. The power provided to the line-buffer SRAM cell is selectively cut off. Alternatively, the power provided to the line-buffer SRAM cell is cut off when the signal on the read enable line is deactivated.
    Type: Application
    Filed: March 13, 2006
    Publication date: September 13, 2007
    Inventors: Cheng-Lung Chiang, Ming-Cheng Chiu
  • Patent number: 7224126
    Abstract: An organic light emitting display (OLED) panel has a plurality of organic light emitting diodes. The organic light emitting diodes are electrically connected to a plurality of segment lines and a plurality of common lines in a matrix structure. The organic light emitting diodes electrically connected to the same common lines are divided into a first group and a second group. Driving currents are separately supplied to the organic light emitting diodes of the first group and the second group according to a first pulse width modulation (PWM) manner and a second PWM manner. The first PWM manner and the second PWM manner have complementary waveforms in a period.
    Type: Grant
    Filed: July 7, 2005
    Date of Patent: May 29, 2007
    Assignee: Himax Technologies, Inc.
    Inventors: Yu-Wen Chiou, Cheng-Lung Chiang
  • Publication number: 20070008256
    Abstract: An organic light emitting display (OLED) panel has a plurality of organic light emitting diodes. The organic light emitting diodes are electrically connected to a plurality of segment lines and a plurality of common lines in a matrix structure. The organic light emitting diodes electrically connected to the same common lines are divided into a first group and a second group. Driving currents are separately supplied to the organic light emitting diodes of the first group and the second group according to a first pulse width modulation (PWM) manner and a second PWM manner. The first PWM manner and the second PWM manner have complementary waveforms in a period.
    Type: Application
    Filed: July 7, 2005
    Publication date: January 11, 2007
    Applicant: HIMAX TECHNOLOGIES, INC.
    Inventors: Yu-Wen Chiou, Cheng-Lung Chiang