Reveal the truth! Take you to know the real "LED tv"

Over the past two years, the development of flat-panel TV technology is very rapid, every year there are several hot topics worthy of debate, such as full HD, recordable TV, 120Hz and 100Hz, etc.. In 09 years of flat-panel TV market, we heard the most word should be "LED TV".

So what is "LED TV"? "LED TV" is a kind of new technology and new concept? In order to allow users to really understand, we come together today to reveal the secret of LED tv.

The difference between the 1, LED TV and LCD TV

At present, many LCD TV brands in the promotion of the product directly with the "LED TV" to promote the term, which brings a lot of misunderstanding, that "LED TV" is a new type of TV, which is wrong.

In fact, "LED TV" is the ordinary CCFL backlight LCD TV replacing LED backlight, more accurately should be called "LED backlight LCD TV", which is not an entirely new display technology with the principle of TV products.

If you want a bit more understanding of the relationship between the LED backlight LCD TV and LCD TV, you can put the LED backlight LCD TV into apple, LCD TV analogy into fruit. Apple is a kind of fruit, "LED backlight LCD TV" is only a "LCD TV".

It is worth noting that, in the television field we can often hear the "OLED TV" followed by "LED TV", although only one letter difference, but "OLED" is a kind of new technology, using the principle of active illumination, and due to the limitation of technology at present in the family TV application is not widespread.

2, LED backlight source Division

LED backlight equipped with LCD TV, can also be divided into many types. According to the classification of LED backlight technology, it can be divided into RGB-LED and white LED at present. According to the incident location of the light source, according to the incident location of the light source, it can be divided into two types: direct type and lateral type.

The difference between RGB-LED and white LED

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, the advantages are mainly reflected in two aspects of color performance and contrast.

Liquid crystal panel with RGB-LED as backlight

Of course, RGB-LED backlight is not perfect in every respect: the first is the cost of no great advantage; second is the heat dissipating structure of RGB-LED dimming circuit and to better separate, this will lead to a certain extent, television complex structure, difficult to light; in addition, the problems in the control of the RGB lamp still needs to be strengthened, for example among them, if a lamp is broken, the screen will be quite obvious.

Currently on the market most of the LED TV using white LED backlight

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. Because RGB-LED does not need to involve 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 backlight 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, the most widely used is the white LED backlight.

Division: straight down LED and side light type LED difference

The straight down backlight technology is simple, does not need the light guide plate, the LED array is placed at the bottom of the lamp box, the light emitted from the LED is reflected by the bottom surface and the side surface, and then the surface of the diffuser plate and the optical module are evenly distributed.

SHARP LX710 series new LED backlight LCD TV with straight down backlight

The thickness of the straight down backlight source is determined by the distance between the bottom of the lamp box and the scattering plate. In the case of the backlight source is thinner, the uniformity of color and brightness becomes the key technology of the direct down backlight.

The backlight module is point light source is arranged in the side of the light guide plate through the special design of the edge as a back light source, using a small number of LED; because the light source is arranged in the side of the light guide plate LED by a number and brightness limit, will still be light evenly dispersed throughout the plane, when the panel will form a larger area, the luminance of the more limited.

Side light type LED backlight LCD TV, the body can be very thin

For LED backlight source on the side of the product, so the back only need to add the light guide plate can be the appearance of thickness of the liquid crystal products can do is very thin, but the light utilization rate is low, and the thinner the utilization rate is small, about 50%.

The side light type LED product because it is made of a point light source composed of light source, rather than by the point source distribution to the TV LCD panel using the whole area, so it can not make the regional control function, cannot partition control is not only on the dynamic contrast value and increasing dynamic image quality without help.

3, LED backlight LCD TV advantage

One advantage: wide color gamut

CCFL (CCFL) backlight is excited luminescence, the luminescence spectra in the miscellaneous components more, color purity is low, resulting in the color gamut small, usually only NTSC 70%. The LED luminescence spectrum is narrow, the color purity is good, with three primary LED mixed light