LED backlighting, an evolution of the LCD

When we talk about a TV with LED screen, we are actually talking about a TV whose LCD panel is equipped with LED backlight. This means that behind the pixels that make up the screen are LEDs, or Light-Emitting Diodes, which make the image much brighter and allow better contrast. This backlight system is widely used today.

Two LED backlighting systems stand out:

The first is Full LED, or Direct LED, which designates LCD panels where LEDs spread across the back of the pixels. It is Direct LED technology that provides the best contrast and the best brightness, since the multiplicity of diodes gives a very homogeneous backlight. Black areas are more uniform and the colorimetry is also more balanced. In addition to these undeniable advantages, there is a disadvantage, which is nevertheless relatively simple to manage: Direct LED panels are slightly thicker than those of other models, due to the multiplicity of diodes inside. Some Thomson televisions embed Direct LED technology, and do it rather well!

The second LED backlighting system is the Edge LED, LEDs are then located only on the edges of the screen. Reflectors are responsible for diffusing light over the entire surface of the LCD panel. If the result is a little less efficient than for a Direct LED backlighting system, it is still very satisfactory, and allows to have a thinner TV, because the backlighting system takes up less space.

QLED, a proprietary technology

QLED differs from other technologies in that it only affects products from a few brands. Like LED, this is an evolution of the LCD. QLED stands for Quantum Light-Emitting Diode, which highlights Quantum Dot technology, which uses quantum dot light emitting diodes. The latter offer a backlighting system presented as more effective than traditional LEDs, particularly in terms of colorimetry and brightness. But this is not without certain constraints: this QLED backlighting technology takes up more space than for LEDs and the TV is thicker. Black areas are generally less black and the picture refresh rate can be a little slower than with other backlighting technologies.

OLED, the organic revolution

OLED, on the other hand, presents a real difference compared to LED. OLED is an acronym for Organic Light-Emitting Diodes, or organic light-emitting diode. Unlike LED systems which combine the pixels of an LCD screen with diodes for the backlight, the OLED consists of pixels which have their own backlighting system: each pixel is therefore its own light source.

The main advantage of OLED is therefore to limit the components, and it allows the design of thinner LCD panels. Another advantage of this technology is that, in order to display black areas, the pixels only have to be switched off, whereas other backlighting technologies cannot and therefore they only can display projected black areas. OLED therefore offers very marked contrast and this is often what purists are looking for. Besides, it is also an energy efficient backlighting system, since a black pixel consumes therefore nothing, when switched off.

Among the disadvantages of OLED panels, we note a limited lifetime to get their full potential, since the red, green and blue sub-pixels tend to lose intensity after a few years. OLED TVs are also more expensive than LED TVs, which is often a disadvantage for consumers. Today, the use of OLED appears to be more sustainable on the side of smartphones than televisions.

To make the right choice among TV panel technologies

Technologies for TV screen panels are therefore numerous and they often have advantages and some disadvantages. Knowing the whole picture allows you to identify all the issues and make a choice that suits your desires. In general, opting for a Direct-LED TV model is an effective and accessible compromise, which allows you to enjoy a good image quality associated with contrasts and a balanced brightness, as well as good colorimetry.