A vane display is a type of

7-segment display A seven-segment display is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic c ...

. Unlike LED and

VFD VFD may refer to: * Factory Workers' Union of Germany, (german: Verband der Fabrikarbeiter Deutschlands, link=no), a former trade union in Germany * Vacuum fluorescent display, a display device on consumer electronics equipment * Variable-freque ...

segmented displays, vane displays are composed of seven physical surfaces (vanes), typically painted white, but occasionally other colors, such as yellow or fluorescent green. If a segment is to be displayed as "off", it will be rotated so that its edge faces forward, with the painted surface pointing away and not visible. A segment that is to be displayed as "on" will be rotated so that the painted surface is shown. Vane displays operate in a similar manner to

flip-disc display The flip-disc display (or flip-dot display) is an electromechanical dot matrix display technology used for large outdoor signs, normally those that will be exposed to direct sunlight. Flip-disc technology has been used for destination signs in ...

s, in that the segments are quickly moved using electromagnets. Some variants used where the display need not necessarily be changed quickly use electric motors to rotate the displays in and out of place. Vane displays have been used in

game show A game show is a genre of broadcast viewing entertainment (radio, television, internet, stage or other) where contestants compete for a reward. These programs can either be participatory or demonstrative and are typically directed by a host, ...

s and on scoreboards in sports arenas and stadiums. Like

eggcrate display A text display is an electronic alphanumeric display device that is mainly or only capable of showing text, or extremely limited graphic characters. This includes electromechanical split-flap displays, vane displays, and flip-disc displays; all ...

s, they are not washed out by bright lights such as those found in a television studio. Another benefit of the vane display is that if the power supply is lost, the display will continue to show whatever the last value was before power was cut. However, like flip-disc displays, if many elements must be changed at the same time, the flipping displays may present a significant amount of noise.

Examples

*American and Canadian

s have used vane displays to display contestants' scores or for countdown clocks. Prior to this, the slide display was more common. *The

Oklahoma Turnpike Authority The Oklahoma Turnpike Authority (formerly Oklahoma Transportation Authority) is an agency of Oklahoma that deals with issues regarding the Oklahoma turnpike system. Along with the Oklahoma Department of Transportation, the Authority is the prima ...

has used vane displays on several of their automatic toll collection baskets to display the toll due. *The New Jersey Turnpike previously used vane displays for all roadway

speed limit Speed limits on road traffic, as used in most countries, set the legal maximum speed at which vehicles may travel on a given stretch of road. Speed limits are generally indicated on a traffic sign reflecting the maximum permitted speed - expre ...

signs; it was not uncommon to see them blank; VMS sign replacements now use a new electronic speed limit sign. Various other locations with variable speed limits also employ either this or eggcrate, flip-disc, or

LED display A LED display is a flat panel display that uses an array of light-emitting diodes as pixels for a video display. Their brightness allows them to be used outdoors where they are visible in the sun for store signs and billboards. In recent ...

s to display the current speed limit for the area. Display technology {{technology-stub