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What The Difference Between LED LCD And OLED Display?

Mar 14, 2019

What the difference between LED LCD and OLED display

LED LCD display will be gradually exit mobile phone market, OLED are becoming the main screen in the future. We have to know what the difference between LED LCD and OLED screen that could help we figure out which one will fit for choose.


In a nutshell, LED LCD screens use a backlight to illuminate their pixels, while OLED’s pixels actually produce their own light. You might hear OLED’s pixels called “emissive”, while LCD tech is “transmissive”.


The light of an OLED display can be controlled on a pixel-by-pixel basis. This sort of dexterity just isn’t possible with an LED LCD – but there are drawbacks, too, which we’ll come to below.


In cheaper LCD-screen phones, LED LCD displays tend to use “edge lighting”, where LEDs actually sit to the side of the display, not right behind it. The light from these LEDs is then fired through a matrix that feeds it through the red, green and blue pixels and into our eyes.


LED LCD screens are brighter than OLED. That’s a big deal in the TV world, but even more so for smartphones, which are often used outdoors, in bright sunlight.


Brightness is generally measured in “nits” – roughly the light of a candle per square metre. The OLED-equipped iPhone X has a typical peak brightness of 625 nits, while the LCD-toting LG G7 claims a peak of 1000 nits. In the TV world it goes further – Samsung’s QLED TVs can go over 2000 nits.


Brightness is important when viewing content in ambient light or sunlight, but also for high dynamic range video. This applies more to TVs, but phones are increasingly boasting of video performance, and so it matters in that market too. The higher the level of brightness, the greater the visual impact, which is half the point of HDR.


Take an LCD screen into a darkened room and you may notice that parts of a purely black image aren’t actually black, because you can still see the backlighting (or edge lighting) showing through.


A decent LCD screen might have a contrast ratio of 1,000:1, which means the whites are a thousand times brighter than the blacks.


Contrast on an OLED display is far higher. When an OLED screen goes black, its pixels produce no light whatsoever. You can’t get darker than that. That means you get an infinite contrast ratio, although how great it looks will depend on how bright the LEDs can go when they’re lit up.


OLED panels enjoy excellent viewing angles, primarily because the technology is so thin and the pixels are so close to the surface. For phones, viewing angles are extra important because you don’t tend to hold your hand perfectly parallel to your face.


Viewing angles are generally worse in LCDs, but this does vary hugely depending on the display technology used. And there are lots of different kinds of LCD panel.

Perhaps the most basic is twisted nematic (TN). This is the type used in budget computer monitors, cheaper laptops and some very low-cost phones. It offers poor angled viewing. If you’ve ever noticed that your computer screen looks all shadowy from a certain angle, then it’s more than likely a twisted nematic panel.


Thankfully, a lot of LCD devices use IPS panels these days. This stands for “in-plane switching” and it generally provides much better colour performance and dramatically improved viewing angles.


It’s important to note that IPS and LED LCD aren’t mutually exclusive; it’s just another bit of jargon to tack on. Beware of the marketing blurb and head straight to the spec sheet.


The latest LCD screens can produce fantastic natural-looking colours. However, as is the case with viewing angles, it depends on the specific technology used.


Where OLED struggles is in colour volume. That is, really bright scenes may challenge an OLED panel’s ability to maintain levels of colour saturation. It’s a weakness that LCD-favouring manufacturers enjoy pointing out.


Display makers are doing their best to tweak and improve the various limitations of LCD. While OLED’s job over the next few years is to become cheaper and brighter, we’re seeing more distinct developments in LCD.


Perhaps the most catchy is the “quantum dot”. It’s a new way to approach the LCD’s backlight. Rather than using white LEDs, a quantum-dot screen uses blue LEDs and  ”nanocrystals” of various sizes to convert the light into different colours by altering its wavelength.


Samsung has been rocking quantum dot tech for a few years now, and the company’s latest development actually puts LCD (nicknamed QLED) a lot closer to OLED performance. Samsung has wrapped nanocrystals in a metallic alloy and rejigged the lighting system, which fixes much of the contrast and viewing angle issues associated with LCD panels.


It’s a close call, but LCD is definitely better than OLED in terms of sheer numbers. LED LCD has been around for much longer and it’s cheaper to make, which gives it a head start when it comes to market saturation. However, OLED is an excellent luxury option, and OLED technology is gaining momentum. OLED is already much better than LED LCD at handling darkness and lighting precision.


If you’re dealing with a limited budget, whether you’re buying a phone, a monitor, a laptop or a TV, you’ll almost certainly end up with an LCD-based screen. OLED, meanwhile, remains a more luxury proposition.


But LCD’s dominance is slowly being chipped away; OLED tech is developing rapidly.


Which is better? Even if you eliminate money from the equation, it really comes down to personal taste. Neither OLED or LCD LED is perfect. Some extol OLED’s skill in handling darkness, and its lighting precision. Others prefer LCD’s ability to go brighter, and maintain colours at bright levels.