Patents by Inventor Meng Liu

Meng Liu 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).

  • Multi-color backlight control circuit and multi-color backlight control method
    Patent number: 8072153
    Abstract: The present invention discloses a multi-color backlight control circuit, comprising: a plurality of pins for electrically connecting with a plurality of LED strings of different LED colors; and a voltage supply circuit for receiving an input voltage and supplying a single output voltage to the plurality of LED strings of different LED colors. The present invention also discloses a multi-color backlight control method, comprising: supplying a single output voltage to a plurality of LED strings of different LED colors.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: December 6, 2011
    Assignee: Richtek Technology Corporation R.O.C.
    Inventor: Jing-Meng Liu
  • FLAT PANEL DISPLAY, LIGHT EMITTING MODULE FOR USE IN FLAT PANEL DISPLAY, AND INTEGRATED CIRCUIT FOR USE IN LIGHT EMITTING MODULE
    Publication number: 20110273101
    Abstract: The present invention discloses a flat panel display (FPD), a light emitting module for use in the FPD, and an integrated circuit for use in the light emitting module. The light emitting module includes: at least one light emitting device string; and a local circuit for controlling current through the light emitting device string and generating a local feedback signal, wherein the local circuit has a first terminal for receiving power, a second terminal for coupling to the light emitting device string to control the current through the light emitting device string, a third terminal for generating the local feedback signal, and a fourth terminal for coupling to ground. The wiring of the FPD is therefore simplified.
    Type: Application
    Filed: April 28, 2011
    Publication date: November 10, 2011
    Inventor: Jing-Meng LIU
  • Universal serial bus charger circuit and charging method
    Patent number: 8049462
    Abstract: The present invention discloses a universal serial bus (USB) charging circuit, comprising: a charging path for charging a battery from a USB host; a charging switch located on the charging path; a current sensing circuit for sensing current information on the charging path; a maximum available current detection circuit for detecting the maximum available current from the USB host; and a loop controller circuit for controlling the charging switch so that the charging current on the charging path is substantially equal to the maximum available current detected by the maximum available current detection circuit, wherein the maximum available current detection circuit detects the maximum available current during circuit initialization and stores it.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: November 1, 2011
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu, Jing-Meng Liu
  • PROTECTION TO AVOID ABNORMAL OPERATION CAUSED BY A SHORTED PARAMETER SETTING PIN OF AN INTEGRATED CIRCUIT
    Publication number: 20110261492
    Abstract: For a system to avoid abnormal operation caused by a shorted parameter setting pin of an integrated circuit, a protection apparatus and method apply a buffered reference voltage to the parameter setting pin to define an internal parameter of the integrated circuit by the buffered reference voltage and an external element connected to the parameter setting pin, and detect the rapid variation of the internal parameter to trigger a shutdown signal or slow down the speed of the variation of the internal parameter reflected to an adjustable signal of the integrated circuit.
    Type: Application
    Filed: April 22, 2011
    Publication date: October 27, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: SHAO-HUNG LU, JING-MENG LIU, JO-YU WANG, ISAAC Y. CHEN, AN-TUNG CHEN
  • Backlight control circuit with low brightness variation when light emitting devices not operating
    Patent number: 8044920
    Abstract: The present invention discloses a backlight control circuit, and a method for controlling light emission devices. The method comprises: providing a plurality of light emission device paths connected in parallel; and setting a total current of the paths connected in parallel to a constant.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: October 25, 2011
    Assignee: Richtek Technology Corporation
    Inventors: Chiawei Liao, Jing-Meng Liu
  • Wireless Remote Control Lighting Unit and Wireless Remote Control Lighting System and Control Method Thereof
    Publication number: 20110248643
    Abstract: The present invention discloses a wireless remote control lighting unit and a wireless remote control lighting system and a control method thereof. The wireless remote control lighting unit comprises a power on detection circuit, which detects and counts the power on times of a power source during a predetermined period. When the power on times reach a threshold number, the wireless remote control lighting unit enters an address setting mode to set its address.
    Type: Application
    Filed: March 27, 2011
    Publication date: October 13, 2011
    Inventors: Jing-Meng Liu, Shen Tu
  • Backlight control circuit with under current detection and start-up control
    Patent number: 8035606
    Abstract: The present invention discloses a backlight control circuit, comprising: a voltage supply circuit for receiving an input voltage and generating an output voltage under control by a control signal; at least one voltage comparison path respectively coupled to at least one light emission device path; a voltage operative amplifier circuit for generating the control signal according to a lowest voltage on the at least one voltage comparison path; and at least one under current detection circuit for detecting whether a corresponding one of the at least one light emission device path is in an under current status, whereby when anyone of the under current detection circuits detects the under current status, it sends an exclusion signal excluding a corresponding one of the at least one voltage comparison path from being an effective input of the voltage operative amplifier.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: October 11, 2011
    Assignee: Richtek Technology Corporation
    Inventors: Chiawei Liao, Jing-Meng Liu
  • Dimming control circuit
    Patent number: 8026676
    Abstract: The present invention discloses a dimming control circuit, comprising: an input terminal for receiving an input signal; an analog and digital dimming circuit receiving the input signal, wherein the analog and digital dimming circuit provides an analog dimming function when a voltage level of the input signal is between a predetermined lower limit and a predetermined upper limit, and a digital dimming function when the voltage level of the input signal switches above and below the predetermined lower limit, and wherein the analog and digital dimming circuit generates an analog signal when the voltage level of the input signal is above the predetermined lower limit; and a power circuit for supplying an output current in correspondence to the analog signal generated by the analog and digital dimming circuit.
    Type: Grant
    Filed: December 4, 2008
    Date of Patent: September 27, 2011
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Jing-Meng Liu, Chiawei Liao, Leng-Nien Hsiu
  • THERMAL FOLDBACK CONTROL FOR A LIGHT-EMITTING DIODE
    Publication number: 20110163696
    Abstract: By monitoring the temperature of an LED and the temperature of a controller chip for the LED, a thermal foldback control is employed to gradually decrease the driving current of the LED before the LED or the controller chip is over heated, so as to prevent an over temperature protection from being triggered to shutdown the controller chip to cause the LED to undesirably flicker.
    Type: Application
    Filed: December 23, 2010
    Publication date: July 7, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: PEI-CHENG HUANG, JING-MENG LIU
  • LIGHT EMITTING DEVICE DRIVER CIRCUIT AND METHOD FOR DRIVING LIGHT EMITTING DEVICE
    Publication number: 20110133657
    Abstract: The present invention discloses a light emitting device driver circuit and a method for driving a light emitting device. In the present invention, the secondary windings of a transformer provide positive and negative secondary voltages, so as to generate positive and negative output voltages. A light emitting device circuit is coupled between the positive and negative output voltages. As such, the specification to withstand high voltage for a device in the circuit is reduced.
    Type: Application
    Filed: November 9, 2010
    Publication date: June 9, 2011
    Inventors: PEI-CHENG HUANG, Jing-Meng Liu, Roland Van Roy
  • Multi-Color Backlight Control Circuit and Multi-Color Backlight Control Method
    Publication number: 20110109234
    Abstract: The present invention discloses a multi-color backlight control circuit, comprising: a plurality of pins for electrically connecting with a plurality of LED strings of different LED colors; and a voltage supply circuit for receiving an input voltage and supplying a single output voltage to the plurality of LED strings of different LED colors. The present invention also discloses a multi-color backlight control method, comprising: supplying a single output voltage to a plurality of LED strings of different LED colors.
    Type: Application
    Filed: January 11, 2011
    Publication date: May 12, 2011
    Inventor: Jing-Meng Liu
  • Reduction of power consumption and EMI of a switching amplifier
    Patent number: 7911273
    Abstract: A switching amplifier has a network including current sources and resistors connected to the two output terminals of the H-bridge of the switching amplifier, to provide a small current to the load connected between the two output terminals at zero input, whereby the common mode voltage bouncing is reduced and the switching amplifier has less power consumption and reduced electro-magnetic interference.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: March 22, 2011
    Assignee: Richtek Technology Corp.
    Inventors: Jing-Meng Liu, Jwin-Yen Guo, Shao-Ming Sun
  • BOUNDARY CONDUCTION MODE SWITCHING REGULATOR AND DRIVER CIRCUIT AND CONTROL METHOD THEREOF
    Publication number: 20110057637
    Abstract: The present invention discloses a boundary conduction mode (BCM) switching regulator, and a driver circuit and a control method of the switching regulator, for controlling a power stage to convert an input voltage to an output voltage or output current. The BCM switching regulator detects whether it is operating in continuous conduction mode (CCM) or discontinuous conduction mode (DCM), and adjusts the On-time, Off-time, or frequency of the power stage accordingly, so that the switching regulator operates in or near BCM.
    Type: Application
    Filed: August 2, 2010
    Publication date: March 10, 2011
    Inventor: Jing-Meng Liu
  • Multi-color backlight control circuit and multi-color backlight control method
    Patent number: 7893626
    Abstract: The present invention discloses a multi-color backlight control circuit, comprising: a plurality of pins for electrically connecting with a plurality of LED strings of different LED colors; and a voltage supply circuit for receiving an input voltage and supplying a single output voltage to the plurality of LED strings of different LED colors. The present invention also discloses a multi-color backlight control method, comprising: supplying a single output voltage to a plurality of LED strings of different LED colors.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: February 22, 2011
    Assignee: Richtek Technology Corporation
    Inventor: Jing-Meng Liu
  • Driver circuit and method for driving load circuit
    Publication number: 20110012537
    Abstract: The present invention discloses a driver circuit and a method for driving a load circuit. The driver circuit includes: a primary side circuit receiving rectified AC power; a transformer coupled to the primary side circuit and converting a primary voltage to a secondary voltage which is supplied to a load circuit; and a secondary side circuit coupled to the transformer, the secondary side circuit detecting current flowing through the load circuit and feedback controlling the primary side circuit accordingly.
    Type: Application
    Filed: April 19, 2010
    Publication date: January 20, 2011
    Inventor: Jing-Meng LIU
  • Synchronous driver circuit and integrated circuit for use therein
    Publication number: 20110012570
    Abstract: The present invention discloses a synchronous driver circuit, comprising: an inductor having one end coupled to an input voltage; a first power transistor having one end coupled to the other end of the inductor and another end supplying an output voltage; a second power transistor having one end coupled to the other end of the inductor and another end coupled to ground; a control circuit for controlling the operation of the first and second power transistors; a gate driver coupled to the control circuit and having an output controlling the gate of the first power transistor; and a bootstrap capacitor having one end coupled to a voltage node and the other end coupled to the other end of the inductor, the voltage across the bootstrap capacitor being provided as the operational voltage of the gate driver.
    Type: Application
    Filed: February 5, 2010
    Publication date: January 20, 2011
    Inventors: Jing-Meng Liu, Chia-Wei Liao, Heng Yun
  • AC Power Line Controlled Light Emitting Device Dimming Circuit and Method Thereof
    Publication number: 20100308749
    Abstract: The present invention discloses an AC power line controlled light emitting device dimming circuit and a method thereof. The AC power line controlled light emitting device dimming circuit includes: a light emitting device driver circuit for controlling current through a light emitting device, wherein the light emitting device is current-controlled; and a level adjustment circuit for detecting power-OFF of an AC power switch and generating a corresponding level adjustment signal which is transmitted to the light emitting device driver circuit to control the current through the light emitting device accordingly.
    Type: Application
    Filed: May 27, 2010
    Publication date: December 9, 2010
    Inventor: Jing-Meng Liu
  • LED Controller with Phase-Shift Dimming Function and LED Phase-Shift Dimming Circuit and Method Thereof
    Publication number: 20100301764
    Abstract: The present invention discloses an LED controller with phase-shift dimming function and an LED Phase-Shift dimming circuit and method thereof. The LED controller includes: a power circuit for supplying DC power to multiple LED channels; and an LED phase-shift dimming circuit for receiving a pulse width modulation (PWM) input signal and generating multiple phase-shifted PWM signals with a shifted phase between one another, wherein a turn-ON timing of each of the multiple phase-shifted PWM signals follows a turn-OFF timing of a previous PWM signal which is the input PWM signal or a previous one of the multiple phase-shifted PWM signals.
    Type: Application
    Filed: April 27, 2010
    Publication date: December 2, 2010
    Inventor: Jing-Meng Liu
  • Tail-less LED Control Circuit
    Publication number: 20100301761
    Abstract: The present invention discloses a tail-less LED control circuit, which includes: a power supply stage having an output terminal which provides electrical power to an LED circuit; an output capacitor coupled to the output terminal; an LED driver circuit coupled to the power supply stage for controlling the power supply stage to provide the electrical power to the LED circuit, the LED driver circuit receiving a PWM dimming signal for adjusting brightness of the LED circuit; and a MOSFET switch coupled to the output capacitor in series, the MOSFET switch switching synchronously with the PWM dimming signal to alleviate LED afterglow, wherein the MOSFET switch includes a body diode having an anode-cathode direction against the discharge direction of the output capacitor.
    Type: Application
    Filed: May 26, 2010
    Publication date: December 2, 2010
    Inventors: Chiawei Liao, Jing-Meng Liu, Leng-Nien Hsiu
  • Light Emitting Device Driver Circuit, Light Emitting Device Array Controller and Control Method Thereof
    Publication number: 20100301760
    Abstract: The present invention discloses a light emitting device array controller which controls a power stage to supply an output voltage to one end of each of a plurality of light emitting device strings. The other end of each of the light emitting device strings is coupled to a corresponding transistor having a current inflow end, a current outflow end and a control end. The present invention obtains signals from the control ends of the transistors instead of the current inflow ends, and feedback controls the output voltage according to the highest voltage of the control ends. Thus, the number of pins required for a circuit chip is reduced.
    Type: Application
    Filed: May 26, 2010
    Publication date: December 2, 2010
    Inventor: Jing-Meng Liu