Active Matrix LCD Cooling Technology
Active matrix liquid crystal display (AMLCD) panels display data, images, symbols and text for human-readable screens. Commercial aviation serves as one of the many applications for this technology. The ability to clearly view instrumentation in varied lighting conditions is critical to safe operation of the aircraft. Thermoelectric modules provide an effective automated means of contrast and brightness adjustment to improve instrumentation readability in bright daylight or pitch darkness.
The thermoelectric cooler (TEC) makes contact with the tube through a "cold shoe" that controls the temperature of a spot on the tube. By increasing and decreasing the temperature of that spot, mercury condenses or vaporizes on the spot with the change in temperature. More vapor in the tube causes the tube to glow brighter. An automatic gain control senses the amount of ambient illumination and controls the thermoelectric cooler. Above the clouds, where sunlight is particularly bright, the AMLCD requires maximum brightness; at night on the ground, it needs little.