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Light emitting diode (LED) backlight driving circuit, liquid crystal display device and manufacturing method

A technology for backlight driving circuits and liquid crystal display devices, which is applied in the arrangement of electric lamp circuits, lighting devices, light sources, etc., can solve the problems of IC temperature rise and cost increase, and achieve the effects of reducing heat generation, reducing power consumption, and reducing temperature.

Active Publication Date: 2015-07-15
CHANGSHA HKC OPTOELECTRONICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since the voltage of each LED strip is different, that is, V F1 , V F2 , V F3 , V F4 are not equal, and the voltage V of the branch where the entire LED light bar is located LED The voltages are equal to, V F1 , V F2 , V F3 , V F4 are not equal, resulting in the voltage V applied to the converter IC LED1 , V LED2 , V LED3 , V LED4 The voltages are also different. If there is a voltage difference, a current will be generated, which will cause the temperature of the IC used in the backlight drive converter to rise. To solve the temperature problem, it is necessary to add a thermal pad or bare copper, which will cause costs. increase

Method used

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  • Light emitting diode (LED) backlight driving circuit, liquid crystal display device and manufacturing method
  • Light emitting diode (LED) backlight driving circuit, liquid crystal display device and manufacturing method
  • Light emitting diode (LED) backlight driving circuit, liquid crystal display device and manufacturing method

Examples

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Embodiment 1

[0029] In this embodiment, the voltage dividing resistor is a fixed resistor with fixed resistance, such as image 3 As shown, except for the LED light strip with the largest voltage difference, all other LED light strips are connected in series with fixed resistors with fixed resistances for equalizing the voltage difference between the LED light strips. Taking the LED light strip with the largest voltage difference as the reference voltage, on the one hand, it can save the resistance of one LED light strip; The consumption of electric energy on the resistor is beneficial to reduce energy consumption.

[0030] Further, in the LED backlight driving circuit, an isolating switch is coupled to the output end of each LED light bar, and a fixed resistor is connected in series between the LED light bar and the isolating switch. Add an isolating switch. When the LED light bar is short-circuited, the isolating switch is disconnected to prevent the branch voltage from being fully load...

Embodiment 2

[0035] In this embodiment, the voltage dividing resistor is a digital potentiometer that adjusts the resistance value through an electrical signal, such as Figure 4As shown in the figure, there are 4 LED light strips, and each digital potentiometer is connected to one LED light strip, which are respectively DVR1~DVR4, so that the resistance of the branch circuit where each LED light strip is located can be adjusted. Furthermore, except for the LED light bar with the largest voltage difference, the other LED light bars are all connected in series with digital potentiometers that adjust the resistance value through electrical signals. Taking the LED light strip with the largest voltage difference as the reference voltage, on the one hand, it can save the resistance of one LED light strip; The consumption of electric energy on the resistor is beneficial to reduce energy consumption.

[0036] Further, such as Figure 5 As shown, the branch where each LED light bar is located is...

Embodiment 3

[0040] In this embodiment, the voltage dividing resistor is a variable resistor with adjustable resistance, such as Figure 6 As shown, there are 4 LED light strips in the figure, and each variable resistor is connected to one LED light strip, which are respectively VR1~VR4, so that the resistance of the branch circuit where each LED light strip is located can be adjusted. Furthermore, except for the LED light bar with the largest voltage difference, all other LED light bars are connected in series with variable resistors with adjustable resistance. Taking the LED light strip with the largest voltage difference as the reference voltage, on the one hand, it can save the resistance of one LED light strip; The consumption of electric energy on the resistor is beneficial to reduce energy consumption.

[0041] Further, such as Figure 7 As shown, the branch where each LED light bar is located is also connected in series with an isolating switch Q1 and a connector. One end of the ...

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PUM

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Abstract

The invention provides an LED backlight driving circuit, an LCD device, and a manufacturing method. The LED backlight driving circuit includes at least two lightbars arranged in parallel connection; at least one LED lightbar is in series connection with a divider resistor(s) used for balancing the voltage difference between the LED lightbars. In the invention, because the LED lightbar(s) is in series connection with the divider resistors used for balancing the voltage difference between the LED lightbars, the divider resistors with different resistance can be connected in series according to different resistance of all the LED lightbars during design, to enable the total voltage difference of each LED lightbar and the divider resistor to be equal; thus, the voltages of all the pins of the IC coupled into the drive converter can be consistent, and no additional current can be generated in the IC because no voltage differences exist between pins basically; thus, the power consumption of the IC is reduced, and the heat productivity of the IC is reduced, thereby reducing the temperature of the IC.

Description

technical field [0001] The invention relates to the field of liquid crystal display, and more specifically, relates to an LED backlight driving circuit, a liquid crystal display device and a manufacturing method. Background technique [0002] A liquid crystal display device includes a liquid crystal panel and a backlight module. In a backlight module using LEDs, if multiple LED strips are used, such as figure 1 , 2 As shown, the LED light strips are connected in parallel, and each LED light strip is connected in series to the same converter. The converter is equipped with a control IC, and the IC is coupled to the output end of each LED light strip through a connector. , There is an isolating switch Q1 in series between the IC and the connector. Since the voltage of each LED strip is different, that is, V F1 , V F2 , V F3 , V F4 are not equal, and the voltage V of the branch where the entire LED light bar is located LED The voltages are equal to, V F1 , V F2 , V F...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G09G3/36H05B37/02
CPCH05B33/0827G09G3/3426Y10T29/49117H05B45/46
Inventor 张先明张裕桦陈明暐
Owner CHANGSHA HKC OPTOELECTRONICS CO LTD