By Chris Chinnock
Modified Off-The-Shelf (MOTS) may soon become the standard method of procurement for military and commercial avionics display systems. With MOTS, display system integrators buy commercial-grade liquid crystal displays (LCDs) from non-U.S. suppliers and ruggedize them to meet the environmental specifications of the platform. Such an approach is becoming common in commercial aircraft and in military applications not considered mission critical.
Despite concerns about the quality and reilability of non-U.S. suppliers, however, even the most demanding applications, like military tactical aircraft cockpits, may soon be using off-shore displays.
Momentum seems to be shifting away from full military display procurement toward a more cost effective MOTS strategy. This could spell big trouble for the North American LCD suppliers. While their products are still considered viable for mission critical applications and where custom sizes are needed, some question whether even these applications will be viable in the future.
Although EDI`s Doyle was reluctant to name the platforms, he noted that, "Production aircraft are out there with holes in them waiting for [North American supplied] displays that are late or don`t meet spec." The next several years should determine if and how this industry shakes out," says Dan Doyle, vice president of display products at Electronic Designs Inc. (EDI) in Westborough, Mass.
This was not the way it was supposed to be. The U.S. Defense Advanced Research Projects Agency, the United States Display Consortium. and private investors have spent millions of dollars to develop the technology and manufacturing infrastructure to enable North American companies to supply LCDs for these applications. But LCD vendors such as Image Quest Technologies in Fremont, Calif., Litton Systems Canada in Etobicoke, Ontario, Optical Imaging Systems Inc. of Northville, Mich., and dpiX, a Xerox Company in Palo Alto, Calif., may be having trouble competing against their Asian counterparts.
The ability of North American display vendors to supply to the military, in fact, is a hot topic of discussion. "Asian suppliers have probably hundreds of times the investment that the U.S. has made in LCD development and production," notes Craig Harwood, program manager for displays at the Rockwell International Corp. Collins Avionics and Communications Division in Cedar Rapids, Iowa. "It`s just hard to compete against that."
Asian suppliers can put $100 million into research and development, and a $1 billion into new plants for high-volume production. This enables Asian manufacturers to build a greater variety of sizes and resolutions as well as fewer defects, higher reliability, and lower costs than their U.S. counterparts, experts believe.
Some North American vendors are reportedly having trouble delivering displays on time and to specification. While many program managers are loathe to talk about this, one thing is clear. Major military suppliers of display systems are covering their bets and lining up Asian display suppliers. For example, integrators at Rockwell-Collins are using displays from Sharp in Camas, Wash., and Honeywell engineers are reportedly using displays from Hosiden-America in Cupertino, Calif., while Lockheed Martin and Allied Signal designers are using displays ruggedized by EDI, which has a close working relationship with Sharp.
Even the primary North American suppliers are evaluating alternative source of glass. Image Quest, Planar and Litton Canada are all looking at buying commercial LCD glass for some less mission critical or cost sensitive applications.
The use of MOTS seems to be most prevalent where cost sensitivity is important. It is also more acceptable in situations where the display is not a key mission critical component. "Losing a display in a tank is not as bad as losing it in a cockpit," says John Wright, Director of Technology at Litton-Canada. "Army vetronics seem to be more cost sensitive too."
But using MOTS has trade-offs, the most important being loss of control over display manufacture. Changes to commercial manufacturing process are common but not documented the way they are in version-controlled manufacturing operations. Thus, it may be difficult to know if a process change will influence ruggedized display performance.
To assure military buyers that the supply chain is safe, display integrators may opt to do rigorous environmental tests on 100 percent of shipped display products. While this may identify gross changes in display manufacturing, it is not likely to capture changes that result in long-term degradation.
But more importantly, "It is critical to have a good relationship with your off-shore supplier so they will tell you about revisions in manufacturing and other technical support issues," says EDI`s Doyle.
The concept of using MOTS displays is not new. In fact, EDI has been a leader in this area for six years. Company designers buy displays from Sharp, modify them as needed, and repackage the displays in a glass sandwich configuration for greater reliability in rugged environmental conditions. "We have said for a long time that ruggedizing commercial displays was the right way to go," Doyle says. "I am glad to see that the market is finally coming our way."
Ruggedizing commercial displays is not an easy task, however. For one, the wider temperature requirements of military platforms requires heaters to maintain the display in cold temperatures. Stronger mechanical packaging is necessary to handle shock and vibration, and different backlights and controllers are required for sunlight readability and dimming for nighttime viewing. Designers must consider even the bonding of the drive electronics to the glass itself.
Anisotropic conductive films tend to delaminate at high temperatures, so integrators must find other methods to solve these problems. Sometimes, even the basic tilt angle orientation of the liquid crystal molecules needs altering to change the orientation of the display from landscape to portrait. Engineers from EDI and Rockwell-Collins now offer 8-by-10-inch active-matrix LCDs in portrait mode with +/- 60 degree horizontal viewing.
