What is Electronic Paper?

Electronic paper is also called digital paper. It is an ultra-thin, ultra-light display, meaning "a paper-thin, soft, rewritable display." In figurative terms, electronic paper is a thin film, and a layer of charged material "painted" on the film is electronic ink. This can also be considered as a thin embedded remote control display board.

E-paper technology is actually a collective name for a class of technology. The English name E-paper mostly uses electrophoresis display (EPD) as a display panel. Its display effect is close to the natural paper effect, which avoids reading fatigue.

Generally, the display technology that can achieve comfortable reading, ultra-thin, lightweight, flexible, ultra-low power consumption like paper is called electronic paper technology; and electronic paper is such a paper-like electronic display, which has the advantages of paper (Such as the visual sense is almost completely the same as paper, etc.), and can continue to change and refresh the display content like our common LCD display, and compared with

The use of electronic paper is quite wide. The first generation of products is used to replace conventional display devices. The second generation of products includes display screens of handheld devices such as mobile communications and PDAs. Relevant application fields, such as portable e-books, e-newspapers, and IC cards, can provide reading functions and usage attributes similar to traditional books and periodicals. For a long time, paper has been used as the main medium for information exchange. However, once the content of graphics and text cannot be changed after it is printed on the paper, it has become the biggest disadvantage of the ink / paper copy process, and it cannot meet the requirements of the modern society for the rapid update of information. Therefore, the development of dynamically changing high-resolution display technology has become a goal pursued by people. It is required that the display material is thin, bendable, and the surface structure is similar to paper, so that it can be a new generation of paper. ^[1]

The ways to realize electronic paper technology mainly include cholesterol liquid crystal display technology, electrophoretic display technology (EPD), and electrowetting display technology.

Among them, electrophoretic display technology is the most promising technical approach. This technology was first mastered by E Ink in the United States, but in fact many international giants have contributed to this technology, including

Electrophoretic display (E-Paper) technology is the technology most likely to realize the industrialization of electronic paper because it combines the advantages of ordinary paper and electronic display. It has emerged from many display technologies and has become one of the flexible electronic display technologies with great development potential. According to iSuppli's forecast, electrophoresis shows that the global market was only $ 9 million in 2006, but it is expected to increase to $ 247 million by 2013, with an average annual growth rate of 60.5%. Most of this growing market is in indicators and novel direct-drive displays, and products such as electronic display cards, flexible electronic readers, electronic paper, and digital signatures will also find applications.

Cholesteric Liquid Crystal Display is a non-traditional display technology. Even if the power of the control board is removed, the image will remain on the display. Its images are comparable to reading on paper. Features include high contrast, wide viewing angles, high reflectivity, and high readability in daylight. In addition, the product has bistable characteristics and low energy consumption.

Cholesterol liquid crystal uses a material structure similar to cholesterol molecules, hence its name. In addition to pure cholesteric liquid crystals, extension materials include nematic liquid crystals with optically active agents, or nematic liquid crystals with cholesteric liquid crystal molecules. Liquid crystals with added materials have different wavelengths and photoelectric properties. After adding the optically active agent to the nematic liquid crystal, the liquid crystal material will have a helical structure. When the cholesteric liquid crystal is placed on two horizontal substrates, the cholesteric liquid crystal will tend to be in a planar spiral arrangement without the application of electric field alignment. Under the reflection of a specific light wavelength, it can reflect colored light, or It is transparent. Cholesterol liquid crystal can achieve bistable effect in two ways: one is Surface Stabilized Cholesteric Texture (SSCT); the other is polymerstabilized cholesteric Texture (PSCT). Both technologies One of the most popular cholesterol LCD technology.

The working principle of a cholesteric liquid crystal display is: on the constituent components, the upper and lower substrates, gaps, and black absorbing materials are included like ordinary passively driven liquid crystals. The upper and lower substrates can be made of glass or plastic substrates, except that they include passive driving electrodes and alignment layers. In addition, in order to achieve a good reflection effect, the size of the spacer is about 6-8 times the pitch. ^[2]

The e-paper based e-book reader is a very lightweight tablet reader, equivalent to a thin paperback, and can store about 200 e-books. It has the characteristics of light weight, large capacity, long battery life, large screen, etc. It is a new choice for office paperless. Some e-book readers have the function of adjusting the font size, and can display black and white images in JPEG, GIF format, Word files, RSS news subscriptions.

The e-paper display achieves visual effects by reflecting ambient light, so it looks more like ordinary paper. The energy efficiency of this display is very high, because once it is turned on, it no longer needs electricity to maintain the display of text, and only consumes energy when turning pages. ^[2]