Display Technologies

The main difference among CRT, LCD, AMOLED displays are the actual composition of each pixel & the working priciples behind it.

 

CRT or Cathode Ray Tubes uses an electron gun to fire pixels at the screen (remember that big hump at the back of your old TV set).

LCDs use liquid crystals (obviously) made on a TFT (Thin Film Transistor).

• When you hear terms like TN (Twisted Nematic - the cheapest and most common panel used) and IPS (In-Plane Switching) , they refer to the display panel being used in the LCD.

 

LEDs or Light Emitting Diodes uses diodes that release light onto the screen when electrons strike them. The phenomena used for emission of light is the inverse of what happens in photoelectric effect.

OLED is just an extension of LED display technology where organic substance - one that has carbon - is used to emit light.

The OLED devices are simple solid-state devices consisting of a thin layer of organic compounds in an emissive electroluminescent layer where the electricity generates. These organic compounds are present between the protective layers of glass or plastic.

• PMOLED stands for Passive Matrix Organic Light Emitting Diode. The PMOLEDs are easy to find and much cheaper than other LEDs, but they cannot work for a long duration as their lifespan is very short. Therefore, this type of display is generally for small devices up to 3 inches.

• AMOLED stands for Active Matrix Organic Light Emitting Diode by the way, uses three discrete LEDs for each pixel. The entire screen therefore produces its own light and does not need a backlight. AMOLED comprises an active matrix of OLED pixels along with an additional layer of TFTs. This extra layer is responsible for controlling the current flow in each pixel. TFT, further consists of a storage capacitor.

Super AMOLED Display: A "Super AMOLED" Display is a Samsung AMOLED Display with a integrated Touch panel.

Other display-manufacturers may also have a Touch panel integrated in their display, but will still just call it AMOLED or OLED Display.

The industry-backstory on that:

After Samsung heavily promoted its AMOLED Displays as unique feature of their Galaxy S smartphone for a while, they were already facing competition from other display manufacturers who also started to offer AMOLED Displays to their customers (handset manufacturers), most prominently LG Display and Sony.

Up to that point Samsung invested alot into the marketing of the "AMOLED" brand, a name they chose instead of "OLED" with the expectation of trademarking it. The idea was to create a term that appears to describe a technology (like "LCD") but is in fact a trademark forbidden to use by anyone else, creating the impression that only Samsung can produce this technology.

But in a unfortunate turn of events their trademark for "AMOLED" was rejected in several regions because, while being a different term than the technology "OLED", it still describes a technology (as it stands for "Active-Matrix” OLED, or ”Organic Light-Emitting Diode").

So, facing the issue of appearing equal to competitors on AMOLED, Samsung Display needed a plan B to push other display vendors out.

At that time the company achieved to merge the touch panel with the glass of the AMOLED Display as part of the panel-production, basically replacing the top glass of the display panel with a touch-panel (a process called "on-cell touch display") as it can be observed in above image.

So Samsung decided that this should be a custom evolution, and trademarked "Super AMOLED" as a brand (which they filed as a advanced type of AMOLED, in detail describing the touch panel as the difference).

With that move they were hitting two birds with one stone:

1. They differentiated from others (by focusing on something very technical with rather minor end-user benefit).
2. They destroyed the "AMOLED" term for the competition, because spending money on marketing using "AMOLED" is quite nonsense if your competitor is promoting "Super AMOLED".

Over the following years Samsung was enjoying a huge success with the Samsung Galaxy Series, leading to Samsung being consistently the largest volume manufacturer AND customer of AMOLED Displays, effectively drying out the competition (other AMOLED display panel manufacturers who failed to secure similar order-volumes to keep up with Samsungs investment in AMOLED).

It's still a brand:

All that said, it's worth to emphasize that also today "Super AMOLED" is not a description of a technology, it remains a BRAND. Which means it is up to the owner of the brand to define what it shall mean (just like Sony defines the meaning of their "Bravia" brand, Coca-Cola defines the meaning of "Coke light" and  Apple defines high resolution IPS LCD display as Retina Display.

Speaking of Retina, People confuse Retina Display as something found only in Apple’s displays in smartphones , tablets and notebooks.

Retina Display is a term coined by Apple when they launched iPhone 4 in June 2010. While iPhone 4 had 640 * 960 pixels on a smaller 3.5″ diagonal screen , competing flagship Android phones of the day like Samsung Galaxy S or Sony Ericsson Xperia X10 were limited to WVGA resolution or 800 * 480 pixels on a larger 4″ screen. And, that's the reason the term was hyped by Apple as a marketing strategy.

whereas it’s just a number Samsung and other Android manufacturers have crossed way back in 2012. The retina display uses LCD technology with large bezels, similar to what you will find on today’s devices and uses a backlight.

Retina Display refers to the sharpness of a display in terms of pixels per inch (ppi) along the diagonal width of the screen , rather than the resolution which is simply specified in terms of x * y pixels. In general , a retina display is any display that has more than 300 pixels per inch. The reasoning behind the name is that these displays have a pixel density so high that the retina in the human eye can't see the individual pixels at a normal distance, hence the name Retina display.

Liquid Retina Display is Apple's terminology for a Retina LCD with thin bezels. Liquid Retina displays use pixel masking and anti-aliasing that can allow those thin bezels.

Liquid Retina XDR displays are everything we just mentioned, with the addition of enhanced HDR technology for improved contrast ratios and brightness. but Apple calls it Extreme Dynamic Range (XDR). Also, these displays feature mini-LED backlighting and ProMotion adaptive refresh rate technology. 

Super Retina XDR display is a custom OLED panel with XDR technology. There isn't a difference in display type between a standard OLED panel and Apple's Super Retina XDR displays.

When comparing Liquid Retina XDR displays and Super Retina XDR displays, the main difference is that the former uses mini-LED backlighting technology, while Super Retina XDR displays use OLED.

 

 

How to choose the best Display for your needs?

Lifetime:

IPS LCD has an edge over OLED displays here. It can last forever.

For OLED, the lifetime requirements of 30,000 hours expressed by the representatives of mobile-phone-terminal makers were felt to be unrealistic to be obtained in 2003, since the lifetime of the blue color was below 1000 hours. Today, 5 years later, lifetimes of AMOLED panels are over 50,000 hours.

 

Contrast Ratio:

The biggest advantage of AMOLED displays is its near infinite contrast. This is because each pixel produces its own light and can be turned off when black needs to be displayed. This cannot be achieved by the retina display because of the backlight behind it. Even when the LCD tries to block the light, some amount is still able to get through and produces a grayish color. The downside to this is the reduced visibility when used under direct sunlight. Because the screen produces its own light, the light of the sun may overpower. 

Saturation:

SuperAMOLED is a display technology that defines what runs a display i.e how it will illuminate the pixels on a screen. SuperAMOLED technology can be explained with the help of bulbs. Suppose if there is only one bulb in your room and no other light source including the sun. Now if you break that bulb or turn it off , your room experiences something close to pitch black darkness. This is what happens to pixels when SuperAMOLED technology is used to light them. Thus SuperAMOLED displays are said to have deeper blacks and more vivid , eye-popping colors compared to LCDs.

LCDs on the other hand , need a separate , constant backlight for their pixels. Hence their blacks are a very dark shade of grey at most. 

 

Power Consumption

Since AMOLED display pixels can be turned off completely , they consume less energy and give fantastic battery life to smartphones in particular.  Another AMOLED display advantage is the fact that each pixel that displays black consumes virtually no power because it produces no light. This results in great power savings if you use a black background instead of white. A good example of this is when reading e-books, since most e-book readers allow the colors to be flipped; resulting in a white text on a black background. LED backlit LCD displays were made for this very purpose. Although you can still flip colors in a retina display but no power will be saved since the backlight behind the screen is still on.

 

Viewing Angles

Since LCDs suffer from the problem of viewing angles, IPS or In Plane Switching panel technology allows users to get the same , constant colours when they move the display or look at it from any angle. Thus they are said to lack color degradation / distortion.

AMOLED offer much better viewing angles as compared to the IPS LCD.

 Conclusion:

However, Liquid Retina XDR displays are better than traditional LCD screens thanks to the mini-LED backlighting zones and XDR technology. They also don't have the same burn-in issues that OLED panels have. But XDR also exists on most Apple products that feature OLED screens now, so the same benefits apply to them in addition to the advantages OLED panels have over mini LED.

OLED displays having a higher contrast ratio and more saturated colors, are reasons why most smartphones moved on from LCD panels. However, Liquid Retina XDR displays are nothing to disregard and mini LED is a great display technology for larger screens. For instance, the high-end MacBook Pro's displays, which are Liquid Retina XDR displays, were praised by the vast majority of reviewers.

In the end, both display technologies are incredible. However, with superior colors, brightness, and unmatched black levels, Super Retina XDR displays still have the edge over Liquid Retina XDR, even though mini LED and XDR have made LCDs more compelling.