Airborne electronic displays

Electronic displays are being increasingly used in aircraft for the presentation of information to aircrew. This trend is due to two principal reasons, the steady improvements in the technology of electronic displays which are finding growing use in a wide range of markets, and the radical changes to the methods of distributing and processing data on board both military and civil aircraft. However, the peculiar environmental and other factors which constrain the design of airborne displays have caused the aircraft world to lag behind other markets in the use of new types of electronic display. It is the aim of the paper to review both the available and potentially promising display technologies, the human factors and environmental constraints, and the integration of the display devices into the total avionic systems, in order to present a balanced view of both the advantages and the problems associated with the use of airborne electronic displays. The design of the aircraft cockpit and the wide range of ambient light levels impose particular problems, and these are considered in relation to the characteristics of the human eye to provide some overall guidelines for display design. The types of information which are typically presented and the design of symbology are reviewed. Electronic display devices described include monochrome and colour CRTs, which are coming into use in the new generation of civil aircraft after many years of use in military aircraft, digitally-addressed CRTs, and a range of solid-state matrix and alphanumeric displays, both emissive and reflective. Image intensifiers for use in night operation are discussed. Some types of display, particularly for military aircraft, incorporate optical elements for magnification, collimation and image combination, and the use of both refractive and diffractive optical techniques is reviewed. The design of complete display systems to provide multifunction capability and protection against component failure is- seen as one of the greatest potential advantages of integrating electronic displays with digital data highways.