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).

  • Analog photovoltaic power circuit
    Patent number: 8853994
    Abstract: The present invention discloses an analog photovoltaic power circuit, including: a photovoltaic device group for receiving photo energy to generate an input voltage, the input voltage corresponding to an input current; a power stage circuit for receiving the input voltage and generating an output voltage; an optimum current or voltage estimation circuit for receiving a predetermined voltage and estimating an optimum current or voltage point corresponding to an optimal output point according to a direction of variation of the input current and a direction of variation of the power generated by the photovoltaic device group; and an analog comparison and control circuit for comparing the optimum current or voltage with the input current or voltage, to thereby control the operation of the power stage circuit.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: October 7, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventor: Jing-Meng Liu
  • IMAGE REGISTRATION AND FOCUS STACKING ON MOBILE PLATFORMS
    Publication number: 20140267833
    Abstract: A mobile device comprising a processor configured to merge a plurality of images each having a distinct focus position in a scene to generate a focus-stacked image that encompasses all focus positions of the plurality of images. Also, an apparatus comprising a camera configured to capture a plurality of color images for one scene each with a distinct focus distance and a processor configured to register the plurality of color images to generate a plurality of registered color images, generate a plurality of luminance (Y) channels from the plurality of registered color images, and stack the plurality of Y channels to generate a focus-stacked Y channel.
    Type: Application
    Filed: March 12, 2013
    Publication date: September 18, 2014
    Applicant: Futurewei Technologies, Inc.
    Inventors: Lulin Chen, Meng Liu, Xudong Song
  • Cross-interference reduction of a buck power converter
    Patent number: 8803492
    Abstract: A power converter includes a first conversion stage for converting an input voltage to a first output voltage and a second conversion stage for converting the first output voltage to a second output voltage. An error signal is generated according to a reference voltage and a feedback signal extracted from the second conversion stage, and a feed forward signal is generated from the error signal and injected into the first conversion stage to stabilize the first output voltage. The feedback signal is a function of the second output voltage and thus, the error signal varies with the second output voltage. As a result, the first output voltage will be stabilized when the second output voltage varies, due to the varied feed forward signal.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: August 12, 2014
    Assignee: Richtek Technology Corp.
    Inventor: Jing-Meng Liu
  • Switching regulator and control circuit and control method thereof
    Patent number: 8780587
    Abstract: A control circuit of a switching regulator, which controls rectified power within a predetermined range, detects an input voltage and an input current to generate a voltage detection signal and a current detection signal respectively, and the voltage detection signal and the current detection signal are multiplied by one the other to generate a power index. The control circuit generates an error signal according to the power index and a reference signal. A low-pass-filter filters a high frequency band in the process. A control signal generation circuit of the control circuit generates a control signal according to the error signal. And a driver circuit of the control circuit generates an operation signal according to the control signal, for switching a power switch to convert the rectified power to an output voltage.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: July 15, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Chia-Wei Liao, Jing-Meng Liu, Leng-Nien Hsiu, Pei-Yuan Chen
  • Light emitting device power supply circuit, and light emitting device driver circuit and control method thereof
    Patent number: 8710755
    Abstract: The present invention discloses a light emitting device power supply circuit, a light emitting device driver circuit and a control method thereof. The light emitting device driver circuit is coupled to a tri-electrode AC switch (TRIAC) dimmer circuit, and it controls the brightness of a light emitting device circuit according a rectified dimming signal. The light emitting device driver circuit includes a power stage circuit and a light emitting device control circuit. The light emitting device control circuit generates a switch control signal. The power stage circuit operates at least one power switch thereof according to the switch control signal to generate a latching current for firing the TRIAC dimmer circuit, and the latching current is inputted to the light emitting device circuit.
    Type: Grant
    Filed: March 15, 2012
    Date of Patent: April 29, 2014
    Assignee: Richtek Technology Corporation
    Inventors: Pei-Yuan Chen, Chia-Wei Liao, Jing-Meng Liu, Leng-Nien Hsiu
  • Protection to avoid abnormal operation caused by a shorted parameter setting pin of an integrated circuit
    Patent number: 8687331
    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: Grant
    Filed: April 22, 2011
    Date of Patent: April 1, 2014
    Assignee: Richtek Technology Corp.
    Inventors: Shao-Hung Lu, Jing-Meng Liu, Jo-Yu Wang, Isaac Y. Chen, An-Tung Chen
  • ANALOG PHOTOVOLTAIC POWER CIRCUIT WITH AUTO ZERO CALIBRATION
    Publication number: 20140077757
    Abstract: The invention provides an analog photovoltaic power circuit with auto zero calibration, which judges whether the current trend or voltage trend has the same direction as or different direction from the power trend, and adjusts an input/output power conversion accordingly, so that an input current approaches to an optimum current corresponding to a maximum power point, in which the judgments of the current trend, voltage trend and power trend is calibrated with auto-zero circuitry.
    Type: Application
    Filed: September 11, 2013
    Publication date: March 20, 2014
    Applicant: RICHTEK TECHNOLOGY CORPORATION
    Inventor: Jing-Meng Liu
  • BOUNDARY CONDUCTION MODE SWITCHING REGULATOR AND DRIVER CIRCUIT AND CONTROL METHOD THEREOF
    Publication number: 20140062444
    Abstract: A boundary conduction mode (BCM) switching regulator controls 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: November 4, 2013
    Publication date: March 6, 2014
    Applicant: RICHTEK TECHNOLOGY CORPORATION, R.O.C.
    Inventor: Jing-Meng Liu
  • Circuit and method for providing absolute information for floating grounded integrated circuit
    Patent number: 8659239
    Abstract: The present invention discloses a circuit and a method for providing absolute information for floating grounded integrated circuit. The method includes: receiving an absolute information sense signal carrying absolute information; converting the absolute information sense signal to a current signal; and generating an internal reference signal according to the current signal, wherein the internal reference signal or a relationship between the internal reference signal and a floating ground level is related to the absolute information.
    Type: Grant
    Filed: July 25, 2011
    Date of Patent: February 25, 2014
    Assignee: Richtek Technology Corporation
    Inventors: Chia-Wei Liao, Roland Van Roy, Jing-Meng Liu, Leng-Nien Hsiu
  • Flat panel display, light emitting module for use in flat panel display, and integrated circuit for use in light emitting module
    Patent number: 8643290
    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: Grant
    Filed: April 28, 2011
    Date of Patent: February 4, 2014
    Assignee: Richtek Technology Corporation
    Inventor: Jing-Meng Liu
  • Backlight Control Circuit with Under Current Detection and Start-up Control
    Publication number: 20140009075
    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: Application
    Filed: August 13, 2013
    Publication date: January 9, 2014
    Applicant: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chiawei Liao, Jing-Meng Liu
  • Boundary conduction mode switching regulator and driver circuit and control method thereof
    Patent number: 8604767
    Abstract: A boundary conduction mode (BCM) switching regulator controls 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: Grant
    Filed: August 2, 2010
    Date of Patent: December 10, 2013
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventor: Jing-Meng Liu
  • POWER SUPPLY CIRCUIT WITH PFC FUNCTION, AND AUTOMATIC GAIN CONTROL CIRCUIT THEREFOR AND CONTROL METHOD THEREOF
    Publication number: 20130250631
    Abstract: The present invention discloses a power supply circuit with power factor correction (PFC) function, and an automatic gain control circuit therefor and a control method thereof. The power supply circuit includes the automatic gain control circuit and a load driver circuit. The automatic gain control circuit converts an input voltage to a regulation voltage, and the load driver circuit generates an output current according to the regulation voltage. The automatic gain control circuit automatically adjust the regulation voltage such that the regulation voltage has a substantially fixed amplitude or fixed average value under different input voltages of different specifications, and the output current provided by the load driver circuit varies in phase with the input voltage to provide a PFC function.
    Type: Application
    Filed: March 18, 2013
    Publication date: September 26, 2013
    Applicant: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chia-Wei Liao, Jing-Meng Liu
  • Control circuit for an organic light emitting diode panel
    Patent number: 8531491
    Abstract: The present invention discloses a current-matching circuit including a hierarchical tree structure having two or more levels, each of which includes multiple matching devices, wherein each matching device at a preceding level corresponds to a predetermined number of matching devices at a next level. Respective matching devices at a last level control currents in respective current channels; the channels of the same group are matched with one another in current.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: September 10, 2013
    Assignee: Richtek Technology Corporation
    Inventor: Jing-Meng Liu
  • LIGHT EMITTING DEVICE DRIVER CIRCUIT AND CONTROL METHOD THEREOF
    Publication number: 20130221875
    Abstract: The present invention discloses a light emitting device circuit and a control method thereof. The light emitting device circuit includes: a light emitting device control circuit, for converting an input voltage to an output voltage according to a control signal, wherein the output voltage is supplied to a light emitting device circuit; a voltage supply circuit, which is coupled to the light emitting device circuit, for generating a supply voltage from the output voltage; and a remote control circuit, which is coupled to the voltage supply circuit, for receiving the supply voltage, and generating the control signal according to a remote signal.
    Type: Application
    Filed: February 23, 2013
    Publication date: August 29, 2013
    Applicant: Richtek Technology Corporation
    Inventors: Chia-Wei Liao, Jing-Meng Liu
  • Isolated Power Converter Circuit and Control Method Thereof
    Publication number: 20130215651
    Abstract: The present invention discloses an isolated power converter circuit and a control method thereof. The isolated power converter circuit includes: a transformer circuit, a power switch circuit, an opto-coupler circuit, and a control circuit. The transformer circuit includes a first winding and a second winding. The power switch circuit is coupled to the transformer circuit to control it according to a driving signal. The opto-coupler circuit generates a feedback signal. The control circuit is coupled to the power switch circuit and the opto-coupler circuit, for generating the driving signal according to the feedback signal. The control circuit includes a distinguishing circuit for distinguishing a status of the feedback signal.
    Type: Application
    Filed: February 12, 2013
    Publication date: August 22, 2013
    Applicant: RICHTEK TECHNOLOGY CORPORATION, R.O.C.
    Inventors: Chia-Wei Liao, Jing-Meng Liu
  • LED bulb, light emitting device control method, and light emitting device controller circuit with dimming function adjustable by AC signal
    Patent number: 8513894
    Abstract: The present invention discloses a light emitting device control method for adjusting the brightness of the light emitting device by an AC signal, comprising: receiving a signal having a turn ON angle and converting the signal to a DC signal; obtaining an average of the DC signal level, the average being a function of the turn ON angle; determining a reference voltage of a current source circuit according to the average of the DC signal level; and controlling a current flow through the light emitting device by the current source circuit.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: August 20, 2013
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Pei-Cheng Huang, Ching-Jung Tseng, Jing-Meng Liu
  • Backlight control circuit
    Patent number: 8508463
    Abstract: The present invention discloses a backlight control circuit, comprising: a voltage supply circuit, under control by a control signal, for receiving an input voltage and generating an output voltage; a plurality of nodes for respectively indicating the current status of corresponding light emission device paths; and a high-low voltage comparison and amplifier circuit for generating the control signal according to a voltage difference between at least two nodes.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: August 13, 2013
    Assignee: Richtek Technology Corporation
    Inventor: Jing-Meng Liu
  • Backlight control circuit capable of distinguishing under current condition
    Patent number: 8508464
    Abstract: The present invention discloses a backlight control circuit capable of distinguishing an under current condition, comprising: at least one light emission device path having a voltage node; at least one current source for controlling the current amount on the light emission device path; and at least one under current detection circuit for generating a first control signal according to the voltage at the voltage node, wherein when the first control signal changes its state, the under current detection circuit generates a second control signal to change the voltage on the voltage node if the light emission device path is normally connected.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: August 13, 2013
    Assignee: Richtek Technology Corporation
    Inventors: Chiawei Liao, Xiaoyong Zhang, Jing-Meng Liu
  • Active Bleeder Circuit Triggering TRIAC in All Phase and Light Emitting Device Power Supply Circuit and TRIAC Control Method Using the Active Bleeder Circuit
    Publication number: 20130169177
    Abstract: The present invention discloses an active bleeder circuit capable of triggering a tri-electrode AC switch (TRIAC) circuit in all phase. The active bleeder circuit receives a rectified signal having an OFF phase and an ON phase. The active bleeder includes: a detection circuit for generating a detection signal according to the rectified signal and accumulating the detection signal in the OFF phase of the rectified signal; and a current sinker circuit coupled to the detection circuit, for generates a latching current to trigger the TRIAC circuit by operating a switch when the detection signal exceeds a predetermined level. The present invention also discloses a light emitting device power supply circuit and a TRIAC control method using the active bleeder circuit.
    Type: Application
    Filed: December 27, 2012
    Publication date: July 4, 2013
    Applicant: Richtek Technology Corporation
    Inventors: Chia-Wei Liao, Leng-Nien Hsin, Pei-Yuan Chen, Roland Van Roy, Jing-Meng Liu