<title>Sunlight-viewable electroluminescent displays for military applications</title>

Abstract

Direct and reflected sunlight on open canopy crew stations can reduce perceived contrast below acceptable levels. A contrast ratio of 4 to 1 or greater in the ambient illumination is required for good discemability. Achieving this level of performance requires that background reflections off the display screen be suppressed while maintaining adequate light output levels from the display. Over the years, the display device which has enjoyed the most widespread use in cockpits is the cathode ray tube (CRT). However, reflected light from a CRT phosphor is typically 90% and light output levels of over 7000fL coupled with high attenuation optical filters are required for high ambient viewability. The resultant power consumption, short operating life and poor form factor have left much room for improvement.