What Is the Difference Between LED and Mini LED?
The alphabet of TV terminology is quite vast, but lately you may have seen a particularly confusing term: mini-LED. LEDs are already tiny, so what exactly does “mini” mean here? Turns out, quite a lot, and this difference can mean the difference between washed-out colors and a brighter display.
The fact is that almost every TV you see is technically an LED display of some sort. Most use bright white LEDs as backlight, which passes through an LCD matrix and a color filter to create a cohesive image. ( The exception is OLED , which illuminates each pixel individually and therefore does not require a backlight.)
Mini LEDs are an improvement over the backlighting part of this process. Traditionally, the backlight of most LCD TVs was either uniform or divided into several sub-zones. Mini LEDs are a much smaller backlight that can be individually controlled, allowing your TV to be bright where it needs to be and dark where it needs to be dark.
How do LED displays work?
Before we get into mini-LEDs, let’s take a little closer look at how most LCDs work. When manufacturers advertise a display as an “LED TV,” they usually mean backlighting, and LED is a given. However, there are several different types of backlight:
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Edge backlighting: This arrangement places LEDs in a row along the outer edge of the screen, which are then illuminated through light guides that distribute light more evenly across the display. This can be more cost-effective, but can sometimes result in bleed at the edges or dimmer areas in the middle of the screen.
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Full backlight. As an alternative, some manufacturers create a grid of LEDs that fills the entire display area. This results in more uniform illumination of the image. More importantly, these LEDs can usually be controlled individually to provide local dimming (more on this below).
This backlight emits white light (or blue, in the case of quantum dot displays ), which is then dimmed or blocked by the LCD matrix. This layer uses tiny liquid crystals to block or transmit light, which then passes through a red, green or blue filter. By controlling how much light passes through each of these filters (or “subpixels”), the TV can control the color of each pixel.
There’s just one small problem here: LCDs can’t completely block out all the light emitted by the backlight. This is why even when your LCD screen is completely black, it still appears “on”. Some light always gets through. To achieve a darker black, you’ll need a different technique.
How does local dimming work?
“Local dimming” refers to a range of techniques for LED-backlit displays that essentially amount to the same thing: dimming or turning off the backlight where you don’t need it. This means less light gets through, resulting in darker black levels and greater contrast with brighter parts of the screen.
The only catch is that the LCD display has literally millions more pixels than individual backlights. Less backlight means less resolution to differentiate between bright and dark areas. This also means you can get what’s called a “blooming effect,” where a bright object glows more than it should. This occurs when backlight leaks into the dark pixels around a bright object.
Each backlight creates a “zone” of dimming, and the more zones, the better . For most LED-backlit TVs, this number can range from a couple of dozen to several hundred. However, mini-LED technology allows TVs to increase this number into the thousands.
How are mini LED displays different?
To put it simply, in a mini LED display, the LEDs are mini LEDs. That’s all. To be more specific, the term is defined as any display whose backlight LEDs are smaller than 0.2mm. They can be smaller than this size, but if they are larger, then they can no longer (or at least should not ) be called “mini-LEDs”.
When they are packaged so small, you can fit many more LEDs in the same space. For example, this 65-inch Sony Bravia Mini LED TV has over 1,500 local dimming zones. This means that each LED light should illuminate an area of just over one square inch. This provides much more flexibility for creating contrast between light and dark parts of the image.
Why do you need mini LED instead of OLED?
This seems a little strange, doesn’t it? OLED displays illuminate each pixel individually, so you only use the pixels you need. Why all this local dimming array nonsense? This is partly due to the fact that OLED displays are more susceptible to burn-in.
Organic LED elements can degrade in such a way that images that appear frequently on the screen, such as menus, taskbars, or lower thirds, become ghosted. This is not an issue for typical LED-backlit displays, where the LCD layer is made of more durable inorganic materials.
LED and mini-LED panels can also be much brighter than OLED displays. This makes them more suitable for TVs that might sit in your living room, near a lot of sunny windows. While OLED TVs exist and are great, they have a hard time competing with the lighting in bright rooms, making them more suitable for viewing at night or in dimly lit rooms.