Dot-matrix display

A dot-matrix display is a low-cost electronic digital display device that displays information on machines such as clocks, watches, calculators, and many other devices requiring a simple alphanumeric (and/or graphic) display device of limited resolution.^[1]

A 16×2-character dot-matrix display, where each character is made from a grid of 5×7 dots

The display consists of a dot 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 dots, text or graphics can be displayed. These displays are normally created using LCD, OLED, or LED technology.^[2][3] A dot-matrix display controller converts instructions from a processor into signals that control the individual dots in the matrix so that the required display is produced.

History

The dot-matrix display is also known by the obsolete term "punktmatrix display”^{[citation needed]} (German for dot-matrix) due to the dot matrix being created in Germany by Rudolf Hell in 1925.

In September 1977, the US Army wrote up a form to the Westinghouse Research and Development Center requesting a more effective energy source that soldiers could use in their technology in the field.^[2] Japan and America were using the LCD matrices to develop Casio TVs from 1984 to 2000 creating and experimenting with different display setups.^[4] In the 1980s and 1990s, dot-matrix displays were introduced into several technologies including televisions, computers, video game systems, and pinball machines. Dot-matrix displays were added into new pieces of technology as a background part of LCD or OLED displays^[5] as the technology improved.

Pixel resolutions

A four-line dot-matrix LCD

Common sizes of dot-matrix displays:

• 128×16 (Two-line)
• 128×32 (Four-line)
• 128×64 (Eight-line)

Other sizes include:

• 92×31 (Four or three-line)

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 6×8). This is seen on most graphic calculators, such as Casio calculators or TI-82 and superior.
• A smaller size is 3×5 (or 4×6 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 a far superior resolution.
• Dot-matrix displays of sufficient resolution can be programmed to emulate the customary seven-segment numeral patterns.
• A larger size is 5×9 pixels, which is used on many "natural display" calculators.

See also

• Display examples
• Flip-disc display
• Fourteen-segment display
• Hitachi HD44780 LCD controller
• LED panel
• Sixteen-segment display
• The military request form source number 2.^[6]
• Detailed manual from SHARP Corporation.^[7]

References

1. "Dot Matrix Definition". techterms.com. Retrieved 2021-09-22.
2. Brody, Thomas P.; Luo, Fang C.; Davies, David H. (1977-09-01). "Thin Film Transistor-Addressed Display Device". Archived from the original on June 1, 2022.
3. "TFT vs. IPS Display: What's the Difference?". Nauticomp. 2017-09-11. Retrieved 2021-09-22.
4. "Part 6: The history of Pocket Television". www.guenthoer.de. Retrieved 2021-09-22.
5. "Dot matrix LCD displays module or as OLED, for text graphics". www.lcd-module.com. Retrieved 2021-09-22.
6. Article title ^{[bare URL PDF]}
7. https://web.archive.org/web/20220609050959/https://eecs.oregonstate.edu/education/docs/datasheets/lcd-spec.pdf ^{[bare URL PDF]}