An LED numeric display for the aircraft cockpit

This paper describes the construction and performance of an LED numeric display designed specifically for aircraft cockpit applications. The display, using yellow or green LED chips, is a 4-character 7-bar numeric with 4-mm character height mounted in a hermetically sealed package to meet full military device specifications. Legibility studies are reported for this display in ambient illuminations up to 100 000 lux, using different, commercially available contrast-enhancement filters. The results show that the display is completely legible in the highest illumination for a relatively modest power consumption.