What is an OLED TV and how does it work? Adv. & Disadv.
OLED stands for Organic Light Emitting Diode.
As the name suggests, it uses organic materials that emit light when electric current is passed through them.
These organic LEDs are incredibly small, nanometer sized and guess what, millions of them are embedded within an OLED display!
Now, you might wonder: Why do we need such tiny LEDs, and that too, why use organic ones?
To understand this, we first need to look at what a pixel is.
A “pixel” or picture element is the smallest unit of a TV display.
The TV screen you see is actually made up of millions of these pixels.
The total number of pixels in a display depends on its resolution.
For example, a 4K TV has approximately 8.3 million pixels.
How does an LCD TV work?
In a conventional LED LCD TV, an LED backlight serves as the source of light.
This backlight emits white light, which then passes through several LCD layers that control how much light should pass through to the screen.
After that, the light travels through RGB (Red, Green and Blue) color filters, which filter out these specific colors required to reproduce a wide range of colors with the required brightness levels on the display.
As we discussed earlier, in an LCD TV, the light from the LED backlight has to travel through multiple layers before it reaches the screen.
Naturally, this process introduces a slight delay in how quickly light reaches the pixels.
This delay is one of the reasons why LED TVs generally have slower response times compared to OLED TVs.
Once the light finally reaches the screen, it hits the pixels, the picture elements of the display.
These pixels then form the images you see on screen, depending on the intensity and color of the light they receive from behind.
Isn’t that fascinating?
Well, there’s even more to uncover!
A display contains millions of pixels, but the LED backlight behind it only has a limited number of LEDs, usually just a few hundred or a few thousand.
To manage how light is distributed, these LEDs are organized into what’s known as lighting or dimming zones.
Let’s say your TV has 100 such dimming zones, and the screen itself has one million pixels.
That means, on average, each dimming zone is responsible for lighting around 10,000 pixels.
So essentially, your TV screen is divided into 100 large groups of pixels.
Each group can only display a single level of brightness and color at a given time, based on the performance of its assigned backlight zone.
These zones work together to render the full image you see on the screen.
Imagine a scene showing a night sky with a few twinkling stars, while the rest of the screen should remain completely dark.
In this case, the dimming zones that correspond to the bright twinkling stars will light up to their fullest, while the zones representing the dark sky will dim down as much as possible to create a sense of darkness.
Even though the dimming zones try to reduce brightness in dark areas, they can’t shut off completely.
That’s because the LED backlight is always on. It continues to shine through the LCD layers and color filters, even when a part of the screen is supposed to be pitch black.
As a result, you get light leakage, where the supposed dark areas appear greyish instead of being truly black.
This phenomenon is called light bleeding.
Moreover, this also causes what’s known as the blooming effect, where light from bright objects spills over into surrounding dark areas, creating a noticeable halo or glow around them.
This is especially visible in high-contrast scenes like a glowing moon or bursting firecrackers in a dark sky.
That’s why regular LED TVs often struggle with contrast ratio.
They simply can’t make dark areas truly dark.
Some advanced TVs, like those with mini LED backlighting, improve this to a great extent.
These TVs use very small LEDs, roughly one-fifth the size of traditional LEDs.
Thanks to their tiny size, manufacturers can pack in thousands of LEDs in the backlight, allowing for a few thousand dimming zones, far more than the few dozen generally present in standard LED TVs.
‘The more dimming zones a TV has, the more precisely it can control brightness and contrast across different parts of the screen.”
Now think of this—What if there were not just a few thousand zones, but millions, one for each and every pixel on the screen?
Just think about the level of precision and picture quality that could be achieved.
The idea behind organic LEDs
What if we could reduce the size of LEDs to such an extent that instead of controlling a group of pixels, each LED could control a single pixel individually?
To achieve this, the LEDs would need to be shrunk down to the size of individual pixels, which can be just a few micrometers.
However, it’s extremely difficult and expensive to fabricate such tiny inorganic LEDs at the pixel level.
This challenge is exactly what micro LED TVs have overcome.
Micro LEDs are individual self-emissive diodes that can be miniaturized to a microscopic level and directly integrated into the display panel.
But there’s a catch: the manufacturing process is highly complex, requiring precise placement of millions of microscopic LEDs on the panel.
As a result, micro LED TVs are currently priced at least 10 to 20 times more than regular TVs, putting them well out of reach for most consumers, at least for now.
Moreover, micro LED TVs are currently being manufactured in very large sizes, often starting from 100 inches and above which makes them unsuitable for most living rooms.
To create such a pixel-level light-emitting display at a cost competitive with regular LED TVs, manufacturers use organic LEDs or OLEDs.
Unlike the traditional inorganic LEDs, organic LEDs are made from carbon-based materials that emit light when an electric current passes through them.
These materials can be easily integrated into display panels and manufactured using techniques which are more scalable and cost-effective at smaller sizes.
Because of their organic nature, OLEDs can also be deposited on flexible substrates, enabling the creation of foldable, rollable, or even transparent displays, something that’s not feasible with rigid inorganic LEDs.
The magic of OLED pixels
The organic LEDs emit light when an electric current is applied to them, meaning they generate their own light, thus do not require a separate LED backlight.
Because each pixel in an OLED TV is made up of its own tiny light source, every single pixel can be turned on or off independently based on the brightness required.
Just imagine, when every tiny unit of the screen responds individually to the content, how precise and vibrant will the image quality be!
How does an OLED TV work?
The working mechanism of an OLED TV can vary depending on the type of OLED technology used.
For example, LG’s WOLED (White OLED) uses white organic light-emitting diodes combined with color filters.
MLA OLED (Micro Lens Array) enhances LG’s WOLED panels by adding a layer of microscopic lenses to boost brightness and viewing angles.
Samsung’s QD-OLED (Quantum Dot OLED) combines blue OLED emitters with quantum dots to produce highly vibrant and accurate colors.
While these technologies differ in structure and performance, they all share one fundamental principle: the use of self-emissive pixels, where each pixel generates its own light.
Now, let’s move ahead and explore the key differences the OLED TV pixels create in terms of contrast, brightness, and other performance parameters.
Contrast
The night sky scene we previously discussed can’t be displayed perfectly on an LCD screen.
But on an OLED TV, it delivers an entirely different level of visual experience.
In an OLED TV, each pixel emits its own light and can turn off completely when not needed.
This means that pixels representing the night sky simply switch off, creating true black with zero light emission.
Since there’s no constant backlight, issues like light bleeding or blooming are completely eliminated.
The result? Perfect contrast.
Bright areas appear vivid and striking, while dark regions are rendered in absolute black.
Watching such scenes on an OLED TV is enough to mesmerize anyone.
Since the blacks on an OLED TV are displayed at absolutely zero nits of brightness, the contrast ratio becomes infinite.
That’s because contrast ratio is calculated as the ratio of the brightness of the brightest white to that of the darkest black.
So, when the blacks are at zero nits of brightness, the contrast ratio becomes infinite.
Color gamut
Since the pixels in an OLED TV are individually controlled, each pixel can emit its own color independently of the ones next to it.
This pixel-level precision ensures that the overall image is extremely accurate.
Because of this high degree of control, OLED TVs can reproduce a vast range of colors with exceptional accuracy, resulting in a wide color gamut.
The colors look vibrant, nuanced, and true to life.
If you ever get the chance to watch an OLED TV in a dark or dimly lit room, you’ll be absolutely blown away by the lifelike colors and the depth of true blacks.
Brightness and HDR performance
OLED TVs use organic pixels, which are at risk of degradation if pushed too hard which may especially happen at high brightness levels.
Because of this, many OLED TVs cannot reach the same peak brightness as LED LCD TVs.
That’s because LED TVs use inorganic LEDs, which are far more resilient and can be driven to much higher brightness levels without the same risk.
As a result, while OLED TVs deliver unmatched picture quality in dark or dimly lit rooms, thanks to their true blacks and rich color; they may struggle to maintain visibility and vibrancy in bright rooms due to their relatively lower brightness.
Nevertheless, many modern OLED TVs such as LG’s MLA-based OLEDs and Samsung’s QD-OLEDs have made significant improvements in peak brightness.
Combined with their superior reflection handling, these TVs can effectively combat glare and perform well even in bright rooms.
With their wide color gamut, high peak brightness, and infinite contrast, these advanced OLED models deliver outstanding HDR performance.
Even OLED TVs that aren’t that much bright still offer excellent HDR quality in dark or dimly lit rooms, where their deep blacks and color precision truly shine.
Viewing Angles
Since OLED TVs can completely switch off individual pixels when not in use, they produce the exact amount of light or color required at every part of the screen.
This precise control over light and color results in the widest viewing angles.
Whether you’re sitting directly in front of the screen or at an off-axis position, the picture quality remains uniform.
Response Time
Unlike conventional LCD TVs, where light must travel from a backlight through several layers before reaching the screen, OLED TVs use self-emissive pixels.
This means each pixel generates its own light and color, with no intermediate layers to slow things down.
As a result, OLED pixels can turn on, turn off, and change color almost instantaneously.
This leads to an exceptionally fast response time, typically around 0.1 milliseconds; which is at least ten times faster than most traditional LED TVs.
Thanks to this near-instantaneous pixel response, OLED TVs are an excellent choice for fast-paced and competitive gaming where even a fraction of second counts.
Thickness and Power consumption
Since OLED TVs don’t require a backlight, they can be made extremely thin and lightweight.
Whether placed on a stand or mounted on a wall, an OLED TV seamlessly blends into its surroundings.
In fact, when viewed from the side, it appears so sleek that it can almost disappear, resembling just a thin line.
In addition to their elegant design, OLED TVs are also more energy-efficient.
Because the pixels can individually turn off when not needed, OLEDs often consume less power than LCD TVs, where the backlight remains on regardless of the on-screen content.
Lifespan
The pixels in an OLED TV are made from organic materials, which naturally degrade over time.
This degradation can eventually lead to a reduction in brightness and color accuracy as the TV ages.
Another issue associated with OLEDs is burn-in.
This can occur when static content like channel logos or scoreboards remains on the screen for extended periods.
Over time, the pixels in those areas may wear out faster, leaving behind a permanent shadow or ghost image, even when the content changes.
For example, if you frequently watch the same sports channel without switching, the channel logo which remains static and bright, may burn into the screen over time.
This is because the pixels in that area undergo more stress, thus wear out faster.
To address this, manufacturers have implemented built-in mitigation features such as pixel refresh, pixel shift, screen savers, and logo luminance adjustment.
These features help reduce the risk of burn-in significantly.
That said, LCD TVs, which use inorganic materials, generally have a longer lifespan and are less susceptible to burn-in, making them a safer choice for people who love to watch the same channel frequently.
Advantages and Disadvantages
We discussed a lot about OLED TVs till now.
Let us see their advantage and disadvantages at a glance.
Advantages
- Infinite contrast ratio
- Accurate colors
- Wide color gamut
- Superb HDR performance
- Very fast response
- Sleek and stylish design
- Less power consumption
Disadvantages
- Limited brightness
- Lesser lifespan compared to the LCDs
- Burn-in risk
Keep in mind, these advantages and disadvantages of OLED TVs are general observations and may not apply to every OLED model.
Should I buy an OLED TV?
The price of an OLED TV is generally on the higher side compared to traditional LCD TVs.
However, once you bring it home, you’ll quickly realize that it’s absolutely worth it.
In a brightly lit showroom, you might not fully appreciate the difference in picture quality due to too much lighting.
But the moment you set it up in your own room with minimal lighting, the OLED’s true potential comes to life.
You’ll witness blacks like you’ve never seen before, deep and pure.
Play any HDR content on it, and you’ll find yourself completely immersed in the stunning visuals.
With its super-fast response time, infinite contrast ratio, true blacks, exceptional HDR performance, and pinpoint color accuracy, an OLED TV allows you to experience every nuance of a scene, just the way it was meant to be seen.
If you’re someone who watches TV mostly in a dark room, values picture quality above all, and enjoys varied content, then there’s no need to think twice—just go for any OLED TV within your budget.
Its deep blacks, accurate colors, and immersive performance will exceed your expectations.
However, if you’re a bright-room viewer, consider investing in an LG MLA-based OLED or a Samsung QD-OLED.
These OLED TVs offer significantly improved brightness and excellent reflection handling, making them much suited for well-lit environments also.
Do note, though, that these models come at a higher price point.
If you’re looking to save some money without sacrificing much in picture quality, a Samsung Neo QLED TV can be a great choice.
While you’ll have to compromise slightly on contrast and black levels as compared to OLEDs, a Neo QLED delivers outstanding HDR performance and handles glare remarkably well in bright rooms.
