Electronic paper

As Electronic paper ( e- paper briefly or English short e-paper, e-paper or ePaper called ) display techniques are referred to, are used to attempt to replicate the look of ink and color on paper. E- paper displays reflect light like ordinary paper, so it is passive ( non-luminous ) displays. Following the English usage such screens are also referred to as reflective displays. Texts or images to be displayed permanently in some display technologies, without the need for a float voltage is required. The display may be changed at a later time. Electronic paper is by some manufacturers - like normal paper - flexible.

Although there are various methods for making electronic paper and in the meantime a large number of companies engaged in the exploration and development, can be found in common usage the term E -Ink often than other synonyms for Electronic Paper. In fact, it is at E Ink just to the brand name of the product of E Ink Corporation, which is currently found in most modern e- book readers, and based on the phenomenon of electrophoresis.

Technology

Gyricon

Nick Sheridon was first developed in the 1970s at the Palo Alto Research Center of Xerox electronic paper. It was called gyricon and consisted of small, statically loaded beads. These were two colors: black on one side, white on the other. The text content of the paper could be changed by an applied electric field. Characterized the beads were rotated up or down, so that either the black or white side was visible. However gyricon could not be produced sufficiently inexpensive so that the company Xerox gyricon LCC was founded to commercialize disbanded in late 2005.

Electrophoresis

Used Joseph Jacobson small microcapsules, in which floated electrically charged white particles in colored oil in the 1990s. By the polarity of an applied electric field, the white particles migrate to the top of the microcapsule (thus visible to the viewer ) or to the bottom, so that the viewer looked at this point, the dark color of the oil. The American company E Ink Corporation developed their current electronic paper based on this based on electrophoresis technique.

This electronic paper includes microcapsules having an average diameter of about 40 microns, which contain positively charged white particles and negatively charged black particles in a transparent viscous polymer. The display is varied by briefly applying an electrical voltage and remains stable for several weeks. Shape and diameter of the microcapsules are irregular, but that has no meaning, because make up a pixel of the display from many microcapsules.

The use of microcapsules also allows flexible plastic instead of glass to be used as support material.

The driving of the pixels occurs at segment displays using passive matrix displays of transparent electrodes and a TFT active - matrix as it is also used for LC - screens.

The appearance of gray levels is controlled by the timing of the applied voltage. Originally, eight gray levels are displayed, the current displays work with 16 levels of gray. In conjunction with known from printing technology and image processing grid method, a seemingly infinite gray scale representation is achieved. Colored displays work with upstream color filters.

The E Ink Corporation has introduced various applications since 1999 and started in 2004 as the first manufacturer to start serial production electronic paper on a larger scale. Products of other manufacturers are, for example, " SiPix Microcup " the American company SiPix, the flexible electronic paper "Plastic Paper " of the manufacturer Plastic Logic, which is manufactured in Dresden, or the flexible e- ink displays from LG Display. Another manufacturer electrophoretic electronic paper with its own technology was Bridgestone, whose development was in 2012 but set.

Since 2002, various prototypes colored electrophoretic e- paper have been presented, for example, presented in May 2007 LG.Philips a flexible, color e-paper based on the electrophoresis technique before, but this is not yet gone into production. E Ink has started in 2011 with the production of colored electronic paper "Triton".

Bistable LCD

Some companies produce electronic paper based on bistable LCDs. These allow a neutral white high albedo ( surface reflectivity ) and resolutions up to 200 dpi. One example is the Cholesteric Liquid Crystal Display.

Electrowetting ( electrowetting )

The Philips Company offshoot Liquavista developed a display technology, in which are superimposed a colored oil and a water layer. The light transmittance of the individual pixels is affected thereby, by the surface tension is changed by means of applied electric voltage ( electrowetting ). Thus, colored and fast reflective displays with high contrast and low power consumption can be produced whose switching speed also allows video playback.

The functional prototype of an e-book reader with a colored 6 " electrowetting display was unveiled at CES 2010.

Beginning of 2011 has been adopted by Samsung Liquavista.

Micro- mechanically controlled interference modulation

The mobile technology maker Qualcomm produced under the name " Mirasol " sold IMOD displays. This based on the fact that the distance between two micro- mechanical reflective layers changes and thus the reflection light is controlled by means of constructive and destructive interference. The display elements are (like e-ink ) bistable and enable the production of low-power reflective displays. Qualcomm has introduced at CES 2010 working prototypes of 5.7 " readers with colored Mirasol displays, which are also applicable for video playback. Recording of production on a larger scale has been announced for 2012.

Advantages and disadvantages over conventional screens and paper

Electronic paper combines the advantages of computer screen and paper. Compared to conventional screens, such as those used for television and graphics rendering, it provides the current state of development the following benefits:

• The image content is apparently due to the small distance of the imaging elements to the surface from any angle, regardless of (an advantage over LCDs).
• There is no flicker through the static display (an advantage over CRTs ).
• It is very thin and light and with appropriate design also flexible.
• It is to be produced in all sizes and shapes - from small display with the current weather display to the large display board or poster panel.
• It requires less energy to produce and maintain the display, since only the change in the image content (page change), a current flow is required.
• It can be read in both normal room light and in bright sunshine, since the image-forming elements are reflective.

The disadvantages compared to print media such as paper are the clear smooth surface of the cover, which reflects noise and stray light. The resolution is 170 dpi still significantly lower than at pressures and possibly pictures at higher than inexpensive paperbacks and newspapers. Both the gray value resolution (currently only 16 levels of gray ) and the contrast are still low, and white areas reach, at best, a bright light gray. The long switching times of the first-generation electronic paper allow only a static display. The color space of the color displays is relatively limited. By Energiesparmechnismen the e -book reader also ghosting effects may occur.

Applications

As a first field trial for delivery of a newspaper, the Belgian business newspaper De Tijd has carried out a test with two hundred readers from April to June 2006. The instrument used was the iLiad iRex of.

A field experiment with electronic paper as advertising space was performed by Hitachi end of 2006. In a Tokyo commuter trains railway line were installed as a replacement for ordinary promotional poster displays based on electronic paper by Bridgestone. Opinion polls should then decide on the marketing ability.

There are now many devices where e-paper displays are used:

• From numerous manufacturers readers for electronic books will be produced and sold as OEM devices with their own firmware. This is currently the main use of electronic paper. An overview of the officially distributed in Germany equipment can be found in the article on e- book reader.
• As the first mobile phone manufactured by Motorola, the Motofone has built F3 to display electronic paper. Motorola describes this display as " EPD " is a segment display with electronic paper by E Ink, the case in comparison to other display method is unusual effect that the display remains at removing the battery from the mobile phone. An advantage over other phone display is that the representation remains readable even in direct sunlight.
• Lexar, the USB sticks her " JumpDrive Secure II Plus" and " Echo MX ", which indicate the level of its memory on a display with electronic paper. Since the display content is preserved without electricity supply, these devices do not require batteries.
• Western Digital sold since August 2009 external hard drives ( Series My Book Elite and My Book Studio) that have on their front on a so-called E -label. The e -label is an arbitrary line of text ( contents of the hard disk), the available free memory and the activation of the Drive Encryption.
• The Seiko introduced in 2005 with the model " Seiko Spectrum" the first watch out that is equipped with an E -Ink -segment display. 2010 appeared the first e-ink Clock with matrix display. The display has 80,000 pixels with a resolution of 300 ppi. Each pixel can display one of four gray scale shades.
• The Austrian retail chain Billa uses e-ink display as price tags, thus the selling prices of certain goods can be changed from the office.

Other Applications

• The magazine Esquire appeared on 8 September 2008 for the 75th anniversary of the first magazine with a cover, which was equipped with electronic paper. The case used e-ink deposit, however, was not a matrix display, but served headlines on and off to invert and to have text areas will blink. The " Special Collector's Edition" was produced 100,000 times.