US Patent 7268004 Thermoelectric control for field emission display

An active matrix display that does not require a transistor or similar current switching device at each pixel. Instead, the display employs in each pixel a temperature-controlled current source that provides to the field emitters of the pixel an amount of electrical current which varies in response to the temperature of a temperature sensor. Each pixel further includes a thermoelectric heat transfer circuit which transfers heat to or from the sensor in an amount which varies in response to the video signal. Consequently, the video signal controls the temperature of the sensor within a pixel's temperature-controlled current source, which controls the current flow through the pixel's field emitters.