OLED TVs in comparison with LCD with LED backlight

OLED technology, involving the production of screens on organic light-emitting diodes, - far from being a newcomer to the consumer electronics market. Mobile phones, in which OLED displays were used in one form or another, they have been produced since 2001. However, today, when OLED TVs manufactured by Samsung and LG are increasingly becoming key exhibits of various exhibitions, consumer interest in this technology is increasing day by day, generating more and more new questions. So what makes a TV with an organic light-emitting diode (OLED) screen better, than a TV with a screen on conventional LEDs (LED) or with a screen on liquid crystals (LCD)? What is the advantage of OLED technology? Does it have any disadvantages? We will try to explain the answers to these and other questions in a clear language for you.

What is LED?

The abbreviation LED means ‘LED’. These are small solid-state elements, which convert the movement of electrons through a semiconductor into light radiation. In comparison with incandescent and fluorescent lamps, LEDs are quite small, however, the light they emit is very bright. However, the size of the LED is still not small enough to, to use a separate such element for each pixel of a television picture – from this point of view, they, alas, too big. Therefore, LEDs are used exclusively as a backlight in televisions with liquid crystal screens.

LED technology

LED light transmission technology is also organized according to the principle of layering. Immediately behind the plastic frame of the monitor is a liquid crystal matrix. It consists of several layers:

  • Back light.
    It supplies light to the polarizing plates.
  • Polarizing plates.
    They pass light through liquid crystals, located between them.
  • Liquid crystals.
    Located in the center of the matrix. Change the direction of the light rays by 90°.
  • Color filter.
    It is used to compose an image. It is presented in the form of an RGB scheme, that is, green, red and blue colors.

Depending on, how are the molecules arranged in liquid crystals, matrices are divided into several varieties.

TN-matrix

In decoding and translation it means ‘twisted nematic crystal’ - by the type of molecules in the cells.

The matrix TN

Consider the pros and cons of this matrix.

The advantages include:

  • the price,
  • system response time,
  • moderate power consumption.

Of the cons:

  • no black color (looks like dark gray or blue on the screen),
  • small viewing angle,
  • weak color saturation.

IPS matrices

The abbreviated name means ’switching in one plane’, based on the type of arrangement of molecules in cells. They rotate 90° when electricity is applied.

The IPS matrix

A relatively small modernization of the matrix has added a significant number of advantages to it:

  • the viewing angle has increased,
  • there have been improvements in color rendering.

At the same time, some of the advantages of the TN matrix turned into the disadvantages of IPS: the price of monitors and the response time of the system increased.

VA -matrices

The newest type, the name translates as ‘vertical alignment’.

Matrix VA

The VA matrix serves as an alternative to the previously described types and has intermediate characteristics in terms of price and response time. Among its advantages are good contrast and rich black color.

Returning to LED technology: LEDs are used in the TV backlight, which helped to significantly improve the quality of the picture compared to that, what was obtained from fluorescent lamps. Depending on the location of the LEDs, there are 2 types of illumination:

  • Edge
    - spreads around the perimeter of the TV.
  • Direct
    - the backlight spreads light over the entire surface of the screen, what benefits the Edge model.

Summarizing the information received, making a conclusion, that LED TV is a TV with LED backlight and a liquid crystal matrix.

What is OLED?

The abbreviation OLED means ‘organic LED’. To put it very simply, organic LEDs are made from special organic components, which are highlighted, when electricity passes through them. At first glance it may seem, that the difference between OLED and LED is not so great, however, organic LEDs can be very thin, small and flexible. On the TV screen, which is made on the basis of organic LEDs, each individual pixel is highlighted by itself, regardless of the others.

Facts about OLED

OLED

The principle of their work is similar to that, what is typical for LED elements. However, the conversion of the flow of electrons into light is carried out in them by means of semiconductors, made of organic materials. The main useful properties of OLED elements are small size and energy efficiency. Therefore, the appropriate type of LEDs can be used as structural elements of the screen matrix, non-complementary liquid crystals (as in LED technology), and used instead of them. Every pixel on the monitor or TV, in this way, it can be illuminated by a separate organic LED.

OLED monitors have a number of advantages over LCD and LED displays:

  • providing a brighter and more readable picture in direct sunlight,
  • absence of noticeable color distortions when viewing images from different viewing angles,
  • higher brightness and contrast of the image,
  • a wider range of displayed colors.

You can note, that OLED technology has gained particular popularity in the mobile gadget industry. Due to the small size and high efficiency of organic LEDs, manufacturers of smartphones and tablets have the opportunity to supply devices with displays to the market, distinguished by excellent characteristics.

Response time – winner: OLED

Despite, that the technical parameters of LED/LCD TVs are constantly being improved, OLED technology simply pushes them to the sidelines in the performance race, characterizing the response time. Actually, OLED technology offers the fastest response time compared to all other TV technologies, used today. Thus, Organic LED is the undisputed winner in this race. The faster the response time– the less motion blur, the fewer artifacts on the screen (regardless of the signal source).

The black color level is the winner: OLED

The ability of the display to perfectly reproduce the ‘deep’ black color is the most important factor, providing excellent image quality. The darker the black color on the screen– the higher the contrast of the image and the richer the color gamut (among other parameters), which in turn makes the image more realistic and fascinating. If we talk about comparing the quality of the black color display, that’s where OLED technology is the undisputed champion. The LED display is a display, in which the LED backlight of the liquid crystal panel is used. Even with the use of modern dimming technologies, dimming LEDs, which do not need to shine at full power, LED TVs cannot cope with the task of reproducing dark black color. In addition, they suffer from some involuntary glow at the edges. Organic light-emitting diodes TVs are not affected by any of the above problems. If no electricity is supplied to the OLED pixel, it emits absolutely no glow and, accordingly, remains black, like anthracite.

Output

To understand the difference between modern models of LED and OLED screens, we recommend reading the table, where the pros and cons of each constructive solution are reflected.

Technologies LED-LCD OLED-LCD
Contrast and black level - The contrast is infinite. The black level is absolute
Screen resolution -
Color rendering -
Brightness -
Viewing angle -
Response time -
Afterimage -
Energy efficiency -
Panel thickness -
Color volume -
Cost -

Based on the results of the analysis of the characteristics of various image transmission technologies, we can conclude, that Oled devices have advantages over top-end LED-lcd panels. The main differences relate to contrast, color rendering and response time. There is no doubt, that after some refinement and cost reduction, organic LED displays will push the ice panels into the background.

If the consumer does not have an amount of several thousand conventional units, then you should give preference to LED TVs with IPS matrix of the following brands: Sony, LG, Samsung. If the buyer is willing to pay for a clear, contrast, realistic picture, then you need to stop the selection on the led panels.

Brightness - winner: LED/LCD

(with a small margin)

If we talk about brightness, then here LED TVs have even a small, but the advantage. LEDs are ideal sources of extremely bright light. The screen of an OLED TV can also be very bright. However, regular switching on of the organic LED, forming a pixel, the maximum brightness is not only shortened by the lifetime of this pixel, but also increase the time period, which is necessary to return this pixel to the black color mode.

Viewing angles - winner: OLED

At the moment, this is a rather difficult question to discuss, since OLED TVs, electronics sold in supermarkets, they are televisions with curved screens. Therefore, despite the fact, that OLED TVs are supposed to offer us an ideal viewing angle based on the fact, that organic LEDs still emit light, and do not try to block it (as it happens in LED/LCD models), the curvature of the screen has its own nuances, causing a number of difficulties. First of all, side, which is curved in the direction from the off-axis viewer, will be less visible, than the side, curved towards this viewer. Secondly, the curvature of the screen leads to, that its anti-glare coating can slightly change the shades of colors of the picture when viewed from sharp angles. But even taking into account all of the above, OLED technology is still in a more advantageous position according to these indicators and is an undisputed winner.

Briefly about the main thing

For those who do not like to read, and he likes to turn the mouse wheel down-down-down, I have specially collected all the pros and cons in the shortest possible chapter - in this chapter. Further, if you want to know the essence of this issue in more detail, you are welcome to read the entire article

‘For’ OLED:

  • Contrast - thanks to, that each crystal in this technology can glow independently of other crystals, or even fade to absolute black, OLED has an infinite contrast ratio,
  • Color depth - wider color gamut, than LED,
  • Viewing angles are quite controversial and difficult to prove, but according to experts - better than the LCD,
  • Response time - OLED screens have better than LED screens,
  • Dimensions - due to the absence of a separate backlight, they have a very thin body,
  • Weight - other things being equal, OLED is easier, than LED, again, due to the lack of illumination,
  • Power consumption is less than that of LED.

‘For’ LED:

  • Price - for a reasonable price, even at $500, you can buy a very cool LED TV. It can be cheaper, much cheaper, but not ‘very cool’ anymore, and just ‘cool’,
  • Brightness - the brightness in LED displays is really an order of magnitude higher, than organic LEDs. Anyway, so far,
  • The size - diagonal of LED LCD TVs can reach 90’ (or even more), OLED has a problem with this so far, and TVs with organic LED displays are currently limited to 55’ screens,
  • Durability - the service life of the LED is higher.

I think it doesn’t make sense to write ‘Against’, after all, it’s already clear, that every plus of one technology is a minus for another. Anyway, in the lists provided by me, this is so. That is, if the OLED price is a plus, that, accordingly, for OLED, this is a minus and so on.

The final verdict and the author’s opinion on the essence of this issue can be read at the end of the article.

And now about everything in order and in more detail.

More on the topic: ‘How to choose a TV and not get lost in a home appliance and electronics store’.

Winning size: LED/LCD

(as of 2014)

One day (we hope, that we won’t have to wait very long for this day) each of us will be free to dream about owning an 80-inch OLED TV. But today, alas, our dreams have a limit of 55 inches. At the same time, Sharp Corporation produces LED/LCD TV sets with a screen diagonal of 90 inches – such mammoths of the television world (if we talk about size), which you can buy today, although their price is just as high, as are the prices for OLED models. Frankly speaking, the fact, what are the sizes of OLED TV screens, despite all the difficulties and problems, which production faced at the initial stage, grew to 55 inches, it is already very indicative. However, today, when the 55-inch OLED display became a reality, it’s very possible, that the progress towards conquering new heights in terms of screen sizes will go faster.

Screen Burnout - winner: LED/LCD

We wrote this section with great reluctance. First of all, because ‘burnout’ is not quite the right term (it’s just a deterioration in quality), and secondly, because most users will not encounter this problem. With effect, which was called ’screen burnout’, we first ran into each other in those days, when televisions were bulky boxes, which were based on a cathode ray tube. In those days, a long display of a static picture on the screen of such a TV led to the ‘burning out’ of its contours on the screen. However, in fact, this was due to, what is long-lasting, the continuous glow of the phosphor coating of the back wall of the television screen led to, that this very coating wore out quickly, what, actually, and it was the reason for the appearance on the screen of a burned-out picture. We think, that this effect should be called something else. But, as they say, ‘may those, maybe’.

Plasma and OLED panels are subject to the same problem, since the components, emitting light, they wear out over time. If you keep one or another pixel turned on for long periods of time, its glow will begin to fade before its allotted lifetime and definitely before other pixels, less used. What, in general, will create certain problems for the entire screen. However, in reality, few viewers can face this problem. You won’t be deliberately ‘raping’ your TV, will you, to make this problem happen? Even a ‘label’ in the form of a graphic logo, used by most TV channels, disappears from the screen from time to time, giving the pixels creating it the necessary time to rest, that will help to avoid burnout. In order for this problem to occur, you will have to watch the STB channel around the clock, days and nights long, for many weeks, at the maximum brightness level. But even this will not necessarily lead to, that the channel’s logo will ‘burn out’ the pixels forming it. But since such a problem potentially exists, it should be mentioned. And since LED/LCD TVs are not subject to burnout, they are the ones who win on this indicator technically.

Winning price: LED/LCD

Currently, if you want to buy yourself an OLED TV, it will cost you either $9,000 (Samsung model), or $15,000 (LG model). It will be amazing, if LG does not reduce the price of its OLED TV in the coming months. But anyway, even $9,000 is too much price for a TV. And even though, that you can spend a significant amount of money to purchase a large-screen TV, the overwhelming number of TVs with a diagonal of 55-65 inches will cost you about half as much (and this is at least), than an OLED TV. Thus, if the question of availability for money is a key factor for you when choosing a TV, then the best option for you will be to buy an LED/LCD model. And, most likely, this situation with prices will continue for at least the next few years.

OLED vs LED: contrast

In LED technology, control over the brightness level on the screen is very limited. Look at the classic LCD display with the light off and you will notice, what are those parts of the screen, where the image should be pure black, it is not, because it is difficult to limit the backlight for each individual part of the display, although it is impossible to say, which is impossible (about the ‘honeycomb’ just below). As a result, unwanted background lighting affects the contrast ratio of the screen, after all, contrast implies the difference between different shades of light and shadows.

The contrast of OLED displays is much better than any other screen

The contrast ratio can be seen in the technical specifications for TVs and monitors, and what is this coefficient higher, the better the display is in terms of its contrast. Good LCD displays start from a contrast ratio of 1000:1, which means, that the whitest pixel will be a thousand times brighter than the blackest.

Contrast of OLED screens by a level higher, than in LED screens, since each individual pixel of the OLED display may not produce light at all, or glow separately from neighboring pixels. In this way, you can get an infinite contrast ratio or an absolute depth of black.

Dynamic contrast

To compensate for this lag in contrast from OLED screens, LED display developers offer a ‘dynamic’ contrast mode, having which, the TV or monitor will be able to change the backlight level according to the image on the screen. That is, in those moments, when the image on the screen is mostly dark, the backlight of the LCD panel decreases, and when there is more light on the screen, the backlight becomes brighter.

Sometimes dynamic contrast can give a very good result

Thus it is possible to achieve a significant increase in the contrast level, at least in numbers. The same 3000:1 using dynamic contrast can turn into 20000000:1 However, hello.

One of the monitors on Yandex.Market

This solution is not suitable for all purposes. If you watch a movie, in which there are no very frequent rapid image changes from dark to bright light, you can still, then work on such a display, when the screen brightness will be constantly changing, it will not only not be convenient, but also most likely irritating.

‘Cells’ or local dimming

As we all know, The LED backlight of the LCD panel can be lateral and straight. In the side illumination, the LED lamps are not behind the liquid crystals, and on the sides (on the left, on the right, below, above). And in a straight line, The LEDs are located behind the LCD panel, which gives a more uniform illumination.

Unlike OLED, direct LED illumination still does not have illumination control at the pixel level. Instead, the display has LEDs or groups of LEDs, which can be darkened. This effect is called ‘honeycomb’, because they resemble honeycombs in their structure.

Honeycomb. The effect of local dimming is very similar to them

This approach can be useful when you need to darken more or less large areas of the screen, such as black side stripes, which appear while watching the movie in the ratio of 16:9, on a screen with an aspect ratio of 21:9. Otherwise, the effect is not so good when solving more complex tasks. For example, looking at a face on a black background, you will be able to see a halo around it, since the illumination zone and the contours of the object on the screen do not match exactly enough.

Panasonic TX-65DX900 is one of the representatives of TVs with local dimming

But, TV manufacturers are making LED displays better and better every year, working hard on improving contrast, and some new models of LED TVs divide the LED backlight into hundreds of individually controlled zones, with strict control of light leakage, which helps to reduce the halo effect.

Lifetime - winner: LED/LCD

(as of 2014)

If we talk about the lifetime of OLED TVs, then, in view of the relative youth of this technology, it is quite difficult to give any clear answers. However, we can make some assumptions, which are based on the fact, what is the component, used in organic light emitting diode to transmit blue light, it has a relatively short life span. And this gives some cause for concern, because if the quality of the transmission of one color deteriorates, the entire gamut will suffer. Samsung Company, looks like, trying to solve this problem, using the ‘blue pixel’, twice the size of other color pixels, and reducing the voltage applied to this pixel. LG uses white sub-pixels and sets color filters over them, to get the desired red, green and blue colors. Possible, these tricks will bring their result, however, only time and the widespread use of OLED TVs will be able to show, how high a margin of safety does the screen have on organic LEDs and how many years it will be able to work. Based on this, we decided to award the title of the winner in this parameter to LED/LCD TVs, since the terms of their life are more or less known and are quite acceptable.

Qled TV what is it?

Qled (Quantum Dot screen) is a trade name, which Samsung uses for their new ice TV.

The abbreviation misleads the masses, because it is very similar to OLED, in good faith or bad faith, Samsung benefits from this similarity. But actually, Qled are traditional backlit LCD panels with LEDs, differing topics, what is between the LCD layer and the backlight. They have a special filter with quantum dot nanoparticles, which react to electrical impulses and filter light, creating cleaner, saturated colors.

QUANTUM TECHNOLOGY USES MATERIAL, WHICH, WHEN EXPOSED TO LIGHT, CREATES COLORS WITH MAXIMUM SATURATION!!!

We have a winner! Wait… Is there a winner?

In terms of image quality, the OLED TV leaves absolutely no chance of winning LED/LCD. Plasma is capable of the same thing, for that matter. However, if the main thing for you is the image quality, you will have to make a lot of compromises. You’ll have to put up with a 55-inch screen size limit., while your neighbors will brag about the new 70-inch TV. You will have to come to terms with the fact, that an OLED TV bought today for crazy money will cost much cheaper in a few years. You will have to come to terms with the fact, that you won’t be able to hang your TV on the wall, while those people, who will grow up to buy their first OLED model in some two years will be able to become owners of a much thinner TV, which will just merge with the interior of their living room. And, finally, you will have to restrain your emotions, trying not to think about, that your TV may not last ten years. Thus, the main question arises: if money is still not a problem for you, is it worth buying an OLED TV today, or is it better to wait a few years?

Author: Caleb Denison