Backlight displays

Figure 4.55. SEM images of an electroluminescent phosphor particle, ZhS (used in backlight displays for cell phcHies, watches, etc.), before (a) and after (b) the deposition of an aluminum oxide thin film. This film is a transparent coating that prevents the phosphor particle from undergoing humidity-accelerated decay. A technique known as fluidized-bed CVD was used, where a carrier gas both delivered the precursors to a vertically aligned CVD chamber, and dispersed the powdery sample in order to expose all surface regions to the precursor vapors.

R.J. Yisser, Application of polymer light-emitting materials in light-emitting diodes, backlights and displays, Philips J. Res., 51 467-477, 1998. 

Y Tung, T Ngo, M Hack, J Brown, N Koide, Y Nagara, Y Kato, and H Ito, High Efficiency Phosphorescent White OLED for LCD Backlight and Display Applications, Proceedings of the Society for Information Display, Digest of Technical Papers, Vol. 35, Seattle, 2004, pp. 48-51. 

FIGURE 10.7 Power consumption simulation for a 2.2-in. full-color OLED display using Universal Display s phosphorescent OLEDs, small-molecule fluorescent devices, and polymer OLEDs along with a comparison of the power consumed by an active-matrix liquid crystal display backlight. R G B= 3 6 1, 50% polarizer efficiency, and 30% of pixels lit. (From Mahon, J.K., Adv. Imaging, June, 28, 2003. With permission.)... 

One application for organic electroluminescent materials is in the construction of lightweight backlights for LC displays (see Chapter 3, section 3.8). If organic electroluminescent (OEL) materials emitted polarised light they could make the polariser... 

For example, active-matrix backplanes for reflective displays using electrophoretic media is a potential application for large-area electronics. Electrophoretic media are usually charged colored particles suspended in an insulating fluid [35-37]. When the fluid is held in an electric field between two conductive plates, the particles will move between the plates creating a dark or a reflective state. Because the contrast in an electrophoretic display is because of reflection, no backlight is required and the display has relatively low-power consumption compared with a transmissive liquid-crystal display. 

At Siemens the effort is directed to develop devices for use in backlighting for the keys on mobile telephones or for the liquid crystal display devices. Polymers displays... 

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