What is a QLED TV?
Samsung has been selling QLED TVs since 2017 (rebranded from SUHD TVs), and almost all premium TVs from the company use QLED panels. But what does a QLED TV actually mean and what’s so special about it? Well, it may sound (and look) a lot like OLED, but QLED TVs actually use display panels that can be considered an improved version of LCD. In this article, we will explain how QLED TVs work and what their advantages are over traditional LCD TVs.
How does a QLED panel work?
QLED TVs use the same LCD panels we’ve seen for years, but they have a special layer of quantum dots on top. This thin layer improves the overall color volume compared to traditional LCD displays, resulting in improved image quality.
Traditional LCD panels use a combination of blue backlight and yellow phosphorous layer to create white backlight. This white backlight is then passed through color filters to create red, green, and blue colors, and a combination of these colors can create any desired color. However, the white backlight isn’t pure white, so the resulting red, green, and blue colors aren’t pure either.
QLED technology solves this problem using a blue backlight combined with a thin quantum dot layer. This special layer features millions of red and green quantum dots. Such quantum dots absorb energy from any backlight to create a monochromatic color (pure single color), so they’re also called QDCC (Quantum Dot Color Converters). Quantum dots are measured in nanometers, and different-sized quantum dots can create different colors. For example, a 2nm quantum dot creates pure blue light when it is energized by a backlight. Similarly, a quantum dot with a diameter of 3nm can create pure green light, while one measuring 4nm can create pure yellow.
So, when blue light is passed through these quantum dots, they can reproduce pure red, green, and blue colors. Since the backlight color is blue, it is passed as it is rather than passing through blue quantum dots (which saves power and improves luminance). Now, you have pure red, pure green, and pure blue colors, and their combination can create purer desired colors than traditional LCDs. Hence, Samsung claims that its QLED TVs can produce 100% color volume and over a billion colors.
How are QLED TVs better than traditional LCD TVs?
As explained earlier, pure red, green, and blue colors from QLED panels help in improving the overall picture quality compared to traditional LCD panels. Hence, QLED TVs offer wider and deeper colors, especially reds and yellows.
How are QLED TVs different from Neo QLED TVs?
Samsung also uses a quantum dot layer in its higher-priced Neo QLED TVs. Regular QLED TVs feature a single backlight, which means you can’t turn off individual parts of that backlight behind the black parts of a picture frame to create perfect blacks. Hence, blacks can appear as dark grey. Only some higher-end QLED TVs use full array backlight, featuring dozens of backlight zones, thus creating perfect black in zones that are turned off, but causing blooming around bright objects in an otherwise dark frame.
In comparison, Neo QLED TVs use QLED panels with a Mini-LED backlight that is divided into hundreds or thousands of different zones and can reach higher brightness levels. The backlight in each of those zones can be turned off individually. This creates inky blacks in completely dark portions of a picture frame, while higher backlight brightness helps achieve higher peak brightness for brighter parts of the image. Since Neo QLED TVs have more backlight zones, blooming is contained in a better way. Hence, Neo QLED TVs offer much better blacks, a massively improved contrast ratio, better control over blooming, and higher peak brightness compared to QLED TVs.
