LED LCDs are part of the family of LCDs. It is simply the backlight neon tube is replaced by a matrix of tiny LED bulbs. This new range of televisions or computer screens does bring benefits?
On TV, LCD LED belong to the family of LCDs. It is simply the backlight fluorescent strips which is replaced by a matrix of tiny LED bulbs. This new range of televisions or computer screens she brings real benefits?
In recent years, small LED bulbs take the place of conventional lighting. It's the same for our TVs LCD panels.
The five main advantages of LCD LED are:
- Reduced thickness: The LED screens allow a significant reduction in the thickness of the screen. In addition to aesthetics, it can hang the TV on a wall as a simple table.
- LED bulbs consume less than fluorescent tubes. End of 2009, consumption is already reduced by 50% compared to fluorescent tubes. This is a clear advantage in the summer of no longer having a computer screen that serves as a radiator.
- Better contrast. Due to their small size, LED light sources are less sensitive to diffusion. Suddenly, the blacks become deeper and the contrast increases, but qualitatively.
- The matrix of tiny LED bulbs ensures greater uniformity of brightness on the slab. If this improvement is not essential on a TV, it is a definite plus on a computer screen, especially in a professional graphics use.
- Ability to reproduce highly saturated colors: The color space or gamut small LCDs has grown thanks to the LED technology. This is not a priority for a TV benefit (see below), but a breakthrough for professionals working on computer graphics industry.
The LED backlight has today reached maturity and has a bright future ahead of him for at least 5 or 6 years before it is eaten by the technologies of the future. Its main advantage is to offer deeper blacks than LCD technology based on the classic neon tube. With the old fluorescent tubes, there is inevitably an effect of light scattering even where the pixels are completely black, that due to the scattering of light from one pixel to another. the conventional LCD is not capable of displaying a perfect black, but a very dark gray which reduced the quality of contrast even though marketing offers huge numbers to describe this contrast.
There are two philosophies in the replacement of tubes by LED diodes. The first is the desire to take advantage of the efficiency of the LED to have a limited consumption and favorable ecological impact. In this case the number of LEDs will be limited and they are often placed on the sides of the screen rather than behind. The second philosophy is to take maximum advantage of this technology and especially power through a large number of LEDs, define areas that will be considered numerically to artificially increase the contrast.
LEDs are small diodes (LED: Light Emitting Diode English) or LED (light emitting diode electro) in French. The matrix consists of small light sources can limit the contagion effect of light on the neighboring pixels. And this quality can be further enhanced digitally by a process which detects dark areas of the image and reduces the intensity of the backlight in these areas. This increases significantly the depth of black. The phenomenon of afterglowing is reduced by exploiting this type of scanning light.
On LCD LED, LCD panel technology is only the light source is changed and of course the quality of LCD LED will be directly proportional to the amount of LED bulbs that the manufacturer will kindly introduce behind screen. LED LCDs entry level remain very close to the LCD screen with a limited number of diodes to reduce the cost, while the high-end performance look with a large number of LEDs. The number of LEDs is very important and it is he who makes the difference with the conventional LCD technology. Screen input range will be happy with 40 LEDs while the high-end LED ask 2000 or more.
Future technologies
The ideal diode is a diode course for each pixel, but if we can build such a screen, the system placed in front LCD which is used to control the brightness and colorimetry becomes useless. Indeed, it suffices to assign this task to each LED coupled to a pixel. This technology already exists that LED technology is very promising, but also OLED, the same technology, but with a variation in the design of the diode. Obviously, the manufacturers do not hesitate to maintain the confusion between LED and LCD LED screen because the term is very seller.
Conclusion
Users computer screen requiring precision will benefit from real progress with increased color gamut and contrast ratio natural, but also a significant improvement in the uniformity of luminance, which was a weak point the high-resolution LCD large as 76 cm (30 ").
LED TV users will be disappointed, because unlike computer screens, the proposed models are often constructed with a limited number of LED or sometimes with LED lighting side. It did not improve the homogeneity light or very little. On the other hand, any increase in the gamut of the slab (number of colors in the color space) is superfluous in the field of TV, because TV sources are only in the sRGB standard, which limits the number at source colors available. And finally, with the diodes in small numbers, the real contrast is not improved, only the dynamic contrast (obtained artificially digital image) will use LED lighting. It remains for fans of television or home theater power consumption really down and aesthetics more likely with a slab thickness that tapers.
