technology. However, several challenges need to be solved before OLED technology becomes pervasive for large displays, as discussed later in this chapter.
One of the most important trends in recent years is the rapid spread of touch displays. Touch technology already has matured to a point where its performance, reliability, and robustness are outstanding. Touch technology was invented in the United States, and many improvements are still coming from U.S. academic and industrial research and development (R&D) laboratories.3 Given that significant innovations and improvements are expected in the next decade, this field has potential for continued U.S. leadership.
One of the technologies changing how people study, spend leisure time, and get information involves e-readers and computer tablets. Within the next generation, it is possible that people will be dependent on e-readers and tablets for many of their educational and general reading needs. With respect to e-readers, a revolution is taking place, from a simple electrophoretic ink (E-ink) product, to a higher-resolution E-ink, to color-passive LCD, to full-blown LCD-based e-readers. As the displays are improved, there are opportunities to develop low-cost, durable, and green materials and manufacturing processes.
An interesting technology that might have a major impact in the future but will require major investment and innovation is that of flexible displays. Flexible material (such as glass or a polymer) could be used for newspapers, magazines, and work papers. The idea is to simulate the paper media that many people are still using, but with a flexible organic or inorganic material that is essentially a computer system with a wireless transceiver. Such flexible displays could communicate with servers to download information and display it as though it were printed on paper. The flexible materials should be lightweight, sturdy, robust, and reusable and should provide exceptional text, picture, and video quality whether indoors or in bright sunlight (similar to printed-paper quality). To create flexible displays, however, it is necessary to develop flexible substrate materials and processes that exhibit chemical resistance, thermal stability, and endurance of high temperatures and pressures during fabrication.
Most of the current state-of-the-art display technologies require backlighting subsystems to provide the necessary brightness. LCDs do not produce light themselves, and so they need illumination to produce a visible image. In general, backlights are needed to illuminate the display panel from the side or the back.
3 A Scopus search on “touch display” gives a total of 2,706 publications, of which the following institutions are the top 10 publishers: University of Tokyo (47), Massachusetts Institute of Technology (39), University of British Columbia (29), University of Calgary (23), University of Toronto (22), KAIST (formerly Korea Advanced Institute of Science and Technology) (22), University of Oxford Medical Sciences Division (20), Stanford University (20), Microsoft Research (20), and Carnegie Mellon University (19). SOURCE: Scopus database. Available at http://www.scopus.com/home.url. Accessed November 28, 2011.