WO2014079029A1 - 一种背光驱动电路、背光模组和液晶显示装置 - Google Patents

一种背光驱动电路、背光模组和液晶显示装置 Download PDF

Info

Publication number
WO2014079029A1
WO2014079029A1 PCT/CN2012/085115 CN2012085115W WO2014079029A1 WO 2014079029 A1 WO2014079029 A1 WO 2014079029A1 CN 2012085115 W CN2012085115 W CN 2012085115W WO 2014079029 A1 WO2014079029 A1 WO 2014079029A1
Authority
WO
WIPO (PCT)
Prior art keywords
inductor
coupled
comparator
controllable switch
backlight
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/CN2012/085115
Other languages
English (en)
French (fr)
Inventor
张华�
杨翔
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TCL China Star Optoelectronics Technology Co Ltd
Original Assignee
Shenzhen China Star Optoelectronics Technology Co Ltd
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 Shenzhen China Star Optoelectronics Technology Co Ltd filed Critical Shenzhen China Star Optoelectronics Technology Co Ltd
Priority to US13/806,804 priority Critical patent/US20140139419A1/en
Publication of WO2014079029A1 publication Critical patent/WO2014079029A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/028—Generation of voltages supplied to electrode drivers in a matrix display other than LCD

Definitions

  • the present invention relates to the field of liquid crystal display, and more particularly to a 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 adopts an LED as a light source.
  • a backlight module using LED as a light source generally connects a plurality of LEDs in series into a light bar, and then drives the light by a boost circuit.
  • the inductance L1 of the boost circuit is a very important component, and the LED load is constant. The amount of inductance will determine whether it operates in current continuous or current discontinuous mode. When the inductor used is less than the inductance in the critical operating mode due to process variation, the inductor operates in the current discontinuous mode.
  • the inductor current has the same rms value, the inductor peak current in the current discontinuous mode is more continuous than the current.
  • some key components such as MOS tube Ql, diode D1 need more bearing capacity, and if the situation is serious, the key components will be damaged.
  • the technical problem to be solved by the present invention is to provide a backlight driving circuit, a backlight module and a liquid crystal display device which can protect the device from being damaged by the peak current of the inductor.
  • a backlight driving circuit includes a power module, an inductor connected to the output end of the power module, and an LED strip connected in series with the inductor, and a monitoring module for detecting an inductor output current is coupled between the inductor and the LED strip, the inductor A controllable switch is connected between the output end and the grounding end of the backlight driving circuit, and the monitoring module is coupled with the controllable switch.
  • the monitoring module controls the controllable switch guide. through.
  • the monitoring module includes a current detecting unit connected in series between the inductor and the light bar, and A control unit coupled to the current sensing unit, the control signal of the control unit being coupled to the controllable switch.
  • the current detecting unit includes a transformer, a primary winding of the transformer is connected in series between the inductor and the light bar, and a second-stage wire is grounded through a voltage dividing resistor, and a sampling voltage of the voltage dividing resistor is coupled to The control unit.
  • the primary winding of the transformer is separated from the secondary winding, so that the primary circuit of the primary winding and the sampling circuit of the secondary winding do not interfere with each other, the circuit on either side has a problem, and the circuit on the other side is not damaged, and the reliability is high;
  • the secondary winding of the transformer is proportional to the current in the primary winding, so that the sampling voltage across the dividing resistor connected to the secondary winding can follow the linear current of the primary winding, thus changing the current. Conversion to voltage changes facilitates data acquisition and control.
  • control unit includes a comparator, a non-directional end of the comparator is coupled to a reference voltage, and the current detecting unit outputs a comparison voltage to an opposite end of the comparator, when the current detecting unit is in the When the inductor output current is lower than the preset value, the magnitude relationship between the comparison voltage and the reference voltage is reversed, and the comparator output control signal drives the controllable switch to be turned on.
  • This is a specific control unit structure, which uses a comparator technology solution and has a low cost.
  • the comparator when the comparison voltage is lower than the reference voltage, the comparator outputs a high level signal to drive the controllable switch to be turned on.
  • This is a specific comparator that outputs a high level when the voltage at the same end is higher than the reverse side; of course, if the controllable switch is low-level, a comparator with the opposite logic can be used.
  • the preset value is zero.
  • the preset value is zero, that is, the inductor has no output current, and the current flowing through the transformer is also zero, so that the secondary line has no current, and the sampling voltage is also naturally zero, which can further increase the sampling voltage and the reference voltage.
  • the pressure difference, the logic judgment of the comparator can be more accurate, avoiding the pressure difference being too small and causing malfunction.
  • the monitoring module includes a current detecting unit connected in series between the inductor and the light bar, a control unit coupled to the current detecting unit, and a control signal of the control unit is coupled to the Controlling the switch;
  • the current detecting unit includes a transformer, and the primary winding of the transformer Connected between the inductor and the light bar, the second stage line ⁇ is grounded through a voltage dividing resistor,
  • the control unit includes a comparator, the same end of the comparator is coupled with a reference voltage, and the control end is coupled to the controllable a sampling voltage of the voltage dividing resistor is coupled to an opposite end of the comparator.
  • the control switch When the inductor output current is zero, the sampling voltage is less than the reference voltage, and the comparator outputs a high level signal to drive The control switch is turned on.
  • This is the circuit structure of a specific monitoring module.
  • the primary winding of the transformer is separated from the secondary winding, so that the primary circuit of the primary winding and the sampling circuit of the secondary winding do not interfere with each other, the circuit on either side has a problem, and the circuit on the other side is not damaged, and the reliability is high;
  • the secondary winding of the transformer is proportional to the current in the primary winding, so that the sampling voltage across the dividing resistor connected to the secondary winding can follow the linear current of the primary winding, thus changing the current. Conversion to voltage changes facilitates data acquisition and control.
  • the cost is lower.
  • the output is high; of course, if the controllable switch is low-level, a comparator with opposite logic can be used.
  • the preset value is zero, that is, the inductor has no output current, and the current flowing through the transformer is also zero, so that the secondary line has no current, and the sampling voltage is also naturally zero, which can further increase the sampling voltage and the reference voltage.
  • the pressure difference, the logic judgment of the comparator can be more accurate, avoiding the pressure difference being too small and causing malfunction.
  • a diode is further connected in series between the inductor and the monitoring module, a positive pole of the diode is coupled to the inductor, and a cathode is coupled to the monitoring module; .
  • This is a specific boost circuit structure.
  • a backlight module comprising the backlight driving circuit of any of the above.
  • a liquid crystal display device includes the above backlight module.
  • the invention adds a monitoring module to the circuit.
  • the monitoring module can control the conduction of the controllable switch to force the output end of the inductor to be grounded, so that the power module, the inductor, and the controllable switch A complete conductive loop is formed between them, and a current flows through the inductor, thus forcing the circuit to skip the zero-crossing current phase and enter the duty cycle of the next booster circuit.
  • the inductor operates in a continuous current mode, which avoids large peak currents, protects the device, and makes the circuit safer.
  • the peak current value of the inductor is reduced, so that it can be selected. Using components with lower specifications will help reduce manufacturing costs.
  • 1 is a schematic diagram of the principle of a conventional backlight driving circuit
  • FIG. 2 is a waveform diagram of an inductor operating in a discontinuous operation mode and a continuous operation mode;
  • FIG. 3 is a schematic diagram of the principle of the embodiment of the present invention.
  • FIG. 4 is a schematic diagram of a specific circuit of an embodiment of the present invention.
  • the invention discloses a liquid crystal display device.
  • the liquid crystal display device includes a liquid crystal panel and a backlight module for providing a light source to the liquid crystal panel.
  • the backlight module includes a backlight driving circuit, and the backlight driving circuit includes a power module, and an inductor connected to the output end of the power module, and the inductor is connected in series.
  • An LED module, a monitoring module for detecting an inductor output current is coupled between the inductor and the LED strip, and a controllable switch is connected between an output end of the inductor and a ground end of the backlight driving circuit, and the monitoring The module is coupled to the controllable switch. When the inductor output current is lower than a preset value, the monitoring module controls the controllable switch to be turned on.
  • the invention adds a monitoring module to the circuit.
  • the monitoring module can control the conduction of the controllable switch to force the output end of the inductor to be grounded, so that the power module, the inductor, and the controllable switch A complete conductive loop is formed between them, and a current flows through the inductor, thus forcing the circuit to skip the zero-crossing current phase and enter the duty cycle of the next booster circuit.
  • the inductor operates in a continuous current mode, which avoids large peak currents, protects the device, and makes the circuit safer.
  • the peak current value of the inductor is reduced, so that components with lower specifications can be selected, which is advantageous for manufacturing cost reduction.
  • the backlight driving circuit in the embodiment includes a power module.
  • the output end of the power module is connected in series with an inductor L1, a diode D1, a monitoring module, and a light bar formed by the LEDs in series, thereby forming a complete main power supply. Loop; connection between the output of the inductor L1 and the ground of the backlight drive circuit There is a controllable switch Q1, and a capacitor CI is also connected in parallel at both ends of the light bar;
  • the monitoring module comprises a current detecting unit connected in series between the inductor L1 and the light bar, a control unit coupled with the current detecting unit, and a control signal of the control unit is coupled to Controllable switch Ql.
  • the monitoring module controls the controllable switch Q1 to be turned on.
  • the monitoring module includes a current detecting unit connected in series between the inductor L1 and the light bar, and a control unit coupled to the current detecting unit.
  • the control signal of the control unit is coupled to the controllable switch Q1.
  • the current detecting unit includes the transformer TR1.
  • the primary line ⁇ of the transformer TR1 is connected in series between the inductor L1 and the light bar, and the second stage line ⁇ is grounded through a voltage dividing resistor R1;
  • the control unit includes a comparator OP, and the same end of the comparator OP is coupled with a reference voltage, and its control The end is coupled to the controllable switch Q1; the sampling voltage of the voltage dividing resistor R1 is coupled to the opposite end of the comparator OP.
  • the primary winding ⁇ and the secondary winding of the transformer TR1 are isolated, so the primary circuit of the primary winding and the sampling circuit of the secondary winding do not interfere with each other, the circuit on either side has a problem, and the circuit on the other side is not damaged, and the reliability is high.
  • the secondary winding ⁇ of the transformer TR1 is proportional to the current in the primary winding ,, so the sampling voltage across the dividing resistor R1 connected to the secondary winding can follow the linear current of the primary winding , so that The change in current is converted into a change in voltage, which is beneficial to the acquisition control of the data.
  • the comparator OP technology scheme is used, and the cost is low. When the voltage at the same end is higher than the reverse terminal, the output is high; of course, if the controllable switch Q1 is low-level, the opposite comparator OP can be used.
  • the preset value can be zero, that is, the inductor L1 has no output current, and the current flowing through the transformer TR1 is also zero, so that the secondary line has no current, and the sampling voltage is also naturally zero, which can further increase the sampling voltage and the reference voltage.
  • the pressure difference between the comparator OP can be more accurate, avoiding the pressure difference being too small and causing malfunction.

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)
  • Liquid Crystal (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

一种背光驱动电路，包括电源模块，与电源模块输出端连接的电感（L1），与电感（L1）串联的LED灯条，电感（L1）和LED灯条之间耦合有用于检测电感输出电流的监控模块，电感（L1）的输出端与背光驱动电路的接地端之间连接有可控开关（Q1），监控模块和可控开关（Q1）耦合，当电感（L1）输出电流低于预设值时，监控模块控制可控开关（Q1）导通。

Description

一种背光驱动电路、 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。参见图 1采用 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， 升压 电路的电感 L1是非常重要的元器件， 在 LED负载一定的情况下， 电感量的大 小将决定其工作在电流连续还是电流非连续模式。 当使用的电感因工艺偏差而 小于临界工作模式下的电感量时， 电感就会工作在电流非连续模式， 虽然电感 电流有效值相同， 但是电流非连续模式下的电感峰值电流要比电流连续模式下 大（如图 2 ), 这样电路中 MOS管 Ql、 二极管 D1等一些关键元器件需要更大 的承受能力， 情况严重的话关键元器件会损坏。
【发明内容】
本发明所要解决的技术问题是提供一种可保护器件不被电感峰值电流损坏 的背光驱动电路、 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：
一种背光驱动电路， 包括电源模块， 与电源模块输出端连接的电感， 与电 感串联的 LED灯条，所述电感和 LED灯条之间耦合有用于检测电感输出电流的 监控模块， 所述电感的输出端与所述背光驱动电路的接地端之间连接有可控开 关， 所述监控模块和可控开关耦合， 当电感输出电流低于预设值时， 所述监控 模块控制可控开关导通。
进一步的， 所述监控模块包括串联在电感和灯条之间的电流检测单元， 与 电流检测单元耦合的控制单元， 所述控制单元的控制信号耦合到所述可控开关。 此为一种通过电流检测单元来检测电感输出电流的技术方案， 当然， 采用电压 检测的技术方案也是可行的。
进一步的， 所述电流检测单元包括变压器， 所述变压器的初级线圏串联到 所述电感和灯条之间， 其次级线圏通过一分压电阻接地， 所述分压电阻的采样 电压耦合到所述控制单元。 变压器初级线圏和次级线圏隔离， 因此初级线圏的 主电路和次级线圏的采样电路互不干扰， 任何一边的电路出问题， 也不会损坏 另外一边的电路， 可靠性高； 另外， 变压器次级线圏与初级线圏中的电流成比 例关系， 因此与次级线圏连接的分压电阻两端的采样电压可以跟随初级线圏的 电流线性变化， 这样就能将电流的变化转化为电压的变化， 有利于数据的采集 控制。
进一步的， 所述控制单元包括比较器， 所述比较器的同向端耦合一基准电 压， 所述电流检测单元输出一个比较电压到所述比较器的反向端， 当电流检测 单元在所述电感输出电流低于预设值时， 所述比较电压和基准电压的大小关系 反转， 所述比较器输出控制信号驱动可控开关导通。 此为一种具体的控制单元 结构， 采用比较器技术方案筒单， 成本较低。
进一步的， 所述比较电压低于所述基准电压时， 所述比较器输出高电平信 号驱动可控开关导通。 此为一种具体的比较器， 在同向端的电压高于反向端时， 输出高电平； 当然如果可控开关是低电平导通的， 可以选用逻辑相反的比较器。
进一步的， 所述预设值为零。 预设值为零， 即电感无输出电流， 流经变压 器的电流也为零， 这样次级线圏也无电流， 采样电压也自然为零， 这样可以进 一步增大采样电压跟基准电压之间的压差， 比较器的逻辑判断可以更为准确， 避免压差过小导致误动作。
进一步的， 所述预设值为零； 所述监控模块包括串联在电感和灯条之间的 电流检测单元， 与电流检测单元耦合的控制单元， 所述控制单元的控制信号耦 合到所述可控开关； 所述电流检测单元包括变压器， 所述变压器的初级线圏串 联到所述电感和灯条之间， 其次级线圏通过一分压电阻接地， 所述控制单元包 括比较器， 所述比较器的同向端耦合一基准电压， 其控制端耦合到可控开关； 所述分压电阻的采样电压耦合到所述比较器的反向端， 当电感输出电流为零时， 所述采样电压小于所述基准电压， 所述比较器输出高电平信号驱动可控开关导 通。 此为一种具体的监控模块的电路结构。 变压器初级线圏和次级线圏隔离， 因此初级线圏的主电路和次级线圏的采样电路互不干扰， 任何一边的电路出问 题， 也不会损坏另外一边的电路， 可靠性高； 另外， 变压器次级线圏与初级线 圏中的电流成比例关系， 因此与次级线圏连接的分压电阻两端的采样电压可以 跟随初级线圏的电流线性变化， 这样就能将电流的变化转化为电压的变化， 有 利于数据的采集控制。 采用比较器技术方案筒单， 成本较低。 在同向端的电压 高于反向端时， 输出高电平； 当然如果可控开关是低电平导通的， 可以选用逻 辑相反的比较器。 预设值为零， 即电感无输出电流， 流经变压器的电流也为零， 这样次级线圏也无电流， 采样电压也自然为零， 这样可以进一步增大采样电压 跟基准电压之间的压差， 比较器的逻辑判断可以更为准确， 避免压差过小导致 误动作。
进一步的， 所述电感和监控模块之间还串接有二极管， 所述二级管的正极 耦合到所述电感， 其负极耦合到所述监控模块； 所述灯条的两端还并联有电容。 此为一种具体的升压电路结构。
一种背光模组， 包括以上任一所述的一种背光驱动电路。
一种液晶显示装置， 包括上述的一种背光模组。
本发明由于在电路中增加了监控模块， 当电感的输出电流低于预设值时， 监控模块可以控制可控开关导通， 让电感的输出端强制接地， 这样电源模块、 电感、 可控开关之间形成完整的导电回路， 电感中仍然有电流流过， 这样就强 制电路跳过了过零电流阶段， 进入下一个升压电路的工作周期， 通过调整可控 开关的占空比， 可以让电感工作在电流连续模式， 这样就能避免产生较大的尖 峰电流， 保护器件， 电路更安全。 另外， 电感的峰值电流值减小， 这样可以选 用规格较低的元器件， 有利于制造成本减少。 【附图说明】
图 1是现有的背光驱动电路的原理示意图；
图 2是电感工作在非连续工作模式和连续工作模式的波形示意图； 图 3是本发明实施例的原理示意图；
图 4是本发明实施例具体电路示意图。
【具体实施方式】
本发明公开了一种液晶显示装置。 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， 所述背光模组包括一种背光驱动电路， 该背光驱动电 路包括电源模块， 与电源模块输出端连接的电感， 与电感串联的 LED灯条， 所 述电感和 LED灯条之间耦合有用于检测电感输出电流的监控模块， 所述电感的 输出端与所述背光驱动电路的接地端之间连接有可控开关， 所述监控模块和可 控开关耦合， 当电感输出电流低于预设值时， 所述监控模块控制可控开关导通。
本发明由于在电路中增加了监控模块， 当电感的输出电流低于预设值时， 监控模块可以控制可控开关导通， 让电感的输出端强制接地， 这样电源模块、 电感、 可控开关之间形成完整的导电回路， 电感中仍然有电流流过， 这样就强 制电路跳过了过零电流阶段， 进入下一个升压电路的工作周期， 通过调整可控 开关的占空比， 可以让电感工作在电流连续模式， 这样就能避免产生较大的尖 峰电流， 保护器件， 电路更安全。 另外， 电感的峰值电流值减小， 这样可以选 用规格较低的元器件， 有利于制造成本减少。
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 3所示， 本实施例中背光驱动电路包括电源模块， 电源模块输出端依 次串接有电感 Ll、 二极管 Dl、 监控模块、 由 LED串联形成的灯条， 这样就形 成一个完整的主供电回路； 电感 L1的输出端与背光驱动电路的接地端之间连接 有可控开关 Ql , 灯条的两端还并联有电容 CI; 监控模块包括串联在电感 L1和 灯条之间的电流检测单元， 与电流检测单元耦合的控制单元， 控制单元的控制 信号耦合到可控开关 Ql。 当电感 L1输出电流低于预设值时， 监控模块控制可 控开关 Q1导通。
如图 4所示， 监控模块包括串联在电感 L1和灯条之间的电流检测单元， 与 电流检测单元耦合的控制单元， 控制单元的控制信号耦合到可控开关 Q1; 电流 检测单元包括变压器 TR1 , 变压器 TR1的初级线圏串联到电感 L1和灯条之间， 其次级线圏通过一分压电阻 R1接地； 控制单元包括比较器 OP, 比较器 OP的 同向端耦合一基准电压， 其控制端耦合到可控开关 Q1 ; 分压电阻 R1的采样电 压耦合到比较器 OP的反向端， 当电感 L1输出电流为零时， 采样电压小于基准 电压， 比较器 OP输出高电平信号驱动可控开关 Q1导通。
此为一种具体的监控模块的电路结构。 变压器 TR1初级线圏和次级线圏隔 离， 因此初级线圏的主电路和次级线圏的采样电路互不干扰， 任何一边的电路 出问题， 也不会损坏另外一边的电路， 可靠性高； 另外， 变压器 TR1次级线圏 与初级线圏中的电流成比例关系， 因此与次级线圏连接的分压电阻 R1两端的采 样电压可以跟随初级线圏的电流线性变化， 这样就能将电流的变化转化为电压 的变化， 有利于数据的采集控制。 采用比较器 OP技术方案筒单， 成本较低。 在 同向端的电压高于反向端时， 输出高电平； 当然如果可控开关 Q1是低电平导通 的， 可以选用逻辑相反的比较器 OP。
预设值可以为零， 即电感 L1无输出电流， 流经变压器 TR1的电流也为零， 这样次级线圏也无电流， 采样电压也自然为零， 这样可以进一步增大采样电压 跟基准电压之间的压差， 比较器 OP的逻辑判断可以更为准确， 避免压差过小导 致误动作。
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、 一种背光驱动电路， 包括电源模块， 与电源模块输出端连接的电感， 与 电感串联的 LED灯条，所述电感和 LED灯条之间耦合有用于检测电感输出电流 的监控模块， 所述电感的输出端与所述背光驱动电路的接地端之间连接有可控 开关， 所述监控模块和可控开关耦合， 当电感输出电流低于预设值时， 所述监 控模块控制可控开关导通。
2、 如权利要求 1所述的一种背光驱动电路， 其中， 所述监控模块包括串联 在电感和灯条之间的电流检测单元， 与电流检测单元耦合的控制单元， 所述控 制单元的控制信号耦合到所述可控开关。
3、 如权利要求 2所述的一种背光驱动电路， 其中， 所述电流检测单元包括 变压器， 所述变压器的初级线圏串联到所述电感和灯条之间， 其次级线圏通过 一分压电阻接地， 所述分压电阻的采样电压耦合到所述控制单元。
4、 如权利要求 2所述的一种背光驱动电路， 其中， 所述控制单元包括比较 器， 所述比较器的同向端耦合一基准电压， 所述电流检测单元输出一个比较电 压到所述比较器的反向端， 当电流检测单元在所述电感输出电流低于预设值时， 所述比较电压和基准电压的大小关系反转， 所述比较器输出控制信号驱动可控 开关导通。
5、 如权利要求 4所述的一种背光驱动电路， 其中， 所述比较电压低于所述 基准电压时， 所述比较器输出高电平信号驱动可控开关导通。
6、 如权利要求 1所述的一种背光驱动电路， 其中， 所述预设值为零。
7、 如权利要求 1所述的一种背光驱动电路， 其中， 所述预设值为零； 所述 监控模块包括串联在电感和灯条之间的电流检测单元， 与电流检测单元耦合的 控制单元， 所述控制单元的控制信号耦合到所述可控开关； 所述电流检测单元 包括变压器， 所述变压器的初级线圏串联到所述电感和灯条之间， 其次级线圏 通过一分压电阻接地， 所述控制单元包括比较器， 所述比较器的同向端耦合一 基准电压， 其控制端耦合到可控开关； 所述分压电阻的采样电压耦合到所述比 较器的反向端， 当电感输出电流为零时， 所述采样电压小于所述基准电压， 所 述比较器输出控制信号驱动可控开关导通。
8、 如权利要求 1所述的一种背光驱动电路， 其中， 所述电感和监控模块之 间还串接有二极管， 所述二级管的正极耦合到所述电感， 其负极耦合到所述监 控模块； 所述灯条的两端还并联有电容。
9、 一种背光模组， 包括一种背光驱动电路， 所述背光驱动电路包括电源模 块， 与电源模块输出端连接的电感， 与电感串联的 LED灯条， 所述电感和 LED 灯条之间耦合有用于检测电感输出电流的监控模块， 所述电感的输出端与所述 背光驱动电路的接地端之间连接有可控开关， 所述监控模块和可控开关耦合， 当电感输出电流低于预设值时， 所述监控模块控制可控开关导通。
10、 如权利要求 9所述的一种背光模组， 其中， 所述监控模块包括串联在 电感和灯条之间的电流检测单元， 与电流检测单元耦合的控制单元， 所述控制 单元的控制信号耦合到所述可控开关。
11、 如权利要求 10所述的一种背光模组， 其中， 所述电流检测单元包括变 压器， 所述变压器的初级线圏串联到所述电感和灯条之间， 其次级线圏通过一 分压电阻接地， 所述分压电阻的采样电压耦合到所述控制单元。
12、如权利要求 10所述的一种背光模组， 其中， 所述控制单元包括比较器， 所述比较器的同向端耦合一基准电压， 所述电流检测单元输出一个比较电压到 所述比较器的反向端， 当电流检测单元在所述电感输出电流低于预设值时， 所 述比较电压和基准电压的大小关系反转， 所述比较器输出控制信号驱动可控开 关导通。
13、 如权利要求 12所述的一种背光模组， 其中， 所述比较电压低于所述基 准电压时， 所述比较器输出高电平信号驱动可控开关导通。
14、 如权利要求 9所述的一种背光模组， 其中， 所述预设值为零。
15、 如权利要求 9所述的一种背光模组， 其中， 所述预设值为零； 所述监 控模块包括串联在电感和灯条之间的电流检测单元， 与电流检测单元耦合的控 制单元， 所述控制单元的控制信号耦合到所述可控开关； 所述电流检测单元包 括变压器， 所述变压器的初级线圏串联到所述电感和灯条之间， 其次级线圏通 过一分压电阻接地， 所述控制单元包括比较器， 所述比较器的同向端耦合一基 准电压， 其控制端耦合到可控开关； 所述分压电阻的采样电压耦合到所述比较 器的反向端， 当电感输出电流为零时， 所述采样电压小于所述基准电压， 所述 比较器输出控制信号驱动可控开关导通。
16、 如权利要求 9所述的一种背光模组， 其中， 所述电感和监控模块之间 还串接有二极管， 所述二级管的正极耦合到所述电感， 其负极耦合到所述监控 模块； 所述灯条的两端还并联有电容。
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/CN2012/085115 2012-11-22 2012-11-23 一种背光驱动电路、背光模组和液晶显示装置 Ceased WO2014079029A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/806,804 US20140139419A1 (en) 2012-11-22 2012-11-23 Backlight driving circuit, backlight module, and lcd device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201210478590.X 2012-11-22
CN201210478590.XA CN103021344B (zh) 2012-11-22 2012-11-22 一种背光驱动电路、背光模组和液晶显示装置

Publications (1)

Publication Number Publication Date
WO2014079029A1 true WO2014079029A1 (zh) 2014-05-30

Family

ID=47969883

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2012/085115 Ceased WO2014079029A1 (zh) 2012-11-22 2012-11-23 一种背光驱动电路、背光模组和液晶显示装置

Country Status (2)

Country Link
CN (1) CN103021344B (zh)
WO (1) WO2014079029A1 (zh)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103269549A (zh) * 2013-05-31 2013-08-28 深圳市华星光电技术有限公司 Led背光驱动电路及电子装置
CN104617775A (zh) * 2013-11-05 2015-05-13 深圳市海洋王照明工程有限公司 开关电源电路及led灯具
CN106253670A (zh) * 2016-08-23 2016-12-21 深圳市华星光电技术有限公司 升压电路及背光光源
CN112233625B (zh) * 2020-10-16 2024-02-09 Tcl华星光电技术有限公司 一种背光恒流控制电路和背光结构
CN121605467A (zh) 2023-02-28 2026-03-03 京东方科技集团股份有限公司 驱动芯片的温控电路和温控方法和时序控制驱动板

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1866709A (zh) * 2005-05-20 2006-11-22 精工电子有限公司 发光二极管驱动电路
US20070285031A1 (en) * 2004-09-21 2007-12-13 Exclara Inc. System and Method for Driving LED
KR20080008759A (ko) * 2006-07-21 2008-01-24 엘지이노텍 주식회사 발광다이오드 백라이트 구동회로의 공진 승압형 컨버터
CN101459381A (zh) * 2008-12-10 2009-06-17 浙江大学 一种Boost型开关变换器的控制装置及控制方法
TW201137831A (en) * 2010-04-20 2011-11-01 Chunghwa Picture Tubes Ltd Voltage converter and driving method for use in a backlight module
CN102761264A (zh) * 2011-04-29 2012-10-31 京东方科技集团股份有限公司 一种Boost升压电路、背光驱动装置及液晶显示器

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101026248B1 (ko) * 2004-09-21 2011-03-31 페어차일드코리아반도체 주식회사 역률 보상 회로
JP5136364B2 (ja) * 2008-11-06 2013-02-06 富士電機株式会社 力率改善回路の制御方式
JP4680306B2 (ja) * 2009-02-05 2011-05-11 三菱電機株式会社 電源回路及び照明装置
CN101860189B (zh) * 2009-04-13 2013-05-08 台达能源技术（上海）有限公司 用于临界连续电流模式的无桥功率因数校正电路及其方法
US9030119B2 (en) * 2010-07-19 2015-05-12 Microsemi Corporation LED string driver arrangement with non-dissipative current balancer
CN101951150A (zh) * 2010-08-30 2011-01-19 深圳市桑达实业股份有限公司 一种开关直流升压电路、升压装置及led照明系统

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070285031A1 (en) * 2004-09-21 2007-12-13 Exclara Inc. System and Method for Driving LED
CN1866709A (zh) * 2005-05-20 2006-11-22 精工电子有限公司 发光二极管驱动电路
KR20080008759A (ko) * 2006-07-21 2008-01-24 엘지이노텍 주식회사 발광다이오드 백라이트 구동회로의 공진 승압형 컨버터
CN101459381A (zh) * 2008-12-10 2009-06-17 浙江大学 一种Boost型开关变换器的控制装置及控制方法
TW201137831A (en) * 2010-04-20 2011-11-01 Chunghwa Picture Tubes Ltd Voltage converter and driving method for use in a backlight module
CN102761264A (zh) * 2011-04-29 2012-10-31 京东方科技集团股份有限公司 一种Boost升压电路、背光驱动装置及液晶显示器

Also Published As

Publication number Publication date
CN103021344B (zh) 2015-11-25
CN103021344A (zh) 2013-04-03

Similar Documents

Publication Publication Date Title
CN103199499B (zh) 一种led驱动电源中的过压保护电路及led驱动电源
CN102118111B (zh) 初级侧调节器集成控制电路、方法及开关电源
CN103280190B (zh) 一种背光驱动电路、液晶显示装置和背光驱动方法
CN103021346B (zh) 一种led背光驱动电路、驱动方法及液晶显示装置
US10761148B2 (en) Indicating circuit for switching power supply and use method thereof
WO2014079029A1 (zh) 一种背光驱动电路、背光模组和液晶显示装置
CN203661377U (zh) 双绕组单级原边反馈的led灯驱动电路
CN103179751B (zh) 一种电感电流全周期采样的led驱动电路
CN102957324A (zh) 电源检测电路
CN102457047A (zh) 电源供应器以及具有多个电源供应器的供电系统
CN105992435A (zh) 抗干扰led过压保护模块以及抗干扰led过压保护系统
US20130099670A1 (en) Method and apparatus for led string short circuit detection and protection
CN104302053A (zh) Led恒流源输出检测控制电路及其控制方法
CN103151000B (zh) 一种背光驱动电路及其驱动方法和一种液晶显示装置
KR101932364B1 (ko) 액정 디스플레이 장비를 위한 led 백라이트 소스 및 액정 디스플레이 장비
CN103731049B (zh) 电流过零点检测电路和方法，驱动电路和方法，开关电源
CN203206529U (zh) 一种电感电流全周期采样的led驱动电路
CN114899802A (zh) 一种应用过压保护电路的led驱动电源
CN102201169A (zh) 动态人行信号灯电路
CN102695320B (zh) 恒流驱动电路
CN201414255Y (zh) 具有开路电压控制的灯管驱动装置
CN202918197U (zh) 电源检测电路
WO2017031694A1 (zh) 单相电子式电能表电源
CN202285443U (zh) 单通道led驱动电路
CN203151808U (zh) 可防过流的led驱动电路

Legal Events

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

Ref document number: 13806804

Country of ref document: US

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

Ref document number: 12888911

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: 12888911

Country of ref document: EP

Kind code of ref document: A1