Things to know about LCD panel technology

Choosing an LCD monitor is one of the most difficult steps in the selection process for desktops. If other components such as RAM, CPU, HDD have quite clear, transparent and understandable parameters, the specifications of the LCD screen cause many people headaches.

One of the most important factors, which greatly affects the image quality of LCD monitors, is not usually announced in the product specifications. That is the technology of the screen panel. So what kind of screen panels are there? How are they different? Let us find out about this issue.

What is the panel?

LCD screen (Liquid Crytal Panel) or liquid crystal display is made up of many different components including panel. Panel (or display frame) is a flat sheet containing liquid crystals, they are responsible for displaying images through each pixel showing different colors when the current is applied.

Panel cannot display images alone. To show the image on the panels, we must have a backlight illuminated behind the panel. This is simple because the panels cannot light themselves.

With the role as above, surely you have envisioned the importance of the panel with the image quality of the screen. How many colors, how accurate and bright the panels are, how the refresh rate greatly affects the quality of the screen.

Current popular panel technologies

Just like the touch screen, although with the same purpose and features, but with different solutions, we also have many types of panels with different price and image quality. Let's take a brief look at the history, characteristics and features of today's popular panel types.

Twisted Nematic (TN)

Twisted Nemaitc effect is one of the basic elements that make LCD screens popular and popular since the early 1990s. The biggest strength of this Panel technology is its low power consumption. Suitable for handheld devices that use batteries (like laptops).

The idea of ​​Panel TN technology started in 1962 by Richard Williams - a physicist working at RCA. He discovered the basic principle used in later LCD panel TN displays, however, when it was needed, the current required for it was too high, not suitable for practical applications, therefore, projected Project suspended. In 1964, Heilmeier joined Louis Zanoni and RCA chemist Lucian Barton to complete the research, and in 1968, RCA announced the first liquid crystal display. Of course, they still use TN panel technology.

This is the most popular LCD display technology in the 1990s and early 2000s. To date, TN is used in most low-cost LCD monitors. The outstanding advantage of TN panel is that it has very low response time (2-5ms) and this is one of the factors that helps manufacturers attract more customers, it is very cheap.

However, TN panel has many disadvantages: poorest color display in panel types. This is because TN has only 6 bits per color (18 bits total), so it does not show enough 16.7 million colors like other panels. Later, NSX used Frame Rate Control (RFC) techniques to display 16.7 million colors. In addition, more importantly, TN's view is extremely narrow (visible on older laptop models) especially vertically. Currently, the TN panel LCD NSX has raised a wider viewing angle but is still very narrow compared to other panels.

With these features, Panel TN is often used only in low-cost displays, low demand (office machines .). In particular, TN panel is usually only suitable for small size LCD screens (usually 19 "or less).

Vertical Alignment (VA)

This panel technology is divided into 2 main types: MVA (Multi-Domain Vertical Alignment) and PVA (Patterned Vertical Alignment). MVA is Fujitsu technology that began to develop in 1998 and PVA is the "darling" of Samsung and Sony. Currently, with the backing of Samsung, PVA has advantages over MVA. Basically, MVA and PVA have the same composition only different in how they work. PVA has an S-PVA upgrade while MVA has P-MVA, A-MVA and S-MVA.

VA technology has the biggest advantage is the ability to express excellent colors. VA supports 8 color bits (24 bit total) however, not all VA panels are 8 bits. Panel VA has a very high contrast ratio, thus improving the image quality of the screens using this technology. Compared to TN, VA has good image quality.

With these characteristics, LCD panels using VA panel are suitable for simple entertainment needs of high quality such as watching movies, sports . In addition, this is also the technology commonly used in the Large size LCD average for entertainment purposes. In fact, in the home screen market, Sony and Samsung have outstanding quality.

In-plane switching (IPS)

IPS is a panel technology developed by Hitachi and in 1996 to enhance the image quality and viewing angles of monitors using TN panels. IPS screen technology gives good display quality and viewing angle. Currently, IPS screen has many upgraded versions with specific upgrade time, you can refer to the following table.

IPS has a high and uniform response speed. IPS has the optimal structure to handle a large number of signals at high speed without losing data by using copper wire with low resistance value. So, the screen using IPS panel has a vivid, clear image. The IPS panel screens are all 8 bits (24 bits total), so it represents 16.7 million colors. IPS panel screen is considered one of the things that made the touch screen idea.

Panel IPS is used in high-end displays, graphic design machines (strict requirements for color quality and images). Currently, most touch screens are IPS screens.