A display device is an output device for presentation of information for visual or tactile reception, acquired, stored, or transmitted in various forms. When the input information is supplied as an electrical signal, the display is called electronic display. Electronic displays are available for presentation of visual and tactile information.
Tactile electronic displays (aka refreshable Braille display) are usually intended for the blind or visually impaired, they use electro-mechanical parts to dynamically update a tactile image (usually of text) so that the image may be felt by the fingers.
Common applications for electronic visual displays are television sets or computer monitors.
Refreshable Braille display
See also Optacon
The "Check Engine" light on an automobile dashboard is the quintessential idiot light, giving only the information that something is amiss, but not what particular subsystem or component, nor how urgent the problem is. Neither does it give any information about issues that may be still within acceptable limits, but trending towards failure.
Some displays can show only digits
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
. There are several types: