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

Although they sound very similar, there are big differences between them. Which display technology is best and why?

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

If you’re also confused by all of these television terms, we’ll help you understand their meaning below.

LCD TVs

LCD is the designation for the “Liquid Crystal Display”. It is a flat screen 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 have 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, however, is just one of the reasons LCD screens fail. The latter emit blue light, which affects vision and general well-being. After prolonged use, individuals may witness slightly blurred vision, experience headaches, and tired eyes. Although LED is only an upgrade of 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. With the development of LEDs, LED TVs have 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 as they use less energy compared to LCDs that use cold cathode fluorescent lamps (CCFL). LED lamps save up to 30%. OLED TVs are competing in today’s market.

OLED TVs

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

The biggest advantage of this design is the superior level of black. Unlike QLED or LED TVs, which need to dim the backlight, OLED simply turns off the picture point. As a result, it does not emit light and color, so we can talk about real black colors. Without separate backlighting or LCD matrix, manufacturers also have more freedom in designing OLED screens. LG has developed several TVs that twist and disappear completely. LG is also the largest manufacturer of OLED screens, and at the same time sells them to other companies such as Sony, Vizio, Philips, Panasonic and others. The direct competition to OLED displays is the upgrade of LED technology to QLED. In the future, however, experts predict that the mini-LED will occupy the screen throne.

QLED TVs

QLED stands for “Quantum Light-Emitting Diode”, which in simple language means that the QLED TV is very similar to a classic LED screen, except that it uses tiny nanoparticles called quantum dots to increase the brightness and dynamism of colors. Although quantum dots sound like some kind of space technology, it is the same principle of illumination as LED screens, that is, using backlighting 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 differently colored light when light strikes. These quantum dots therefore create a brighter image and deeper colors.

Which display technology is best?

You now have a better understanding of what different abbreviations mean and how different display technologies work. It is time to compare them based on the parameters that are most important 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 the lightest part of the image. If the TV can display true blacks, then the bright parts don’t need to be very bright to achieve good contrast levels. When it comes to black levels, OLED is the undisputed champion because of its ability to turn off individual pixels.

If QLED TVs want to achieve true blacks, they need to dim the LED lighting and block out the remaining 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 reduce the gap between QLED and OLED contrast quality with mini-LED lighting.

Winner: OLED

Light

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

Individual pixels on OLED screens simply cannot produce the same amount of light. In a darkened room, this difference will not be noticeable. But in well-lit rooms or places where there is a lot of daylight, QLED TVs are more visible, especially if you play HDR content in these conditions.

Winner: QLED

Color space

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

Winner: draw

Viewing angle

QLED screens have the best viewing angle in the middle, and image quality, brightness and contrast are reduced as you scroll away from the center of the screen. The content on OLED screens does not deteriorate even at more drastic viewing angles. Some QLED TVs have improved their viewing angles with the help of anti-reflective layers, but OLED maintains a clear advantage. An OLED TV is the best choice for group viewing of movies or series.

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 make larger screens.

Winner: QLED

Dead spots

Both QLED and OLED TVs may experience occasional 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 a long time. Retention usually disappears on its own, but in OLED, its permanent version, image burning, can occur. Combustion occurs when the brightness of an OLED image point is permanently reduced to a lower state. The only solution to this is to lower all the remaining pixels to the same level, but this is not a practical solution.

Winner: QLED

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