Sixteen-segment display

Arabic numerals and letters of the ISO basic Latin alphabet on a typical 16-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 and splitting the three horizontal segments in half. Other variants include the fourteen-segment display which does not split the top or bottom horizontal segments, and the twenty-two-segment display^[1] that allows lower-case characters with descenders.

Often a character generator is used to translate 7-bit ASCII character codes to the 16 bits that indicate which of the 16 segments to turn on or off.^[2]

Applications

Sixteen-segment displays were originally designed to display alphanumeric characters (Latin letters and Arabic digits). Later they were used to display Thai numerals^[3] and Persian characters.^[4] Non-electronic displays using this pattern existed as early as 1902.^[5]

Before the advent of inexpensive dot-matrix displays, sixteen and fourteen-segment displays were some of the few options available for producing alphanumeric characters on calculators and other embedded systems. However, they are still^[update] sometimes used on VCRs, car stereos, microwave ovens, telephone Caller ID displays, and slot machine readouts.

Sixteen-segment displays may be based on one of several technologies, the three most common optoelectronics types being LED, LCD and VFD. The LED variant is typically manufactured in single or dual character packages, to be combined as needed into text line displays of a suitable length for the application in question; they can also be stacked to build multiline displays.

As with seven and fourteen-segment displays, a decimal point and/or comma may be present as an additional segment, or pair of segments; the comma (used for triple-digit groupings or as a decimal separator in many regions) is commonly formed by combining the decimal point with a closely 'attached' leftwards-descending arc-shaped segment. This way, a point or comma may be displayed between character positions instead of occupying a whole position by itself, which would be the case if employing the bottom middle vertical segment as a point and the bottom left diagonal segment as a comma. Such displays were very common on pinball machines for displaying the score and other information, before the widespread use of dot-matrix display panels.