A fourteen-segment display (FSD) (sometimes referred to as a starburst display or Union Jack display) is a type of display based on 14 segments that can be turned on or off to produce letters and numerals. It is an expansion of the more common

seven-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, bas ...

, having an additional four diagonal and two vertical segments with the middle horizontal segment broken in half. A seven-segment display suffices for numerals and certain letters, but unambiguously rendering the

ISO basic Latin alphabet The ISO basic Latin alphabet is an international standard (beginning with ISO/IEC 646) for a Latin-script alphabet that consists of two sets ( uppercase and lowercase) of 26 letters, codified in various national and international standards and ...

requires more detail. A slight variation is the

sixteen-segment display A sixteen-segment display (SISD) is a type of display based on sixteen segments that can be turned on or off to produce a graphic pattern. It is an extension of the more common seven-segment display, adding four diagonal and two vertical segments ...

which allows additional legibility in displaying letters or other symbols. A decimal point or

comma The comma is a punctuation mark that appears in several variants in different languages. It has the same shape as an apostrophe or single closing quotation mark () in many typefaces, but it differs from them in being placed on the baseline ...

may be present as an additional segment, or pair of segments; the comma (used for triple-digit groupings or as a

decimal separator A decimal separator is a symbol used to separate the integer part from the fractional part of a number written in decimal form (e.g., "." in 12.45). Different countries officially designate different symbols for use as the separator. The choi ...

in many regions) is commonly formed by combining the decimal point with a closely 'attached' leftwards-descending arc-shaped segment. Electronic alphanumeric displays may use LEDs, LCDs, or

vacuum fluorescent display A vacuum fluorescent display (VFD) is a display device once commonly used on consumer electronics equipment such as video cassette recorders, car radios, and microwave ovens. A VFD operates on the principle of cathodoluminescence, roughly ...

devices. The LED variant is typically manufactured in single or dual character packages, allowing the system designer to choose the number of characters suiting the application. Often a

character generator A character generator, often abbreviated as CG, is a device or software that produces static or animated text (such as news crawls and credits rolls) for keying into a video stream. Modern character generators are computer-based, and they can ...

is used to translate 7-bit ASCII character codes to the 14 bits that indicate which of the 14 segments to turn on or off.

Character encoding

By lighting different elements, different characters can be displayed. In a 14-segment display, there is also an optional 15th segment which is a decimal point (denoted as "DP").

Decimal

Latin alphabet

A 14-segment display is mostly used to display text because the 14 elements allow all

Latin letters The Latin script, also known as Roman script, is an alphabetic writing system based on the letters of the classical Latin alphabet, derived from a form of the Greek alphabet which was in use in the ancient Greek city of Cumae, in southern ...

to be displayed both in

upper case Letter case is the distinction between the letters that are in larger uppercase or capitals (or more formally ''majuscule'') and smaller lowercase (or more formally ''minuscule'') in the written representation of certain languages. The writing ...

and

lower case Letter case is the distinction between the letters that are in larger uppercase or capitals (or more formally ''majuscule'') and smaller lowercase (or more formally ''minuscule'') in the written representation of certain languages. The writing ...

(with a few exceptions like "s").

Applications

Multiple-segment display devices use fewer elements than a full dot-matrix display, and may produce a better character appearance where the segments are shaped appropriately. This can reduce power consumption and the number of driver components. Fourteen-segment gas-plasma displays were used in

pinball machines Pinball games are a family of games in which a ball is propelled into a specially designed table where it bounces off various obstacles, scoring points either en route or when it comes to rest. Historically the board was studded with nails call ...

from 1986 through 1991 with an additional

and period part making for a total of 16 segments. Fourteen and sixteen-segment displays were used to produce

alphanumeric Alphanumericals or alphanumeric characters are a combination of alphabetical and numerical characters. More specifically, they are the collection of Latin letters and Arabic digits. An alphanumeric code is an identifier made of alphanumeric c ...

characters on

calculator An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. The first solid-state electronic calculator was created in the early 1960s. Pocket-sized ...

s and other

embedded system An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded ...

s. Applications today include displays fitted to telephone

Caller ID Caller identification (Caller ID) is a telephone service, available in analog and digital telephone systems, including voice over IP (VoIP), that transmits a caller's telephone number to the called party's telephone equipment when the call i ...

units, gymnasium equipment, VCRs,

car stereo Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants. Until the 1950s it consisted of a simple AM radio. Additions since then have included FM radio (1952), ...

microwave oven A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce ...

slot machine A slot machine (American English), fruit machine (British English) or poker machine (Australian English and New Zealand English) is a gambling machine that creates a game of chance for its customers. Slot machines are also known pejoratively a ...

s, and DVD players. Such displays were very common on pinball machines for displaying the score and other information, before the widespread use of dot-matrix display panels.

Incandescent lamp

Multiple segment alphanumeric displays are nearly as old as the use of electricity. A 1908 textbook describes an alphanumeric display system using incandescent lamps and a mechanical switching arrangement. Each of 21 lamps was connected to a switch operated by a set of slotted bars, installed in a rotating drum. This ''commutator'' assembly could be arranged so that as the drum was rotated, different sets of switches were closed and different letters and figures could be displayed. The scheme would have been used for "talking" signs to spell out messages, but a complete set of commutator switches, drums and lamps would have been required for each letter of a message, making the resulting sign quite expensive.

Cold-cathode neon

A few different versions of the fourteen segment display exist as cold-cathode neon lamps. For example, one type made by Burroughs Corporation was called "Panaplex". Instead of using a filament as the incandescent versions do, these use a cathode charged to a 180 V potential which causes the electrified segment to glow a bright orange color. They operated similarly to

Nixie tube A Nixie tube ( ), or cold cathode display, is an electronic device used for displaying numerals or other information using glow discharge. The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbo ...

s but instead of the full-formed numeric shapes, used segments to make up numerals and letters.http://www.ineedcaffeine.com/content/the-burroughs-b7971/ Burroughs B7971 segmented display tube illustration, retrieved 2012 July 19

Examples

File:14segment LED Display.jpg, A four-character 14-segment display. Note unbroken top and bottom segments in comparison with a sixteen-segment display. File:14segtxt.png, LCD fourteen-segment display as used on Hewlett-Packard's HP-41 range of programmable engineering calculators from the late 1970s File:14 Segment LCD.jpg, 14-segment LCD as used on the Hewlett-Packard HP3478A Multimeter File:Car stereo display.jpg, LCD fourteen-segment characters on an after-market car stereo File:Sony MHC-EC55.jpg, alt=A Sony Mini Hi-Fi Component System which utilizes a fourteen-segment display., An inverted, backlit fourteen-segment LCD display used in a Sony MHC-EC55 Mini Hi-Fi Component System

References

External links

{{DEFAULTSORT:Fourteen-Segment Display Display technology