Backlighting is one of the key components of an LCD TV. Unlike OLED displays, an LCD panel cannot produce light by itself, so it needs a light source behind the screen. The backlight shines through the LCD pixels, allowing the image to appear on the screen.
There are two basic types of LED backlighting: Direct LED and Edge LED. Over time, manufacturers have developed many variations and improvements based on these technologies, including FALD, Mini LED, RGB LED, and Micro RGB LED.
TV manufacturers have also introduced their own marketing terms for different backlight technologies, such as LED Plus and NANO Full LED.
Edge-lit LED backlighting
In an edge-lit LED backlighting system, the LEDs are positioned along the edges of the screen rather than across the entire area behind the LCD panel. Typically, the LEDs are located along the bottom edge of the screen. The light is then distributed across the entire display by a special light-guiding reflective substrate, which spreads the light from the bottom to the top of the screen.
The main advantage of this design is that it allows manufacturers to create very thin TVs. Since the LEDs, typically arranged in two LED strips, are mounted along the edge of the display, less space is needed behind the LCD panel. Edge-lit screens are also cheaper to manufacture. However, they have some drawbacks. It is practically impossible to implement a local dimming system because a single LED illuminates a large area of the screen.
Direct LED Backlighting
In a Direct LED backlighting system, the LEDs are placed directly behind the LCD panel. They are spread across the entire rear surface of the screen and shine light toward the panel. Special lenses can be used to spread the light more evenly, and the display also has a reflective layer that helps direct the light toward the screen.
The simplest Direct LED systems use a relatively small number of LEDs. In these TVs, the entire backlight may work as a single system, without separate control of individual areas of the screen. There are also several variations of Direct LED technology, including different ways of arranging the LEDs and different types of LEDs.
The main drawback is that the TV needs more space behind the LCD panel to accommodate the LEDs and the optical components that distribute the light. As a result, a Direct LED TV can be thicker than a model with Edge LED backlighting. However, modern Direct LED displays can be quite thin because the technology has developed significantly.
Direct LED is sometimes abbreviated as DLED. It is important to understand that the term Direct LED only describes the arrangement of the LEDs. It does not mean that the TV has local dimming or a large number of independently controlled backlight zones.
Full Array LED
Full Array LED is an advanced form of Direct LED backlighting. Instead of placing LEDs only in certain areas behind the screen, a Full Array system distributes them across the entire back of the display.
This arrangement allows the manufacturer to control the backlight more evenly across the screen and provides a better foundation for local dimming. By dividing the LEDs into separate zones, different areas of the screen can be brightened or dimmed independently.
The term Full Array describes the physical arrangement of the LEDs. It does not tell you how many LEDs are used or how many independently controlled dimming zones the TV has.
There are also several more advanced variations of Full Array backlighting, including Mini LED, RGB LED, and Micro RGB LED. They use different types and arrangements of light-emitting elements to improve backlight control and picture quality.
As a result, two Full Array TVs can have very different picture quality. One model may have relatively few backlight zones, while another may have hundreds or even more.
Local Dimming and Backlight Zones
Local dimming allows a TV to control different areas of the backlight independently. The more independently controlled zones a TV has, the more precisely it can adjust the brightness in different parts of the image.
For example, TVs with Edge LED backlighting typically have only two dimming zones, while standard Direct LED TVs may have several large zones. With such large zones, it is difficult to adjust the backlight precisely according to the image on the screen. As a result, some light may appear in areas that should be black. This is normal for LCD TVs.
In general, the more zones there are and the smaller they are, the more precisely the TV can control the backlight. Mini LED and similar technologies are particularly effective in this regard because they can use a very large number of small backlight zones.
However, the number of zones alone does not determine picture quality. The LCD panel itself also plays an important role. A TV with a large number of dimming zones can still produce a worse picture than a high-quality, top-of-the-line display with fewer zones.
LCD backlight screen
LCD – the first name of flat liquid crystal screens, the backlight of the screen was realized by special lamps, they were placed behind the screen or on the side along special optical fibers, the light flux was directed to the screen.
LED backlight screen
LED – instead of lamps for the backlight began to use LEDs. This was a new solution, LEDs reduced power consumption. And also it became possible to turn off the backlight of a part of the screen. The thickness of the TV also decreased.
Direct LED backlight screen
Direct LED – LED lights positioned in the entire area of the screen, the advantages of the possibility of using local dimming, a disadvantage is a large TV thickness. This technology is used in television sets of various series.
EDGE LED backlight screen
EDGE LED – The screen is backlighted by LEDs located on the side of the screen, the advantages are the thickness of the TV less. The disadvantages include: you can not use full local dimming.
LED Plus backlight screen
LED Plus – the same EDGE LED only realized the possibility of local dimming, but not in small areas, but in large ones, for example, either the left or right area of the screen.
NANO Full LED backlight screen
NANO Full LED – the same Direct LED but as they say in the scattering layer added microparticles, which makes the backlight softer. But in principle, this is simply a marketing move of the company.
So there are only two types of highlighting Direct and EDGE. All other names are improvements to the backlight. Namely, the implementation of the ability to control the backlight focusing on the displayed image. Also, let’s not forget marketing, if even on TV nothing has changed, then inventing a new name for the screen backlight, an increase in sales of televisions is achieved.
When choosing a TV, you need to focus on the type of backlight. Also, TVs with Direct backlight and the ability to control the brightness of the backlight, depending on the image on the screen, will show a better image.
