With the stimulation of LCD display market, LED backlight industry presents a boom development, making continuous progress in the display technology. After years of development, LED display industry is gradually stepped into mature stage. According to statistics from recent years, there are about 140 LED enterprises with annual production value more than 100 million yuan. From the market perspective, LED backlight technology has huge potentials. In this article, we will compare LED backlight with CCFL backlight. What specific advantages that LED backlight has?

 

 

LED backlight technology has better color gamut. Its color presenting capability is much better than that CCFL backlight source, having compensation to the LCD technology with insufficient CRI, providing better color rendition effects.

 

The general service life of LED Tube is around 100,000 hours. Even if used continuously for 10 hours a day. Theoretically, these LEDs can be used for 27 years, greatly extending the lifetime of LCD TVs. Certainly, this is just a experimental result. The practical lifetime of LED backlight LCD TVs far less than 100,000 hours.

 

Have wide brightness adjustment range. It is relatively easy for LED technology to realize power control, unlike CCFL, which has a limitation (threshold) for the minimum brightness. Thus, no matter in where, bright outdoor or all black indoor, users can easily adjust the brightness of their display devices to a comfortable level.

 

Perfect moving images. Traditional CCFL lamps have relatively low light-emitting frequency. Dynamic scenes may produce screen beatings. LED backlight technology can adjust luminous frequencies flexibly, which are much higher than CCFL and presenting motion pictures perfectly.

 

Real-time color management. Independently send out light by red, green and blue LEDs. It is easily for LED backlight LCD TV sets to control their color characteristics.

 

The backlit white balance is adjustable, without upsetting the contrast. When the video source is switched between computer and DVD, LED backlight can easily realize adjustment between 9600K and 6500K, without destroying brightness and contrast.

 

Can provide continuous plane array light four sources for large screens. LED is a kind of planar light source. LED chips with 3-5mm package are the basic light unit. Combination of these LED chips can easily form planar light sources, with even light distribution (brightness). That’s another advantage that for LED technology to be the backlight of LCD TVs. Unlike CCFL, LED backlight LCD TVs need no complex assisted optical components.

The real popularization of RGB LED backlight technology is a long journey. There are still a lot of problems need to be solved. Clearly, among these problems, high production cost is the key issue. LCD TV sets usually have high luminance. Thus need to use LED chips (usually greater than 1W) with high efficiency and high luminance. If use back lighting mode, the increasing of back panel size will also increase the number of LED chips, which consequently brings another problem: the thermal effect. The thermal effect will exponentially grow with the increasing of RGB LED chips. Therefore, more heat sinks, fans, cooling tubes are needed to maintain the internal operation temperature. Besides, too many LED chips will make producers hard to maintain a well color unity. They need to carefully choose LED chips with similar wavelength, adjust RGB color differences via Color Sensors. The impact of doing so is increasing the production cost. Selling prices usually far exceeded the expectation of consumers. Absolutely, there are some other solutions could solve this problem: enlarging panel size without increasing the number of RGB LED chips.

 

 

Reducing the power consumption of LED backlight models is not the only way that LED backlight module makers and LCD TV manufacturers need to concentrate on. LED chip makers also played a very important role. If the luminous efficiency of LED chips could be improved, LED-related technologies would be reduced dramatically, including LED backlight technology.

 

According to the current expectation of Japanese Lighting Association, LED will step into the practical stage in the next few years by realizing the production cost of 1yen per 100lm/W. The average color rendering of LED Panel Light will increase, too. In this part, phosphors played a very important role. Fluorescent powder together with blue-ray LEDs could generate (simulate) white-ray LEDs. However, this type of technology is relatively weak in presenting red and green rays (low CRI). Thus some producers start to develop a new method: UV LED + RGB fluorescent powder, which is rather complicated. Fluorescent powder with different colors cannot be simply mixed together. In order to obtain a white-ray effect with high CRI, fluorescent powder with different colors should be mixed proportionally. It is generally believed that the uniformity of light-emitting characteristic has nothing to do with the production technology of fluorescent powder.