E-paper could be one of those tectonic shifts in reality... If you though advertising was choking the visual environment today, just wait when everything is covered with programmable displays...
------ http://neasia.nikkeibp.com/neasia/003542 E-Paper Enters Practical Use Equipment using electronic paper (E-paper) is becoming increasingly prevalent. More companies have entered the market, and have been developing a wide range of E-paper products, many of which are available now. In December 2005, passers-by stopped at the sight of an unfamiliar object that had appeared in one of the concourses of JR Tokyo station. Equipped with six monitors, the object cycled through displays of news, weather, station guidance and other subjects at about 5-minute intervals. The displays offered good contrast, but were monochrome, and the appearance was significantly different from the color displays with which everyone is familiar these days. Upon closer scrutiny, it was possible to read: "Demonstration test for electronic paper displays in progress." In 2006 a variety of equipment using E-paper is likely to start appearing here and there (Fig 1). In January of 2006, for example, Seiko Watch Corp of Japan released a watch using E-paper for the face display, while Ishida Co Ltd of Japan began marketing a shelf price tag using an E-paper display to supermarkets and other retailers. Other recent developments have included a practical, general-purpose E-paper display from Hitachi Ltd of Japan, and an equipment clock using E-paper from Citizen Watch Co Ltd of Japan for public facilities like stations and schools. Meanwhile Asahi Glass Co Ltd of Japan is developing a practical public display terminal. And this is only the tip of the iceberg. After-Image Improvements There have been practical E-paper examples in the past, but limited to only a few applications. There are few manufacturers who can supply it, and even the method developed by industry pioneer E Ink Corp of the US faced problems with after-images. These after-images occurred after letters and symbols had been displayed; they remained faintly visible after the display image had been changed. This problem has been resolved lately, and a range of new E-paper designs is being developed to the practical level by various manufacturers, driving sample applications in a large number of fields (Fig 2). E Ink has developed an electronic ink with improved after-image characteristics, and has already begun to supply it to equipment manufacturers. "The ink we supply now is the one with no after-images," said Ryosuke Kuwada, vice president at E Ink. The wristwatch sold by Seiko Watch from January 2006, the equipment clock sold by Citizen Watch from March 2006, and other recent developments all use this new electronic ink from E Ink for its improved after-image characteristics. A number of other electronic inks from manufacturers other than E Ink have also evolved to the practical stage, and some equipment manufacturers are beginning to use them. The shelf price tag system released by Ishida in January 2006, for example, uses E-paper from SiPix Imaging Inc of the US. "We began investigating the possibilities for E-paper in shelf tagging three years ago, but E-paper technology wasn't well enough developed then. It is finally usable now, including points like readability and quality stability," said Tsuyoshi Kikukawa, general manager, ESL Business Manager at Ishida. According to Kaoru Suzuki, project manager, Transportation Systems Planning Dept, Transportation Information Systems Div of Hitachi, which plans to release E-paper general-purpose displays in spring 2006, "We wanted to be the first to ship them, and decided to tie up with an E-paper manufacturer capable of providing practical technology then." Low Power Consumption The goal of equipment manufacturers adopting E-paper is to make it possible to create equipment too difficult or impractical to accomplish with conventional displays. The wristwatch from Seiko Watch, for example, has a bracelet-type band, and the user can twist the display just like the band. The shelf price tag system from Ishida uses E-paper with a plastic substrate to combine lightness with breakage resistance. A liquid crystal display (LCD) panel in the same application would be heavy and easily broken, and therefore impractical, said a source at the firm. In comparison with conventional displays, though, the most outstanding difference is the low power consumption. The device only consumes electricity when the display is changed, which could mean significant power savings, depending on how the system is utilized. The equipment clock from Citizen Watch, which updates the display once a minute, for example, features power consumption "...about one-twentieth that of the same-size LCD equipment clock, and only a few thousandths that of a backlight-equipped clock," said Yasushi Kaneko, manager, Ep Project, Technical Lab, MHT R&D Div at the firm. This makes battery drive possible, which eliminates the need for power supply construction prior to equipment installation, and means that the equipment can be installed in places where no power supply is available. The demonstration system installed at Tokyo station, described earlier, is also battery-driven, with no power supply construction needed. The displays are equipped with a set of four 1.2V, 1350mAh polymer Li-ion rechargeable batteries which can power about 1,000 display redraws, although battery life varies with the frequency of communication. Smart Cards, Notebook PCs As is evident from the examples mentioned, E-paper is being considered for use in not only a few announced applications, but in a wide range of perhaps less obvious applications. Examples of such applications include various cards, such as smart cards and electronic money, displays for devices like universal serial bus (USB) memory, advertising above windows or on hand straps in trains, rear displays on mobile phones, and mobile viewers. E-paper is also being eyed for possible use in products like home appliances and toys. The flurry of activity is also apparent in the messages received by E-paper manufacturers. In July 2005, when Fujitsu Ltd of Japan announced the development of E-paper, "They came calling on us before we even had a chance to try to market it. Most equipment manufacturers already had clearly defined ideas of what they wanted to do with it," revealed Fumiyuki Hashimoto, manager, Planning Div, Marketing Unit of Fujitsu. While yet in the future, there is also great hope that E-paper can be used in notebook personal computers (PC). In March 2005, Intel Corp of the US disclosed that Intel Capital Corp of the US had invested into E Ink. A source at Intel explained: "About a third to a half of power used in today's notebook PCs is used by the display. If notebooks could use E-paper it would mean a significant reduction in power consumption, and at the same time provide a big improvement in readability outdoors." Even though it's entering volume production, however, E-paper has its pros and cons, and is still not able to fulfill all the demands equipment manufacturers make of it. Flexible varieties, for example, can't handle dot displays, while dot-display models are not flexible. One E-paper manufacturer commented that a major consumer electronics manufacturer wants to use flexible E-paper with color dot displays at once, but admitted they just can't manufacture it effectively yet. Further development in E-paper technology is needed before it can be adopted by a large number of equipment manufacturers and experience major market growth. Exclusive Features Pushed The development of E-paper technology is under way around the world, but in general the E-papers expected to reach the practical level in 2006 to 2007 can be broadly divided into the particle-based type from firms like E Ink, SiPix Imaging and Bridgestone Corp of Japan, and the cholesteric liquid crystal type from companies including Asahi Glass, Fuji Xerox Co Ltd of Japan and Fujitsu. Even under a single type category, though, the implementation technology may be widely different, with each manufacturer stressing the unique advantages of its own approach (Table 1). Particle-based E-paper uses an electric field to move black and white particles up and down to change the image. The E Ink method of handling black and white particles is probably the best-known of the microcapsule liquid approaches, but the Bridgestone approach, for example, moves the particles up and down in air for an extremely fast response speed of only 0.2ms. Unlike E Ink's device, which is designed for dot display with active drive, the Bridgestone design offers high-definition dot displays even with a passive drive. Dr Hiroaki Wada, general manager, Dept of High Performance Product Development, Research & Development Div, Bridgestone, pointed out: "We have already prototyped a high-definition E-paper using the cheap and simple passive-drive design, achieving XGA resolution (1,024 x 768 pixels) on a 7.5-inch screen." Cholesteric liquid crystal E-paper is stable in both transparent and reflective states, making use of the unique properties of liquid crystal. Fujitsu stacked three cholesteric liquid crystal layers, each selectively reflecting a different wavelength, to prototype a 4,096-color design. The firm's Hashimoto commented, "We will also develop a 260,000-color model before the end of fiscal 2005." Asahi Glass's Satoshi Niiyama, unit leader, Research Center, said, "We have built in a technology to eliminate the 'burning in' that can occur with cholesteric liquid crystal." Ultimate Goal: "Paper" As various E-paper technologies compete with unique features, firms like Toppan Forms Co, Ltd of Japan and Fuji Xerox Co, Ltd of Japan have entered into tie-ups with SiPix Imaging to make it clear they are pursuing characteristics including low cost and alternatives to paper. In October 2005 Toppan Forms made it clear it was entering the E-paper market by announcing a strategic tie-up with SiPix Imaging, which has been developing E-paper technology. The agreement called for Toppan Forms to create modules using the E-paper developed by SiPix Imaging, with the modules being marketed in Japan by Toppan Forms and elsewhere by SiPix Imaging. There will also be cases where Toppan Forms develops the final product. The technology is expected to be ready for practical application in fiscal 2006. Toppan Forms chose to tie up with SiPix Imaging because "We thought it could be realized for lower cost than any of the available methods," according to Kazumichi Shibuya, manager, EP Project Group, Information Media Business Div of the firm. This judgment was largely based on the roll-to-roll production method. SiPix Imaging's E-paper consists of microcups formed on a plastic substrate, filled with white particles and liquid colorant. The particles are raised or lowered to switch between the color of the particle and the color of the liquid. Roll-to-roll production is used for microcup manufacture, particle/colorant fill and other processes (Fig 3). The firm will supply Toppan Forms with E-paper in roll form. Rewriting with Light The E-paper under development by Fuji Xerox is also designed to replace paper. "We are aiming for use in situations where content is difficult to view on a computer monitor, but not worth printing out," said Tsunemasa Mita, manager, Advanced Devices & Materials Laboratory, Corporate Research Group at Fuji Xerox. For example, content such as E-mail, maps and similar items would be written to E-paper instead of being printed on real paper, and carried about. The technology developed by Fuji Xerox is called the "optical rewritable" method, and as the name suggests, new data can be projected onto the paper from the rear to rewrite the displayed image. This is possible because of a unique structure, with a photosensitive layer positioned under the cholesteric liquid crystal film. When irradiated by light from the side opposite the liquid crystal, the resistance of the photosensitive layer changes in proportion to optical intensity. The liquid crystal film, connected in series to the photosensitive layer, changes the displayed image because the voltage input changes in relation to that resistance. This principle of operation makes it possible to eliminate electrode patterning, for pixels. In fact, the only drive electrode is the single one covering the entire plane. Because of this, explained Fuji Xerox's Mita, "Our approach is not limited by the drive electrodes, making it a lot easier to drop costs and fabricate larger screen sizes." In the future, the firm hopes to make it possible to just press this E-paper against a computer monitor in the office to automatically write the screen image to the E-paper. At present, however, a dedicated writer is required to provide the high optical intensity and directional light beams required. Constituent Technology For dot displays development is proceeding apace toward multi-functionality, including such characteristics as color and flexibility. The most aggressive player in this field is E Ink, which displayed a prototype E-paper full of original technology at FPD International 2005, in October 2005. The prototypes included a 4,096-color model made using color filters developed by Toppan Printing Co, Ltd of Japan; a model with improved display performance, such as reflectivity, made with an improved ink which retains brightness even when used with color filters; and a flexible model using thin-film transistors (TFT) on a stainless steel substrate, developed jointly with LG Philips LCD Co, Ltd of Korea and others. At present these characteristics are implemented in independent products, but the firm plans to bring all of the constituent technologies together into one E-paper product in about 2007. According to E Ink there are a number of equipment manufacturers that want this type of E-paper by about 2007. As the firm's Kuwada said, "There are a number of concrete proposals, such as terminals to read digitally-distributed newspaper and magazine content." A prototype with a glass substrate was first evaluated by these users, but the glass broke during trials. As a result, the users have made flexibility a mandatory product requirement. The E Ink method, based on active drive, will have to provide TFT on a flexible substrate to satisfy this requirement. Organic TFT and other materials are not expected to be ready for commercial use by around 2007, though, meaning that the firm could lose the business window of opportunity. It identified TFT on stainless steel substrate as a strong candidate; it can be manufactured on the same equipment used to make amorphous Si TFT, leading Kuwada to believe that it "...is the technology for TFT on a flexible substrate likely to be brought to the practical level first." Looking Forward Development of next-generation E-paper has also been picking up speed recently. At the International Display Workshops/Asia Display (IDW/AD) '05, held December 6-9, 2005, there were a number of papers presented on technologies for future generations of E-paper. For example, there are a number of competitors for TFT on flexible substrate. Seiko Epson has a proprietary technology to transfer TFT from a glass substrate to a plastic one, using Surface Free Technology by Laser Ablation/Annealing (SUFTLA). The firm is applying SUFTLA in the development of peripheral technologies such as microprocessors and memory, in addition to E-paper (Fig 4). If the technology can be perfected it will lead to a major expansion in the range of E-paper applications. by Takuya Otani --~--~---------~--~----~------------~-------~--~----~ TELECOM-CITIES Current searchable archives (Feb. 1, 2006 to present) at http://www.mail-archive.com/[email protected]/ Old searchble archives at http://www.mail-archive.com/[email protected]/ -~----------~----~----~----~------~----~------~--~---
