LED TV, LCD, OLED and QLED what is the difference?


LED TV, LCD, OLED and QLED what is the difference?

Learn everything you need to know

Creating or updating a home theater setup can result in a lot of different things, but it often comes down to one important question: What kind of TV should I buy? Television as flashy OLED models of LG or Sony or the QLED TVs from Samsung could receive many reviews, but when it comes to many of us, budget constraints limit our options and we will find two words that are repeated: LED e LCD.

But what is the difference? It is a question that often make the home theater buyers budding. Here are the quick response: an LED TV is a LCD TV, but the way in which the two are confused with each other could be a surprise.


Despite having a different acronym, an LED TV is just a specific type of LCD TV. The correct name would actually “LCD TV with LED backlight”, but it is too much for the conversation everyday, so people generally refer to them only as LED TV.

Both types of TV using a liquid crystal panel (LCD) to control where you see the light on the screen. These panels are typically composed of two sheets of polarizing material with a liquid crystal solution between them, then when an electric current passes through the liquid, causes the crystals align so that light can (or can not) go through. Think of each crystal as a shutter, allowing light to pass through or block.

Now, since both LED and LCD TV uses LCD technology, you are probably wondering what the difference. The LCD TV that you think do not exist anymore. Here because: backlight. The old LCD TV used cold cathode fluorescent lamps (CCFL) to provide backlighting, while the LED TV used a series of light-emitting diodes (LED) smaller and more efficient to illuminate the screen, which gave them some advantages. Now, all LCD TVs use LED lights and are colloquially considered LED TV. Here's how it works.


There are three different forms of lighting that were used in LCD TVs: CCFL backlight, Full-array LED backlighting and LED lighting. Each of these lighting technologies is different from each other in important ways, and each has pros and cons. Let's analyze each.

CCFL Backlight

The CCFL backlight is an older form of technology that has been largely abandoned, although some manufacturers use CCFL LCD in the lower level because they are less expensive to make. A series of CCFL is positioned inside the TV behind the LCD display. Lights illuminate the crystals fairly evenly, which means that all the regions of the image will have similar levels of brightness. This affects some aspects of qualitàdell'immagine, which we will discuss later. Since the CCFL is larger than the LED array, LCD CCFL tend to be thicker than their LCD counterparts. Since this is an obsolete technology, you will not find many models that use this style lighting. Some tend to spring up here and there, but they are almost always in the budget end.

full-array backlight

The backlight of the entire array replaces obsolete CCFL to LED. A series of LEDs extends to the back of the LCD screen, with LED zones that can be switched on or dimmed in a process called local dimming. Televisions that use full-array LED backlighting are a piece of the market of LCD TV and high-end, rightly, lighting with more precise and uniform, They can create better images than those achievable by the CCFL LCD TV. They also have lower energy consumption compared to LCD CCFL. Given these advantages, the transition to LEDs as the industry standard makes little sense.

side lighting

Another form of the LCD screen illumination is the illumination of the LED edges. As the name suggests, The edge-lit LED TVs have along the edges of a screen. Within this type of lighting, there are some different configurations, including LEDs along the bottom; LEDs on the top and bottom; Left and right LED; and LEDs along all four edges. These different configurations lead to differences in the quality of the images, but the overall capabilities brightness still exceed what the CCFL could get. While there are some disadvantages in the illumination of the edges than the full-array backlight or direct, the result is the illumination of the edges that allows manufacturers to create thinner TV that cost less to produce.

To better close the local dimming quality gap between edge-lit TVs and full-array backlit TVs, manufacturers like Sony and Samsung have developed their own advanced forms of edge lighting. The Sony technology is known as “Slim Backlight Master Drive”, while Samsung has “Infinite Array” It used in its line of televisions QLED. These keep slim form factor achieved through an enlightened design from the edges, but with a local brightness more similar to that of full-array backlight in these cases (although still not quite the same).


The local dimming is a feature of LEDs where the light source LED LCD TV behind the LCD screen is amplified or attenuated to fit that it requires the image. The LCD can not completely prevent the light to pass through, although during dark scenes, then the attenuation of the light source helps to create deeper blacks and a more impressive image contrast. This is achieved by selectively attenuating the LED when that particular part of the image or region is intended to be dark.

The local dimming LCD TVs helps to correspond more closely to the quality of plasma TVs and OLED, which are by their nature contrast levels best – LCD CCFL thing he could do. However, the quality of the effect of local dimming varies depending on the type of backlight of the LCD display and the processing quality. Here is an overview of how effective local dimming of each type of LCD TV.

Live Local and full-array backlight

Televisions with full-array backlight are the most precise local dimming and then tend to offer the best contrast. Since a series of LED covers the entire LCD screen, regions can be darkened with higher fineness compared with the edge-lit televisions, and the brightness tends to be more uniform over the entire screen.

“Direct local Dimmer” It is essentially the same as the dimming full-array, only with a smaller number of LEDs in the array further away. It is worth noting, however, many manufacturers do not differentiate “direct local dimming” attenuation of the entire array as two separate forms of local attenuation. However, I believe that it is important to note the difference, since a smaller number of more spaced LEDs will not have the same accuracy and consistency of the complete LED array.

side lighting

The side lighting is a process by which the light from the LEDs positioned on the edge or edges of the screen is projected onto the back of the LCD screen, instead of directly behind it. It works quite well but can result in blocks or very thin bands of lighter pixels inside or around areas that should be dark. For this reason, the local attenuation of the edge-lit TVs can sometimes result in the dark in dark areas when compared with full-array LED TV. It should also be noted that not all TVs with LED lighting offer blackout, reason why it is not uncommon to see streaks of light lit at the edges of a television set and a slightly lower brightness towards the center of the screen.

CCFL Backlight

Since the CCFL backlit LED TVs do not use, models with this type of lighting do not have ability to attenuation. instead, the LCD panel of the LCD CCFL is constantly lit evenly, which makes a noticeable difference in picture quality than LCD LED. This is particularly evident in high-contrast scenes, since the dark parts of the image may appear too bright or faded. When you look in a well-lit room it is easier to ignore or lose the difference, but in a dark room, It will be clear.


Here I open a separate chapter for these two recent technologies with an explanation as possible of the main strengths and weaknesses of the two characteristics.


In general, the QLED TVs are LED TVs that use quantum dots to improve performance in key areas of picture quality. Samsung, however, He says that its QLED televisions are special, offer brightness levels that meet and exceed any technology TV contestant and black levels better than other LED TV, and can reproduce more colors than LED TV without quantum dots.

The quantum dots behave almost like a filter that produces purer light of the LEDs can provide. To meet the Alliance Ultra HD standard for television Ultra HD Premium, most LED TVs to be used in some way quantum dots. Because quantum dots are now so widely distributed on premium TVs, Samsung thinks that would reduce confusion if all the manufacturers would start to call them TV QLED. The goal is to differentiate them from simple LED TV and counter the OLED, since Samsung does not produce an OLED TV show right now. However, now he is known to have its own response all'OLED the MICROLED. This is a separate technology from its televisions QLED, so here will not come into play, but based on what we saw at CES 2018, MICROLED has the potential to bring serious competition all'OLED, especially with regard to the brightness and the black levels.


QSD is not an emissive display technology, come plasma, O OLED MicroLED. Quantum dots are not directly emit colors that you see; They are scattered on a piece of film that acts almost as a filter within an LED TV panel. Are the LEDs through this film, It is finished in an ideal color temperature, and from there the brightness and color are greatly improved.


OLED stands for organic light-emitting diode. In simple terms, OLEDs are made with organic compounds that illuminate when supplied with electric energy – hence the term emissive display. A single OLED has the size of a pixel, so it takes millions of lights on and off independently to fill the TV screen. Because of this flexibility, when the pixel of a OLED TV will be turned off, They are completely turned off and appear completely blacks. While QLED televisions can be made very thin, OLED TVs can be made even thinner and even flexible.


Now we put the two technologies against each other point by point and see how you stack up in terms of contrast, viewing angle, brightness and other performance considerations.


The ability of a screen to produce deep blacks and dark is probably the most important factor to achieve excellent image quality. The deepest blacks enable a higher contrast and richer colors (among other things) e, then, a more realistic and dazzling. When it comes to black levels, OLED reigns as the undisputed champion.

The QLED TVs to enhance performance of the LED display level, but still they rely on backlighting reflected behind an LCD panel. Even with advanced dimming technology, that selectively obscures the LED that should not be activated at full power, the QLED televisions still suffer from an effect called “Light bleed”, the backlight spills on what should be a black section of the screen.

These problems have been present since the advent of QLED, and they are intrinsic to the nature of the panels, but Samsung has made a quantum leap in 2018 improving black levels and picture performance closer to the OLED further levels , thanks to the addition of a new anti-reflective layer in the panels. We expect that the gap continues to shrink as the technology grows QLED.

OLED TVs do not have any of these problems. If a pixel OLED does not receive electricity, It does not produce any light and is, then, totally black.

Winner: YOU ARE


When it comes to brightness, QLED the TVs have a significant advantage. The LED TVs were already able to become extremely bright, but the addition of quantum dots allows them to become even brighter. For this reason, the QLED televisions claim a “color volume” higher, which means that they are able to make all the colors of the available spectrum brighter without losing saturation. The TV manufacturers QLED also state that are better for HDR content because the spectral images in images – the glow of the light reflected on a lake or shiny car, eg – They are more powerful and easier to see.

In the rooms with a lot of ambient light, the advantage of brightness QLED can be very useful.

As for the argument HDR, however, you can tell a lot by the total contrast offered by blacks perfect levels of an OLED TV. When you start from the perfect black, the perceived contrast requires a less intense brightness in those areas highlighted for programming the HDR, and the end result for the viewer is similar to that of a TV QLED much brighter – at least in a dark room, anyway.

Winner: QLED


The response time refers to the time taken by each diode to switch “on” a “off”. With faster response time is less ghosting and have fewer artifacts.

YOU ARE, with its smaller diodes that function as individual pixels, QLED the waste in terms of response time. In fact, OLED currently offers the fastest response time of any TV technology in use today, making it a clear winner in this sense.

Winner: YOU ARE


YOU ARE, again, is the winner here. With QLED screens, the better viewing angle is the center point and the image quality decreases both in terms of color contrast as it moves sideways or up and down.

OLED screens can be viewed without degradation of the luminance of drastic viewing angles – until 84 degrees. Some QLED televisions have improved in terms of viewing angle, OLED but still maintains an advantage.

Winner: YOU ARE


OLEDs have come a long way in this category. When the technology was still rising, OLED screens reached the 55 inch. Today an OLED is available from 88 inch. Said this, there are fewer restrictions on the size of the LCD display, with QLED that grows up to 100 inches and above. All’IFA 2018, LG showed off an OLED 8K by 88 inch, while Samsung has shown off a television QLED 8K by 85 inch. The main difference? The Samsung TV will be launched in 2018, while the massive 8K OLED LG remains substantially a prototype at this stage.

Winner: QLED


The effect comes from the days of CRT TV, when the prolonged display of a still impressed the screen and the phosphors were burned permanently losing the ability to turn off the image “burn” on the screen. The QLED TVs are not susceptible to burn-in.

The same issue is at stake with OLED TVs because the compounds that turn degrade over time.

This potential exists and it should be noted. It happens especially by connecting the TV to a game console for a long time. Ma, since the QLED TVs are not susceptible to burn-in, win this battle.

Winner: QLED


The OLED panels are extremely thin and require no backlighting. Consequently, OLED TVs tend to be lighter than QLED televisions and thinner. They require less energy, making them more efficient.

Winner: YOU ARE


Istallando l'app Samsung SmartThings, with newer models automatically extract information from your smartphone, allowing them to download all your apps streaming and access them with one touch (they will do the same for Wi-Fi).

It's not all: The mounting system gapless Samsung and Invisible One Connect box mean mount a QSD and hide cables is incredibly simple. The Tizen OS Samsung is fast and easy to manage. They make the competition with OLEDs nonexistent.

Winner: QLED


This category would be easily conquered by QLED televisions, but the OLED TVs have fallen even have prices similar price.

Winner: QLED


When you are comparing QLED than OLED in terms of image quality, OLED Vince, it is lighter, thinner, consumes less energy, It offers the best viewing angle, and, although it is still a bit 'more expensive, It fell dramatically.

QLED has its own distinct advantages in terms of brightness and, with recent changes, even black levels and viewing angle are improved out. For many, TV QLED will make more sense since a QLED displayed during the day will offer a more attractive. But when the lights dim, OLED is a more attractive option. Probably with the next marketing MicoLED there will be a redistribution of the cards going to match or even exceed the salient features of OLEDs, at the time until there will be a real marketing I can not give any judgment.

Hoping to have been beneficial for someone by the time I leave.

5 replies
    ANTONIO says:

    Good morning Amilcare, I now know a lot more about “QLED / OLED” but to make a choice I still need help : I have a samsung UE55HU8500Z curved 4k 55″ with 3d and thought to change with a 65″ or meglio75″ away from the couch 4mt. going on the proposals on-line and also on the sites of brands offering QSD / OLED remain disoriented because with this technology there are ,equal measures, Dual prices also 3 times, I tried to put various models compare in features and I missed them for the technicalities incomprehensible to me why the facts of acronyms ,as I think for most people, then you present them in all wonderful descriptions, I think the difference is due , over the year of production also to the improvement of the performances, but perhaps there are too many things that I do not use such. connections with smartphone gaming etc.. , then I ask for help because I would choose a model that was in line with the use that I do that I look ” even old films, documentaries, sport,sky (skyQ now I can not use) and old home movies and family trips on vhs dvd drives with various connected devices , so I wish she had:
    A) all the digital standard / TV / Other ,future already planned so as not to have problems for many years to come
    B) the function of improving and reworking of the image with old standard sources (Today I see them worse than the old tube tv)
    D) maximum definition , faithfully and naturally as possible, as we see with our eyes,no amazing color effects bogus, I see with my
    close-ups of faces unwatchable with pitted skin and in the filming of tremendous study.
    So I just need to have “solo” the highest possible quality image in all conditions and from all sources and therefore it has the best technology possible today in this sense,the situation of environment is bright dimmable day until dark when needed , the sound is less important because there are wanting soundbar etc..
    greetings and thanks

    • Amilcare
      Amilcare says:

      First I want to clarify something, visual artifacts are not eliminated totally because formed by algorithms that try to imagine what could be the missing pixels. Sometimes the result is unwatchable. This problem is known to manufacturers seeking to every new product to correct errors or at least reduce these. The advice is always to choose the newer product. The problem with the old movies is primarily due to the fact that the resolution of a VHS was 250 lines for the best quality and we can compare today with the vertical resolution of a 4k who 2160 pixels more or less with real data pixels each 10, alone you understand that miracles still fail to get them. For colors careful adjusting colors made with RAI channels if possible shows the vision as much as possible corresponding to reality. Some of Mediaset programs deliberately transmit with too bright or saturated colors to hide facial imperfections. A prime example are the transmissions with Durso. For future standards already for two years or products sold they are suitable to receive for new standards.
      In the future transmissions will move most of the satellite. The broadcasts in 4K are not thinkable with normal antennas, a single transmission occupy a high number of channels without thinking that the next 5g take away more space to television broadcasts. If you have children be careful with OLEDs, the continuing search for minimum thickness made of glass increasingly thin and fragile screens. I know of people who have just broken the screen to remove the TV from its packing. For the rest I do not know what to answer you is like asking whether it is better diesel or gasoline, each has its strengths and weaknesses depends on the weight that is given to the individual aspects.
      Certainly being produced at the top of the range are surely good.

  2. Amilcare
    Amilcare says:

    good morning to you, as it is always the rule of common sense
    Never watch TV in the dark environment and always at a distance of at least twice the diameter of the screen
    If, however, you can limit the viewing time to a minimum would be the ideal choice
    The TV should not be a substitute nanny
    Amilcare Greetings

  3. don
    don says:

    Good morning Amilcare, to safeguard a little eye health, especially children, what type of TV (YOU ARE, Oh man QLED) suggest? Which parameter setting (brightness, color temperature, blu, rosso, verde, etc.) suggest to minimize the impact on the view of the small?
    thank you in advance

    • Amilcare
      Amilcare says:

      I do not think a typology is too different from the others, worth more to personal taste, precisely for this reason that adjustments exist.
      Personally, I try to give a good contrast to the images leaving the hue and saturation as far as possible so as to be natural and similar to what you would see in reality.
      A TV is essentially a lamp and as such, its intensity should not be much stronger than the ambient light so as not to cause eyestrain


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