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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 layout of electric lamp circuits, lighting devices, light sources, etc., can solve the problems of IC temperature increase and cost increase, and achieve the effects of reducing heat generation, reducing power consumption, and reducing temperature.

Active Publication Date: 2012-10-17
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 discloses a light emitting diode (LED) backlight driving circuit, a liquid crystal display device and a manufacturing method. The LED backlight driving circuit comprises at least two LED lamp strips which are arranged in parallel; and at least one LED lamp strip is serially connected with a divider resistor which is used for balancing the voltage difference between the LED lamp strips. Because at least one LED lamp strip is serially connected with the divider resistor which is used for balancing the voltage difference between the LED lamp strips, the LED lamp strips with different resistance values can be serially connected with divider resistors with different resistance values when in design, the sum of voltage differences of the LED lamp strips is equal to that of voltage differences of the corresponding divider resistors, the voltages of pins of an integrated circuit (IC) coupled in a drive converter can keep consistent, voltage differences among the pins do not exist basically, extra current does not generate in the IC, the power consumption of the IC is reduced, the heating value of the IC is also reduced, and the temperature of the IC falls.

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 Applications(China)
IPC IPC(8): G09G3/36H05B37/02
CPCH05B33/0827G09G3/34G09G3/36H05B37/02G09G3/3426H05B45/46Y10T29/49117
Inventor 张先明张裕桦陈明暐
Owner CHANGSHA HKC OPTOELECTRONICS CO LTD