LED TV fierce three mainstream LED backlight technology analysis

According to the analysis of the last two years LED TV product development route, we can find that LED TV according to the type of the backlight, there have been three branches of technology, namely: RGB-LED, LED and LED edge emitting white light.

RGB-LED tricolor LED backlight

RGB-LED backlight is a relatively early birth of a technology. RGB-LED through red, green, blue tricolor LED modulation into white light, has the best optical properties. Therefore, the quality of Japanese manufacturers are widely used.

RGB-LED in the composition of the backlight source, is not entirely in accordance with the number of 1:1:1. Currently the most common solution is composed of 1 red LED, 1 blue LED and 2 green LED. This combination is because there is a certain difference in the luminous efficiency of each color LED, must be achieved through the combination of three kinds of light source matching.

SONY's first generation RGB-LED micro junction

The position of the RGB-LED backlight source is not much different from that of the previous CCFL, and is still behind the LCD panel. Therefore, from a structural point of view, the use of this technology LED TV, in appearance and ordinary LCD LCD TV and there will be no obvious difference.

SONY's second generation RGB-LED micro structure

The advantages of RGB-LED TV is mainly reflected in the color and contrast of the two aspects: due to the use of RGB color independent light emitting element, so the color gamut of RGB-LED TV can reach more than 120% of the NTSC, after a good part of the set-up model can even reach the color gamut of around 150%, fully meet or exceed the level of plasma tv.

In addition, RGB-LED TV can also support backlight area adjustment technology, it is very easy to achieve brightness adjustment, in contrast, are often able to reach ten: dynamic contrast level 1, which has a very important role in improving the image quality of the tv.

Of course, although the performance of RGB-LED TV is very good, but it is not perfect: first, there is no great advantage in terms of cost. Second is the need for a separate dimmer circuit and a better heat dissipation structure, which will also lead to a certain extent, RGB-LED TV structure is complex, it is difficult to achieve thin.

White LED

White light LED relative to the RGB-LED will be much simpler, it uses only the white light emitted by the LED light source instead of the original CCFL fluorescent tube.

Regional control of white LED is very easy to implement, so the white LED TV contrast index is often very high

White LED is not as light as the RGB-LED need to relate to the dimming of the backlight, so the requirements of the circuit structure is relatively high. However, the spectral characteristics of white LED and RGB-LED compared to a lack of, which also led to the performance of such LED TV is not as good as RGB-LED tv.

However, the advantages of white LED TV is also more obvious, such as the brightness of the dynamic adjustment, regional backlight control can be achieved, but also to achieve a good contrast. In the color gamut can also be improved than ordinary CCFL LCD tv. Coupled with the cost advantage, so we believe it will become the future of the most popular LED TV program priority.

Edge emitting LED

Edge light-emitting LED industry is called the third generation LED backlight technology. Although the use of white LED as a backlight, but through the application of the structure and special materials, while improving the color gamut and contrast indicators, but also to the thickness of the fuselage dropped significantly.

Anatomy of a certain brand of edge emitting LED TV, we can see that the direction of the light and liquid crystal panel level

LED is the edge of the LED light source placed in the TV frame position, most of the liquid crystal panel next to a layer, it is very space saving. However, the edge of the light emitted by the LED is not the same as the first two programs directly through the LCD panel, but parallel to the LCD panel. The light must pass through a special light guide plate to change the propagation direction before passing through the liquid crystal panel.

Public information SONY notebook LED LCD screen, LED TV is very similar to the structure of due to the position of LED at the side edge of the liquid crystal panel, so it uses the light guide plate has not only change the direction of light propagation, but also to the light scattered energizer uniform, otherwise there will be a serious television image edge light the middle, dark problem.

Edge emitting LED schematic diagram of

Due to the location of the edge of the LED is not in the rear of the LCD panel, so this type of LED TV is difficult to achieve backlight dimming. This is also a technical problem to be solved in the next step on the edge of LED tv.

Samsung LED TV thickness is very slim, because the use of edge emitting LED

Currently available on the market to see the edge of LED TV only Samsung's full range of LED TV and SONY's two types of ultra-thin 40ZX1. This type of LED TV are the main slim appearance, in performance compared with the two LED TV there is still a little lack of.

Summary:

Although the invention has been around for 30 years, the LED technology is one of the youngest of the three kinds of lighting technology used in human being. The application of LED technology in flat panel TV is only a start. I believe that with LED companies mature and various television to have better color performance, more expressive, more detail to slim LED TV, will quickly become the new darling of the market in the next few years.