Optoelectronic displays

Advantages and disadvantages of active (emissive) and passive optoelectronic displays of various kinds are summarized. The discussion covers LEDs, gas discharge displays, electroluminescent powder panels, tungsten filament displays, CRTs, liquid crystals, electrophoretic displays, and electrochromic displays. Formats (7-bar, 16-bar alphanumeric cells), addressing schemes, and other display matrices are compared. The low power drain of passive displays and the night visibility of active displays are pointed out. Erasable display exhibited only when required, elimination of the saturation of instrument boards with electromechanical gages and displays, and easy legibility in bright sunlight as in cockpits of high-flying aircraft are discussed. The floor discussions takes up some practical problems relevant to maritime navigation, cockpit legibility, and color perception and response time.