Glossary A–ZLetter L
LCD
An LCD (liquid crystal display) creates its picture by having liquid crystals let more or less of a backlight’s light through at each pixel.
The crystals do not emit light themselves; they act like tiny light valves. LCD is the widespread technology in signage displays.
LCDs range from small room signs to large displays for video walls, both as indoor devices and as bright devices for shop windows and outdoor use. There are different panel types, such as IPS with wide viewing angles and VA with high contrast. Separate professional product lines exist for continuous operation.
Operators should know the limits: an LCD cannot show black as completely black, because some backlight always shines through. If it overheats, for example behind glass in direct sun, the picture can darken or fail completely. The panel and the backlight age separately; brightness decreases over time. The term “LED television” usually means an LCD with LED backlighting.