Electronic paper—better known as e-paper—is a display technology with amazing potential, and a bright outlook that is driving intense competition in this segment of the business world. Not surprisingly, Taiwanese companies became actively involved in the development of e-paper very early on, and now occupy an important position in the global e-paper industry.

E-paper’s history

At its most basic level, the technology underlying e-paper is pretty straightforward.

Whereas traditional paper utilizes ink on a page to display information, present-day mainstream e-paper makes use of electrophoretic display technology or cholesteric liquid crystal display technology.

Electrophoretic displays contain positively charged white pigment chips and negatively charged black pigment chips. Changes in the electrical field move the chips, enabling them to display different words and images. After running through these basics, Kao Wen-chung, a professor in the Department of Electrical Engineering at National Taiwan Normal University, explains that the technology was long bottlenecked by its sluggish response time and poor image quality. That began to change in 1996, when the Media Lab at the Massachusetts Institute of Technology successfully produced a working prototype of an electrophoretic display in which the charged chips were encapsulated in microcapsules of about the same diameter as a human hair. The developers called their invention “e-paper” and went on to found the E Ink Corporation in the following year.

SiPix Imaging also drew on electrophoretic principles when it created its own e-paper. Its solution involved “microcups,” which hold charged particles in square cup-like structures to prevent them from moving at random.

Cholesteric liquid crystal displays (ChLCDs) are yet another solution. The technology’s interesting name stems from the chiral arrangement of its liquid crystals, which resembles the structure of cholesterol. You can imagine the molecules in a ChLCD acting something like window blinds: an electrical field changes the angle of the liquid crystal “slats” to control how light is reflected and so display an image. Since ­ChLCDs can reflect light in different colors, they don’t need to be equipped with filters to display color pictures. Moreover, unlike conventional LCDs, ­ChLCDs are “bistable,” meaning that they need no power to retain information on a screen, making them well suited to e-paper applications.
 

Forging an industry alliance

How then did Taiwan come to occupy its important place in the global e-paper industry? We visited Kao in his lab to get the story.

Kao was the first well known scholar in Taiwan to work on designing e-paper systems. Recalling ­MiTAC founder Hou Ching-hsiung’s request that he get into the e-paper business, Kao says, “He thought that this new tech could change humanity.” Excited about e-­paper’s potential, Hou established SiPix in the US, and then had that side of the company handle materials R&D. Kao was put in charge of the Taiwan branch’s R&D, which focused on system design. “SiPix was led from Taiwan, and Hou wanted to bring its core back to Taiwan.” SiPix would go on to become a subsidiary of Taiwanese LCD panel heavyweight AUO.

In those days, SiPix’s main competitor was the E Ink Corporation, the developer of microcapsule technology. E Ink would itself be bought by a different Taiwanese panel maker, Prime View International (PVI), which subsequently changed its name to E Ink Holdings.

Established in 1992, PVI was a subsidiary of Yuen Foong Yu Paper (now YFY Inc.), a leading ­Taiwanese paper manufacturer. In 2005, PVI expanded into the e-paper business and in 2008 formed a strategic alliance with Taiwanese precision systems maker ­Netronix, Inc. that had the latter handle e-book reader software and hardware integration and device assembly on a contract basis. PVI’s profile rose when it became the sole provider of e-paper modules for Amazon’s Kindle e-reader. In 2009, PVI acquired the US’s E Ink Corporation, which held the patents to e-ink technology, and changed its own name to E Ink Holdings. In 2012, E Ink acquired SiPix, giving it control over both the microcapsule and the microcup electro­phoretic technologies, and unifying the e-paper market.

In April 2021, E Ink Holdings integrated up-, mid- and downstream supply-chain participants into a new alliance aimed at working towards color displays. Since then, E Ink has come to dominate the electro­phoretic e-paper field, and now controls 90% of the e-paper market.

A promising technology

Albert Liao is the chair of Iris Optronics. A former employee of the Industrial Technology Research Institute, he tells us that ITRI has long provided guidance to Taiwanese semiconductor firms entering the LCD business. “When we [at ITRI] also began thinking about where the technology would go from there, we decided to support the development of flexible electronics, because we saw them having even broader applications.”

ITRI designated ChLCD technology as a development focus more than a decade ago, and Liao invented the technologies in some of the important patents, winning numerous international awards for his work. Japan’s Fujitsu, Ltd. was also conducting ChLCD research at the time, and the two sides came to know one another at international gatherings. Liao subsequently invited Fujitsu to set up a joint venture with him in Taiwan with the aim of establishing a factory and beginning production. Unfortunately, the effort never came to fruition. Liao then founded Iris and acquired a number of ChLCD patents from Japan to go with those he had accumulated at ITRI. The Japanese side was willing to part with the patents because of its long-standing relationship with Liao, and because its own industrial transformation prevented it from continuing its internal research. Liao’s strong ties to the older generation at Fujitsu made it feel as if he was carrying their dreams forward, and he promised he would achieve the commercialization of the technology.

Keeping in tune with the times, Iris transitioned into a design house with no production facilities, one focused on developing technologies and licensing out patents. Showing off the company’s array of patents, Liao explains, “E-paper isn’t just for e-readers. We are always looking for new applications for the technology that help invigorate panel makers. We also develop ways for LCD firms to use their LCD manufacturing equipment to also produce e-paper.”

AUO marked its return to the e-paper market by demonstrating a reflective display using ChLC technology that incorporated Iris’s Infinity Display patents. The prototype broke new ground in terms of color depth and power savings by producing 16 million colors while using very little power. The display includes a selectively reflective ChLC panel that makes use of ambient lighting both to illuminate the screen—resulting in tremendous power savings versus traditional LCDs, which rely on a backlight—and to power the device via a solar panel layered behind the screen. “Outdoors in the sun, the brighter the light, the brighter our display becomes,” says Liao.
 

An energy-saving technology

To date, the market has largely equated e-paper with e-readers, but the technology has uses beyond this single application.

For example, at the 2022 Consumer Electronics Show in the United States, the German automotive company BMW revealed a concept car called the iX Flow that used e-paper technology developed by E Ink to change its color on demand.

In the field of air transport, Netronix, E Ink, inter­national luggage maker Rimowa, and airlines are working together to develop smart luggage that digitizes the information on luggage tags. Netronix CEO Alvin Lin explains that in 2019, the last full year before the Covid-19 pandemic, airlines worldwide carried a total of roughly 4.5 billion passengers, which required a truly startling number of luggage tags. The group subsequently began developing electronic luggage tags as a carbon reduction and sustainability measure.

In the department store and retail sector, workers spend a great deal of time and labor attaching price labels to shelves. Replacing these with electronic shelf labels (ESL) enables instantaneous changes and updates via wireless networks and RFID technology. Many large-scale retailers in other countries have already made the switch to ESLs.

In the smart healthcare space, Netronix noted the time and effort that it takes hospital workers to update patient charts by hand. It therefore partnered with domestic medical institutions including Taipei Veterans General Hospital, National Taiwan University Hospital, and Cathay General Hospital to develop e-paper charts that are wireless, save energy, and can be remotely updated at any time with new care ­information.

E-paper also has applications in a “smart city” setting. Lin points out that smart public transportation signage built with e-paper doesn’t need a backlight to provide clearly visible route and status information for buses regardless of the weather. More, the bistability of e-paper means that it retains information on the display even when the power goes out, making it especially useful for public announcements in the event of a natural disaster.

Lin walks us through a back-of-the-envelope calculation of the scale of energy savings from just ESLs: “Assuming the digital shelf labels already installed worldwide are updated once per day, they reduce the world’s carbon emissions by about 30,000 tons [per year]. A single tree absorbs about 12 kilograms of CO2 per year. That means it would take 2.5 million trees to balance out those emissions.”

Rooted in Taiwan

Even though a whole range of industries are optimistic about the outlook for e-paper, the market has yet to take off. Many companies around the world have embarked on e-paper development only to abandon their work midstream. However, those that have recognized the sector’s potential and committed to its development have succeeded.

Taiwanese companies currently control the entire e-paper industrial chain from top to bottom. How did Taiwan come to be in this fantastic position? Kao says, “Taiwan’s electronics industry and panel manufacturing provide us with a great foundation. Hou Ching-­hsiung’s investment in e-paper enabled Taiwan to get into the field early, and then PVI’s work with E Ink led to the merger of the two companies. With the two foremost names in the industry in Taiwan, it’s only natural that we would dominate the whole industry.”

The invention of paper brought the world knowledge and revolutionized civilization. It also made dia­logue between different communities possible. Now, Taiwan is reimagining paper and, in so doing, making a positive contribution to our sustainable future.

For more pictures, please click《“Paper” Reinvented: E-Paper on the Rise》