A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal the display is called an electronic display.
Common applications for electronic visual displays are television sets or computer monitors.
Main article: Electronic visual display
These are the technologies used to create the various displays in use today.
Some displays can show only digits or alphanumeric characters. They are called segment displays, because they are composed of several segments that switch on and off to give appearance of desired glyph. The segments are usually single LEDs or liquid crystals. They are mostly used in digital watches and pocket calculators. Common types are seven-segment displays which are used for numerals only, and alphanumeric fourteen-segment displays and sixteen-segment displays which can display numerals and Roman alphabet letters.
Cathode-ray tubes were also formerly widely used.
2-dimensional displays that cover a full area (usually a rectangle) are also called video displays, since it is the main modality of presenting video.
Full-area 2-dimensional displays are used in, for example:
Underlying technologies for full-area 2-dimensional displays include:
The multiplexed display technique is used to drive most display devices.
Further information: Volumetric display