E-Paper Display for Economy Mobile Phones

August 14, 2008

E-paper is widely known as electronic paper that refers to an advanced technology, which effectuates displays emulate the impression of common ink on paper. A chief characteristic of such displays is the absence of a backlight to light up the screen. Instead, these displays, like ordinary paper reflect light. Hence, contributes to energy conservation by holding text as well as images without drawing power. This technology has come up as a shot in the hands of mobile phone manufacturers that they can now successfully target the low end users with low budget mobile phones that much defines power conservation. However, this technology has not yet hit the mobile phone world widely, though it is widely applied in digital schoolbooks, e-books, electronic version of newspapers and smart cards as embedment.

History

A technologist called Nick Sheridon developed the first Electronic paper in 1970s at Palo Alto Research Center of Xerox. This contraption was then known by the name Gyricon. This smart invention proved to be the foundation on which an advanced information display device called electrophoretic display was developed. It explains an information display that rearranges charged pigment particles with the help of an applied electric field to form visible images. This was followed by the development of more enhanced versions like Bistable LCD and cholesteric LCD.

Electrophoretic Film in Mobile Phones

Motorola was the first mobile phone manufacturing company that came forth to use this technology in the making of a mobile phone. They termed it ‘Clear Vision’. Here, titanium dioxide particles of a micrometre approximately in diameter get dispersed in an oil form of hydrocarbon. This oil comes mixed with a dark-coloured dye and then treated with surfactants as well as charging agents that help the titanium dioxide particles to take on an electric charge. Later, a couple of conductive plates arranged in a parallel way, separated by a break of 10 to 100 micrometres, hold the mixture. The particles electrophoretically migrate to the opposite charge bearing plate as a voltage is induced across the two plates. The particles, due to a smart light scatter towards the viewer’s side, appear white, when rested at the viewing side of the display. This smart scattering of light is caused by the presence of high index titania particles. Vice-versa, these particles while on the backside of the display, appears dark. This happens because; the coloured dye absorbs the incident light. An image is formed here, when each region of the display receives the appropriate voltage to realise a pattern of absorbing as well as reflecting regions. This is possible only by a smart division of the rear electrode into numerous tiny picture elements.

Merits and Demerits

The chief advantages of engaging this technology in a mobile phone display are; it very much contributes to a mobile phone’s thinness especially for the absence of glass, allows longer battery life and explicit reflectivity like paper. The screen is illuminated by the keypad’s backlight through a projected slit below just below it, making it visible in darkness. However, there are a few drawbacks too with this concept. Major ones are the display’s restrictive characteristics that tell on text messaging and data services largely and the usage of a font that is very much like a fixed digital clock. Apart from these, a limited provision of non-alphabetic characters also disappoints the users of phones using electrophoretic imaging display.

Share and Enjoy: These icons link to social bookmarking sites where readers can share and discover new web pages.