Electronic paper 9225 225651324 2008-07-14T19:06:53Z ToePeu.bot 4082686 robot Modifying: [[ca:Paper electrònic]] {{Cleanup|date=June 2007}} {{Mergefrom|Electronic paper display|date=September 2007}} <!-- Deleted image removed: [[Image:E-Ink Flex Tablet Display.jpg|200px|thumb|right|A prototype electronic paper display.]] --> '''Electronic paper''', also called '''e-paper''', is a [[display device|display]] technology designed to mimic the appearance of ordinary [[ink]] on [[paper]]. Unlike a conventional [[flat panel display]], which uses a [[backlight]] to illuminate its [[pixel]]s, electronic paper reflects light like ordinary paper and is capable of holding text and images indefinitely without drawing electricity, while allowing the image to be changed later. There are several different technologies to build e-paper, some of which can use plastic substrate and [[Plastic electronics|electronics]], so that the display is flexible. It is considered more comfortable to read than conventional displays. This is due to the stable image which does not need to be constantly refreshed, the large viewing angle, and the fact that it uses reflected ambient light. It has a similar [[contrast ratio]] to that of a newspaper and is lightweight and durable, however it still lacks good color reproduction. Applications include [[List of e-book readers|e-book readers]] capable of displaying digital versions of books and e-paper magazines, electronic pricing labels in retail shops <ref>{{cite web | url = http://www.sipix.com/applications/pricinglabels.html | title = SiPix pricing labels | accessdate = 2008-01-13}} </ref>, time tables at bus stations <ref>{{cite journal | last = Graham-Rowe | title = Electronic paper rewrites the rulebook for displays | journal = Nature Photonics | volume = 1 | pages = 248 | date = 2007 | doi = 10.1038/nphoton.2007.53}} [http://www.diginfo.tv/archives/fujitsu_03-thumb.jpg Photo] </ref>, and electronic billboards <ref>{{cite web | url = http://www.magink.com/product.php | title = magink e-paper billboards | accessdate = 2008-01-13}} </ref>. Electronic paper should not be confused with [[digital paper]], which is a pad to create handwritten digital documents with a digital pen. ==Technology== Electronic paper was first developed in the 1970s by Nick Sheridon at [[Xerox]]'s [[Xerox PARC|Palo Alto Research Center]]. The first electronic paper, called [[Gyricon]], consisted of polyethylene spheres between 20 and 100 micrometres across. Each sphere is composed of negatively charged black plastic on one side and positively charged white plastic on the other (each bead is thus a [[dipole]]<ref name="gyroid_dipole">Crowley, J. M.; Sheridon, N. K.; Romano, L. "[http://dx.doi.org/10.1016/S0304-3886(01)00208-X Dipole moments of gyricon balls]" Journal of Electrostatics 2002, 55, (3-4), 247.</ref>). The spheres are embedded in a transparent silicone sheet, with each sphere suspended in a bubble of oil so that they can rotate freely. The polarity of the voltage applied to each pair of electrodes then determines whether the white or black side is face-up, thus giving the pixel a white or black appearance.<ref name="newscientist_1">[[New Scientist]]. [http://www.newscientist.com/article/mg16221864.700.html Paper goes electric (1999)]</ref> ===Electrophoretic=== [[Image:Electrophoretic display 001.svg|thumb|275px|right|Schema of an electrophoretic display.]] [[Image:Epd color.svg|thumb|275px|right|Schema of an electrophoretic display using color filters.]] An '''electrophoretic display''' is an [[information display]] that forms visible images by rearranging charged pigment particles using an applied [[electric field]]. In the simplest implementation of an electrophoretic display, [[titanium dioxide]] particles approximately one micrometre in diameter are dispersed in a hydrocarbon oil. A dark-colored dye is also added to the oil, along with surfactants and charging agents that cause the particles to take on an electric charge. This mixture is placed between two parallel, conductive plates separated by a gap of 10 to 100 micrometres. When a voltage is applied across the two plates, the particles will migrate [[electrophoresis|electrophoretically]] to the plate bearing the opposite charge from that on the particles. When the particles are located at the front (viewing) side of the display, it appears white, because light is scattered back to the viewer by the high-index titania particles. When the particles are located at the rear side of the display, it appears dark, because the incident light is absorbed by the colored dye. If the rear electrode is divided into a number of small picture elements ([[pixels]]), then an image can be formed by applying the appropriate voltage to each region of the display to create a pattern of reflecting and absorbing regions. Electrophoretic displays are considered prime examples of the [[electronic paper]] category, because of their paper-like appearance and low power consumption. Examples of commercial electrophoretic displays include the high-resolution [[active matrix]] displays used in the [[Amazon Kindle]], [[Sony Librie]], [[Sony Reader]], and [[iRex iLiad]] e-readers. These displays are constructed from an electrophoretic imaging film manufactured by [[E Ink Corporation]]. The [[Motorola Motofone]] is the first mobile phone which uses the technology to help eliminate glare from direct sunlight during outdoor use<ref>{{cite web | url = http://www.motorola.com/mediacenter/news/detail.jsp?globalObjectId=7076_7025_23 | title = Motorola Introduces MOTOFO - New, Market-Defining Mobile Designed to Keep Everyone Connected | accessdate = 2007-12-03 }}</ref>. Another producer of electrophoretic displays is the California based company SiPix<ref>{{cite web | url = http://www.sipix.com/technology/ | title = SiPix Imaging | accessdate = 2007-11-15 }}</ref>. Sipix, along with manufacturing partner SmartDisplayer, received a 1996 Society for Information Display Gold Award for an IC smart card with an integrated electrophoretic display<ref>{{cite web | url = http://www.sid.org/pressroom/060607.html | title = Philips 3D, Sharp, SmartDisplayer Technology, Samsung, Dai Nippon Printing, and 3M Win 2005 Display of the Year Awards | accessdate = 2007-11-20 }}</ref>. Electrophoretic displays can be manufactured using the [[EPLaR|Electronics on Plastic by Laser Release (EPLaR)]] process developed by [[Philips|Philips Reasarch]] to enable existing [[AM-LCD]] manufacturing plants to create flexible plastic displays. In the 1990s another type of electronic paper was invented by [[Joseph Jacobson]], who later co-founded the [[E Ink Corporation]] which formed a partnership with [[Philips|Philips Components]] two years later to develop and market the technology. In 2005, Philips sold the electronic paper business as well as its related patents to Prime View International. This used tiny microcapsules filled with electrically charged white [[molecules|particle]]s suspended in a colored [[Mineral oil|oil]].<ref name="e_ink_nature">Comiskey, B.; Albert, J. D.; Yoshizawa, H.; Jacobson, J. "[http://dx.doi.org/10.1038/28349 An electrophoretic ink for all-printed reflective electronic displays]" Nature 1998, 394, (6690), 253-255.</ref> In early versions, the underlying [[circuitry]] controls whether the white particles were at the top of the capsule (so it looked white to the viewer) or at the bottom of the capsule (so the viewer saw the color of the oil). This was essentially a reintroduction of the well-known [[Electrophoresis|electrophoretic]] display technology, but the use of microcapsules allowed the display to be used on flexible plastic sheets instead of glass. One early version of electronic paper consists of a sheet of very small transparent capsules, each about 40 [[micrometre]]s across. Each capsule contains an oily solution containing black dye (the electronic ink), with numerous white [[titanium dioxide]] particles suspended within. The particles are slightly negatively [[electric charge|charged]], and each one is naturally white.<ref name="newscientist_1" /> The microcapsules are held in a layer of [[liquid]] [[polymer]], sandwiched between two arrays of electrodes, the upper of which is made from [[indium tin oxide]], a transparent conducting material. The two arrays are aligned so that the sheet is divided into pixels, which each pixel corresponding to a pair of electrodes situated either side of the sheet. The sheet is laminated with transparent plastic for protection, resulting in an overall thickness of 80 micrometres, or twice that of ordinary paper. [[Image:E-ink.png|center|585px]] The network of electrodes is connected to display circuitry, which turns the electronic ink 'on' and 'off' at specific pixels by applying a voltage to specific pairs of electrodes. Applying a negative charge to the surface electrode repels the particles to the bottom of local capsules, forcing the black dye to the surface and giving the pixel a black appearance. Reversing the voltage has the opposite effect - the particles are forced from the surface, giving the pixel a white appearance. A more recent incarnation<ref>New Scientist. [http://www.newscientist.com/article/dn659.html Roll the presses (2001)]</ref> of this concept requires only one layer of electrodes beneath the microcapsules. ===[[Electrowetting| Electro-wetting]] displays=== The technology is based on controlling the shape of a confined water/oil interface by an applied voltage. With no voltage applied, the (coloured) oil forms a flat film between the water and a hydrophobic (water-repellent), insulating coating of an electrode, resulting in a coloured pixel. When a voltage is applied between the electrode and the water, the interfacial tension between the water and the coating changes. As a result the stacked state is no longer stable, causing the water to move the oil aside. This results in a partly transparent pixel, or, in case a reflective white surface is used under the switchable element, a white pixel. Because of the small size of the pixel, the user only experiences the average reflection, which means that a high-brightness, high-contrast switchable element is obtained, which forms the basis of the reflective display. Displays based on [[Electrowetting|electro-wetting]] have several attractive features. The switching between white and coloured reflection is fast enough to display video content. Furthermore, it is a low-power and low-voltage technology, and displays based on the effect can be made flat and thin. The reflectivity and contrast are better or equal to those of other reflective display types and are approaching those of paper. In addition, the technology offers a unique path towards high-brightness full-colour displays, leading to displays that are four times brighter than reflective LCDs and twice as bright as other emerging technologies <ref>LiquaVista electrowetting display technologies http://www.liquavista.com</ref>. Instead of using red, green and blue (RGB) filters or alternating segments of the three primary colours, which effectively result in only one third of the display reflecting light in the desired colour, electro-wetting allows for a system in which one sub-pixel is able to switch two different colours independently. This results in the availability of two thirds of the display area to reflect light in any desired colour. This is achieved by building up a pixel with a stack of two independently controllable coloured oil films plus a colour filter. The colours used are cyan, magenta and yellow, which is a so-called subtractive system, comparable to the principle used in inkjet printing for example. Compared to LCD another factor two in brightness is gained because no polarisers are required. <ref>[http://www.hinduonnet.com/seta/2003/10/02/stories/2003100200060200.htm The Hindu : Technology for reflective full-colour display<!-- Bot generated title -->]</ref> ===Bistable LCD=== Some companies also produce e-paper displays based on bistable LCD technology. The French company [http://www.nemoptic.com Nemoptic] commercializes bistable nematic e-paper displays (B&W and color) based on a unique principle called “surface anchoring breaking”. The technology used, called BiNem, has two stable states, the Uniform (U) state and the Twisted (T) state, which are selected by applying simple pulses. Once either state is selected, it stays like it is forever without consuming any additional power. An electrical pulse drives from one state to the other one. This pulse first lifts the molecules on the surface with the weak anchoring layer up to the point where the anchoring is broken. Then, depending on the shape of the falling edge of the pulse, the molecules organize either in U or T state. Bistable LCD displays offer high reflectivity, resolution up to 200 ppi and a quite neutral white point. ===Other technologies=== Electronic paper has also been produced using technologies such as cholesteric LCD (Ch-LC). Other research efforts into e-paper have involved using [[OFET|organic transistors]] embedded into flexible substrates,<ref name="organic_transistors">Huitema, H. E. A.; Gelinck, G. H.; van der Putten, J. B. P. H.; Kuijk, K. E.; Hart, C. M.; Cantatore, E.; Herwig, P. T.; van Breemen, A. J. J. M.; de Leeuw, D. M. "[http://dx.doi.org/10.1038/414599a Plastic transistors in active-matrix displays]" Nature 2001, 414, (6864), 599.</ref><ref name="org_nat_mater">Gelinck, G. H. et al. "[http://dx.doi.org/10.1038/nmat1061 Flexible active-matrix displays and shift registers based on solution-processed organic transistors]" Nature Materials 2004, 3, (2), 106-110.</ref> including attempts to build them into conventional paper.<ref name="org_on_paper">Andersson, P.; Nilsson, D.; Svensson, P. O.; Chen, M.; Malmström, A.; Remonen, T.; Kugler, T.; Berggren, M. "[http://www3.interscience.wiley.com/cgi-bin/abstract/99018467/ABSTRACT Active Matrix Displays Based on All-Organic Electrochemical Smart Pixels Printed on Paper]" Adv Mater 2002, 14, (20), 1460-1464.</ref> Simple color e-paper<ref>New Scientist. [http://www.newscientist.com/article/dn837.html Read all about it]</ref> consists of a thin colored optical filter added to the monochrome technology described above. The array of pixels is divided into [[Triad (computers)|triad]]s, typically consisting of the standard cyan, magenta and yellow, in the same way as CRT monitors (although using subtractive primary colors as opposed to additive primary colors). The display is then controlled like any other electronic color display. ==Applications== {{Refimprove|date=May 2007}} Several companies are simultaneously developing electronic paper and ink. While the technologies used by each company provide many of the same features, each has its own distinct technological advantages. All electronic paper technologies face the following general challenges: * A method for encapsulation * An ink or active material to fill the encapsulation * Electronics to activate the ink Electronic ink can be applied to both flexible and rigid materials. In the case of flexible displays, the base requires a thin, flexible material tough enough to withstand considerable wear, such as extremely thin plastic. The method of how the inks are encapsulated and then applied to the substrate is what distinguishes each company from each other. These processes are complex and are carefully guarded industry secrets. The manufacture of electronic paper promises to be less complicated and less costly than traditional LCD manufacture. There are many approaches to electronic paper, with many companies developing technology in this area. Other technologies being applied to electronic paper include modifications of [[liquid crystal display]]s, [[electrochromic]] displays, and the electronic equivalent of an [[Etch A Sketch]] at Kyushu University. Advantages of electronic paper includes low power usage (power is only drawn when the display is updated), flexibility and better readability than most displays. Electronic ink can be printed on any surface, including walls, billboards, product labels and T-shirts. The ink's flexibility would also make it possible to develop [[rollable display]]s for electronic devices. The ideal electronic paper product is a digital book that can typeset itself and could be read as if it were made of regular paper, yet programmed to download and display the text from any book. Another possible use is in the distribution of an electronic version of a daily paper. ===Commercial applications=== [[Image:Motorola F3.JPG|thumb|right|150px|The [[Motorola F3]] uses an e-paper display instead of a conventional LCD display]] ====Education: digital schoolbooks==== * In January 2007, the Dutch specialist in e-Paper [http://edupaper.nl/inhoud/welcome edupaper.nl] started a pilot project in a secondary school in Maastricht, using e-Paper as digital schoolbooks. This reduces students' daily burden of books and reduces costs. Their website has additional information. ====e-Books==== * In September 2006 [[Sony]] released the PRS-500 [[Sony Reader]] e-book reader. On October 2, 2007, [[Sony]] announced the PRS-505, an updated version of the Reader. * In November 2006 the [[iRex]] [[iLiad]] was ready for the consumer market. Consumers could initially read e-Books in PDF and HTML formats, and in July 2007 support for the popular [[Mobipocket]] PRC format was added, but price was still a problem. With the introduction of the competing [[Cybook]] prices have decreased almost 50%. * In late 2007 Amazon began producing and marketing the [[Amazon Kindle]], an e-book with an e-paper display. ====Newspapers==== * In September 2007, the [[French language|French]] daily ''[[Les Echos]]'' announced the official launch of an electronic version of the paper on a subscription basis. Two offers are available, combining a one year subscription and a reading device. One interesting point of the offer is the choice of a light (176g) reading device (adapted for Les Echos by Ganaxa) or the iRex [[iLiad]]. Two different processing platforms are used to deliver readable information of the daily, one based on the newly developed GPP electronic ink platform from ''[[Ganaxa]]'', and the other one developed internally by Les Echos. * In February 2006, the [[Flanders|Flemish]] daily ''[[De Tijd]]'' distributed an electronic version of the paper to select subscribers in a limited marketing study, using a pre-release version of the iRex iLiad. This was the first recorded application of electronic ink to newspaper publishing.| * Since January 2008, the [[Netherlands|Dutch]] daily ''[[NRC Handelsblad]]'' is distributed for the iRex iLiad reader. ====Displays embedded in smart cards==== * Flexible display cards enable financial payment cardholders to generate a [[one-time password]] to reduce [[online banking]] and transaction fraud. Electronic paper could offer a flat and thin alternative to existing [[key fob]] tokens for data security. The world’s first ISO compliant [[smart card]] with an embedded display was developed by Smartdisplayer using [http://www.sipix.com/technology/index.html SiPix Imaging’s electronic paper]. ====Cell phone displays==== *Motorola's low-cost mobile phone, the [[Motorola F3]], also uses an alphanumeric black/white [[electrophoretic display]]. ==See also== {{portalpar|Electronics|Nuvola_apps_ksim.png}} * [[Electronic paper display]] * [[E-book device#Specialized devices|E-book device]] ==Further reading== * [http://www.newscientist.com/article/mg17723785.000.html New Scientist - Electric paper (2003)] * [http://www.newscientist.com/article/dn4202.html New Scientist - E-paper may offer video images (2003)] * [http://www.newscientist.com/article/mg17924141.200.html New Scientist - Paper comes alive (2003)] * [http://www.newscientist.com/article/dn4602.html New Scientist - Most flexible electronic paper yet revealed (2004)] * [http://www.newscientist.com/channel/mech-tech/mg18524907.100.html New Scientist - Roll-up digital displays move closer to market (2005)] * [http://www.electronista.com/articles/07/11/16/seiko.ultra.dense.e.paper/ Electronista - Seiko Epson develops ultra-dense e-paper display (11-2007)] ==References== {{reflist}} ==External links== <!--Links to product sites for the sake of advertising will be removed. This is an encyclopedia, not the Yellow Pages.--> * [http://hantarto.definitionroadsafety.org/epublishing.php Electronic Paper:Merging between Traditional Publishing & e-Publishing] * [http://www.wired.com/news/technology/0,1282,42056,00.html Wired article on E Ink-Philips partnership, and background] * {{HSW|page=e-ink|name=How Electronic Ink Will Work|author=Bosner, Kevin}}. Retrieved on [[2007]]-[[08-26]]. * [http://www.media.mit.edu/micromedia/elecpaper.html MIT ePaper Project] * [http://www2.parc.com/hsl/projects/gyricon/ Xerox PARC epaper project] * [http://mi-lab.org/projects/office-of-tomorrow/ Office of Tomorrow] * {{cite news |first=Naoki |last=Tanaka |title=Fuji Xerox Exhibits Color Electronic Paper w/ Optical Writing System |url=http://techon.nikkeibp.co.jp/english/NEWS_EN/20071206/143736/ |publisher=Tech-On! |location=[[Japan]] |id= |pages= |page= |date=2007-12-06 |accessdate=2007-12-10 }} * [http://www.display-magazin.net The Online Magazine for displays] * [http://www.tfot.info/articles/1000/the-future-of-electronic-paper.html The Future of Electronic Paper] - Past, present and future of e-paper including an interview with Nick Sheridon, Father of E-paper at Xerox {{Display Technology}} [[Category:Display technology]] [[Category:Electronic engineering]] [[Category:Paper]] [[Category:Electronic paper technology| ]] [[ca:Paper electrònic]] [[de:Elektronisches Papier]] [[es:Tinta electrónica]] [[fr:Papier électronique]] [[ko:전자종이]] [[it:E-ink]] [[he:תצוגה אלקטרופורטית]] [[nl:Elektronisch papier]] [[ja:電子ペーパー]] [[pl:Papier elektroniczny]] [[pt:Papel eletrônico]] [[ru:Электронная бумага]] [[sl:Elektronski papir]] [[sv:Elektroniskt papper]] [[th:กระดาษอิเล็กทรอนิกส์]] [[vi:Giấy điện tử]] [[zh:电子纸]]