WO2014079038A1 - 一种led背光驱动电路、背光模组和液晶显示装置 - Google Patents

一种led背光驱动电路、背光模组和液晶显示装置 Download PDF

Info

Publication number
WO2014079038A1
WO2014079038A1 PCT/CN2012/085152 CN2012085152W WO2014079038A1 WO 2014079038 A1 WO2014079038 A1 WO 2014079038A1 CN 2012085152 W CN2012085152 W CN 2012085152W WO 2014079038 A1 WO2014079038 A1 WO 2014079038A1
Authority
WO
WIPO (PCT)
Prior art keywords
led
light bar
constant current
led light
resistor
Prior art date
Application number
PCT/CN2012/085152
Other languages
English (en)
French (fr)
Inventor
胡安乐
黎飞
Original Assignee
深圳市华星光电技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 深圳市华星光电技术有限公司 filed Critical 深圳市华星光电技术有限公司
Priority to US13/806,807 priority Critical patent/US8890417B2/en
Publication of WO2014079038A1 publication Critical patent/WO2014079038A1/zh

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/395—Linear regulators
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Definitions

  • the present invention relates to the field of liquid crystal display, and more particularly to an LED backlight driving circuit, a backlight module, and a liquid crystal display device.
  • the liquid crystal display device comprises a liquid crystal panel and a backlight module for providing a light source to the liquid crystal panel.
  • the existing backlight module mostly uses an LED as a light source.
  • the backlight module of LED as a light source generally connects a plurality of LEDs in series into a light bar, and then drives the light by a booster circuit.
  • the LED output terminal is connected in series with the MOS transistor, and the constant current chip controls the turn-on/turn-off of the MOS, and the MOS is adjusted.
  • the duty cycle of the tube controls the effective current flowing through the LED strip to achieve dimming.
  • the technical problem to be solved by the present invention is to provide an LED backlight driving circuit, a backlight module and a liquid crystal display device which can realize LED short-circuit fault protection.
  • An LED backlight driving circuit comprises an LED light bar and a constant current chip for controlling current flowing through the LED light bar, wherein the LED backlight driving circuit further comprises a comparison module, wherein the comparison module collects an output voltage of the LED light bar, when the LED When the voltage at the output end of the light bar is higher than a preset reference voltage, the comparison module controls the current of the constant current chip to turn off the LED light bar.
  • the comparison module includes a comparator, an input of the comparator is coupled to the reference voltage, and another input is coupled to an output of the LED strip; the comparator compares a reference voltage and The magnitude of the voltage at the output of the LED strip controls the constant current chip. This is a specific Compare the circuit structure of the module.
  • a non-inverting input terminal of the comparator is connected to the reference voltage, and an inverting input end is coupled to an output end of the LED light bar; when an output voltage of the LED light bar is higher than the reference voltage, The comparator outputs a low level signal to an enable control terminal of the constant current chip, and controls a current of the constant current chip to turn off the LED strip.
  • the enable control terminal of the constant current chip can realize the turn-off/conduction control of the constant current chip only by the high/low level signal of the single chip.
  • the control mode is simple, which is beneficial to reduce the tube control circuit and reduce the development and design cost.
  • a non-inverting input end of the comparator is coupled to a working power terminal of the constant current chip, and an operating power supply of the constant current chip provides the reference voltage.
  • the operation of the constant current chip itself requires a constant operating power supply. Therefore, the working power supply can be used as the reference voltage to realize multiplexing of the circuit, and the control circuit can be further cooled to reduce the cost.
  • the working power terminal of the constant current chip and the ground end of the LED backlight driving circuit are sequentially connected in series with a first resistor and a second resistor, and a voltage of the second resistor is coupled to the same input end of the comparator.
  • This is a resistor divider circuit, and the operating voltage of the constant current chip is constant and non-changeable.
  • the actual LED short-circuit protection scheme is different, and different reference voltages are needed, such as starting protection when a single LED is short-circuited or starting protection when two or more LEDs are short-circuited.
  • the corresponding reference voltage is different in size, and a voltage dividing circuit can be used.
  • the second resistor is an adjustable resistor. In this way, it is not necessary to consider different protection schemes during design, and the size of the second resistor can be adjusted according to the required protection scheme in actual use, thereby obtaining the required reference voltage, which is convenient for later production and maintenance.
  • a non-inverting input terminal of the comparator is connected to a reference voltage, and an inverting input end is coupled to an output end of the LED light bar; when an output voltage of the LED light bar is higher than the reference voltage, The comparator outputs a low level signal to the enable control end of the constant current chip, and controls the current of the constant current chip to turn off the LED strip; the working power end of the constant current chip is connected in series with the ground end of the LED backlight driving circuit.
  • a first resistor and a second resistor the voltage of the second resistor being coupled to the comparator input
  • the second resistor is an adjustable resistor. This is a specific embodiment.
  • a dimming controllable switch and a third resistor are serially connected between the output end of the LED light bar and the ground end of the LED backlight driving circuit, when the output voltage of the LED light bar is higher than a preset reference voltage
  • the constant current chip controls the dimming controllable switch to be turned off. This is a specific dimming control scheme.
  • a backlight module includes any of the above LED backlight driving circuits.
  • a liquid crystal display device includes the above backlight module.
  • the invention adopts a comparison module, and the comparison module can collect the output terminal voltage of the LED light bar.
  • the comparison module detects that the voltage of the output end of the LED light bar exceeds the reference voltage, the constant current chip is controlled to turn off the current of the LED light bar, that is, the light source of the backlight module is extinguished. , to achieve protection of LED short-circuit faults, to avoid further damage to the constant current chip and related circuit boards.
  • FIG. 1 is a block diagram showing the overall structure of an LED backlight driving circuit according to an embodiment of the present invention
  • FIG. 2 is a schematic structural view of an LED backlight driving circuit according to an embodiment of the present invention.
  • the present invention discloses a liquid crystal display device including a backlight module.
  • the backlight module includes an LED backlight driving circuit, and the LED backlight driving circuit includes an LED light bar and controls current flowing through the LED light bar.
  • the constant current chip, the LED backlight driving circuit also has a comparison module, and the comparison module collects the output voltage of the LED light bar. When the output voltage of the LED light bar is higher than the preset reference voltage, the comparison module controls the constant current chip to turn off the LED light. The current of the strip.
  • the invention adopts a comparison module, and the comparison module can collect the output terminal voltage of the LED light bar.
  • the LED of the LED light bar When the LED of the LED light bar is short-circuited, the output voltage of the entire LED light bar will rise, so that only a ratio is set.
  • the reference voltage of the high voltage at the output of the normal LED strip when the comparison module detects When the voltage at the output end of the LED light bar exceeds the reference voltage, the constant current chip is controlled to turn off the current of the LED light bar, that is, the light source of the backlight module is extinguished, and the protection of the LED short circuit fault is realized, and the user can go to the after-sales maintenance. Eliminate the fault.
  • the LED backlight driving circuit of the present embodiment includes an LED light bar and a constant current chip for controlling current flowing through the LED light bar, and the LED backlight driving circuit is further provided with a comparison module.
  • the LED light bar is composed of a plurality of LED lights connected in series.
  • the input end of the LED light bar has an input voltage VLED+, and the output voltage of the LED light bar is VLED-, and the output end of the LED light bar is connected in series with the ground end of the LED backlight drive circuit.
  • the dimmable controllable switch Q1 and the third resistor R3 are dimmed.
  • the working power terminal VCC of the constant current chip and the ground terminal GND of the LED backlight driving circuit are sequentially connected in series with a first resistor R1 and a second resistor R2.
  • the comparison module uses comparator OP1 and the inverting input of comparator OP1 is connected to VLED -.
  • the non-inverting input terminal of the comparator OP1 is connected between the first resistor R1 and the second resistor R2, and the voltage of the second resistor R2 is collected as a reference voltage.
  • the comparator OP1 When the output voltage VLED- of the LED strip is higher than the reference voltage, the comparator OP1 outputs a low level signal to the enable control terminal ENA of the constant current chip, and controls the current of the constant current chip to turn off the LED strip.
  • the enable control terminal of the constant current chip can realize the turn-off/conduction control of the constant current chip only by the high/low level signal of the single-chip, and the control mode is simple, which is beneficial to reduce the tubular control circuit and reduce development. Design cost.
  • the operation of the constant current chip itself requires a constant operating power supply, so it can be used as a reference voltage to realize multiplexing of the circuit, further simplify the control circuit, and reduce the cost.
  • the operating voltage of the constant current chip is constant and unchangeable, but the actual LED short-circuit protection scheme is different, and the corresponding reference voltage is different. Therefore, in order to expand the application range of the present invention, a voltage dividing circuit can be used, and by adjusting the ratio of the first resistor R1 and the second resistor R2, different reference voltages can be obtained in the voltage range of VCC.
  • the second resistor R2 can be selected as an adjustable resistor, so that it is not necessary to consider different protection schemes during design, and the size of the second resistor R2 can be adjusted according to the required protection scheme in actual use, thereby Get the required reference voltage for later production and maintenance.
  • the reference voltage source of the present invention is not limited to VCC, as long as a power source capable of providing a stable voltage can be used as a source of the reference voltage of the present invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

一种LED背光驱动电路包括LED灯条以及控制流经LED灯条电流的恒流芯片，所述LED背光驱动电路还设有比较模块，所述比较模块采集LED灯条输出端电压，当LED灯条输出端电压高于预设的基准电压时，所述比较模块控制恒流芯片关断LED灯条的电流。

Description

一种 LED背光驱动电路、 背光模组和液晶显示装置
【技术领域】
本发明涉及液晶显示领域， 更具体的说， 涉及一种 LED背光驱动电路、 背 光模组和液晶显示装置。
【背景技术】
液晶显示装置包括液晶面板和给液晶面板提供光源的背光模组，随着 LED 的成本降低， 现有的背光模组多采用 LED作为光源。 LED作为光源的背光模组 一般是将多个 LED 串联成灯条， 然后用升压电路驱动发光， LED输出端串联 MOS管， 由恒流芯片来控制 MOS的导通 /关断， 通过调整 MOS管的占空比， 就能控制流经 LED灯条的有效电流， 从而达到调光的目的。 当 LED灯条中有 LED发生短路异常， 整个 LED串的亮度都会变低， 但此时恒流芯片并不会关掉 LED灯条的电流， 不仅降低了用户观看的舒适度， 且会对恒流芯片及相关电路 板造成一定影响。
【发明内容】
本发明所要解决的技术问题是提供一种能实现 LED短路故障保护的 LED背 光驱动电路、 背光模组和液晶显示装置。
本发明的目的是通过以下技术方案来实现的：
一种 LED背光驱动电路， 包括 LED灯条以及控制流经 LED灯条电流的恒 流芯片，所述 LED背光驱动电路还设有比较模块，所述比较模块采集 LED灯条 输出端电压， 当 LED灯条输出端电压高于预设的基准电压时， 所述比较模块控 制恒流芯片关断 LED灯条的电流。
进一步的， 所述比较模块包括比较器， 所述比较器的一输入端耦合到所述 基准电压， 另一输入端耦合到所述 LED灯条的输出端； 所述比较器通过比较基 准电压和 LED灯条的输出端电压的大小来控制所述恒流芯片。 此为一种具体的 比较模块的电路结构。
进一步的， 所述比较器的同向输入端连接到所述基准电压， 其反向输入端 耦合到所述 LED灯条的输出端； 当 LED灯条的输出电压高于所述基准电压时， 所述比较器输出低电平信号到所述恒流芯片的使能控制端， 控制恒流芯片关断 LED灯条的电流。 此为一种具体的比较器和恒流芯片电路结构， 采用恒流芯片 的使能控制端， 只需要筒单的高 /低电平信号就能实现恒流芯片的关断 /导通控 制， 控制方式筒单， 有利于降低筒化控制电路， 降低开发设计成本。
进一步的， 所述比较器的同向输入端耦合到所述恒流芯片的工作电源端， 所述恒流芯片的工作电源提供所述基准电压。 恒流芯片的工作本身需要一个恒 定的工作电源， 因此以该工作电源作为基准电压可以实现电路的复用， 进一步 筒化控制电路， 降低成本。
进一步的， 所述恒流芯片的工作电源端与 LED背光驱动电路的接地端依次 串联有第一电阻和第二电阻， 所述第二电阻的电压耦合到所述比较器的同向输 入端。 此为一种电阻分压电路， 恒流芯片的工作电压是一定的、 不可变动的。 但实际的 LED短路保护方案不同，需要不同的基准电压，如单颗 LED短路时启 动保护还是两颗以上 LED短路时启动保护， 对应的基准电压的大小是不一样， 而且采用分压电路， 可以通过调整第一电阻和第二电阻的比例， 得到不同的基 准电压， 拓展了本发明的适用范围。
进一步的， 所述第二电阻为可调电阻。 这样在设计的时候无需考虑不同的 保护方案， 可以在实际的使用中根据要求的保护方案来调整第二电阻的大小， 从而得到需要的基准电压， 方便后期的生产和维护。
进一步的， 所述比较器的同向输入端连接一基准电压， 其反向输入端耦合 到所述 LED灯条的输出端； 当 LED灯条的输出电压高于所述基准电压时，所述 比较器输出低电平信号到所述恒流芯片的使能控制端， 控制恒流芯片关断 LED 灯条的电流； 所述恒流芯片的工作电源端与 LED背光驱动电路的接地端依次串 联有第一电阻和第二电阻， 所述第二电阻的电压耦合到所述比较器的同向输入 端； 所述第二电阻为可调电阻。 此为一种具体的实施方式。
进一步的，所述 LED灯条的输出端跟 LED背光驱动电路的接地端之间依次 串接有调光可控开关和第三电阻， 当 LED灯条输出端电压高于预设的基准电压 时， 所述恒流芯片控制所述调光可控开关关断。 此为一种具体的调光控制方案。
一种背光模组， 包括上述任意一种 LED背光驱动电路。
一种液晶显示装置， 包括上述的一种背光模组。
本发明由于采用了比较模块， 比较模块可以采集 LED灯条的输出端电压， 当该 LED灯条的 LED发生短路时， 整个 LED灯条的输出端电压将会升高， 这 样只要设定一个比正常 LED灯条输出端电压高的基准电压， 当比较模块检测到 LED灯条输出端的电压超出基准电压的时候，就控制恒流芯片关断 LED灯条的 电流， 即灭掉背光模组的光源， 实现 LED短路故障的保护， 避免了对恒流芯片 及相关电路板的进一步损伤。
【附图说明】
图 1是本发明实施例的 LED背光驱动电路的整体结构框图；
图 2是本发明实施例的 LED背光驱动电路的结构示意图。
【具体实施方式】
如图 1 所示， 本发明公开一种液晶显示装置， 包括背光模组， 该背光模组 包括一种 LED背光驱动电路， 该 LED背光驱动电路包括 LED灯条以及控制流 经 LED灯条电流的恒流芯片， LED背光驱动电路还设有比较模块， 比较模块 采集 LED灯条输出端电压， 当 LED灯条输出端电压高于预设的基准电压时， 比 较模块控制恒流芯片关断 LED灯条的电流。
本发明由于采用了比较模块， 比较模块可以采集 LED灯条的输出端电压， 当该 LED灯条的 LED发生短路时， 整个 LED灯条的输出端电压将会升高， 这 样只要设定一个比正常 LED灯条输出端电压高的基准电压， 当比较模块检测到 LED灯条输出端的电压超出基准电压的时候，就控制恒流芯片关断 LED灯条的 电流， 即灭掉背光模组的光源， 实现 LED短路故障的保护， 此时用户就可以到 售后维修， 消除故障。
下面结合附图和较佳的实施例对本发明作进一步说明。
如图 2所示，本实施方式的 LED背光驱动电路包括 LED灯条以及控制流经 LED灯条电流的恒流芯片， LED背光驱动电路还设有比较模块。 LED灯条由 多颗 LED灯串联组成， LED灯条的输入端有输入电压 VLED+, 其输出端的电 压为 VLED- , LED灯条的输出端跟 LED背光驱动电路的接地端之间依次串接有 调光可控开关 Q1和第三电阻 R3。
恒流芯片的工作电源端 VCC与 LED背光驱动电路的接地端 GND依次串联 有第一电阻 R1和第二电阻 R2。 比较模块采用比较器 OP1 , 比较器 OP1的反向 输入端连接到 VLED -。 比较器 OP1的同向输入端连接到第一电阻 R1和第二电 阻 R2之间， 采集第二电阻 R2的电压作为基准电压， 当 LED灯条的输出电压 VLED-高于基准电压时， 比较器 OP1输出低电平信号到恒流芯片的使能控制端 ENA, 控制恒流芯片关断 LED灯条的电流。
采用恒流芯片的使能控制端， 只需要筒单的高 /低电平信号就能实现恒流芯 片的关断 /导通控制， 控制方式筒单， 有利于降低筒化控制电路， 降低开发设计 成本。 恒流芯片的工作本身需要一个恒定的工作电源， 因此可以作为基准电压 来使用， 实现电路的复用， 进一步筒化控制电路， 降低成本。 不过恒流芯片的 工作电压是一定的、 不可变动的， 但实际的 LED短路保护方案不同， 需要不同 对应的基准电压的大小是不一样。 因此为了拓展本发明的应用范围， 可以采用 分压电路，通过调整第一电阻 R1和第二电阻 R2的比例，就能在 VCC的电压范 围内得到不同的基准电压。
第二电阻 R2可以选用可调电阻，这样在设计的时候无需考虑不同的保护方 案， 可以在实际的使用中根据要求的保护方案来调整第二电阻 R2的大小， 从而 得到需要的基准电压， 方便后期的生产和维护。
当然本发明的基准电压来源不局限于 VCC, 只要可提供稳定电压的电源都 可以作为本发明的基准电压的来源。
以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明， 不 能认定本发明的具体实施只局限于这些说明。 对于本发明所属技术领域的普通 技术人员来说， 在不脱离本发明构思的前提下， 还可以做出若干筒单推演或替 换， 都应当视为属于本发明的保护范围。

Claims

权利要求
1、一种 LED背光驱动电路， 包括 LED灯条以及控制流经 LED灯条电流的 恒流芯片，所述 LED背光驱动电路还设有比较模块，所述比较模块采集 LED灯 条输出端电压， 当 LED灯条输出端电压高于预设的基准电压时， 所述比较模块 控制恒流芯片关断 LED灯条的电流。
2、 如权利要求 1所述的一种 LED背光驱动电路， 其中， 所述比较模块包 括比较器， 所述比较器的一输入端耦合到所述基准电压， 另一输入端耦合到所 述 LED灯条的输出端；所述比较器通过比较基准电压和 LED灯条的输出端电压 的大小来控制所述恒流芯片。
3、 如权利要求 2所述的一种 LED背光驱动电路， 其中， 所述比较器的同 向输入端连接到所述基准电压， 其反向输入端耦合到所述 LED灯条的输出端； 当 LED灯条的输出电压高于所述基准电压时， 所述比较器输出低电平信号到所 述恒流芯片的使能控制端， 控制恒流芯片关断 LED灯条的电流。
4、 如权利要求 2所述的一种 LED背光驱动电路， 其中， 所述比较器的同 向输入端耦合到所述恒流芯片的工作电源端， 所述恒流芯片的工作电源提供所 述基准电压。
5、 如权利要求 4所述的一种 LED背光驱动电路， 其中， 所述恒流芯片的 工作电源端与 LED背光驱动电路的接地端依次串联有第一电阻和第二电阻， 所 述第二电阻的电压耦合到所述比较器的同向输入端。
6、 如权利要求 5所述的一种 LED背光驱动电路， 其中， 所述第二电阻为 可调电阻。
7、 如权利要求 1所述的一种 LED背光驱动电路， 其中， 所述比较器的同 向输入端连接一基准电压，其反向输入端耦合到所述 LED灯条的输出端；当 LED 灯条的输出电压高于所述基准电压时， 所述比较器输出低电平信号到所述恒流 芯片的使能控制端， 控制恒流芯片关断 LED灯条的电流； 所述恒流芯片的工作 电源端与 LED背光驱动电路的接地端依次串联有第一电阻和第二电阻， 所述第 二电阻的电压耦合到所述比较器的同向输入端； 所述第二电阻为可调电阻。
8、 如权利要求 7所述的一种 LED背光驱动电路， 其中， 所述 LED灯条的 输出端跟 LED 背光驱动电路的接地端之间依次串接有调光可控开关和第三电 阻， 当 LED灯条输出端电压高于预设的基准电压时， 所述恒流芯片控制所述调 光可控开关关断。
9、一种背光模组， 包括一种 LED背光驱动电路， 所述 LED背光驱动电路， 包括 LED灯条以及控制流经 LED灯条电流的恒流芯片， 所述 LED背光驱动电 路还设有比较模块，所述比较模块采集 LED灯条输出端电压， 当 LED灯条输出 端电压高于预设的基准电压时， 所述比较模块控制恒流芯片关断 LED灯条的电 流。
10、 如权利要求 9所述的一种背光模组， 其中， 所述比较模块包括比较器， 所述比较器的一输入端耦合到所述基准电压， 另一输入端耦合到所述 LED灯条 的输出端； 所述比较器通过比较基准电压和 LED灯条的输出端电压的大小来控 制所述恒流芯片。
11、 如权利要求 10所述的一种背光模组， 其中， 所述比较器的同向输入端 连接到所述基准电压，其反向输入端耦合到所述 LED灯条的输出端； 当 LED灯 条的输出电压高于所述基准电压时， 所述比较器输出低电平信号到所述恒流芯 片的使能控制端， 控制恒流芯片关断 LED灯条的电流。
12、 如权利要求 10所述的一种背光模组， 其中， 所述比较器的同向输入端 耦合到所述恒流芯片的工作电源端， 所述恒流芯片的工作电源提供所述基准电 压。
13、 如权利要求 12所述的一种背光模组， 其中， 所述恒流芯片的工作电源 端与 LED背光驱动电路的接地端依次串联有第一电阻和第二电阻， 所述第二电 阻的电压耦合到所述比较器的同向输入端。
14、如权利要求 13所述的一种背光模组， 其中， 所述第二电阻为可调电阻。
15、 如权利要求 9所述的一种背光模组， 其中， 所述比较器的同向输入端 连接一基准电压，其反向输入端耦合到所述 LED灯条的输出端； 当 LED灯条的 输出电压高于所述基准电压时， 所述比较器输出低电平信号到所述恒流芯片的 使能控制端， 控制恒流芯片关断 LED灯条的电流； 所述恒流芯片的工作电源端 与 LED背光驱动电路的接地端依次串联有第一电阻和第二电阻， 所述第二电阻 的电压耦合到所述比较器的同向输入端； 所述第二电阻为可调电阻。
16、 如权利要求 15所述的一种背光模组， 其中， 所述 LED灯条的输出端 跟 LED 背光驱动电路的接地端之间依次串接有调光可控开关和第三电阻， 当 LED灯条输出端电压高于预设的基准电压时， 所述恒流芯片控制所述调光可控 开关关断。
17、 一种液晶显示装置， 包括如权利要求 9所述的一种背光模组。
PCT/CN2012/085152 2012-11-22 2012-11-23 一种led背光驱动电路、背光模组和液晶显示装置 WO2014079038A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/806,807 US8890417B2 (en) 2012-11-22 2012-11-23 LED backlight driving circuit, backlight module, and LCD device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201210478373.0 2012-11-22
CN2012104783730A CN103021343A (zh) 2012-11-22 2012-11-22 一种led背光驱动电路、背光模组和液晶显示装置

Publications (1)

Publication Number Publication Date
WO2014079038A1 true WO2014079038A1 (zh) 2014-05-30

Family

ID=47969882

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2012/085152 WO2014079038A1 (zh) 2012-11-22 2012-11-23 一种led背光驱动电路、背光模组和液晶显示装置

Country Status (2)

Country Link
CN (1) CN103021343A (zh)
WO (1) WO2014079038A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104981073A (zh) * 2015-07-10 2015-10-14 成都市宏山科技有限公司 适用于led的恒流驱动电路

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103295547B (zh) * 2013-05-08 2015-05-20 深圳市华星光电技术有限公司 一种led背光驱动电路及其驱动方法、液晶显示装置
US9258862B2 (en) 2013-05-08 2016-02-09 Shenzhen China Star Optoelectronics Technology Co., Ltd LED backlight driving circuit, LCD device, and method for driving the LED backlight driving circuit
CN104717813B (zh) * 2013-07-11 2017-11-07 青岛海信电器股份有限公司 Led光源短路检测方法及装置、led背光及液晶显示设备
CN103500558B (zh) 2013-10-21 2016-04-27 深圳市华星光电技术有限公司 一种led背光驱动电路和驱动方法
CN103531156B (zh) 2013-10-25 2016-06-29 深圳市华星光电技术有限公司 背光驱动电路以及液晶显示装置
CN104282281B (zh) * 2014-10-20 2016-11-09 深圳市华星光电技术有限公司 一种 led 背光驱动电路及其故障检测方法
CN104821156B (zh) * 2015-05-19 2018-03-02 深圳市华星光电技术有限公司 一种led背光驱动电路
CN105611665A (zh) * 2015-11-24 2016-05-25 芜湖锐芯电子科技有限公司 一种分流led电路
CN106407844A (zh) * 2016-11-15 2017-02-15 上海华虹集成电路有限责任公司 光检测电路
CN106409241B (zh) * 2016-11-29 2019-01-04 青岛海信电器股份有限公司 液晶显示装置及多分区led背光的短路保护方法
CN107945746A (zh) * 2017-11-17 2018-04-20 深圳市华星光电技术有限公司 Led背光驱动电路以及液晶显示装置
CN108983453B (zh) * 2018-07-26 2021-11-05 武汉天马微电子有限公司 背光模组的检测装置、检测治具及显示模组
CN109192148A (zh) * 2018-10-29 2019-01-11 青岛海信电器股份有限公司 一种背光控制方法及装置、显示装置
CN109272949B (zh) * 2018-12-07 2023-09-26 合肥惠科金扬科技有限公司 一种显示装置的背光驱动电路、驱动方法及显示装置
CN112419961A (zh) * 2019-08-20 2021-02-26 深圳市洲明科技股份有限公司 调压节能电路以及led显示模块
CN111986625A (zh) * 2020-08-05 2020-11-24 深圳市华星光电半导体显示技术有限公司 背光驱动电路及显示装置
CN112908232B (zh) * 2021-03-26 2022-10-18 四川长虹电器股份有限公司 Led多分区背光故障检测系统及故障判断方法
CN113823229A (zh) * 2021-09-03 2021-12-21 惠州视维新技术有限公司 驱动电路及其故障检测方法、背光模组和显示装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201927998U (zh) * 2010-11-25 2011-08-10 康佳集团股份有限公司 Led背光灯串短路保护电路
CN102637412A (zh) * 2012-04-28 2012-08-15 深圳市华星光电技术有限公司 一种led背光驱动电路、液晶显示装置和一种驱动方法
CN102740567A (zh) * 2012-07-04 2012-10-17 深圳市华星光电技术有限公司 一种led背光驱动电路、背光模组和液晶显示装置

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102123536B (zh) * 2010-01-12 2013-10-30 冠捷投资有限公司 发光二极管驱动电路
CN101801145B (zh) * 2010-04-23 2013-08-14 海洋王照明科技股份有限公司 Led灯具控制电路及led灯具
CN102446492A (zh) * 2010-10-08 2012-05-09 联咏科技股份有限公司 短路侦测电路及方法与发光二极管驱动芯片及装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201927998U (zh) * 2010-11-25 2011-08-10 康佳集团股份有限公司 Led背光灯串短路保护电路
CN102637412A (zh) * 2012-04-28 2012-08-15 深圳市华星光电技术有限公司 一种led背光驱动电路、液晶显示装置和一种驱动方法
CN102740567A (zh) * 2012-07-04 2012-10-17 深圳市华星光电技术有限公司 一种led背光驱动电路、背光模组和液晶显示装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104981073A (zh) * 2015-07-10 2015-10-14 成都市宏山科技有限公司 适用于led的恒流驱动电路

Also Published As

Publication number Publication date
CN103021343A (zh) 2013-04-03

Similar Documents

Publication Publication Date Title
WO2014079038A1 (zh) 一种led背光驱动电路、背光模组和液晶显示装置
CN105491761B (zh) 可调节色温的led灯和led灯的色温调节方法
WO2014190577A1 (zh) 一种背光驱动电路、液晶显示装置和背光驱动方法
WO2014180057A1 (zh) 一种led背光驱动电路、背光模组和液晶显示装置
JP6240762B2 (ja) Ｌｅｄバックライトシステム及び表示装置
WO2016095309A1 (zh) 液晶显示装置、背光模块及其背光源驱动电路
US9271361B2 (en) Backlight driving circuit, LCD device, and method for driving the backlight driving circuit
WO2014187005A1 (zh) 一种背光驱动电路、液晶显示装置和背光驱动方法
TWI477192B (zh) 直流調光型led驅動電路
WO2014005340A1 (zh) 一种led背光驱动电路、背光模组和液晶显示装置
CN102695319B (zh) 一种led无级调光电路
WO2014153793A1 (zh) 一种背光驱动电路及其驱动方法和液晶装置
US8890417B2 (en) LED backlight driving circuit, backlight module, and LCD device
WO2014180054A1 (zh) 一种led背光驱动电路及其驱动方法、液晶显示装置
WO2014187015A1 (zh) Led背光驱动电路、液晶显示装置和一种驱动方法
WO2014172986A1 (zh) Led背光源及液晶显示装置
WO2014101313A1 (zh) 一种液晶显示装置的驱动电路、驱动方法和液晶显示装置
WO2015000179A1 (zh) 一种led背光驱动电路及其驱动方法、液晶显示装置
CN103384436A (zh) Led背光恒流电路
US20180182276A1 (en) Apparatus for controlling brightness of mobile phone screen
TWM451772U (zh) 直流調光型led驅動電路
TWI451809B (zh) 發光模組驅動電路及其短路保護方法
TW201352055A (zh) Ｌｅｄ小串之控制裝置
WO2014153791A1 (zh) 一种led背光驱动电路和液晶显示装置
WO2014139154A1 (zh) 一种led背光驱动电路、液晶显示装置和一种led背光驱动电路的驱动方法

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 13806807

Country of ref document: US

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12888624

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12888624

Country of ref document: EP

Kind code of ref document: A1