Active‐Matrix Electroluminescent Displays

Abstract

There is a strong quest for large-area displays that are thin in profile, lightweight, have good saturated color, low-power consumption, and with an active-matrix backplane as a basis for high-information content. The ubiquitous flat panel display (FPD) meets these requirements. While the FPD is very much dominated by the liquid crystal display (LCD), we are witnessing an emergence of the flat-panel electroluminescent display based on the light-emitting diodes (LEDs). In contrast to the LCD, which is voltage-driven, the latter is current-driven and provides for high contrast ratio, ultrafast response, vivid color appearance, and is ultrathin and mechanically robust. The issues generally faced with current-driven displays is the critical requirement of stable pixels with spatially and temporally uniform current and current-luminance behavior. These nonidealities call for instability compensation of the drive transistor in the active matrix as well as the LED. This chapter on flat panel electroluminescent displays reviews the various light-emitting technologies ranging from the organic- and quantum-dot-LED to micro-LEDs, and the associated pixel circuits and driving schemes going back the last 20 or so years. Also addressed are pertinent design considerations for higher resolution, faster frame rates, and low-power consumption.