What is the difference between LCD, LED, QLED and OLED displays?

Buying a TV in 2022 is still extremely difficult. TV manufacturers use many terms such as HDR, Ultra HD 4K, HDMI 2.1, Dolby Atmos, Dolby Vision, which make it very difficult for users to know what they need and what is worth their money. Recently, you could see the two most popular terms - QLED and OLED TVs. Although the difference is only one letter, the two technologies are completely different.

If you're also confused by all these TV terms, we'll help you understand what they mean below.

LCD TVs

LCD stands for "Liquid Crystal Display". It is a flat panel technology commonly used in smart TVs and computer monitors. They are the successors of CRT screens, in front of which many generations spent their childhood. They also replaced plasma screens, which were among the most popular in the previous decade. LCD technology is slowly becoming obsolete with the advent of LED and OLED screens. Better technology is only one of the reasons for the failure of LCD screens. The latter emit blue light, which affects vision and general well-being. After prolonged use, individuals may experience slightly blurred vision, headache and tired eyes. Although LED is just an upgrade to LCD screens, it has quite a few advantages that make it one of the most used technologies on the market.

LED TVs

Most of today's TVs fall into the LED category. LED (Light Emitting Diode) TVs have evolved to become one of the most popular choices among consumers, mainly due to attractive prices, better viewing angles and more dynamic colors compared to their predecessors. LED TVs are also more energy efficient, consuming less power compared to LCDs that use cold cathode fluorescent lamps (CCFLs). LED lamps enable savings of up to 30 %. Their competition in today's market is OLED TVs.

OLED TVs

OLED stands for "Organic Light-Emitting Diode". Although at first glance it sounds similar to LED, they are actually very different technologies. The LED in OLED has nothing to do with the backlight of the display (unlike an LED display). Rather, it refers to the fact that each individual pixel in an OLED is also a tiny, tiny LED that can produce both light and color in a single element. Simply put, OLED TVs do not need a backlight because each OLED pixel produces its own light.

The biggest advantage of this form factor is the superb black level. Unlike QLED or LED TVs, which have to dim the backlight, OLED simply turns off the pixel. As a result, it does not emit light and color, so we can talk about true black colors. Without a separate backlight or LCD matrix, manufacturers also have more freedom in designing OLED displays. LG has developed several TVs that roll up and disappear completely. LG is also the largest manufacturer of OLED displays, while also selling them to other companies such as Sony, Vizio, Philips, Panasonic and others. The direct competition to OLED screens is the upgrading of LED technology to QLED. In the future, however, experts predict that mini-LED will occupy the display throne.

QLED TVs

QLED is an abbreviation for "Quantum Light-Emitting Diode", which in simple language means that a QLED TV is very similar to a classic LED screen, except that it uses tiny nanoparticles, called quantum dots, to increase the brightness and dynamic colors. Although quantum dots sound like some kind of space technology, it is the same lighting principle as LED screens, that is, using a backlight consisting of hundreds or thousands of LED lamps. What really defines a QLED TV is the quantum dot filter, a film of tiny molecules that emit different colored light when struck by light. These quantum dots therefore create a brighter image and deeper colors.

Which display technology is the best?

Now you have a better understanding of what different abbreviations mean and how different display technologies work. It's time to compare them based on the parameters that matter most when buying a TV: contrast, viewing angles, lifespan, response time, and the like.

Black color and contrast

Contrast is the difference between the darkest and lightest parts of an image. If the TV can display true blacks, then highlights don't need to be very bright to achieve good contrast levels. When it comes to black levels, OLED is the undisputed champion due to its ability to turn off individual pixels.

If QLED TVs want to achieve true blacks, they need to dim the LED backlight and block out the rest of the light, which is very difficult to do completely. In some cases, light may spill into adjacent black pixels. Is the difference noticeable? Definitely, especially in dark scenes. QLED TV manufacturers hope to bridge the gap between QLED and OLED contrast quality with mini-LED lighting.

Winner: OLED

Brightness

QLED TVs have a significant advantage when it comes to brightness. Because they use a separate backlight, they can achieve higher brightness than OLED versions. The inclusion of quantum dot technology further enhances the light by creating brighter hues in the color spectrum without losing saturation. The end result is a screen that captures enough light to make the image clearly visible even in the most brightly lit of rooms.

Individual pixels on OLED screens simply cannot produce the same amount of light. In a darkened room, this difference will not be noticed. But in well-lit rooms or rooms with a lot of daylight, QLED TVs are more visible, especially if you're playing HDR content in those conditions.

Winner: QLED

Color space

Until recently, OLED TVs had no competition in this area. With the development of QLED technology, the progress of color accuracy, brightness and color volume is more than obvious and comparable to OLED technology.

Winner: a draw

Visible angle

With QLED displays, the best viewing angle is in the center, and image quality, brightness, and contrast decrease as you move away from the center of the screen. Content on OLED screens does not deteriorate even at more drastic viewing angles. Some QLED TVs have improved their viewing angles, aided by anti-reflective coatings, but OLED maintains a clear edge. For group viewing of movies or series, an OLED TV is the best choice.

Winner: OLED

Size and price

When OLED technology was still at the beginning of the development cycle, their size stopped at 55 inches. Today we find OLED screens with a diagonal of up to 97 inches, of course for absurdly high prices. QLED technology is simpler and cheaper to produce larger screens.

Winner: QLED

Dead spots

Both QLED and OLED TVs may occasionally experience image retention. This happens when the TV temporarily continues to display part of the picture while the original scene has already disappeared. Image retention occurs when the same visual element is on the screen for an extended period of time. Retention usually goes away on its own, but OLED's permanent version, image burn-in, can occur. Burn-in occurs when the brightness of an OLED pixel is permanently reduced to a lower state. The only solution to this is to reduce all the remaining pixels to the same level, but this is not a practical solution.

Winner: QLED

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