WO2018152924A1 - 一种直流负调光电路及液晶显示设备 - Google Patents

一种直流负调光电路及液晶显示设备 Download PDF

Info

Publication number
WO2018152924A1
WO2018152924A1 PCT/CN2017/078633 CN2017078633W WO2018152924A1 WO 2018152924 A1 WO2018152924 A1 WO 2018152924A1 CN 2017078633 W CN2017078633 W CN 2017078633W WO 2018152924 A1 WO2018152924 A1 WO 2018152924A1
Authority
WO
WIPO (PCT)
Prior art keywords
resistor
dimming
signal
electrical switch
liquid crystal
Prior art date
Application number
PCT/CN2017/078633
Other languages
English (en)
French (fr)
Inventor
李文东
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 US15/552,272 priority Critical patent/US10178728B2/en
Publication of WO2018152924A1 publication Critical patent/WO2018152924A1/zh

Links

Images

Classifications

    • 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]
    • H05B45/10—Controlling the intensity of the light
    • 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
    • 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

Definitions

  • the present invention relates to the field of display technologies, and in particular, to a DC negative dimming circuit and a liquid crystal display device.
  • the LCD TV There are two ways to dim the LCD TV at this stage.
  • One is DC dimming and the other is PWM dimming.
  • the PWM dimming mode continuously turns on and off the current flowing through the LED string through the high frequency switch. Brightness adjustment is achieved by controlling the turn-on duty cycle of the light string. Therefore, in the process of PWM dimming, the LED light-emitting diode is actually blinking continuously.
  • TV manufacturers generally raise the dimming frequency to above 100 Hz.
  • the DC dimming mode achieves dimming by linearly adjusting the LED string current. There is no switch in the DC dimming mode to achieve stroboscopic dimming.
  • Another object of the present invention is to provide a liquid crystal display device.
  • the invention provides a DC negative dimming circuit, which is applied to a liquid crystal display device, and converts a first dimming signal outputted by a main chip of the liquid crystal display device into a second dimming signal, and outputs the same to a backlight module.
  • the DC negative dimming circuit includes a first electrical switch, a second electrical switch, and a first resistor.
  • the control end of the first electrical switch is connected to the dimming signal output end of the main chip through the first resistor to receive the first dimming signal
  • the first electrical switch The first end is connected to the voltage terminal through the second resistor to receive the first high level signal
  • the second end of the first electrical switch is connected to the control end of the second electrical switch
  • the second The first end of the electrical switch is connected to the dimming signal receiving end of the backlight module to output a second dimming signal to the dimming signal receiving end
  • the first end of the second electric switch further passes the
  • the third resistor is grounded, and the second end of the second electrical switch receives a second high level signal, the first dimming signal being opposite to the level of the second dimming signal.
  • the DC negative dimming circuit further includes a fourth resistor and a fifth resistor, the fourth resistor and the fifth resistor are connected in series between the voltage terminal and the ground, and the second electrical switch is second.
  • the terminal is connected to the node between the fourth resistor and the fifth resistor to receive the second high level signal.
  • the DC negative dimming circuit further includes a sixth resistor, and the first end of the first electrical switch is connected to the dimming signal output end of the main chip through the sixth resistor.
  • the DC negative dimming circuit further includes a capacitor connected in parallel at both ends of the third resistor.
  • the first electrical switch is a PNP type triode
  • the second electric switch is an NPN type triode
  • the control end, the first end, and the second end of the first electric switch and the second electric switch are respectively Base, emitter and collector.
  • the voltage of the first high level signal is less than or equal to the voltage of the first dimming signal.
  • the resistance of the second resistor is smaller than the resistance of the first resistor.
  • the invention also provides a liquid crystal display device, which comprises a main chip, a backlight module and the above-mentioned DC negative dimming circuit.
  • the liquid crystal display device is a liquid crystal television.
  • the DC negative dimming circuit of the present invention is applied to a liquid crystal display device to convert a first dimming signal outputted by a main chip of the liquid crystal display device into a second dimming signal, and output the same to a backlight module
  • the DC negative dimming circuit includes a first electrical switch, a second electrical switch, a first resistor, a second resistor, and a third resistor, and the control end of the first electrical switch is connected to the dimming of the main chip through the first resistor a signal output end for receiving the first dimming signal, a first end of the first electrical switch being connected to the voltage terminal through the second resistor to receive a first high level signal, the first electrical switch
  • the second end is connected to the a control end of the second electrical switch, the first end of the second electrical switch is connected to the dimming signal receiving end of the backlight module, to output a second dimming signal to the dimming signal receiving end,
  • the first end of the second electrical switch is also grounded through the third resistor,
  • FIG. 1 is a circuit diagram of a DC negative dimming circuit according to a first embodiment of the present invention
  • FIG. 2 is a block diagram of a liquid crystal display device according to a second embodiment of the present invention.
  • connection In the description of the present invention, it should be noted that the terms “installation”, “connected”, and “connected” are to be understood broadly, and may be fixed or detachable, for example, unless otherwise explicitly defined and defined.
  • the ground connection, or the integral connection may be a mechanical connection; it may be directly connected, or may be indirectly connected through an intermediate medium, and may be internal communication between the two elements.
  • the ground connection or the integral connection; may be a mechanical connection; it may be directly connected, or may be indirectly connected through an intermediate medium, and may be internal communication between the two elements.
  • a first embodiment of the present invention provides a DC negative dimming circuit 100 .
  • the DC negative dimming circuit 100 is applied to a liquid crystal display device to convert a first dimming signal outputted by a main chip of the liquid crystal display device into a second dimming signal, and output the same to a backlight module.
  • the DC negative dimming circuit 100 includes a first electrical switch Q1, a second electrical switch Q2, a first resistor R1, a second resistor R2, and a third resistor R3.
  • the control end of the first electrical switch Q1 passes the a resistor R1 is connected to the dimming signal output end of the main chip to receive the first dimming signal, and the first end of the first electric switch Q1 is connected to the voltage terminal VREF through the second resistor R2 to receive The first high level signal.
  • the second end of the first electrical switch Q1 is connected to the control end of the second electrical switch Q2, and the first end of the second electrical switch Q2 is connected to the dimming signal receiving end of the backlight module to output a second dimming signal is received at the receiving end of the dimming signal, a first end of the second electrical switch is further grounded through the third resistor R3, and a second end of the second electrical switch Q2 receives a second high voltage a flat signal, the first dimming signal being opposite to a level of the second dimming signal.
  • the first electrical switch Q1 is a PNP-type triode
  • the second electrical switch Q2 is an NPN-type triode
  • the control ends of the first electrical switch Q1 and the second electrical switch Q2 are One end and the second end are a base, an emitter and a collector, respectively.
  • the first electrical switch Q1 may also be other transistors of the PNP type.
  • the second electrical switch Q2 may also be other transistors of the NPN type.
  • the first dimming signal when the first dimming signal is at a low level, the first electrical switch Q1 is turned on, and the voltage outputted by the first electrical switch Q1 to the control end of the second electrical switch Q2 is high. Level. The second electrical switch Q2 is turned on, and the second high level signal is output to the dimming signal receiving end of the backlight module through the second electrical switch Q2. The second high level signal is the second dimming signal. When the first dimming signal is at a high level, the first electrical switch Q1 is turned off, the first An electrical switch Q1 does not output a signal to the control terminal of the second electrical switch Q2.
  • the second electrical switch Q2 is turned off, and the dimming signal receiving end of the backlight module is pulled low by the third resistor R3, so the second dimming signal is a low level signal. That is, the first dimming signal is opposite to the level of the second dimming signal.
  • the dimming signal receiving end of the backlight module receives the high level signal, the backlight module is bright.
  • the dimming signal receiving end of the backlight module receives the low level signal, the backlight module is dark. Therefore, the first dimming signal of the main chip can be directly supplied to the backlight module after being converted into the second dimming signal, thereby satisfying the requirement of the liquid crystal display device for DC negative dimming.
  • the first high level signal is a positive 5V voltage
  • the first dimming signal is a low level signal 0V
  • the first electrical switch Q1 is turned on
  • the first high level The signal is output to the control end of the second electrical switch Q2, so that the second electrical switch Q2 is turned on
  • the second high level signal is output to the dimming signal receiving end of the backlight module, that is, the The second dimming signal is a high level signal.
  • the first dimming signal is a high level signal 5V
  • the first electric switch Q1 is turned off, and the control end of the second electric switch Q2 is suspended, so that the second electric switch Q2 is turned off.
  • the second high level signal is not output to the dimming signal receiving end of the backlight module, that is, the second dimming signal is a low level signal.
  • the DC negative dimming circuit 100 further includes a fourth resistor R4 and a fifth resistor R5.
  • the fourth resistor R4 and the fifth resistor R5 are connected in series at the first voltage signal voltage terminal VREF and the ground.
  • the second end of the second electrical switch Q2 is connected to a node between the fourth resistor R4 and the fifth resistor R5 to receive the second high level signal.
  • the DC negative dimming circuit 100 further includes a sixth resistor R6, and the first end of the first electrical switch Q1 is connected to the dimming signal output end of the main chip through the sixth resistor R6.
  • the DC negative dimming circuit 100 further includes a capacitor C.
  • the capacitor C is connected in parallel at both ends of the third resistor R3. Wherein, the capacitor C functions as a filter.
  • the resistance of the second resistor R2 is smaller than the resistance of the first resistor R1, so that when the first dimming signal is a high level signal, and the first high level voltage is equal to the first tone In the case of an optical signal, it is ensured that the first electrical switch Q1 is turned off.
  • a second embodiment of the present invention provides a liquid crystal display device 200.
  • the liquid crystal display device 200 includes a main chip 210, a backlight module 220, and a DC negative dimming circuit.
  • the DC negative dimming circuit may be the DC negative dimming circuit 100 provided in the first embodiment. Since the DC negative dimming circuit 100 has been described in detail in the above first solution, it is not further entered here. Parallel description.
  • the liquid crystal display device 200 may be a liquid crystal television. In other embodiments, the liquid crystal display device 200 can also be other liquid crystal devices.
  • the DC negative dimming circuit 100 includes a first electrical switch Q1, a second electrical switch Q2, a first resistor R1, a second resistor R2, and a third resistor R3.
  • the first electrical switch Q1 The control terminal is connected to the dimming signal output end of the main chip 210 through the first resistor R1 to receive the first dimming signal, and the first end of the first electrical switch Q1 is connected through the second resistor R2 To the voltage terminal VREF to receive the first high level signal.
  • the second end of the first electrical switch Q1 is connected to the control end of the second electrical switch Q2, and the first end of the second electrical switch Q2 is connected to the dimming signal receiving end of the backlight module 220, and The second end of the second electrical switch Q2 receives the second high level, and the first electric switch Q1 is turned on when the first dimming signal is low.
  • the second electrical switch Q2 is turned on, and the second dimming signal received by the dimming signal receiving end of the backlight module 220 is the second high level signal.
  • the first dimming signal is at a high level
  • the first electrical switch Q1 is turned off
  • the second electrical switch Q2 is turned off
  • the dimming signal receiving end of the backlight module 220 passes through the third resistor R3 Pulled low, so the second dimming signal is a low level signal. That is, the first dimming signal is opposite to the level of the second dimming signal.
  • the dimming signal receiving end of the backlight module 220 receives the high level signal
  • the backlight module 220 is bright.
  • the dimming signal receiving end of the backlight module 220 receives the low level signal
  • the backlight module 220 is dark. Therefore, the first dimming signal of the main chip 210 can be directly supplied to the backlight module 220 after being converted into the second dimming signal, thereby satisfying the requirement of the liquid crystal display device 200 for DC negative dimming.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Liquid Crystal Display Device Control (AREA)

Abstract

一种直流负调光电路(100)，以将液晶显示设备的主芯片输出的第一调光信号转换为第二调光信号，并输出给背光模组，其包括第一及第二电开关(Q1,Q2)及第一至第三电阻(R1，R2，R3)。第一电开关(Q1)的控制端通过第一电阻(R1)连接至主芯片的调光信号输出端，以接收第一调光信号，第一电开关(Q1)的第一端通过第二电阻(R2)连接至电压端(VREF)，以接收第一高电平号，第二端连接至第二电开关(Q2)的控制端。第二电开关(Q2)的第一端连接至背光模组的调光信号接收端，以输出第二调光信号，并通过第三电阻(R3)接地，第二端接收第二高电平信号，第一与第二调光信号的电平相反。因此，主芯片的第一调光信号通过转换为第二调光信号后可以直接供给背光模组，从而满足了液晶显示设备对直流负调光的要求。

Description

一种直流负调光电路及液晶显示设备
本发明要求2017年2月21日递交的发明名称为“一种直流负调光电路及液晶显示设备”的申请号2017100938754的在先申请优先权，上述在先申请的内容以引入的方式并入本文本中。
技术领域
本发明涉及一种显示技术领域，尤其是涉及一种直流负调光电路及液晶显示设备。
背景技术
现阶段液晶电视机调光方式有两种。一种是直流调光，另一种是PWM调光。其中，PWM调光方式通过高频开关，使流过LED灯串的电流不断地导通和关断。通过控制灯串导通占空比，实现亮度调节。因此在PWM调光的过程中，LED发光二极管实际上是在不停地闪烁。为了避开人眼的识别范围，各电视机厂家普遍把调光频率抬高到100Hz以上。直流调光方式通过线性调节LED灯串电流，实现调光。直流调光方式不存在开关，实现无频闪调光。其中，大部分具备模拟调光功能的LED驱动芯片均要求直流正调光(低电平暗，高电平亮)。但是，对于部分电视主芯片而言，直流负调光(低电平亮，高电平暗)更利于系统设计。但是，主芯片的调光信号无法直接供给LED背光控制芯片，从而不能满足电视系统对直流负调光的要求。
发明内容
本发明的目的在于提供一种直流负调光电路，以满足电视机系统对直流负调光的要求。
本发明的另一目的在于提供一种液晶显示设备。
为了实现上述目的，本发明实施方式提供如下技术方案：
本发明提供一种直流负调光电路，应用于液晶显示设备中，以将液晶显示设备的主芯片输出的第一调光信号转换为第二调光信号，并输出给背光模组，其特征在于：所述直流负调光电路包括第一电开关、第二电开关、第一电阻、 第二电阻及第三电阻，所述第一电开关的控制端通过所述第一电阻连接至主芯片的调光信号输出端，以接收所述第一调光信号，所述第一电开关的第一端通过所述第二电阻连接至电压端，以接收第一高电平信号，所述第一电开关的第二端连接至所述第二电开关的控制端，所述第二电开关第一端连接至所述背光模组的调光信号接收端，以输出第二调光信号至所述调光信号接收端，所述第二电开关的第一端还通过所述第三电阻接地，所述第二电开关的第二端接收第二高电平信号，所述第一调光信号与所述第二调光信号的电平相反。
其中，所述直流负调光电路还包括第四电阻及第五电阻，所述第四电阻及所述第五电阻串联在所述电压端与地之间，所述第二电开关的第二端连接至所述第四电阻及所述第五电阻之间的节点上，以接收所述第二高电平信号。
其中，所述直流负调光电路还包括第六电阻，所述第一电开关的第一端通过所述第六电阻连接至所述主芯片的调光信号输出端。
其中，所述直流负调光电路还包括电容，所述电容并联在所述第三电阻的两端。
其中，所述第一电开关为PNP型三极管，所述第二电开关为NPN型三极管，所述第一电开关及所述第二电开关的控制端、第一端及第二端分别为基极、发射极及集电极。
其中，当所述第一调光信号为高电平时，所述第一高电平信号的电压小于或等于所述第一调光信号的电压。
其中，所述第二电阻的阻值小于所述第一电阻的阻值。
本发明还提供一种液晶显示设备，其特征在于，包括主芯片、背光模组及上述的直流负调光电路。
其中，所述液晶显示设备为液晶电视。
本发明实施例具有如下优点或有益效果：
本发明的一种直流负调光电路，应用于液晶显示设备中，以将液晶显示设备的主芯片输出的第一调光信号转换为第二调光信号，并输出给背光模组，所述直流负调光电路包括第一电开关、第二电开关、第一电阻、第二电阻及第三电阻，所述第一电开关的控制端通过所述第一电阻连接至主芯片的调光信号输出端，以接收所述第一调光信号，所述第一电开关的第一端通过所述第二电阻连接至电压端，以接收第一高电平信号，所述第一电开关的第二端连接至所述 第二电开关的控制端，所述第二电开关第一端连接至所述背光模组的调光信号接收端，以输出第二调光信号至所述调光信号接收端，所述第二电开关的第一端还通过所述第三电阻接地，所述第二电开关的第二端接收第二高电平信号，所述第一调光信号与所述第二调光信号的电平相反。因此，主芯片的第一调光信号通过转换为第二调光信号后可以直接供给所述背光模组，从而满足了液晶显示设备对直流负调光的要求。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本发明第一方案实施例提供的一种直流负调光电路的电路图；
图2是本发明第二方案实施例提供的一种液晶显示设备的框图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动的前提下所获得的所有其它实施例，都属于本发明保护的范围。
此外，以下各实施例的说明是参考附加的图示，用以例示本发明可用以实施的特定实施例。本发明中所提到的方向用语，例如，“上”、“下”、“前”、“后”、“左”、“右”、“内”、“外”、“侧面”等，仅是参考附加图式的方向，因此，使用的方向用语是为了更好、更清楚地说明及理解本发明，而不是指示或暗指所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。
在本发明的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸地连接，或者一体地连接；可以是机械连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员 而言，可以具体情况理解上述术语在本发明中的具体含义。
此外，在本发明的描述中，除非另有说明，“多个”的含义是两个或两个以上。若本说明书中出现“工序”的用语，其不仅是指独立的工序，在与其它工序无法明确区别时，只要能实现该工序所预期的作用则也包括在本用语中。另外，本说明书中用“～”表示的数值范围是指将“～”前后记载的数值分别作为最小值及最大值包括在内的范围。在附图中，结构相似或相同的用相同的标号表示。
请参阅图1，本发明第一方案实施例提供一种直流负调光电路100。所述直流负调光电路100应用于液晶显示设备中，以将液晶显示设备的主芯片输出的第一调光信号转换为第二调光信号，并输出给背光模组。
所述直流负调光电路100包括第一电开关Q1、第二电开关Q2、第一电阻R1、第二电阻R2及第三电阻R3，所述第一电开关Q1的控制端通过所述第一电阻R1连接至主芯片的调光信号输出端，以接收所述第一调光信号，所述第一电开关Q1的第一端通过所述第二电阻R2连接至电压端VREF，以接收第一高电平信号。所述第一电开关Q1的第二端连接至所述第二电开关Q2的控制端，所述第二电开关Q2第一端连接至所述背光模组的调光信号接收端，以输出第二调光信号至所述调光信号接收端，所述第二电开关的第一端还通过所述第三电阻R3接地，所述第二电开关Q2的第二端接收第二高电平信号，所述第一调光信号与所述第二调光信号的电平相反。
在本实施例中，所述第一电开关Q1为PNP型三极管，所述第二电开关Q2为NPN型三极管，所述第一电开关Q1及所述第二电开关Q2的控制端、第一端及第二端分别为基极、发射极及集电极。当所述第一调光信号为高电平时，所述第一高电平信号小于或等于所述第一调光信号，所述第一电开关Q1截止。
在其他实施例中，所述第一电开关Q1也可以为PNP型的其他晶体管。所述第二电开关Q2也可以为NPN型的其他晶体管。
需要说明的是，当所述第一调光信号为低电平时，所述第一电开关Q1导通，所述第一电开关Q1输出至所述第二电开关Q2的控制端的电压为高电平。所述第二电开关Q2导通，所述第二高电平信号通过所述第二电开关Q2输出至所述背光模组的调光信号接收端。其中，所述第二高电平信号为所述第二调光信号。当所述第一调光信号为高电平时，所述第一电开关Q1截止，所述第 一电开关Q1未输出信号至所述第二电开关Q2的控制端。所述第二电开关Q2截止，所述背光模组的调光信号接收端通过所述第三电阻R3拉低，故第二调光信号为低电平信号。即所述第一调光信号与所述第二调光信号的电平相反。所述背光模组的调光信号接收端接收到高电平信号时，所述背光模组亮。所述背光模组的调光信号接收端接收到低电平信号时，所述背光模组暗。因此，主芯片的第一调光信号通过转换为第二调光信号后可以直接供给所述背光模组，从而满足了液晶显示设备对直流负调光的要求。
例如，当所述第一高电平信号为正5V电压时，当所述第一调光信号为低电平信号0V时，所述第一电开关Q1导通，所述第一高电平信号输出至所述第二电开关Q2的控制端，使得所述第二电开关Q2导通，所述第二高电平信号输出至所述背光模组的调光信号接收端，即所述第二调光信号为高电平信号。而当所述第一调光信号为高电平信号5V时，所述第一电开关Q1截止，所述第二电开关Q2的控制端悬空，使得所述第二电开关Q2截止，所述第二高电平信号输出不到所述背光模组的调光信号接收端，即所述第二调光信号为低电平信号。
进一步地，所述直流负调光电路100还包括第四电阻R4及第五电阻R5，所述第四电阻R4及所述第五电阻R5串联在所述第一电压信号电压端VREF与地之间，所述第二电开关Q2的第二端连接至所述第四电阻R4及所述第五电阻R5之间的节点上，以接收所述第二高电平信号。
所述直流负调光电路100还包括第六电阻R6，所述第一电开关Q1的第一端通过所述第六电阻R6连接至所述主芯片的调光信号输出端。
进一步地，所述直流负调光电路100还包括电容C。所述电容C并联在所述第三电阻R3的两端。其中，所述电容C起到滤波的作用。
所述第二电阻R2的阻值小于所述第一电阻R1的阻值，以当所述第一调光信号为高电平信号，且所述第一高电平电压等于所述第一调光信号时，确保所述第一电开关Q1截止。
请参阅图2，本发明第二方案实施例提供一种液晶显示设备200。所述液晶显示设备200包括主芯片210、背光模组220及直流负调光电路。所述直流负调光电路可以为上述第一方案实施例提供的直流负调光电路100。由于所述直流负调光电路100已经在上述第一方案中进行了详细的说明，故在此不再进 行赘述。
在本实施例中，所述液晶显示设备200可以为液晶电视。在其他实施例中，所述液晶显示设备200也可以为其他液晶设备。
在本实施例中，所述直流负调光电路100包括第一电开关Q1、第二电开关Q2、第一电阻R1、第二电阻R2及第三电阻R3，所述第一电开关Q1的控制端通过所述第一电阻R1连接至主芯片210的调光信号输出端，以接收所述第一调光信号，所述第一电开关Q1的第一端通过所述第二电阻R2连接至电压端VREF，以接收第一高电平信号。所述第一电开关Q1的第二端连接至所述第二电开关Q2的控制端，所述第二电开关Q2第一端连接至所述背光模组220的调光信号接收端，并通过所述第三电阻R3接地，所述第二电开关Q2的第二端接收第二高电平，当所述第一调光信号为低电平时，所述第一电开关Q1导通，所述第二电开关Q2导通，所述背光模组220的调光信号接收端接收到的第二调光信号为所述第二高电平信号。当所述第一调光信号为高电平时，所述第一电开关Q1截止，所述第二电开关Q2截止，所述背光模组220的调光信号接收端通过所述第三电阻R3拉低，故第二调光信号为低电平信号。即所述第一调光信号与所述第二调光信号的电平相反。所述背光模组220的调光信号接收端接收到高电平信号时，所述背光模组220亮。所述背光模组220的调光信号接收端接收到低电平信号时，所述背光模组220暗。因此，主芯片210的第一调光信号通过转换为第二调光信号后可以直接供给所述背光模组220，从而满足了液晶显示设备200对直流负调光的要求。
在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示例”、“具体示例”或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本发明的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不一定指的是相同的实施例或示例。而且，描述的具体特征、结构、材料或特点可以在任何的一个或多个实施例或示例中以合适的方式结合。
以上所述的实施方式，并不构成对该技术方案保护范围的限定。任何在上述实施方式的精神和原则之内所作的修改、等同替换和改进等，均应包含在该技术方案的保护范围之内。

Claims (15)

  1. 一种直流负调光电路，应用于液晶显示设备中，以将液晶显示设备的主芯片输出的第一调光信号转换为第二调光信号，并输出给背光模组，其中，所述直流负调光电路包括第一电开关、第二电开关、第一电阻、第二电阻及第三电阻，所述第一电开关的控制端通过所述第一电阻连接至主芯片的调光信号输出端，以接收所述第一调光信号，所述第一电开关的第一端通过所述第二电阻连接至电压端，以接收第一高电平信号，所述第一电开关的第二端连接至所述第二电开关的控制端，所述第二电开关第一端连接至所述背光模组的调光信号接收端，以输出第二调光信号至所述调光信号接收端，所述第二电开关的第一端还通过所述第三电阻接地，所述第二电开关的第二端接收第二高电平信号，所述第一调光信号与所述第二调光信号的电平相反。
  2. 如权利要求1所述的直流负调光电路，其中，所述直流负调光电路还包括第四电阻及第五电阻，所述第四电阻及所述第五电阻串联在所述电压端与地之间，所述第二电开关的第二端连接至所述第四电阻及所述第五电阻之间的节点上，以接收所述第二高电平信号。
  3. 如权利要求2所述的直流负调光电路，其中，所述直流负调光电路还包括第六电阻，所述第一电开关的第一端通过所述第六电阻连接至所述主芯片的调光信号输出端。
  4. 如权利要求3所述的直流负调光电路，其中，所述直流负调光电路还包括电容，所述电容并联在所述第三电阻的两端。
  5. 如权利要求1所述的直流负调光电路，其中，所述第一电开关为PNP型三极管，所述第二电开关为NPN型三极管，所述第一电开关及所述第二电开关的控制端、第一端及第二端分别为基极、发射极及集电极。
  6. 如权利要求1所述的直流负调光电路，其中，当所述第一调光信号为高电平时，所述第一高电平信号的电压小于或等于所述第一调光信号的电压。
  7. 如权利要求1所述的直流负调光电路，其中，所述第二电阻的阻值小于所述第一电阻的阻值。
  8. 一种液晶显示设备，其中，包括主芯片、背光模组及直流负调光电路，直流负调光电路用于将液晶显示设备的主芯片输出的第一调光信号转换为第 二调光信号，并输出给背光模组，其中，所述直流负调光电路包括第一电开关、第二电开关、第一电阻、第二电阻及第三电阻，所述第一电开关的控制端通过所述第一电阻连接至主芯片的调光信号输出端，以接收所述第一调光信号，所述第一电开关的第一端通过所述第二电阻连接至电压端，以接收第一高电平信号，所述第一电开关的第二端连接至所述第二电开关的控制端，所述第二电开关第一端连接至所述背光模组的调光信号接收端，以输出第二调光信号至所述调光信号接收端，所述第二电开关的第一端还通过所述第三电阻接地，所述第二电开关的第二端接收第二高电平信号，所述第一调光信号与所述第二调光信号的电平相反。
  9. 如权利要求8所述的液晶显示设备，其中，所述直流负调光电路还包括第四电阻及第五电阻，所述第四电阻及所述第五电阻串联在所述电压端与地之间，所述第二电开关的第二端连接至所述第四电阻及所述第五电阻之间的节点上，以接收所述第二高电平信号。
  10. 如权利要求9所述的液晶显示设备，其中，所述直流负调光电路还包括第六电阻，所述第一电开关的第一端通过所述第六电阻连接至所述主芯片的调光信号输出端。
  11. 如权利要求10所述的液晶显示设备，其中，所述直流负调光电路还包括电容，所述电容并联在所述第三电阻的两端。
  12. 如权利要求8所述的液晶显示设备，其中，所述第一电开关为PNP型三极管，所述第二电开关为NPN型三极管，所述第一电开关及所述第二电开关的控制端、第一端及第二端分别为基极、发射极及集电极。
  13. 如权利要求8所述的液晶显示设备，其中，当所述第一调光信号为高电平时，所述第一高电平信号的电压小于或等于所述第一调光信号的电压。
  14. 如权利要求8所述的液晶显示设备，其中，所述第二电阻的阻值小于所述第一电阻的阻值。
  15. 如权利要求8所述的液晶显示设备，其中，所述液晶显示设备为液晶电视。
PCT/CN2017/078633 2017-02-21 2017-03-29 一种直流负调光电路及液晶显示设备 WO2018152924A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/552,272 US10178728B2 (en) 2017-02-21 2017-03-29 Direct current negative dimming circuit and liquid crystal display device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201710093875.4 2017-02-21
CN201710093875.4A CN106710533B (zh) 2017-02-21 2017-02-21 一种直流负调光电路及液晶显示设备

Publications (1)

Publication Number Publication Date
WO2018152924A1 true WO2018152924A1 (zh) 2018-08-30

Family

ID=58917285

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/078633 WO2018152924A1 (zh) 2017-02-21 2017-03-29 一种直流负调光电路及液晶显示设备

Country Status (3)

Country Link
US (1) US10178728B2 (zh)
CN (1) CN106710533B (zh)
WO (1) WO2018152924A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110267396B (zh) * 2019-06-11 2021-10-01 惠科股份有限公司 直流负调光电路及显示装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102325401A (zh) * 2011-06-17 2012-01-18 深圳Tcl新技术有限公司 Led驱动装置、灯条和背光装置
CN102833916A (zh) * 2012-08-23 2012-12-19 冠捷显示科技（厦门）有限公司 一种直流调光型led驱动电路
KR20130015852A (ko) * 2011-08-05 2013-02-14 엘지디스플레이 주식회사 백라이트 유닛
CN103310740A (zh) * 2013-04-26 2013-09-18 明基电通有限公司 显示装置的影像处理方法及其显示装置
EP2843650A1 (en) * 2013-09-03 2015-03-04 Samsung Electronics Co., Ltd Display apparatus, light source driving apparatus and driving method thereof
CN105282907A (zh) * 2014-07-07 2016-01-27 盛群半导体股份有限公司 发光二极管背光驱动装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101789681B1 (ko) * 2010-09-10 2017-10-25 삼성전자주식회사 발광 구동 장치, 디스플레이 장치 및 그 구동 방법

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102325401A (zh) * 2011-06-17 2012-01-18 深圳Tcl新技术有限公司 Led驱动装置、灯条和背光装置
KR20130015852A (ko) * 2011-08-05 2013-02-14 엘지디스플레이 주식회사 백라이트 유닛
CN102833916A (zh) * 2012-08-23 2012-12-19 冠捷显示科技（厦门）有限公司 一种直流调光型led驱动电路
CN103310740A (zh) * 2013-04-26 2013-09-18 明基电通有限公司 显示装置的影像处理方法及其显示装置
EP2843650A1 (en) * 2013-09-03 2015-03-04 Samsung Electronics Co., Ltd Display apparatus, light source driving apparatus and driving method thereof
CN105282907A (zh) * 2014-07-07 2016-01-27 盛群半导体股份有限公司 发光二极管背光驱动装置

Also Published As

Publication number Publication date
US10178728B2 (en) 2019-01-08
CN106710533B (zh) 2018-06-29
US20180332679A1 (en) 2018-11-15
CN106710533A (zh) 2017-05-24

Similar Documents

Publication Publication Date Title
TWI377871B (en) Power supply system and liquid crystal display device having the same
US7446487B2 (en) Dimming mode selecting circuit and driving device using the same
US9672779B2 (en) Liquid crystal display device, backlight module, and drive circuit for backlight source thereof
US10140931B2 (en) Shadow mask assemblies and reusing methods of shadow mask assemblies thereof
US20070247450A1 (en) LED driving device of overvoltage protection and duty control
TWI735865B (zh) 發光二極體驅動系統及發光二極體驅動裝置
US8911111B2 (en) LED backlight system and display device
JP4686434B2 (ja) アクティブ型電流調整回路及びその発光構造
GB2524213A (en) Backlight drive board and liquid crystal display
WO2018157345A1 (zh) Led灯具及led亮度调节电路
WO2022095664A1 (zh) Led驱动系统及电子设备
GB2542533A (en) LED backlight for liquid crystal display device and liquid crystal display device
WO2018152924A1 (zh) 一种直流负调光电路及液晶显示设备
US20090160359A1 (en) Light emitting diode control circuit with constant-current circuit
TWI442828B (zh) 發光二極體驅動電路
CN212115733U (zh) 一种调光电路
CN102122495B (zh) 一种用于液晶显示屏的对比度调节电路
CN217788005U (zh) 一种应用于tv背光的调光电路及tv背光电源电路
CN206533572U (zh) 调光补偿电路
US7944154B2 (en) Fluorescent tube power supply and backlight
CN110267396B (zh) 直流负调光电路及显示装置
US20090009106A1 (en) Circuit for driving light sources using balanced feedback signal
CN103177695B (zh) 具有电路保护模块的显示装置及其保护方法
CN212086543U (zh) Led调光调色电路及装置
TWI662859B (zh) 可隨調光訊號改變響應的回授電路

Legal Events

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

Ref document number: 15552272

Country of ref document: US

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

Ref document number: 17897924

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: 17897924

Country of ref document: EP

Kind code of ref document: A1