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Dimming circuit, backlight module and liquid crystal display equipment

A dimming circuit and dimming mode technology, applied in the circuit field, can solve problems such as unreasonable use, different constant current backlights, and limited backlight dimming accuracy

Inactive Publication Date: 2018-11-09
GUANGZHOU SHIYUAN ELECTRONICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The problems of this solution are: 1. For the output of different constant current backlights, different control chips need to be used. For the design of solutions with different needs, different hardware designs need to be used for the control of constant current backlights.
2. The dimming accuracy of the backlight is limited by the control chip itself
3. Linear dimming and PWM square wave dimming have their own advantages and disadvantages. The same scheme can only realize one dimming method, and cannot make reasonable use of their respective advantages

Method used

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  • Dimming circuit, backlight module and liquid crystal display equipment
  • Dimming circuit, backlight module and liquid crystal display equipment
  • Dimming circuit, backlight module and liquid crystal display equipment

Examples

Experimental program
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Embodiment 1

[0051] figure 2 A structural schematic diagram of a dimming circuit provided by Embodiment 1 of the present invention. This embodiment is applicable to the case where the same dimming circuit realizes switching between linear dimming and PWM square wave dimming at the same time. The circuit can be integrated in In any device with a dimming circuit, it is especially suitable for liquid crystal display devices. The dimming circuit provided in this embodiment includes a control module 110 , a constant current output module 120 and an LED light source 130 .

[0052]Wherein, the constant current output module 120 is connected to the LED light source 130 to supply power to the LED light source 130, and the control module 110 is connected to the constant current output module 120 to output the constant current to the constant current according to the dimming mode. The module 120 outputs a linear dimming signal or a PWM dimming signal.

[0053] Optionally, it also includes: a sampl...

Embodiment 2

[0070] Figure 8 It is a structural schematic diagram of a dimming circuit provided in Embodiment 2 of the present invention. This embodiment is a further detailed explanation of the working principle and process of the constant current output module 120 in the above embodiment. The constant current output module 120 includes: a backlight MOS 121, a diode 122, a resistor 123, an inductor 124 and a power supply unit 125;

[0071] The first end of the inductor 124 is connected to the power supply module 125, and the second end is connected to the first end of the diode 122 for increasing the supply voltage;

[0072] The second end of the diode 122 is connected to the LED light source 130 for rectification;

[0073] The drain of the backlight MOS 121 is connected to the first end of the diode 122, the source is grounded, and the gate is connected to the driving circuit for controlling the on-off state of the LED light source 130;

[0074] The first end of the resistor 123 is gr...

Embodiment 3

[0079] Figure 10 A schematic structural diagram of a dimming circuit provided by Embodiment 3 of the present invention. This embodiment is applicable to the case where the same dimming circuit realizes switching between linear dimming and PWM square wave dimming at the same time. The circuit can be integrated in In any device with a dimming circuit, it is especially suitable for liquid crystal display devices. The dimming circuit provided in this embodiment includes a control module 210 , a constant current output module 220 , an LED light source 230 , a linear dimming module 240 , a PWM dimming module 250 and a switch 260 .

[0080] Wherein, the constant current output module 220 is connected with the LED light source 230 to supply power for the LED light source 230, one end of the switch 260 is connected with the constant current output module 220, and the control module 210 The other end controlling the switch 260 is connected to the linear dimming module 240 or the PWM d...

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Abstract

The embodiment of the invention discloses a dimming circuit, a backlight module and liquid crystal display equipment. The circuit comprises a control module, a constant-current output module and an LED light source, the constant-current output module is connected to the LED light source so as to supply power for the LED light source, and the control module is connected to the constant-current output module so as to output a linear dimming signal or a PWM dimming signal to the constant-current output module according to a dimming mode. According to the technical scheme of the dimming circuit, the backlight module and the liquid crystal display equipment, a constant-current control chip is removed and is completely replaced by a TV controller so as to simultaneously realize the switching between linear dimming and PWM square-wave dimming based on the dimming circuit.

Description

technical field [0001] Embodiments of the present invention relate to circuit technology, and in particular to a dimming circuit, a backlight module and a liquid crystal display device. Background technique [0002] The traditional constant current output uses an external constant current control chip to control the output of the backlight. At present, the mainstream LED backlight driving schemes are linear dimming and PWM square wave dimming. Figure 1A is a structural diagram of a linear dimming circuit in the prior art, Figure 1B It is a structural diagram of a PWM square wave dimming circuit in the prior art. The output current of linear dimming can be regarded as a straight line, so it is called linear dimming; the output current of PWM square wave dimming is a square wave , so it is called PWM square wave dimming. The principle of linear dimming is to change the output current by changing the output duty cycle of the backlight MOS in the constant current output modul...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G09G3/34
Inventor 廖胜峰
Owner GUANGZHOU SHIYUAN ELECTRONICS CO LTD