LCD - The Veteran
Technology
LCD stands for "Liquid Crystal Display" and is the oldest of all display types on this list. LCDs consist of two main components: a backlight and a liquid crystal layer embedded between two polarised glasses with colour filters.
In simple terms, liquid crystals are tiny rod-shaped molecules that change their orientation and thus their light transmission in the presence of an electric current. The individual colour values are generated by means of colour filters.
The backlighting traditionally used consists of cathode fluorescent lamps or CFLs.
Advantages:
Affordable and reliable, LCD displays offer solid picture quality and are available in a wide range of sizes.
Disadvantages:
Contrast and black levels lag behind other technologies and colour intensity can vary depending on the viewing angle.
LED - The Trendy One
Technology
LED stands for "Light-Emitting Diode" and is probably the most misleading category on our list, as commercially available LED displays are basically LCDs (hence the term LED-LCD). However, there are also miniLEDs, MicroLEDs and others, which we will list below.
LED-LCDs
These so-called LED displays still use a liquid crystal layer. The only difference is that the backlight uses LEDs instead of cathode fluorescent lamps or CFLs. LEDs are a better light source than CFLs in almost every way. They are smaller, consume less power and last longer. However, the displays are still basically LCDs.
Advantages:
Consume less power, last longer than CFL LCDs.
Disadvantages:
Contrast and black levels lag behind other technologies and colour intensity can vary depending on the viewing angle.
OLED - The Elegant One
Technology
OLED stands for "Organic Light-Emitting Diode". The organic part here simply refers to carbon-based chemical compounds. These compounds are electroluminescent, i.e. they emit light in response to an electric current.
This description alone makes it easy to recognise how OLED differs from LCD and earlier display types. As the compounds used in OLEDs emit their own light, they are an emissive technology. In other words, OLEDs do not require a backlight. For this reason, OLEDs are generally thinner and lighter than LCD panels.
As each organic molecule in an OLED panel emits, you can control whether a particular pixel lights up or not. Remove the power and the pixel switches off. This simple principle allows OLEDs to achieve remarkable black levels, outperforming LCDs that have to use a backlight that is always on. Switching off the pixels not only ensures a high contrast ratio, but also reduces power consumption.
The contrast alone would make the technology worthwhile, but there are other advantages too. OLEDs are characterised by high colour accuracy and are extremely versatile. Without the physical flexibility of AMOLED, foldable smartphones such as the Samsung Galaxy Flip series would simply not exist.
The Achilles heel of OLED is that it is susceptible to permanent image retention or screen burn-in. This is the phenomenon where a static image on the screen becomes imprinted or burnt in over time or simply ages differently. However, manufacturers are now using several remedial strategies to prevent burn-in.
Advantages:
High colour accuracy, wide viewing angles, exceptional contrast, brighter than conventional LCDs, thinner than LCDs
Disadvantages:
Expensive, risk of burn-in after prolonged use
Mini-LED - The Detail Lover
Technology
In the section on LCDs, we saw how the technology can vary due to differences in the liquid crystal layer. Mini-LED instead attempts to improve contrast and image quality at the backlight level.
Mini-LED is a new display technology that promises improved contrast ratios and deeper blacks compared to LED-LCD panels, which are illuminated with normal LEDs (light-emitting diodes). As the name suggests, mini-LEDs are much smaller than normal LEDs.
Dioden, die kleiner als 0,2 mm sind, werden im Allgemeinen als Mini-LEDs bezeichnet. Diese werden verwendet, um ein normales LCD-Panel zu beleuchten, genau wie es bei einem herkömmlichen LED-beleuchteten Display der Fall wäre. Der wesentliche Unterschied besteht darin, dass im Vergleich zu älteren Fernsehern viel mehr Mini-LEDs vorhanden sind. Genauer gesagt misst jede Mini-LED nur 0,008 Zoll oder 200 Mikrometer im Durchmesser.
With mini LEDs, display manufacturers can increase the number of local dimming zones from a few hundred to several thousand. As you would expect, more zones mean more detailed backlight control. Their smaller footprint also makes them perfect for smaller devices such as smartphones, tablets and laptops. Finally, the abundance of LEDs also helps to increase the overall brightness of the display.
While mini-LED technology cannot quite match the picture quality of an OLED or micro-LED display, mini-LED models are significantly cheaper to produce. The larger the panel, the greater the saving. The production of large OLED televisions is still difficult and expensive.
Tiny, bright objects against a black background look much better on a mini LED display than on one with conventional LED backlighting. However, the contrast ratio is still not on a par with OLED.
Advantages:
Improved contrast and deeper black tones, higher brightness
Disadvantages:
Relatively expensive, increased complexity, making backlight repairs more difficult
Quantum Dot Technology or QLED - The Colourful One
Technology
Quantum dot technology is becoming increasingly common and is usually seen as a key selling point for many mid-range TVs. You may also recognise it from Samsung's marketing shorthand: QLED. Similar to Mini-LED, however, it is not a radically new panel technology. Instead, quantum dot displays are basically conventional LCDs with an additional layer in between.
Conventional LCDs pass white light through several filters to obtain a specific colour. This approach works well, but only up to a certain point.
Many older display types are able to fully cover the decades-old standard RGB colour space (sRGB). However, the same does not apply to larger colour scales such as DCI-P3. Coverage of the latter is important as this is the colour space that is predominantly used in HDR content.
How do quantum dots help? Well, they are essentially tiny crystals that emit colour when you shine blue or ultraviolet light on them. For this reason, quantum dot displays use a blue backlight instead of a white one.
A quantum dot display contains billions of these nanocrystals distributed on a thin film. When the backlight is switched on, these crystals are able to produce very specific shades of green and red. The exact colour tone depends on the size of the crystal itself.
In combination with conventional LCD colour filters, quantum dot displays can cover a greater percentage of the visible light spectrum. Simply put, you get richer and more accurate colours - enough to provide a satisfying HDR experience. And because the crystals emit their own light, you also get a noticeable increase in brightness compared to conventional LCDs.
However, quantum dot technology does not improve other weak points of LCDs such as contrast and viewing angle. For this, quantum dots would have to be combined with local dimming or mini-LED technologies. Samsung's high-end Neo QLED televisions, for example, combine QLED with mini-LED technology to achieve the deep blacks of OLED.
Advantages:
High colour accuracy, high brightness, no burn-in or durability problems
Disadvantages:
Depending on the LCD implementation, low contrast and slow response times may occur
MicroLED - The Trendsetter
Technology
MicroLED is the newest display type on this list and, as expected, the most exciting. Put simply, microLED displays use LEDs that are even smaller than those used in mini-LED backlights. While most mini-LEDs are around 200 microns in size, micro-LEDs are only 50 microns. By comparison, human hair is 75 micrometres thicker.
Due to their small size, you can build an entire display from microLEDs alone. The result is an emitting display - similar to OLED, but without the disadvantages of the organic component of this technology. There is also no backlight, so each pixel can be completely switched off to display black. Overall, the technology delivers an exceptionally high contrast ratio and wide viewing angles.
Brightness is another aspect in which microLED displays manage to outperform existing technologies. Even the highest quality OLED displays on the market today, for example, achieve peak values of 2,000 nits. On the other hand, manufacturers claim that microLED can ultimately deliver a peak brightness of 10,000 nits.
Finally, MicroLED displays can also be modular. In some of the earliest demonstrations of the technology, manufacturers created huge video walls from a grid of smaller microLED panels.
Samsung offers its flagship MicroLED display The Wall in configurations from 72 inches to 300 inches and more. As the retail price is still relatively high, it is not a consumer product. Nevertheless, it offers a glimpse into the future of televisions and display technology in general.
It is almost certain that MicroLED displays will become more accessible and cheaper in the coming years. After all, OLED is only a decade old at this point and is already ubiquitous.
Advantages:
Highest brightness of all display types, exceptional contrast, deep black levels, no burn-in of images, modular
Disadvantages:
Expensive, not yet commercially produced in smaller sizes
