What Is Mini LED?

How is it different than LED and Micro LED?

TCL Q82X LED/LCD TV with Quantum Dots and Mini LEDs
TCL

One application of LED technology is to provide backlighting for LCD TVs and PC monitors.  However, not all LEDs used in those applications are the same. Mini LED, which is sometimes called sub-millimeter light emitting diode, is one of those technologies that lands squarely between Micro LED and Standard LED.

Mini LED vs Standard LED

Mini LEDs work in a similar way as LEDs used in LED/LCD and QLED TVs and most PC monitors but are much smaller.

"LED TVs" are LCD TVs that use LEDs as their blacklight system. QLED TVs are LCD TVs that combine an LED backlight system with Quantum Dots.

"Standard" size LEDs used in LCD TVs/PC monitors are about 1,000 microns (0.04-inches) in size, while Mini LEDs measure about 200 microns (0.02-inches).

The smaller size of Mini LEDs allows up to several thousand to be placed on a blacklight panel (depending on TV screen size) instead of the 10's or 100's of standard-sized LED's used in most LCD TVs/PC Monitors.

However, just like standard size LEDs, Mini LEDs don't contain image content. Their function is to send light through LCD chips (the pixels) containing the image information. Color is added after the light passes through LCD chips to a layer of red, green, and blue filters before reaching the screen surface.

LEDs or Mini LEDs can, at the manufacturer's discretion, be brightened or dimmed (aka Local Dimming) in small groups (aka Dimming Zones) in synchronization with the image information. 

Some LCD TVs incorporate LEDs located along one or more edges of the screen—this is referred to as Edge Lighting. If a TV incorporates LEDs placed behind the LCD screen layer, this is referred to as Direct Lighting or Full Array Backlighting. If Full Array LEDs are placed in zones and can be dimmed, this is labeled Full Array with Local Dimming (aka FALD).

How Local Dimming and Dimming Zones Work

Local Dimming determines how even black and white levels are displayed across the screen surface when using LEDs as the light source. If LEDs always remain on and not dimmed, black levels are more like dark gray rather than black. The result is a narrow contrast and color range. 

However, if the LEDs are brightened and dimmed according to the light and dark properties of the image content, then objects that are supposed to be dark will look darker and areas that are supposed to be white will look whiter. This also helps to extend the color range.

vizio-full-array-zones-large.jpg
Vizio Full-Array Active LED Zone Illustration. Image provided by Vizio, Inc.

The precision at which this can be accomplished is the result of grouping one or more LEDs into a Zone. The more zones that can be dimmed independently at any given time, means images with multiple objects displayed in different parts of the screen can be made brighter or darker as needed.

The Importance of Transitioning From LED to Mini LED

The reason Mini LEDs are important to TV viewers is the added precision they provide for the local dimming process.

TCL Mini LED Chart
How different LED Local Dimming options work for both LED and Mini LED. TCL

With other advancements such as 4K and HDR, 8K, and expanded color gamut, the more controllable dimming zones Mini LEDs support make images look more realistic with regards to light and shade across all objects. Since light and shade also affect color, Mini LEDs aid in providing more accurate color intensity in both light and dark areas of an image.

Mini LED vs Micro LED

While Mini LEDs are extremely tiny (approaching microscopic size), an even smaller size LED solution is being implemented: Micro LED.

Micro LEDs are not only much smaller than Mini LEDs (100 microns/.004 inches or less) but serve an expanded role. 

LED, Mini LED, Micro LED Size Comparison
A size comparison between standard LEDs, Mini LEDs, and Micro LEDs (um stands for microns). MicroLED-Info.com

When used for TV or other video display applications, Micro LEDs are more than just microscopic-sized light bulbs. Each Micro LED produces the light, displays the image, and adds color without the need for LCD chips, additional color filters, or layers. 

A Micro LED pixel is made up of red, green, and blue "subpixels". Micro LED's can not only be brightened or dimmed individually or in groups, but they can also be turned on or off very rapidly. Micro LEDs closely match the performance of OLED technology used in select TVs marketed by LG, Sony, Panasonic, and a few others.

Micro LEDs are more expensive to make than LEDs or Mini LEDs. As a result, they are currently applied in high-end applications, such as self-illuminating home video walls, cinema screens in select theaters, and digital signage.

The Bottom Line

Mini LED is being positioned as an improvement over standard LEDs used in TVs and PC monitors. Although this adds cost for those applications, it's a more affordable performance solution than TVs and monitors that may use Micro LED or OLED technology. 

Several TV makers are introducing TVs with Mini LED backlighting, TCL is the first out of the gate to offer models for sale in the U.S. market. However, Acer and Asus are coming on board with PC monitors featuring this improvement. 

Acer Concept D CM7321K PC Monitor with Mini LED Backlight
Acer

As Mini LEDs become more common, different manufacturers will probably add their own terminology for this feature. TCL, for example, refers to Mini LED as providing "Quantum Contrast."