Today, almost every cockpit display uses cathode ray tube (CRT) technology. CRTs are a proven technology, have a long history and are fabricated by Thomas Electronics - which undertook this ATP project - for use in the manufacture of cockpit displays. CRT displays have a well-known drawback, however: the surface is glass, and the view one gets through it depends on the amount of light in the cockpit and the direction the light is coming from. In some circumstances, such as bright sunlight, visibility of displays may be seriously diminished.

Liquid-crystal displays (LCDs) - the flat-panel displays used in notebook computers - would be a good alternative to CRT displays. The drawback to LCDs, however, is that their light source is not nearly bright enough for use in airplane cockpits. This ATP project addressed that problem by developing the technology needed to make a flat, bright fluorescent lamp for backlighting an LCD. The new lamp would be about a quarter of an inch thick, have the same length and width as the LCD, and be attached to its back.

Flat fluorescent lamps for flat panel display back-lighting, in a variety of sizes, ranging form 1.5 inches to 12.5 inches on the diagonal.

In conventional fluorescent lamps, a cathode discharges electrons that excite mercury vapor to emit ultraviolet light that, in turn, induces the phosphor coating on the interior of the lamp to glow white. Flat fluorescent lamps were not developed earlier because of the difficulty in generating a bright plasma in the thin space between wide, flat sheets. Conventional cathodes are too inefficient to create enough light for the color LCDs used in avionic displays. And although barium dispenser cathodes (BDCs) are efficient enough for the task, they were never used in the presence of mercury, which is believed to "poison" the barium and quickly reduce both the efficiency and life span of the device. Thomas solved the mercury problem with BDCs by using a new hollow-cathode design that enabled the company to construct a truly flat fluorescent lamp.

In addition, Thomas introduced new materials to flat fluorescent lighting. The front of the lamp is glass. But the back is hardier ceramic material and has all the light-producing components embedded in it. The ceramic back enables the lamp to withstand severe shock and vibration much better than if both sides were glass. In addition, the thermal properties of the ceramic material allow the lamp to operate at significantly higher temperatures than comparable lamps made solely of glass. As a result, these new lamps can be used for rugged flat-panel displays in applications such as military tanks.

Follow-on research and development work is on track to meet the project's commercialization goal - the introduction into commercial and military airplane cockpits of flat-panel displays containing the new fluorescent lamp. To date, Thomas has invested more of its own money in the effort than it received from ATP, and the work is beginning to pay off. The company is completing a pilot production plant and has received orders for further evaluation and field testing of the new technology from Optical Image Systems, AlliedSignal, Honeywell, Litton Industries, Kaiser Electronics and five other companies. The field testing must yield positive results before the Federal Aviation Administration will certify the flat-panel displays for use in cockpits.

About 10,000 displays are installed in airplane cockpits each year. Compared with CRT devices, the new flat-panel displays will be more effective (they produce more light), more reliable (the ceramic material is hardier than glass) and less-costly (the ceramic material can be machined more easily than glass). Ultimately, their use is expected to benefit aircraft passengers, who will enjoy safer air travel because pilots have more-effective, more-reliable instrument displays. It is also expected to benefit flat-panel display manufacturers, aircraft manufacturers and airlines through cost reductions and quality improvements.

Potential uses for the flat-lamp technology include displays in military ground vehicles, such as tanks. Displays in these applications must withstand greater extremes in vibration, temperature and other operating conditions than ordinary displays. Three companies specializing in such displays have ordered flat-lamp prototypes from Thomas.

ATP Bolsters U.S. Technology

Without the ATP award, Thomas officials say, the company would not have done the research and development work for this project. The company would have struggled along with its conventional CRT technology and would have stood virtually no chance of competing with other display-component suppliers, all of which are foreign companies. In addition, the award helped Thomas establish connections with scientists at Princeton University and form alliances with contractors.

Go to other sections of Chapter 5: ELECTRONICS
	Expanding the Number of Light Signals in an Optical Fiber
	Manufacturing Technology for High-Performance Optoelectronic Devices
	Processes for Growing Large, Single Silicon Carbide Crystals
	Harnessing Cheap Diode Lasers to Power a Low-Cost Surgical Laser
	Lowering the Cost and Improving the Quality of Computer Chips
	A Gas Method to "Dry" Clean Computer-Chip Wafers
	Low-Cost Night-Vision Technology
	Large-Scale Diode-Array Laser Technology for X-Ray Lithography
	Using High-Temperature Superconductivity to Improve Cellular Phone Transmission
	Exploiting Alexandrite's Unique Properties for a Less-Expensive, More-Reliable Tunable Laser
	Precision Mirrors for Advanced Lithography
	Joining Several Chips Into One Complex Integrated Circuit
	Computer RAM Chips That Hold Memory When Power Is Off
	A Feedback-Controlled, Metallo-Organic Chemical Vapor Deposition Reactor
	Flat Fluorescent Lamps for Displays