E-paper is a technology that combines the best of both paper and display, and can improve the reading experience while compensating for the shortcomings of traditional paper media. Despite initial technical limitations, e-paper is rapidly spreading across a variety of sectors, including publishing, education, advertising, healthcare, and more, and has the potential to significantly change the way we consume media in the future.
A man chased by the police flees and hides in a subway, buried in a crowd of people. He is relieved to see that no one recognizes him and sinks deeper into the seat, but then his eyes suddenly lock with a man across from him who is reading a newspaper. His newspaper suddenly updates and begins to show a video with the wanted man’s information. The man has no choice but to run away again. It’s a scene from the movie Minority Report. This sci-fi movie may soon be in your backyard.
Electronic paper, also known as e-paper, is a display that combines the benefits of paper with the advantages of a display. The first e-paper was developed in the 1970s by Nick Sheridon at Xerox’s Feller-Elto Laboratory under the name Gyricon. In 2007, Amazon created an e-book reader from e-paper and released it as the Kindle. Just four years later, Amazon announced that e-book sales had surpassed paper book sales. This rapid development of e-paper is not just limited to the publishing industry, but has also led to new innovations in education, advertising, healthcare, and more. For example, digital textbooks, menus, and billboards are increasingly utilizing e-paper. In the healthcare sector, e-paper is gaining traction because of its ability to deliver information with a paper-like texture, making it easier for patients to see important information clearly without straining their eyes.
Unlike traditional displays, e-paper utilizes reflected light. Inside, e-paper contains millions of microcapsules the diameter of a human hair (or smaller). These capsules contain a transparent oil and black and white particles, each with a different electrical charge. An electronic circuit runs across the bottom of the e-paper on which these capsules are placed, and the particles move according to the voltage of this electronic circuit. For example, if the electronic circuit underneath a capsule has a negative voltage, positively charged white particles will approach the circuit and negatively charged black particles will float to the surface, marking the location of the capsule with a black dot. This principle of e-paper is similar to how the positive and negative poles of a magnet attract and repel each other. This characteristic gives e-paper a huge advantage: it consumes very little power. This is because the e-paper screen only uses energy when a voltage is applied to it, and it consumes almost no power when the screen is stationary. This has made it possible for things like e-book readers and electronic menu boards to run for long periods of time on a single charge.
Traditional displays are backlit, which means that each dot decides what color to show and emits light from behind. While this has the advantage of being responsive and easy to see in the dark, it also strains the eyes over long periods of time and is difficult to see under intense external light. Anyone who’s ever used a smartphone has probably experienced the frustration of trying to make a shadow with their hand in the sun to see the phone screen. E-paper, on the other hand, reads just like a book, even outdoors, and is free of flicker and glare, so it’s easy on the eyes over long periods of time. Because of this, e-paper provides a natural reading experience and is especially popular among people who are active outdoors. E-papers are also energy-saving, which is why more and more people are choosing them over paper books.
Another feature of e-paper is its flexibility. Since displays are illuminated by shooting light from behind, the position of each pixel that receives the light must be fixed. This doesn’t allow for even minimal flexibility. E-paper can have a high degree of flexibility because the position of the microcapsules is not critical and their size is small. E-paper has been developed to be flexible enough to roll up a ballpoint pen, and it may soon be possible to fold it like paper. This flexibility opens up a wide range of applications for e-paper. For example, it can be attached to clothing, bendable billboards, and even wearable smart devices.
However, e-paper has its limitations. One of them is the inability to display a wide range of colors. A few companies have come up with products that address this, but there are no low-cost products for the average consumer yet. Another challenge is the slow screen response time due to the direct movement of the particles. This is why you can’t play videos or play games on current e-paper. The relatively low resolution and the inability to display pristine whites due to the presence of black and white particles also remains a challenge. These technical limitations still need to be addressed, but this hasn’t stopped the progress of e-paper. Researchers around the world are working to overcome the limitations of e-paper by exploring new materials and processes. For example, research is underway to improve color reproduction and responsiveness, and it’s entirely possible that we’ll soon see a new e-paper that significantly improves on the existing ones.
Despite the problems with e-paper, a growing number of people are attracted to its advantages. As mentioned earlier, Amazon’s sales of e-books have exceeded the sales of paper books, and not only Amazon, but also many companies in Korea and abroad are launching e-book readers using e-paper. In 2007, a middle school in Maastricht, the Netherlands, began using e-paper as a digital textbook. The day when e-paper replaces paper with the best of both worlds, you may find yourself sitting on your couch, sipping your morning coffee, flipping through an e-paper newspaper and watching a video of yesterday’s summit. The evolution of e-paper is more than just a technological innovation; it will transform our daily lives and the way we consume media. These changes will allow us to enjoy a more convenient and richer information experience.
