For over four decades the Head Up Display (HUD) has been a critical instrument in tactical aircraft, as well as in an increasing number of commercial air transports. HUDs provide a unique means to present vital information to the pilot, precisely overlaid on the real world, without the need to look down or refocus onto the instrument panel displays. HUD imaging technology, using high brightness CRTs, has remained largely unchanged during this period, despite dramatic advances in display technology across the remainder of the avionics spectrum. As reliability improvements have reduced life cycle costs for other avionics systems, the relative cost of ownership for CRT-based HUDs has become increasingly unacceptable. Further, as special-purpose CRTs have steadily been replaced by digital display alternatives the number of potential sources has dwindled, raising growing parts obsolescence issues.
These issues can be resolved by replacing the CRT and its associated electronics with a solid-state digital image engine. Such "digital" HUDs (DHUDs) have been certified for use in a number of commercial air transports, and are gaining wide acceptance in the user community. The operational and environmental requirements for DHUDs for tactical aircraft are more demanding than for transports, however the core technologies are in place to meet these needs. The stage is set to achieve excellent performance, dramatic life cycle cost reductions and low cost, for both legacy and new tactical aircraft.
This paper describes digital HUD development efforts to date and summarizes key performance parameters and design issues.
Direct-view CRT and AMLCD multifunction displays (MFDs) in legacy aircraft are often upgraded for purposes of improved performance, reduced cost and/or avoidance of parts obsolescence. Rear projection technology is an attractive option in dealing with all these issues, as is discussed herein. Specifically, the design and features of a compact full-color rear projection MFD intended to replace a monochrome CRT-based system in a tactical military aircraft is described. Because of its small size and high performance, this system can be adapted for various other applications.
Avionics projection displays are entering production in advanced tactical aircraft. Early adopters of this technology in the avionics community used projection displays to replace or upgrade earlier units incorporating direct-view CRT or AMLCD devices. Typical motivation for these upgrades were the alleviation of performance, cost and display device availability concerns. In these systems, the upgraded (projection) displays were one-for-one form / fit replacements for the earlier units. As projection technology has matured, this situation has begun to evolve. The Lockheed-Martin F-35 is the first program in which the cockpit has been specifically designed to take advantage of one of the more unique capabilities of rear projection display technology, namely the ability to replace multiple small screens with a single large conformal viewing surface in the form of a panoramic display. Other programs are expected to follow, since the panoramic formats enable increased mission effectiveness, reduced cost and greater information transfer to the pilot. Some of the advantages and technical challenges associated with panoramic projection displays for avionics applications are described below.
Projection display technology has been found to be an attractive alternative to direct view flat panel displays in many avionics applications. The projection approach permits compact high performance systems to be tailored to specific platform needs while using a complement of commercial off the shelf (COTS) components, including liquid crystal on silicon (LCOS) microdisplay imagers. A common projection engine used on multiple platforms enables improved performance, lower cost and shorter development cycles. This paper provides a status update for projection displays under development for the F-22A, the F/A-18E/F and the Lockheed Joint Strike Fighter (JSF) aircraft.
Avionics displays often require custom image sources tailored to demanding program needs. Flat panel devices are attractive for cockpit installations, however recent history has shown that it is not possible to sustain a business manufacturing custom flat panels in small volume specialty runs. As the number of suppliers willing to undertake this effort shrinks, avionics programs unable to utilize commercial-off-the-shelf (COTS) flat panels are placed in serious jeopardy. Rear projection technology offers a new paradigm, enabling compact systems to be tailored to specific platform needs while using a complement of COTS components. Projection displays enable improved performance, lower cost and shorter development cycles based on inter-program commonality and the wide use of commercial components. This paper reviews the promise and challenges of projection technology and provides an overview of Kaiser Electronics' efforts in developing advanced avionics displays using this approach.
Avionic displays are required to be fully functional over a wide range of ambient illumination, encompassing bright sunlight during the day and dim starlit sky at night. Additionally, in most applications the night operation is required to be compliant with night vision imaging system (NVIS A or B) goggles. This article describes a patented dual lighting system, employing a hot cathode fluorescent lamp for the day mode and a filtered cold cathode fluorescent lamp against a light pipe (edgelit) for the night mode of operation. Since the two modes of operation are decoupled from each other, the day mode can be designed for high luminance and broad color gamut, regardless of NVIS requirements, while the night mode can be designed to be compatible with either the NVIS-A or NVIS-B systems with no impact to the day mode. This unique blacklight design provides a wide dimming range for the display and delivers excellent performance under all viewing conditions. Furthermore, this approach provides excellent uniformity in the night mode with minimal color shifts over view angles and has been successfully implemented on two cockpit display programs.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.