The world of television technology can be daunting, especially with the plethora of jargon that floods the market. Among the latest buzzwords making rounds is “mini-LED.” While LEDs are already diminutive, what does the “mini” designation truly imply? The answer is significant, as it directly influences the vibrancy and depth of colors displayed on screen.

In reality, virtually every television on the market is classified as some form of LED display. Most utilize bright white LEDs as a backlight, which illuminates an LCD matrix alongside a color filter to create a complete image. An exception exists in OLED technology, where each pixel is self-luminous, eliminating the need for a traditional backlight.

Mini-LED technology is an enhancement to the backlighting process. Historically, the backlight in many LCD televisions has either been uniform or segmented into a limited number of zones. In contrast, mini-LEDs are significantly smaller backlights that can be individually addressed, enabling the screen to shine brightly in certain areas while remaining darker in others, thus enhancing the overall picture quality.

How LED Displays Function

Before diving deeper into mini-LEDs, it’s essential to understand how conventional LCD displays operate. When a television is marketed as an “LED TV,” it generally refers to the backlight system, which inherently involves LEDs. There are primarily two backlight configurations to be aware of:

• Edge-lit Backlighting: In this setup, LED lights are positioned around the periphery of the screen, projecting light through guides that help distribute it uniformly. This is often cost-effective but can sometimes lead to light bleeding from the edges and less brightness in the central area.

• Full Array Backlighting: This configuration features a grid of LEDs that occupy the display more comprehensively. This methodology leads to improved light distribution because these LEDs can typically be controlled on an individual basis, facilitating the process of local dimming.

The backlights emit white (or blue, in the case of quantum dot displays) light, which is then moderated by an LCD matrix. This matrix consists of tiny liquid crystals that either block or permit the light to pass through until it reaches either red, green, or blue filters. By adjusting the intensity of light passing through these subpixels, the television can dictate the color output for each pixel.

However, there’s a catch: LCD displays often struggle to entirely block the light from the backlight. Consequently, even when the screen is meant to display black, it may still appear lit. Achieving profound black levels requires additional technology.

The Mechanics of Local Dimming

“Local dimming” encompasses a variety of techniques applied in LED-backed displays aimed at reducing or turning off backlights in areas where they are not necessary. This practice minimizes light bleeding, resulting in deeper black levels and a more pronounced contrast between lighter and darker sections of the display.

The challenge lies in the sheer number of pixels on an LCD screen, which far surpasses the number of individual backlights. Consequently, fewer backlights mean there’s a limit to the resolution of light and dark differentiation. This can lead to a phenomenon known as the “bloom effect,” where bright objects appear to glow excessively due to backlight bleed from adjacent dark pixels.

Every backlight setup creates a dimming “zone,” and the more zones available, the better the performance. Common LED-lit televisions might offer dozens to several hundred zones. In contrast, mini-LED technology can greatly increase this count into the thousands.

Differentiating Mini-LED Displays

The essence of mini-LED technology lies in its size—specifically, the LED diodes used as backlight sources measure no larger than 0.2 mm. While they can indeed be smaller, anything exceeding this size typically doesn’t qualify as “mini-LED.”

This reduction in size allows for the arrangement of a significantly larger number of LEDs in the same area. For instance, the Sony 65-inch Bravia Mini-LED TV boasts over 1,500 local dimming zones, enabling each LED to only illuminate a small section—roughly one square inch. This flexibility greatly enhances the ability to contrast light and dark components of the displayed image.

Why Opt for Mini-LED Over OLED?

It may seem counterintuitive at first: OLED displays illuminate each pixel independently, suggesting that the minimalistic approach would be preferable. However, a notable drawback of OLED technology is its propensity for burn-in.

The organic materials in OLED can deteriorate, often leaving behind ghostly images from static content like menus or logos that remain on the screen for too long. In contrast, LED frameworks, which comprise more durable, inorganic elements, do not encounter this issue.

Additionally, LED and mini-LED displays tend to achieve much higher brightness levels compared to OLED panels. This characteristic makes them ideal for bright living spaces where sunlight might wash out the image on an OLED screen. Thus, while OLED technology has its merits, mini-LED displays may be preferable in brightly lit environments or for all-day viewing.