Sonia R. Dodd

Active matrix OLED using 150ºC a-Si TFT backplane built on flexible plastic substrate

Flexible displays fabricated using plastic substrates have a potential for being very thin, light weight, highly rugged with greatly minimized propensity for breakage, roll-to-roll manufacturing and lower cost. The emerging OLED display media offers the advantage of being a solid state and rugged structure for flexible displays in addition to the many potential advantages of an AM OLED over the currently dominant AM LCD. The current high level of interest in flexible displays is facilitating the development of the required enabling technologies which include development of plastic substrates, low temperature active matrix device and backplane fabrication, and display packaging. In the following we will first discuss our development efforts in the PEN based plastic substrates, active matrix backplane technology, low temperature (150°C) a-Si TFT devices and an AM OLED test chip used for evaluating various candidate designs. We will then describe the design, fabrication and successful evaluation and demonstration of a 64x64 pixel AM OLED test display using a-Si TFT backplane fabricated at 150°C on the flexible plastic substrate.

AM OLED using a-Si TFT backplane on flexible plastic substrate

Amorphous silicon TFT technology continues to show promise for fabricating large area high resolution flexible AM OLED displays. This paper describes the recent progress in the flexible AM OLED development efforts at Honeywell since our publication in this conferences proceedings in 2003, describing the feasibility of fabricating a 64x64 pixel AM OLED on a flexible plastic substrate. In this paper we describe the design, and fabrication of a 160x160(x3) pixel AM OLED on a flexible plastic substrate with an equivalent 80cgpi resolution. Flexibility characteristics of the fabricated displays are discussed. Further advances and improvements required for extending the size and resolution of flexible AM OLED displays are discussed.

Improved lamp and polarizers for subtractive color displays

— A new lamp and a set of color polarizers have been developed for use with subtractive-color active-matrix liquid-crystal displays (AMLCDs). The lamp is a xenon-based ac-operated short-arc design with metal halides added to produce radiation at the desired wavelengths. The polarizers are made from crosslinked cholesteric liquid-crystal silicones and have spectral polarization functions that are tuned to match the lamps emission spectrum. The resulting subtractive-color AMLCD has substantially greater transmittance, contrast, and color gamut than our previous designs.

Biopolymer-based gate dielectric for organic field effect transistors

Organic field effect transistors (O-FETs) are of considerable interest for the development of flexible displays and a variety of other macro-electronic applications. We investigated a DNA-based biopolymer material as a gate dielectric for fabricating O-FET backplanes using the organic semiconductor material Pentacene having small geometry devices and improved performance characteristics required for high resolution displays. The results to date continue to show the potential of this approach for low-cost O-FET backplanes for the next generation flexible displays and other macro-electronic applications.

Accommodation of COTS LCDs in military displays

Commercial off the shelf (COTS) liquid crystal displays are attractive as an alternative to LCDs that are custom designed and manufactured for the military environment. Commercial displays require significant modification to accommodate their use. This paper describes specific modifications that create a thermal cocoon around a nominal 3.6 X 4.6-inch commercial industrial/automotive display. The thermal design techniques allow the display to function in the particularly challenging F-16 thermal environment without exceeding the displays operating specification. The work is extended to examine what additional design extensions are required for still larger displays.