How QLED and OLED Displays Work and Which One Is Right for You

Of all the confusing terms associated with display technologies, few are easier to confuse than OLED and QLED. They’re only half a letter apart, but they operate very differently, and those differences can make a big difference when it comes to the quality of your TV or monitor. Let’s take a look at the differences and why you should consider window displays.

There are many subcategories within both of these display types, but for the purposes of this article, I’m going to focus primarily on the main differences between these two main groups. It’s also worth noting that while you may occasionally see OLED panels in smartphones, QLED smartphones don’t exist yet.

OLED vs QLED: the simple version

If you’re shopping for a TV and just want a quick summary, here it is: OLED displays use pixels that emit their own light individually, resulting in perfect blacks, greater contrast and brighter images, but a greater risk of image burn-in. OLED displays typically cannot be as bright as competing display technologies and may have a shorter lifespan (though this is still typically measured in many years).

Meanwhile, QLED displays use blue backlights and “quantum dot” pixels to turn that light into red, green, or blue light. This allows QLED displays to be much brighter than OLED, making it easier to view in sunny rooms with lots of natural light. They’re also less prone to burn-in, although they’re typically thicker than OLED (making them poorly suited for smartphones) and have worse black levels.

Easy, right? Well, this might get a little tricky, so let’s dive in.

How do OLED displays work?

Typical liquid crystal displays (LCDs) use a backlight shining through liquid crystals that filter the backlight color to create the hue of each pixel. The downside to this method is that these liquid crystals cannot completely block the backlight, so even when your monitor has a completely black screen, it still appears “on.”

Organic light-emitting diode (OLED) displays solve this problem by using pixels that light up individually, without the need for a backlight. This means that if part of the screen displays pure black, those pixels will simply be turned off. At this point, the only light coming from that part of the screen will be any ambient light reflecting off it.

Why should I buy an OLED display?

This type of display has a number of advantages:

• Perfect black levels and incredible contrast. Because OLED displays have no backlight, black levels are technically perfect. Or more accurately, they’re as dark as the room you’re looking in. This also means that the contrast between dark and light parts of the screen can be much higher.

• Wide viewing angles. Because you’re looking at pixels, which are essentially a series of tiny lights without any filters, there are fewer issues with viewing angles. You can watch OLED TV from afar and still see it clearly.

• Thinner displays. Because OLED displays do not require a separate backlight, the displays can be made very thin. Many smartphones use this type of display for this (and other) reasons.

• Less power consumption (sometimes). Technically, OLED displays require more power to achieve the same level of uniform brightness compared to LCD displays, but per-pixel lighting means this is not always necessary. Some smartphones take advantage of this by offering minimal displays where a few pixels are lit to show the time or notifications, while the rest of the display remains dark to save power. This also means that in some cases, switching to dark mode can extend the life of your phone.

However, OLED also has some disadvantages. The biggest problem is burnout. Although modern OLED displays have become better at this task, images that remain on the screen for long periods of time (such as menus, taskbars, or the lower thirds) can leave “ghost” images that persist even when they are no longer displayed.

They also cost more than LCD displays, and this cost depends on the size of the display. For smartphones this may not be a big deal (even some budget phones now have OLED panels), but for TVs it can mean several hundred or thousands of dollars for the largest screen. Since OLED displays may have a shorter lifespan, it’s worth considering before making a huge investment.

How do QLEDs work and what are quantum dots?

So, how are quantum light-emitting diode (QLED) displays different? To explain this, we need to talk about quantum dots. Without going too deep into the physics of how they work, quantum dots are nanoparticles that emit different colors of light depending on their size (on an atomic scale).

In practice, QLED displays start with a blue backlight (since blue light has the shortest wavelength and therefore the highest energy), which is then hit by a layer of quantum dots. This layer contains a mixture of quantum dots that are sized to emit either green or red light when backlit.

This subtle difference can make a big difference when creating bright, vibrant displays. With white backlighting, all wavelengths of color are present, and LCDs create specific colors by blocking light at wavelengths that are not needed. In a quantum dot display, you only need to start with blue light and then let the quantum dot layer essentially “slow down” it to red or green wavelengths.

So why do I need a QLED display?

This process is more energy efficient than using a pure white backlight, meaning colors can be much more saturated and vibrant than conventional LCD displays. It still doesn’t achieve pure black levels like OLED displays, but it can provide much better contrast than LCDs without a quantum dot layer.

Also, notice how I keep saying “LCD”? That’s right, even though “QLED” sounds similar to “OLED”, they are still LCD panels. The blue backlight is LEDs, but these displays still use the LCD layer to filter the light. Some manufacturers have started using quantum dots on OLED panels, and they are called QD-OLED. Which is not at all confusing.

QLED displays have some useful advantages over OLED panels. Including:

• High peak brightness: QLED TVs can be much brighter than similar OLED displays, making them best suited for large, bright rooms. For example, if your living room has a lot of windows, you may need one of these.

• Wide and bright color range. Because quantum dots reproduce colors more efficiently, you can get truly vibrant and accurate colors from a QLED panel. This is great for high dynamic range content , which makes all your colorful movies and shows really pop.

• No risk of burn-in: QLED displays do not suffer from burn-in issues because inorganic quantum dots do not degrade like OLED pixels do. This also results in a longer lifespan for your TV overall.

• Larger TVs at lower prices. Generally speaking, OLED TVs can get very expensive if you start looking at larger TVs. However, QLEDs will generally be more affordable without sacrificing size.

One of the biggest disadvantages of QLED TVs compared to OLED is that some models have shorter viewing angles, meaning your friend sitting on the far side of the couch may have a worse view. Some TV manufacturers use features such as local dimming (essentially dimming the backlight for darker parts of the picture) to improve black levels, but these may vary by manufacturer.

To make things even more confusing, some manufacturers use quantum dots for their LCD displays but don’t call them “QLED.” Hisense, for example, uses the ULED labeling. The company says the term refers to the “special sauce” of different TV technologies, but the combination includes LED-backlit quantum dots and an LCD matrix.

It’s frustrating to get lost in the marketing jargon, but if you’re looking for a bright TV that can compete with the sunlight streaming through your windows, QLED TVs are your best bet. Otherwise, if you prefer really deep contrast, usually watch in a dark room, and perhaps have too much money to spend, OLED TVs will be better for you.

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