Technical Interpretative Glossary: Image Technology of LCD Displays

In modern electronics, LCD displays are the most common. But some companies are pushing their alternative, OLED displays, to the forefront. They work on a slightly different principle. 

How does the LCD work? 

LCD stands for Liquid Crystal Display. It consists of several layers. Backlighting is the basis, which is usually done with LED lights. Then there is a polarising filter, a TFT glass, a layer of the liquid crystal itself, a colour filter, and another polarising filter. 

The principle of operation can be simply described as the light emitted by the LEDs passing through a polarizing filter and TFT glass, where it is slightly modified. The real magic occurs in the liquid crystal layer, which changes the light transmittance based on the input electrical voltage. The modified rays pass through a colour filter, where the individual colours are created, and exit the display through a polarising filter. 

What about OLED displays? Unlike the LCD, it is not backlit with LED lights. Special electroluminescent crystals take care of the light generation. The advantage is the ability to achieve slightly better contrast and blacker colours than with LCD technology.

AMOLED displays use an active matrix, so they can display moving objects even more smoothly.

In contrast, PMOLED displays have a passive matrix, so they are suitable for displaying static images and texts. 

LCD display technologies 

Of course, not every LCD display is the same. There are several types, which differ in their layers and their arrangement. The most common ones you will come across are. 

IPS

In-Plane Switching LCDs are used in the most expensive equipment, as they provide very good viewing angles and a faithful display of a wide range of colours. However, they have the disadvantage of slower response and lower contrast. 

PLS

Plane-To-Line Switching LCDs have a similar technology to IPS, but with minor design modifications that make it suitable for use in touchscreen displays. Its main advantage is the fact that no trace is left on the display when a finger is swiped, and no colour modification occurs. It is pleasing to see very good brightness combined with large viewing angles. The PLS display was first launched by Samsung. 

TN

Twisted Nematic LCD technology may be getting on in years, but it still excels in high brightness and responsiveness. However, compared to IPS, these displays don't have as wide viewing angles and their colour rendering is more limited. Due to their low price, they are often used in simpler applications where speed of response is most important. 

VA

Vertical Alignment LCDs combine the features of IPS and TN, offering a balanced ratio of brightness, viewing angles, and fast response times. In terms of price, they are somewhere between IPS and TN displays. There are two types - PVA and MVA, with PVA being a slightly better technology in terms of viewing angles and contrast. 

QLED

Quantum Dot Light Emitting Diodes is one of the most advanced LCD display technologies introduced, once again, by Samsung. It dominates with its superior brightness and added quantum dots that improve the overall image quality and the spectrum of colours displayed. QLED technology is thus the closest competitor to OLED displays. 

Mini-LED and Micro-LED

One of the most advanced LCD display technologies are Mini-LEDs and Micro-LEDs. These consist of a larger number of small LEDs backlighting the screen. Thanks to them, it is possible to achieve higher image quality, a wider colour spectrum, greater fluidity, and better contrast. 

Although LCD displays have excellent durability (better than OLED), they can also break occasionally. When this happens, just visit our e-shop to buy genuine displays for most makes and models of smartphones, tablets, and laptops. You can also use our repair guides for easier servicing.