Patent application number | Description | Published |
20140070723 | LED Backlight Driving Circuit and LED Backlight Driving Method - The present invention provides an LED backlight driving circuit and an LED backlight driving method. The circuit includes an isolation MOS transistor, a dimming MOS transistor connected in parallel to the isolation MOS transistor, and first and second resistors. The first resistor and the second resistor are connected to each other in parallel and are connected between the dimming MOS transistor and a ground wire. The isolation MOS transistor and the dimming MOS transistor are arranged for electrical connection with an LED light. The LED backlight driving circuit arranges the isolation MOS transistor and the dimming MOS transistor to connect in parallel to each other so as to make the electrical current flowing through the isolation MOS transistor lessened to reduce the amount of heat emitting therefrom and enhance operation safety and also allow the MOS transistor used to be of a downgraded specification to lower down the manufacture cost. | 03-13-2014 |
20140132160 | Method for Reducing Standby Power Consumption - The present invention provides a method for reducing standby power consumption, which includes providing an LED driving chip; connecting an integrator to a brightness control terminal of the driving chip, connecting the integrator to a comparator, connecting the comparator to a field-effect transistor, connecting the field-effect transistor to the driving chip; connecting the driving chip to a first power source, connecting a high voltage switch terminal of the driving chip via a resistor to a second power source, connecting the brightness control terminal and the integrator to a control source, and connecting the integrator to a reference voltage; and conducting the first and second power sources, the control source, and the reference voltage to allow the integrator and the comparator to pull down voltage of the high voltage switch terminal of the driving chip according to the conduction of the field-effect transistor by a signal of the brightness control terminal. | 05-15-2014 |
20140167633 | BACKLIGHT DRIVING CIRCUIT AND LIQUID CRYSTAL DISPLAY WITH THE SAME - A backlight driving circuit is disclosed. The backlight driving circuit includes a steady voltage circuit, a boost converter, a current setting circuit, and a control circuit. The steady voltage circuit receives an input voltage, filters the input voltage and outputs a steady DC voltage. The boost converter connects to the steady voltage circuit to receive the steady DC voltage. The control circuit provides a first PWM square wave such that the boost converter may supply power to the LED light bar. Wherein the boost converter includes a first MOSFET or a triode. At least three parallel connected resistors are arranged between a source of the first MOSFET or a collector of the triode and the ground, and the three resistors have the same or similar resistance. In addition, a liquid crystal display includes the backlight driving circuit is also disclosed. | 06-19-2014 |
20140184959 | OVERVOLTAGE PROTECTION METHOD FOR BACKLIGHT DRIVE CIRCUIT OF 2D/3D MODE AND BACKLIGHT DRIVE CIRCUIT USING SAME - The present invention provides an overvoltage protection method for backlight drive circuit of 2D/3D mode and a backlight drive circuit using the method. The method includes: providing a liquid crystal display, the liquid crystal display having a 2D mode and a 3D mode, the liquid crystal display including a backlight drive circuit; the backlight drive circuit using the first overvoltage protection voltage level as an overvoltage protection voltage level when the liquid crystal display is set in the 2D mode; and the backlight drive circuit using the second the overvoltage protection voltage level as an overvoltage protection voltage level when the liquid crystal display is set in the 3D mode, the second the overvoltage protection voltage level being greater than the first overvoltage protection voltage level. Different overvoltage protection voltage levels are provided for the 2D and 3D modes so as to alleviate impact on components by over voltage. | 07-03-2014 |
20140292202 | LED Backlight Driving Circuit and Backlight Module - An LED backlight driving circuit has a voltage converting unit having an output terminal connected to a positive electrode of an LED to provide a driving voltage required by the LED, a driving unit to control the voltage converting unit to achieve a voltage conversion, and a protection unit connected in series between a negative electrode of the LED and the driving unit. A maximum allowable power of the protection unit is less than a power when the driving voltage of the LED is directly applied to the protection unit. The circuit also includes a control unit for outputting a control signal for stopping working to the driving unit when the protection unit forms an open circuit. Thus, the circuit parts can be protected, and the short-circuit protection function is more safe and reliable. | 10-02-2014 |
20140307351 | Over-current Protection Circuit for Light Source Driving Module and Related Backlight Module - The present invention discloses an overcurrent protection circuit for a light source driving module and a related backlight module. The overcurrent protection circuit includes an average value overcurrent protection circuit for detecting an average voltage at a node where the switch is connected to the detection resistor and generating the turning-off signal to turn off the switch when the average voltage is larger or equal to a threshold average voltage, wherein the average voltage is formed by an average current of the switch. Through the above-mentioned mechanism, the present invention can prevent the working power of a power device from being larger than its rated power. Therefore, it also prevents the power device from catching a fire due to a potential high temperature. | 10-16-2014 |
20140333859 | Backlight Driving Board and LCD Device - The present invention discloses a backlight driving board for driving a backlight source, comprising a microprocessor and a constant current driver chip. The microprocessor receives a display mode switching signal and a synchronization signal from a liquid crystal driving board, and generating a first pulse width modulation signal corresponding to the backlight source according to the display mode switching signal and the synchronization signal. The constant current driver chip controls an operation state of the backlight source according to the first pulse width modulation signal. The present invention can reduce the signal lines between the backlight driving board and the liquid crystal driving board in order to avoid the backlight driving board from external interference because of too many signal lines, and thus be able to enhance the stability of the LCD device when operatin | 11-13-2014 |
20150145424 | LCD BACKLIGHT DRIVING CIRCUIT AND LIQUID CRYSTAL DEVICE - A LED backlight driving circuit is disclosed. The LED backlight driving circuit includes a driving module, a detecting module, and an adjusting module. The driving module receives a control voltage generated by a voltage control module, receives a feedback voltage generated by a feedback voltage module, and generates driving signals to a LED unit. The detecting module generates adjusting signals for the adjusting module according to a detected value of the driving signals. The adjusting module controls the feedback voltage according to the adjusting signals generated by the detecting module so as to adjust the driving signals. In this way, not only the current precision within the LED unit is enhanced, but also the light source is kept stable. Also, the life cycle of the LED units is also increased. In addition, a LED backlight driving circuit includes the above LED backlight driving circuit is also disclosed. | 05-28-2015 |
20150189716 | LED BACKLIGHT DRIVING CIRCUIT AND LIQUID CRYSTAL DEVICE - A LED backlight driving circuit is disclosed. The LED backlight driving circuit includes a boost circuit for converting an input voltage to an output voltage for a LED unit, a driving IC for controlling the boost circuit such that the boost circuit converts the input voltage to the output voltage for the LED unit, a discharging module for releasing charges stored within the boost circuit after the driving circuit is turned off, and a detecting module for detecting a voltage at an output end of the boost circuit and then for generating enable signals for controlling the operations of the driving IC. The LED backlight driving circuit is capable of detecting a discharging state of the boost circuit after being quickly rebooted. The driving circuit can be rebooted only if the output voltage is smaller than a reference voltage as the charges stored within the boost circuit is released. As such, the flashing issue is avoided. In addition, the liquid crystal device including the above LED backlight driving circuit is also disclosed. | 07-02-2015 |
20150294615 | Light Source Driving Circuit of Light Emitting Semiconductor and Backlight Module - A light source driving circuit of light emitting semiconductor and a backlight module are provided. The light source driving circuit of light emitting semiconductor includes a driving control circuit and a constant current driving circuit coupled to the driving control circuit for controlling a current flowing through the light emitting semiconductor. When the driving control circuit receives a display-mode-switch signal which has an indication for switching from a present display mode to a new display mode, the driving control circuit controls the constant current driving circuit such that in the process of switching from the present display mode to the new display mode, the current flowing through the light emitting semiconductor changes gradually. | 10-15-2015 |
Patent application number | Description | Published |
20130335923 | PCB for LCD Device and LCD Device - The invention relates to the field of LCDs, and more particularly to a PCB for an LCD device and an LCD device. The PCB includes a front face and a back face; the front face of the PCB is a face for densely arranging components, and the back face is a face without densely arranged components; the back face of the PCB is provided with a jumper wire for dissipating heat, and the jumper wire is connected with a terminal of the component. The heat of the component is transmitted to the jumper wire by the terminal, and the jumper wire is used for auxiliarily strengthening heat dissipation. Because the back face of the PCB is the face without densely arranged components, the temperature of the back face is lower than that of the front face of the PCB, and the temperature difference between the jumper wire and the environmental of the back face of the PCB is large. Thus, the heat is rapidly transmitted, and the heat dissipating effect is significantly improved. | 12-19-2013 |
20130342108 | Backlight Driving Circuit, LCD module, and Manufacturing Method Thereof - The invention provides a backlight driving circuit, an LCD device, and a manufacturing method thereof. The backlight driving circuit includes at least two LED lightbars arranged in parallel connection, the output end of each of the LED lightbars is coupled with a variable current circuit, and the variable current circuit is provided with adjustable variable resistors used for balancing the voltage difference between the LED lightbars. In the invention, because the adjustable variable resistors are arranged in the variable current circuit which is connected in series with the LED lightbars, the resistance of the adjustable variable resistors can be adjusted according to the resistance of different LED lightbars before being used; thus, the total voltage of each LED lightbar and the variable resistor connected with ed LED lightbars in series can keep consistent. Therefore, the voltages of all the pins of the control IC coupled into the driver converter can be consistent, and no additional current can be generated in the control IC because no voltage differences exist between pins basically; thus, the power consumption of the control IC is reduced, and the heat productivity of the control IC is reduced, thereby reducing the temperature of the control IC. | 12-26-2013 |
20130342118 | LED Backlight Driving Circuit, LCD Device, and Manufacturing Method - The invention provides an LED backlight driving circuit, an LCD device, and a manufacturing method. The LED backlight driving circuit includes at least two lightbars arranged in parallel connection; at least one LED lightbar is in series connection with a divider resistor(s) used for balancing the voltage difference between the LED lightbars. In the invention, because the LED lightbar(s) is in series connection with the divider resistors used for balancing the voltage difference between the LED lightbars, the divider resistors with different resistance can be connected in series according to different resistance of all the LED lightbars during design, to enable the total voltage difference of each LED lightbar and the divider resistor to be equal; thus, the voltages of all the pins of the IC coupled into the drive converter can be consistent, and no additional current can be generated in the IC because no voltage differences exist between pins basically; thus, the power consumption of the IC is reduced, and the heat productivity of the IC is reduced, thereby reducing the temperature of the IC. | 12-26-2013 |
20130343039 | DRIVING CIRCUIT FOR LED BACKLIGHT, LCD DEVICE, AND METHOD FOR MANUFACTURING DRIVING CIRCUIT FOR LED BACKLIGHT - The driving circuit for a light emitting diode (LED) backlight includes at least two lightbars arranged in parallel connection. An output end of each of the LED lightbars is coupled with a converter module, and the converter module is configured with a digital potentiometer balancing a voltage difference between the LED lightbars and adjusting a resistance by an electric signal. In the present disclosure, the digital potentiometer adjusting the resistance by the electric signal is arranged in the converter module connected with the LED lightbar in series, and the resistance of the digital potentiometer is dynamically adjusted according to the resistance of different LED lightbars during use. Thus, the total voltage of each LED lightbar and the digital potentiometer connected with the LED lightbar in series is constant. | 12-26-2013 |
20140145646 | LED VOLTAGE ADJUSTMENT DEVICE AND DRIVE SYSTEM THEREOF - The present invention provides LED voltage adjustment device and drive system thereof. The device includes PI regulator, with negative terminal connected to negative terminal of LED light bar to receive negative terminal voltage of light bar and positive terminal of PI regulator being for receiving reference voltage; integrator, for performing integral on output signal of PI regulator; a subtractor, with positive input terminal receiving output signal from PI regulator and negative terminal receiving overcurrent protection detection voltage from boost converter for driving light bar, and subtracting overcurrent protection detection voltage from output signal of PI regulator; comparator, with positive terminal receiving output signal from integrator and negative terminal receiving output signal from subtractor; and integrated circuit (IC) module, for receiving output signal from comparator and based on received output signal to control a control signal to conduct or cut off switch transistor of boost converter. | 05-29-2014 |
20140168052 | LED BACKLIGHT DRIVING CIRCUIT AND LCD DEVICE - A light emitting diode (LED) backlight driving circuit includes an LED lightbar, and a driver integrated circuit (IC) coupled to the LED lightbar. The driver IC is configured with a protection pin that controls the driver IC to enter a protection mode when a voltage of the protection pin exceeds a preset voltage range, an undervoltage module is coupled between a power input end of the LED lightbar and the protection pin, and an overvoltage protection module is coupled between a power output end of the LED lightbar and the protection pin. An output overvoltage protection module is coupled between the power output end of the LED lightbar and the protection pin. The input undervoltage protection module outputs a first control voltage that exceeds the preset voltage range to the protection pin when the power input end of the LED lightbar is in an undervoltage state. The output overvoltage protection module outputs a second control voltage that exceeds the preset voltage range to the protection pin when the power input end of the LED lightbar is in an overvoltage state. | 06-19-2014 |
20140176020 | PROTECTION CIRCUIT FOR BACKLIGHT DRIVER CIRCUIT, BACKLIGHT MODULE, AND LCD DEVICE - A protection circuit of a backlight driver circuit includes a backlight driver circuit. The backlight driver circuit includes a backlight driver integrated circuit (IC), and the backlight driver IC includes a protection pin that controls the backlight driver IC to enter a protection mode. The backlight driver circuit further includes a protection circuit, and the protection circuit includes a monitoring unit that monitors a temperature of the backlight driver circuit. When the temperature of the backlight driver circuit exceeds a preset temperature, the monitoring unit sends the protection signal to the protection pin to control the backlight driver IC to enter the protection mode. | 06-26-2014 |
20140184482 | LCD DEVICE DRIVER CIRCUIT, DRIVING METHOD, AND LCD DEVICE - A driver circuit of a liquid crystal display (LCD) device includes a drive line driving a lightbar of the LCD device. A discharge module and a switch module are in series connection between the drive line and a ground end of the LCD device driver circuit in sequence; a starting signal sent by the LCD device is coupled to the switch module. When the starting signal is an OFF signal, the switch module is turned on, and when the starting signal is an ON signal, the switch module is turned off. | 07-03-2014 |
20140253846 | LIQUID CRYSTAL DISPLAY, LED BACKLIGHT SOURCE, AND THE DRIVING METHOD THEREOF - A liquid crystal display, a LED backlight source and the driving method thereof are disclosed. The LED backlight source includes a DC voltage input for inputting DC voltage, a boost circuit for increasing the voltage of the DC input and outputting the boosted DC voltage, a LED strip and a constant current driving circuit. The LED strip includes a plurality of serially connected LEDs and a first resistor (R | 09-11-2014 |
20140267447 | BACKLIGHT DRIVING CIRCUIT, LCD DEVICE, AND DRIVING METHOD - The present disclosure provides a backlight driving circuit, a liquid crystal display (LCD) device, and a driving method. The backlight driving circuit includes a monitoring device and a conversion device, the conversion device includes a microcontroller (MCU) and a switch module. A control end of the switch module is coupled to the monitoring device, and the monitoring device outputs a monitoring signal to turn on or turn off the switch module. An input end of a power source of the MCU is coupled to a power end of the backlight driving circuit through the switch module. | 09-18-2014 |
20140292200 | BACKLIGHT DRIVING CIRCUIT, LCD DEVICE, AND METHOD FOR DRIVING BACKLIGHT DRIVING CIRCUIT - A backlight driving circuit includes a power module and a constant current driver chip. The power module includes a first controllable switch. An adjustable load is connected between the first controllable switch and a round terminal of the backlight driving circuit, and the adjustable load includes a switching module controlling a resistance value of the adjustable load, a switching mode signal of the backlight driving circuit is sent to a control end of the switching module. A first end of the adjustable load that is connected to the first controllable switch is coupled to an over current protection (O(P) port of the constant current driver chip, | 10-02-2014 |
20140292630 | LED BACKLIGHT DRIVING CIRCUIT, LCD DEVICE, AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT - A light emitting diode (LED) backlight driving circuit of the present disclosure includes a monitor module, a first light cluster, a first boost voltage module that drives the first light cluster a second light cluster, and a second boost voltage module that drives the second light cluster. The first boost voltage module includes a first detection unit that detects an output current of the first boost voltage module, and the second boost voltage module includes a second detection unit that detects an output current of the second boost voltage module. The monitor module includes a current comparing unit coupled to the first detection unit and the second detection unit, and an actuator coupled to the current comparing unit. The actuator controls running states of the first boost voltage module and the second boost voltage module. | 10-02-2014 |
20140333204 | LED BACKLIGHT DRIVING CIRCUIT, LCD DEVICE, AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT - A light emitting diode (LED) backlight driving circuit includes an LED light bar, a power supply that drives the LED light bar to light, a short-circuit protection unit, and a divider resistor. An output end of the LED light bar is coupled to the short-circuit protection unit and the divider resistor. The short-circuit protection unit includes a comparing unit and a driving unit coupled to the comparing unit. Voltage of two ends of the divider resistor is regarded as a feedback voltage, and the feedback voltage and a first reference voltage are input to the comparing unit. When a difference value of the first reference voltage subtracted from the feedback voltage is greater than a preset deviation value; the driving unit controls the power supply to turn off. When brightness of one normal LED light bars reaches a maximum, the first reference voltage is greater than or equal to voltage of two ends of the divider resistor corresponding to the one normal LED light bar. | 11-13-2014 |
20140333518 | LED BACKLIGHT DRIVING CIRCUIT, LCD DEVICE, AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT - A light emitting diode (LED) backlight driving circuit includes a power module, a constant current driving module, and an LED light bar coupled to the power module. The power module is coupled to a power-voltage collecting module outputting a second comparison voltage, and the LED light bar is coupled to a light-bar-voltage collecting module outputting a first comparison voltage. The constant current driving module includes a switching unit and a control unit coupled to the switching unit and adjusting an output voltage of the power module, the first comparison voltage and the second comparison voltage are sent to the switching unit, and a preset reference voltage is sent to the switching unit. When the first comparison voltage deviates from the reference voltage, and an absolute value of the reference voltage VF subtracted from the first comparison voltage exceeds a preset deviation range of a voltage, the switching unit outputs the first comparison voltage to the control unit. When the absolute value of the reference voltage VF subtracted from the first comparison voltage is within the preset deviation range of the voltage, the switching unit ouputs the second comparison voltage to the control unit. | 11-13-2014 |
20140375213 | LED BACKLIGHT DRIVING CIRCUIT AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT - A light emitting diode (LED) backlight driving circuit includes a plurality of LED light bars, a power supply driving the LED light bars to light, and comparing units corresponding to the LED light bars one by one. A first input end of the comparing unit is coupled to a cathode end of the LED light bar, and a second input end of the comparing unit receives a first reference voltage. Each of the LED light bars is connected in series with a switching unit, an output end of the comparing unit is coupled to a statistic unit, an output end of the statistic unit is coupled to driving units corresponding to the switching units one by one and controlling the switching units to turn on/off. The statistic unit divides the LED light bars into two groups according to a logic state output by the comparing unit, and controls the driving unit to turn off one of two groups of LED light bars having a fewer number than the other group of the LED light bars. | 12-25-2014 |
20150130361 | LED BACKLIGHT DRIVING CIRCUIT AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT - A light emitting diode (LED) backlight driving circuit includes a power supply, at least two connected-in-parallel LED lightbars coupled to an output end of the power supply, a power feedback assembly coupled to each of the LED lightbars, and an adjusting-power block coupled to the power feedback assembly. A reference end of the power feedback assembly receives a reference power, and the power feedback assembly receives an output power of each of the LED lightbars. The power feedback assembly obtains a difference value of the reference power compared with the output power of the LED lightbar, and the adjusting-power block adjusts the output power of a corresponding LED lightbar according to the difference value until the difference value is less than a preset threshold value. | 05-14-2015 |
20150155896 | INTERFERENCE AVOIDANCE METHOD OF PULSE SIGNAL AND TERMINAL APPLICABLE THERETO - The present disclosure provides an interference avoidance method of a pulse signal. According to the method, before the pulse signal is transmitted, the pulse signal is split into two parallel pulse sub-signals which can be synthesized using a subtraction synthesis method and thus restored to the pulse signal. In this way, in the parallel transmissions of the two parallel pulse sub-signals, interferences from which the two sub-signals suffer are identical to each other. Thus, after the two parallel pulse sub-signals are synthesized using the subtraction synthesis method, the interference signals offset each other to allow the synthesized pulse signal to carry no interference signals, which effectively avoids false control caused by the interference signals carried in the transmission of the pulse signal and simultaneously avoids the false control caused by an attenuation or a distortion of the pulse signal due to the traditional filtering method. | 06-04-2015 |
20150181674 | SINGLE STRING OVER POWER PROTECTION AND LIGHT SOURCE DRIVER CIRCUIT USED IN DISPLAY DEVICE - The present disclosure provides a single-string light bar over power protection device and a light source driver circuit for a display. The over power protection device comprises: a voltage detection unit, with an input terminal being connected to a resistor in the circuit of a single-string light bar at both ends, for obtaining the voltage across the resistor; an integral unit, with an input terminal being connected to the output terminal of the voltage detection unit, for performing an integral transform on the voltage obtained; a comparisoncomparison unit, which is connected to the output terminal of the integral unit, for comparing the voltage after the integral transform with a reference voltage determined by the system parameters, so as to output an effective over voltage signal when the voltage after the integral transform is higher than the reference voltage; and a latch unit connected to the comparisoncomparison unit to lock the output standby signal according to the effective over voltage signal. The protection device according to the present disclosure can avoid overheat caused by over current of the single-string light bar, and further refrain from abnormality to the whole backlight module, and thus providing better protection for the LCD display. | 06-25-2015 |