IMPACT PRINTER

DOT MATRIX PRINTER

Dot-matrix printer is an impact printer that produces text and graphics when tiny wire pins on the print head strike the ink ribbon. The print head runs back and forth on the paper like a typewriter. When the ink ribbon presses on the paper, it creates dots that form text and images. Higher number of pins means that the printer prints more dots per character, thus resulting in higher print quality.

Dot-matrix printers were very popular and the most common type of printer for personal computer in 70’s to 80’s. However, their use was gradually replaced by inkjet printers in 90’s. As of today, dot matrix printers are only used in some point-of-sales terminals, or businesses where printing of carbon copy multi-part forms or data logging are needed.

Advantages of dot matrix printer:

1) Can print on multi-part forms or carbon copies

2) Low printing cost per page

3) Can be used on continuous form paper, useful for data logging

4) Reliable, durable

Disadvantages of dot matrix printer:

1) Noisy

2) Limited print quality

3) Low printing speed

4) Limited color printing



LINE MATRIX PRINTER

Line matrix printer is an impact printer that prints a line at a time. Printronix pioneered this technology in 1974. Line matrix and band printers are the surviving line printer technologies, but line matrix can print graphics, whereas band printers cannot. Line matrix resolution is in the 70 to 140 dpi range and speeds range from 400 to 1,400 lpm.



Line matrix printers offer medium resolution, monochrome printing with a very low ribbon cost. They also provide high speed; for example, printing a three-part form at 1,200 lpm is equivalent to a 65 ppm page printer. Line matrix printers can exist in harsh conditions and are often found in warehouses and other industrial environments.



The print mechanism is a row of dot hammers that is almost as wide as the page. The hammers are mounted on a shuttle that oscillates back and forth approximately two inches in a track. The hammers are magnetically released at the appropriate time and bang into a ribbon and onto the paper.



BAND PRINTER

Band printer is a line printer that uses a metal band, or loop, of type characters as its printing mechanism. The band contains a fixed set of embossed characters that can only be changed by replacing the band. The band spins horizontally around a set of hammers, one for each print column. When the required character in the band has revolved to the selected print column, the hammer pushes the paper into the ribbon and against the embossed image of the letter, digit or symbol.


Band printers can print up to approximately 2,000 lpm and can exist in very harsh industrial environments, although they are mostly used in datacenters. Band printers and line matrix printers are the two surviving line printer technologies.