1. LED Backlight is dominating the market while CCFL Backlight is disappearing
The power consumption of LED backlight is much lower than CCFL backlight’s in the same amount of brightness. For example: the power consumption of 12 inch LED backlight laptop computer is less than 3 watt, but traditional CCFL backlight’s is between 3.5-4 watt. The power consumption of laptop computer not only determines the performance of the laptop computer and the lifespan of the battery but also affects the thermal problem and the reliability problem of the laptop computer which are the most critical issues. The thermal problem and the reliability problem are closely connected. If the thermal problem is perfectly solved, the reliability increases a lot. The thermal problem is the most critical technical obstacle in developing LED backlight at the present stage. Though some backlight manufacturers repeat that the thermal problem has been solved, the reliability only can be tested by the time.
Finding an acceptable cost to solve the thermal problem at the present stage is the main direction, at the same time the reliability must be considered. If the thermal problem is solved, LED backlight will replace CCFL backlight immediately. Besides, the laptop computers which adopt LED backlight are much thinner so that they can meet people’s fashion sense.
We are not saying that LED as the green and environment-friendly light source is perfect. In fact, there are several aspects of LED light source is less perfect such as the overall cost and color saturation. With the development of technology, the overall cost is going to be lower and the color saturation is getting better. But so far, the color saturation of white LED lamp is lesser than CCFL’s. The LED lamp with RGB triple chips which emits white light is neither too big nor too little brightness. If RGB three individual LED lamps to emit white lights by mixing lights together, the brightness will decrease while the temperature of the main board goes up. For example, the red LED lamp is the most affected by the temperature. Therefore, the thermal problem is the most urgent problem to be solved in technology. We can see the following image explanation.
2. The True Reasons LED backlight is Replacing CCFL Backlight
People often talk about that LED backlight is replacing CCFL backlight in LCD TV because of the mercury problem of CCFL backlight, the better color performance of LED backlight and something like that. If you think this is the end of the story, you certainly underestimate the advantages of LED backlight. The deeper reasons of “why LED backlight is replacing CCFL backlight” is that fast driving speed, blur avoiding and region control. Also, they are the developing direction of LED backlight technology.
There are some wrong opinions. Some people refer LED as a green product without mercury. But as a matter of fact, EU environmental standards require that mercury is less than 5mg, which is not a problem for CCFL backlight. Meanwhile, some people think that the color performance of CCFL backlight can only reach 72% of NTSC and LED backlight can easily exceed 100% of NTSC. But CCFL backlight technology which can reach 100% of NTSC color performance has already been invented.
Tips: National Television Standards Committee (NTSC)
We notice that LED backlight technicians in Japan and Korea dedicate to develop features of LED, such as regional control. Therefore, the direction of research and development will move towards the high density of LED, which will make small region control design better.
Besides, the driving speed of LED backlight is much faster than the driving speed of CCFL backlight. It takes 1-2 seconds to start-up for CCFL backlight which may cause the independent colors, while it takes only 50 ns to start-up for LED backlight which can adopt dynamic driving method, such as color filter-less. If backlight adopts color filter, it will block the two-thirds of the light. On the contrary, if backlight does not adopt color filter, the light will double increase. In addition, liquid crystal display constantly turns on/off light to display the images, but the power of CCFL is always on, which may cause the backlight bleeding and poor contrast, even the problem of blurred images. And LED backlight could easily solve these problems, which makes regional control of LED backlight even better.
