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.
Variations of Direct LED Backlighting
Direct LED backlighting has evolved into several different designs. Manufacturers have increased the number of LEDs, reduced their size, changed the type of light they produce, and developed different ways to control the backlight.
Full Array LED uses LEDs distributed across the entire area behind the screen. This provides more even illumination than a basic backlight with fewer LEDs. The number of LEDs can vary considerably between models, so the Full Array name alone does not indicate how advanced the backlight is.
FALD, or Full Array Local Dimming, divides the Full Array backlight into independently controlled zones. The TV can brighten some areas while dimming others according to the image. More and smaller zones generally allow more precise control of the backlight and better contrast.
Dual LED uses two types of LEDs with different color temperatures. One produces warmer light and the other produces cooler light. The TV adjusts the balance between them to change the color temperature of the backlight. Samsung has used the Dual LED name in some of its QLED TVs.
Mini LED uses much smaller LEDs than conventional LED backlights. This allows manufacturers to place many more LEDs behind the screen and create a larger number of dimming zones. More zones provide more precise control of bright and dark areas.
RGB LED uses separate red, green, and blue LEDs instead of conventional white LEDs. Controlling the three colors separately gives the backlight greater control over the light spectrum and can help expand the display’s color range.
RGB Mini LED combines RGB LEDs with Mini LED technology. The smaller LEDs allow a dense backlight with many individually controlled areas, while the RGB light sources provide additional control over the color of the backlight.
Manufacturers also use their own names for particular backlight systems. These are marketing names rather than separate types of backlighting.
Samsung Direct Full Array is Samsung’s marketing name for its Full Array backlight. Samsung has used names such as Direct Full Array 8×3 and Direct Full Array 16×3 for different TV models.
Samsung Quantum Matrix is Samsung’s marketing name for its Mini LED backlight with local dimming. Quantum Matrix Pro is a more advanced version of this system used in some Samsung TV models.
Sony XR Backlight Master Drive is Sony’s marketing name for its Mini LED backlight control system. It is used together with Mini LED and local dimming in some Sony TVs.
LG Full Array Dimming is LG’s marketing name for its Full Array local dimming system. It refers to a backlight with LEDs distributed across the rear of the screen and controlled in separate areas.
LED Plus is another manufacturer-specific marketing name used for certain LED backlight systems. The exact implementation can vary between manufacturers and TV generations.
NANO Full LED is also a manufacturer-specific name associated with Full Array backlighting. It refers to LEDs distributed behind the screen rather than only around its edges. NANO Full LED should not be confused with NanoCell, which is a separate LG display technology.
| Backlight or name | What it describes | Main characteristic |
|---|---|---|
| Full Array LED | LEDs distributed across the back of the screen | More even backlight distribution |
| FALD | Full Array with independently controlled zones | Local dimming and improved contrast |
| Dual LED | Two types of LEDs with different color temperatures | Control over backlight color temperature |
| Mini LED | Smaller LEDs used in large numbers | More LEDs and more dimming zones |
| RGB LED | Red, green, and blue light sources | Greater control over the backlight spectrum |
| RGB Mini LED | RGB light sources combined with Mini LEDs | More precise brightness and color control |
| Samsung Direct Full Array | Samsung marketing name | Full Array backlight |
| Samsung Quantum Matrix | Samsung marketing name | Mini LED with local dimming |
| Sony XR Backlight Master Drive | Sony marketing name | Mini LED backlight control |
| LG Full Array Dimming | LG marketing name | Full Array local dimming |
| LED Plus | Manufacturer marketing name | Additional backlight control |
| NANO Full LED | Manufacturer marketing name | Full Array backlighting |
