by Peter Smith
The quantity of information currently available via mobile devices is amazing and ever-increasing. For example, it is now possible to watch a movie on one's mobile phone or surf the Web via a personal digital assistant (PDA) – not long ago, mobile phones were "brick-like" and employed LED indicator lights. A substantial advance was made with the incorporation of monochrome liquid-crystal displays (LCDs).
More recent developments in content, wireless delivery, carrier services, and, of course, display technology have enabled significant growth in these mobile devices, the associated displays, and the services that route the information to the user. The proliferation of devices and services has created a platform for future growth and innovation that is led, or greatly impacted by, display technology. For example, color thin-film-transistor LCDs (TFT-LCDs) now are routinely employed in mobile devices. In addition, new display technology appears to be gaining traction in this form factor. Display technologies including organic light-emitting-diode (OLED) and electrophoretic-ink technology have achieved adoption.
This issue of Information Display magazine looks at the display developments through several lenses. Contributions from Nokia, the U.S. Army Research Laboratory, Plextronics, DuPont Displays, and Pacific Media Associates span a wide gamut of perspectives that can impact mobile and flexible displays and devices.
First, Nokia provides a comparison of the emerging display technologies that can find a socket or home in a mobile phone. The Nokia article focuses on rigid mobile displays and clearly describes the challenge imposed by the incumbent TFT-LCD technology and poses the question of whether or not any newcomers will be potential displacements. In addition, Nokia goes on to call out industrial design aspects of mobile phones and relates the display specifications and features to the form factors that result in favorable consumer responses.
Second, the U.S. Army Research Laboratory has described their investment and interest in flexible displays. Since military applications are typically more demanding than consumer applications, this is a space to watch for the next wave of innovation that will impact mobile displays and devices. In this article, the historical investments in new display technology are highlighted. This lesson provides a foundation for the U.S. Army's investment in the Flexible Display Center at Arizona State University as well as the driving force behind the interest in flexible-display technology. The advances in consumer technology that permit Web access on a handheld device have seeded emerging ideas; new display form factors will enable new and useful information to be delivered to the soldier.
To alter form factors from rigid to flexible and to make thicknesses slimmer, new materials will ultimately be required. Quite simply, if the required materials were now available, the aforementioned technologies would be further toward commercialization. In the third article, Plextronics describes emerging materials that enable OLED displays as well as transistors based on printing technology. Both of these material developments will positively impact the development of mobile and flexible displays. In the fourth article, DuPont Displays delves into its work in this area as well, explaining its solution-processing methods for OLEDs that were introduced earlier in 2007.
The final article comes from our friends at Pacific Media Associates and is a more applications-focused analysis of the next generation of portable projection devices. Technological breakthroughs have enabled the introduction of these relatively small and low luminance (below 500 lm) projectors, which have the advantages of low power, weight, and cost over their next larger cousins.
In summary, it is an exciting time for mobile and flexible displays. Advances throughout the value chain are being pursued simultaneously. Over the next several years, we can anticipate new form factors, new display aesthetics, and new content to be in the hands of the consumer. To obtain advance notice of the pipeline, look to the military, including the U.S. Army, to see displays and uses of an early adopter of new mobile and flexible technology. •