Dot-matrix display

Example of an animated dot matrix display. Note unlit dots.

A dot matrix display is a display device used to display information on machines, clocks, railway departure indicators and many other devices requiring a simple display device of limited resolution. The display consists of a matrix of lights or mechanical indicators arranged in a rectangular configuration (other shapes are also possible, although not common) such that by switching on or off selected lights, text or graphics can be displayed. A dot matrix controller converts instructions from a processor into signals which turns on or off lights in the matrix so that the required display is produced.

Usual resolutions

Common sizes of dot matrix displays:

• 128×16 (Two lined)
• 128×32 (Four lined)
• 192×64 (Eight lined)

Dot Matrix is used in displays

Classic 5x7 dot matrix LCD display used in some early cellphones and vending machines

Usual character resolutions

• A common size for a character is 5×7 pixels, either separated with blank lines with no dots (in most text-only displays), or with lines of blank pixels (making the real size 6x8). This is seen on most graphic calculators, such as CASIO calculators or TI-82 and superior.
• A smaller size is 3×5 (or 4x6 when separated with blank pixels). This is seen on the TI-80 calculator as a "pure", fixed-size 3×5 font, or on most 7×5 calculators as a proportional (1×5 to 5×5) font. The disadvantage of the 7×5 matrix and smaller is that lower case characters with descenders are not practical. A matrix of 11×9 is often used to give far superior resolution.
• Dot matrix displays of sufficient resolution can be programmed to emulate the customary seven-segment numeral patterns.

See also

• Flip-disc display
• Seven-segment display
• Fourteen-segment display
• Sixteen-segment display
• LED panel
• Display examples