Display Technology: The Coexistence of LCD, OLED, and MiniLED

Author: Wang Shuyi

Images by: Merck, Online

Display technology is one of the most important branches of human-computer interaction, with numerous outstanding companies long engaged in this field, from materials and panels to display applications. The speed of upgrades and iterations in display technology is extremely fast; in just a few decades, CRT displays have faded away, LCD once dominated the market, and now OLED is on the rise, while new directions such as MiniLED and MicroLED are also quite eye-catching. Recently, at the 2021 Display Technology and Application Innovation Expo (DIC EXPO 2021), the globally renowned display materials manufacturer Merck showcased several products, demonstrating the latest achievements in the research and development of LCD, OLED, and graphical materials on-site, as well as expanding the application of LCD to fields such as architecture with the eyrise™ LCD windows and the licriOn™ LCD smart antenna solutions.

At the expo, Allan Gabor, President of Merck China and Managing Director of Merck’s Electronic Technology Business in China, and Sui Yu, General Manager of Merck’s Display Technology Division in China, accepted interviews from media such as Techsugar, discussing Merck China’s strategic layout and the development trends of display technology.

Merck can trace its origins back to 1668, with a history of over 300 years, experiencing numerous ups and downs over the centuries. The Merck Group has evolved from its early pharmaceutical roots to now encompass three major fields: healthcare, life sciences, and electronic technology.

Merck’s electronic technology business started with LCD; as early as 1904, before the application direction of LCD was clear, Merck purchased LCD patents, laying the groundwork for future investments. It took 70 years before Merck began to see real returns, and after 2000, it shared in the rapid growth of LCD. According to statistics, as of 2016, Merck had applied for over 4,200 LCD materials patents globally, accounting for about one-third of the world’s total applications; in the OLED field, Merck currently holds over 3,000 OLED technology patents and continues to expand its intellectual property portfolio.

Although the demand for OLED applications has not met expectations due to the pandemic, Allan Gabor is optimistic about the medium to long-term development of the OLED market. He stated that Merck China has been continuously investing in OLED product development. In 2018, Merck officially launched the OLED China Technology Center, which aims to promote innovation and application development in China’s OLED industry, providing tailored solutions to local customers. Recently, Merck China has been closely preparing to establish an OLED materials production base. Allan Gabor said, “We are very optimistic about the long-term development of OLED in the Chinese market; Chinese consumers have a particularly strong demand for innovative flexible screen electronic products.”

Flexibility and foldability are among the standout advantages of OLED screens, which Merck refers to as “free-form displays.” OLED panels can be bent, folded, stretched, or rolled, and Merck’s focus is on promoting the liviFlex packaging technology, which addresses key issues in manufacturing flexible, foldable, and slideable OLED displays.

Regarding the continuous emergence of new display technologies, Allan Gabor expressed that Merck welcomes a flourishing scene where different technologies coexist, as this is beneficial for exploring innovative applications in display technology. Breakthroughs in display technology and chips cannot be separated from material science and chemical innovation.

Sui Yu also stated that currently, various display technologies complement each other rather than replace one another. OLED has a very promising outlook, but it is currently concentrated on small sizes of 9 inches and below, while large sizes will still be dominated by LCD for a long time. MiniLED and MicroLED are more avant-garde, and currently, the main role of MiniLED is to help LCD consolidate its position, as LCDs with MiniLED backlighting perform better.

Whether OLED can break through the process limitations in large sizes and how to reduce the costs of MiniLED are two focal points for the future development of large-sized displays. Sui Yu believes that solely betting on the technical route of large-sized OLED development may not lead to success in the end.

In addition to traditional display technologies, Merck also showcased many new solutions related to display technology at this expo. For example, the LCD internal antenna technology licriOn™—an electronic beam scanning smart antenna solution that combines the antenna element array with the licriOn™ liquid crystal thin layer. The licriOn™ antenna solution can electronically control the adjustment of the beam direction without mechanical adjustments, achieving efficient, precise, and energy-saving beam scanning. Compared to traditional mechanical antennas that require frequent maintenance, repair, or replacement, this smart antenna technology offers a more compact, efficient, energy-saving, and modular solution that significantly reduces manufacturing costs, making it possible to deploy in remote areas where high-speed network connections are unavailable or unaffordable. It can also be easily integrated into vehicles, aircraft, and ships, and as technologies like 5G and 6G continue to develop, its application potential will become increasingly apparent.

In addition to being used in display screens, LCD technology can also be applied to glass windows and curtain walls. licrivision® LC is a dye-modified or cholesteric liquid crystal mixture developed and produced by Merck, which is embedded between two layers of glass or plastic substrates coated with transparent conductive oxide (TCO) and polyimide (PI), forming a liquid crystal battery. By applying a low AC voltage to the liquid crystal battery, the components of the liquid crystal mixture can be switched to control the light flux of the window. Due to the liquid crystal mixture’s highly sensitive response to applied voltage, it can quickly and precisely adjust the window’s light intensity, haze, glare, and transparency.

In short, the liquid crystal windows manufactured using licrivision® LC technology can change the glass’s transparency with a single click, protecting against direct sunlight, reducing heat absorption, and lowering maintenance costs. To some extent, they can effectively replace blinds and air conditioning, avoiding the problems of high energy consumption, heat absorption, and cooling costs associated with traditional curtain walls, and the liquid crystal materials can be customized for specific applications.

They can also be used for indoor privacy glass—because liquid crystal materials can quickly switch between transparent and opaque, in offices, hospitals, conference centers, and other places, glass can be switched from transparent to opaque as needed, creating private spaces in open areas and making indoor layouts more flexible.

In addition to liquid crystal windows, Merck has a secret weapon for reducing carbon emissions. That is the UB-FFS technology, which increases the transmittance of the display backlight, achieving a high transmittance rate of 15%. This optimization of light utilization can reduce the energy consumption of each display screen by one-third, while also improving image quality, extending battery life, and increasing the brightness of the display. Sui Yu stated that Merck has calculated that if all TVs on the market adopted high-transmittance liquid crystals supported by UB-FFS technology, it could save carbon emissions equivalent to the annual consumption of 900 large aircraft.

In recent years, geopolitical conflicts have escalated, and the COVID-19 pandemic has ravaged the globe, posing unprecedented risks to the global supply chain in the electronics industry. To stabilize the supply for the world’s largest electronic application market, Merck has made thorough efforts in localization; for example, in the case of LCD, Merck has achieved full supply chain localization, from material innovation and product development to production, transportation, and technical services, all completed locally in China.

Allan Gabor emphasized that Merck places great importance on supply chain security, as the center of the display panel industry chain is in China. Therefore, Merck has focused its display technology layout in China, investing significant manpower and resources in building LCD and OLED production capacity in the country. Additionally, establishing technology innovation application centers in China is also an extremely important strategic move. Merck has successively established the OLED Technology China Center and the Electronic Technology China Center in Shanghai, with the mission of helping customers promote and apply new technologies, leveraging Merck’s technological accumulation in electronic materials to assist Chinese customers in overcoming challenges encountered in the application of new technologies. Allan Gabor believes that the technology center and local manufacturing are equally important; both are crucial efforts Merck is making to ensure a stable and sustainable supply chain for its Chinese customers.

He provided an example to illustrate this: with the joint efforts of Merck’s China Technology Center and customers, the previously mentioned UB-FFS high-transmittance technology has been successfully mass-produced in 8K LCD displays. Allan Gabor stated, “This is the world’s first mass-produced UB-FFS 8K LCD screen, and our technology center is dedicated to helping customers bring better technologies and applications to the market.”