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Protection circuit for backlight driving circuit, backlight module and liquid crystal display device

A backlight drive circuit and protection circuit technology, applied in optics, nonlinear optics, static indicators, etc., can solve problems such as failure of dimming function and affecting service life of backlight drive circuit

Active Publication Date: 2016-03-02
TCL CHINA STAR OPTOELECTRONICS TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existing backlight drive circuit still has relatively high faults. After a period of use, the dimming function fails and there are faults such as no backlight output. Even if there is no problem with the backlight drive chip itself, and its temperature drops below the protection value, the fault Still exists, affecting the service life of the backlight drive circuit

Method used

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  • Protection circuit for backlight driving circuit, backlight module and liquid crystal display device
  • Protection circuit for backlight driving circuit, backlight module and liquid crystal display device
  • Protection circuit for backlight driving circuit, backlight module and liquid crystal display device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Such as figure 2 As shown, the backlight driving circuit 5 of the present embodiment includes a backlight driving chip 1, and the backlight driving chip 1 is provided with a protection pin 2 for controlling the backlight driving chip 1 to enter a protection state. The backlight driving circuit 5 also includes a protection circuit, and the protection circuit includes Monitoring unit with temperature detection function.

[0030] The monitoring unit includes a controllable switch Q1, which is connected in series between the protection pin 2 and the ground terminal GND of the backlight driving circuit 5; its control terminal is coupled with a temperature control component 3 .

[0031] The temperature control component 3 includes a high-level first reference voltage V1, and a first resistor R1 and a thermistor R are connected in series between the first reference voltage V1 and the ground terminal GND of the backlight drive circuit 5; the control terminal of the controllable ...

Embodiment 2

[0035] Such as image 3 As shown, the backlight driving circuit 5 of the present embodiment includes a backlight driving chip 1, and the backlight driving chip 1 is provided with a protection pin 2 for controlling the backlight driving chip 1 to enter a protection state. The backlight driving circuit 5 also includes a protection circuit, and the protection circuit includes Monitoring unit with temperature detection function.

[0036] The monitoring unit includes a controllable switch Q1, which is connected in series between the protection pin 2 and the ground terminal GND of the backlight drive circuit 5; its control terminal is coupled with a temperature control component 3 .

[0037] The temperature control component 3 includes a comparator U1, a high-level first reference voltage V1, a first resistor R1 and a thermistor R are connected in series between the first reference voltage V1 and the ground terminal GND of the backlight drive circuit 5; the controllable switch The ...

Embodiment 3

[0042] Such as Figure 4 As shown, the backlight driving circuit 5 of the present embodiment includes a backlight driving chip 1, and the backlight driving chip 1 is provided with a protection pin 2 for controlling the backlight driving chip 1 to enter a protection state. The backlight driving circuit 5 also includes a protection circuit, and the protection circuit includes Monitoring unit with temperature detection function.

[0043] The monitoring unit includes a controllable switch Q1, which is connected in series between the protection pin 2 and the ground terminal GND of the backlight drive circuit 5; its control terminal is coupled with a temperature control component 3 .

[0044] The temperature control assembly 3 includes a high-level third reference voltage V3, and a second resistor R2 and a bimetal thermostat W are connected in series between the third reference voltage V3 and the ground terminal GND of the backlight drive circuit 5; the controllable switch The cont...

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PUM

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Abstract

A protection circuit (7) of a backlight drive circuit (5), backlight module and liquid crystal display device, capable of preventing an element from being damaged by high temperature, thus realizing temperature protection for the element of the backlight drive circuit. The backlight drive circuit (5) comprises a backlight drive chip (1) provided with a protective pin (2) for controlling the backlight drive chip (1) to enter a protected state. The backlight drive circuit (5) further comprises a protection circuit (7) comprising a monitor unit (6) having a temperature detection function. When the temperature of the backlight drive circuit (5) exceeds a preset temperature, the monitor unit (6) couples a protection signal to the protective pin (2), the protection signal controlling the backlight drive chip (1) to enter the protected state.

Description

technical field [0001] The invention relates to the field of liquid crystal display, and more specifically relates to a protection circuit of a backlight driving circuit, a backlight module and a liquid crystal display device. Background technique [0002] The liquid crystal display device includes a backlight driver. The backlight driver usually uses a backlight driver chip to adjust the brightness of the backlight. The backlight driver chip itself has a temperature protection function. When the chip temperature rises and affects its normal operation, the backlight driver chip will Automatically enter the protection mode, reduce the brightness of the backlight or stop working directly, which is beneficial to improve the service life of the backlight drive circuit. However, the existing backlight drive circuit still has relatively high faults. After a period of use, the dimming function fails and there are faults such as no backlight output. Even if there is no problem with ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G09G3/34G09G3/36
CPCG02F2201/50G09G3/3406G09G2320/041G02F1/133612
Inventor 张先明
Owner TCL CHINA STAR OPTOELECTRONICS TECH CO LTD