IPS matrix – how does it work and what are its characteristics? Compendium of knowledge

The IPS (short for In-Plane Switching) matrix is one of the most popular types of matrices used in monitors, TVs and mobile devices. It features wide viewing angles, faithful color reproduction and no grayscale inversion effect found in cheaper TN matrices. So let’s find out what the phenomenon of IPS matrices is and why they are so eagerly used by consumer electronics manufacturers.

History of IPS technology

IPS matrices were developed in the 1990s. It was developed in the 1970s by the Japanese company Hitachi. It was a response to the shortcomings of the then-popular TN (Twisted Nematic) and VA (Vertical Alignment) matrices, which featured narrow viewing angles. This meant that the image lost color and contrast when looking at the screen slightly from the side.

Another problem of TN matrices was grayscale inversion, a phenomenon in which the colors of an image are inverted when viewed at a certain angle. The result was distorted, unrealistic colors. To change this, Hitachi engineers developed IPS technology, revolutionary for the time.

Hitachi’s innovative solution was to use a different way of stacking the of the liquid crystals relative to the plane of the matrix. This allowed to eliminate the disadvantages of TN matrices and create a screen with unprecedented performance. Since its release in the second half of the 1990s, IPS matrices have gradually displaced older TN and STN designs, now becoming one of the most popular screen technologies in the world.

IPS matrix – what exactly is it? Construction and principle of operation

IPS matrix is a type of panel LCD , which enables excellent color reproduction and wide viewing angles. How does it differ from other technologies? IPS technology aligns the liquid crystal molecules parallel to the glass, while other technologies such as TN and VA align them vertically. This fundamental difference has made it possible to achieve significant improvements in image quality.

More precisely explained, liquid crystal displays use special substances called liquid crystals, which change their structure under the influence of an applied electric field. Hitachi engineers used an innovative solution, stacking liquid crystals parallel to the die. With this arrangement, the crystals can be switched very quickly using electric fields. This allows for precise control of their alignment and thus control of the amount of transmitted light for each pixel of the matrix. As a result, IPS matrices can display images with much wider viewing angles (up to 178-180 degrees) and better color reproduction compared to TN. In addition, there is no problem of grayscale inversion, which has been the bane of cheap TN panels.

It is worth mentioning that modern IPS matrices, in addition to the innovative liquid crystal arrangement, also feature improvements in the design of the pixels themselves. Each pixel is divided into smaller subpixels, improving color reproduction and viewing angles. Many modern IPS matrices also have an anti-glare coating to reduce annoying glare.

IPS matrix types

Depending on specific needs and applications, there are many different types of IPS matrices. Each of these types offers different levels of performance and image quality, allowing you to customize your screen to meet your specific needs. Here are some examples:

• H-IPS (Horizontal IPS) – a variation of IPS with increased brightness and contrast, dedicated to applications requiring very clear and dynamic images.
• S-IPS (Super-IPS) – a variant of IPS matrices optimized for the shortest possible response time, useful for games and action movies.
• AH-IPS (Advanced High Performance IPS) – a development of the original IPS technology, providing even greater color accuracy through the use of a new sub-pixel array.
• IPS-Pro (IPS Alpha) – a matrix with higher contrast and color gamut.

For example, the S-IPS matrix is an improved version of the IPS matrix that offers better color reproduction and higher contrast. The AH-IPS matrix, on the other hand, is designed to provide even better image quality and performance, making it ideal for professional graphics applications.

As you can see, IPS matrices have seen a number of improvements and modifications that have improved their performance over the original technology from the 1990s. This has allowed IPS panels to expand their applications to the monitor, TV, as well as tablet and smartphone markets.

Advantages and applications of IPS matrices

IPS matrices have a number of advantages that make them popular for use in many devices:

• Wide viewing angles – reaching up to 178-180 degrees, far superior to TN matrices. They allow you to see the image clearly even from the side or from a significant angle.
• Faithful color reproduction – IPS matrices perfectly reproduce colors and shades thanks to advanced pixel design. The colors do not change when viewed at an angle.
• Deep blacks – Blacks in IPS matrices are intense and deep, providing high contrast and dynamic images.
• No grayscale inversion effect – a problem known from cheap TN matrices, causing unrealistic color changes when viewed at an angle.
• Short response time – in modern IPS varieties reaching 4-5 ms, sufficient for games and action movies.
• Pressure resistance – less image distortion with touch compared to TN.

Thanks to these properties, IPS matrices work well in industrial screens, computer monitors and televisions, as well as in tablets and smartphones. They provide great image quality regardless of the viewing angle, minimize distortion with touch operation and present images, videos and text in vivid, accurate colors. This makes IPS matrices ideal for applications that require high color accuracy, such as medical applications, precision-intensive HMI devices, and professional graphic design, photography and video. In addition, because of their wide viewing angles, IPS screens are an ideal choice for environments where the screen is shared. In business applications such as conference rooms, office spaces and educational facilities.

The disadvantages of IPS panels compared to low-cost TN matrices are sometimes slightly higher production cost, power consumption and longer response time. However, these differences diminish with each generation, and the advantages of IPS prevail for most applications.

Differences between IPS matrix and other types

To better understand the unique advantages of IPS technology, let’s look at the differences from the most popular competing matrix types.

TN vs IPS matrix

A comparison of TN vs IPS matrix shows that these two types of matrices have their own unique characteristics and applications. TN matrices, being the oldest type of LCD matrices, offer very fast response times, making them ideal for gamers who require instant response from their screen. However, they have very narrow viewing angles and the problem of grayscale inversion.

IPS matrices have eliminated these drawbacks by arranging the liquid crystals differently and precisely controlling each subpixel. This made it possible to achieve viewing angles of up to 178-180 degrees without color distortion. In addition, IPS matrices provide much more faithful and natural colors than TN.

The disadvantages of IPS are a slightly higher production cost and longer response time. However, for most applications, especially multimedia, the advantages of superior image quality far outweigh the benefits. That’s why IPS matrices have almost completely displaced TN technology from modern TVs, monitors and mobile devices.

VA or IPS matrix

VA technology (and its development MVA) is another matrix design after TN, offering wide viewing angles and high contrast. However, standard VA matrices suffer from slow response times and poorer color reproduction than IPS.

MVA or IPS matrix

Multi-domain Vertical Alignment (MVA) matrices minimally correct these drawbacks by using additional domains within the pixels. Nevertheless, IPS panels still prevail in terms of color fidelity and stability, as well as image smoothness. Hence VA and MVA matrices are now less common than IPS.

TFT or IPS matrix

The term TFT matrix is very general and means all liquid crystal displays with an active matrix, that is, with electronics controlling each pixel individually. This includes both TN and VA matrices, as well as IPS.

Read also: The most important parameters of LCD-TFT displays

So we can say that the IPS matrix is a specific type of TFT matrix, which additionally uses an innovative method of switching liquid crystals to achieve better image quality. Hence, the terms TFT matrix and IPS matrix are not synonymous and should not be used interchangeably.

Summary of differences between die technologies

IPS matrices are currently one of the most advanced and widely used image display technologies. A revolutionary solution by Hitachi engineers more than 20 years ago made it possible to create screens with unprecedented performance.

In summary, IPS technology has brought significant advances in image quality on LCD screens. Using a unique arrangement of liquid crystal particles, IPS matrices offer excellent color reproduction and wide viewing angles. Different types of IPS matrices allow customization for a variety of applications, from professional graphics environments, medical devices and HMIs to conference rooms. Despite competition from cheaper TN and VA technologies, IPS panels have displaced them almost entirely from modern monitors and TVs, and dominate the mobile device market.