Seven Segment Display
A seven-segment display, or 7 segment indicator, is a form of the 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 calculators, and other electronic devices that display numerical information.
An LED or Light Emitting Diode, is a solid-state optical PN-junction diode which emits light energy in the form of “photons” when it is forward biased by a voltage allowing current to flow across its junction, and in Electronics we call this process electroluminescence.
Seven Segment Display Features
The seven elements of the display lights in different combinations to represent the Arabic numerals. Often the seven segments arranged in an oblique (slanted) arrangement, which aids readability. In most applications, the seven segments are of nearly uniform shape and size (usually elongated hexagons, though trapezoids and rectangles can also be used), though in the case of adding machines, the vertical segments are longer and more oddly shaped at the ends in an effort to further enhance readability.
The numerals 6 and 9 are visible by two different glyphs on seven-segment displays, with or without a ‘tail’.
The numeral 7 also has two versions, with or without segment F.
The seven segments arrange as a rectangle of two vertical segments on each side with one horizontal segment on the top, middle, and bottom.
Additionally, the seventh segment bisects the rectangle horizontally.
There are also fourteen-segment displays and sixteen-segment displays; however, these have mostly been replaced by dot matrix displays.
Twenty-two segment displays capable of displaying the full ASCII character set were briefly available in the early 1980s but did not prove popular.
The segments of a 7-segment display are referred to by the letters A to G, where the optional decimal point (an “eighth segment”, referred to as DP) is used for the display of non-integer numbers.