Printers that create the image on a paper by a ribbon physically against the paper are known as the Impact printers. Quite an impact they make there. There was a kind of printer known as the daisy printer which essentially was an electric typewriter have vanished now, but their relative dot-matrix printers still stuck around to some degree.
Advantages and disadvantages of impact printers
They are not quite popular in a home office or home since they do not deliver high-quality, and flexibility at a low cost, but they are widely popular in business. This is for two major reasons – one, they have a large installed base, and they can be used as something called ‘Multiform parts’ due to the fact that they literally strike the paper.
On the other hand, impact printers are actually quite fast in terms of speed and incredibly flexible, but they can be quite noisy as well. Impact printer’s print quality is not critical, and the result is quite acceptable. Computers that print multipart forms like a point of sale (POS) machines, use a kind of special paper known as impact paper, that can be used to print receipts in duplicate, triplicate, and more. POS machines represent the major market change that uses impact printers and is largely getting replaced by older dot-matrix, which is still used to some degree.
The way dot-matrix printers work is that they use a grid, or matrix, of tiny pins known as print wires. These things together are then struck on an inked printer ribbon and generate images on paper. The printhead is the case that holds the print wires. It uses either a 9-pin or 24-pins and treats each page as a picture broken down into a dot-based raster image. The significant difference between these two is that the 9-pin produces a draft quality image while the 24-pins produces a letter quality or near letter quality (NLQ).
The BIOS that these printers have, which can come in as a built-in printer driver, generates and interprets the image the same way a monitor does. Based on the individual dots. Essentially, the more pins you have, the better the quality is.
Continuous-feed paper technology
Many of these dot-matrix printers use a technique called continuous-feed paper that has holes on its sides, engaged by metal sprockets to pull out the paper through. This is called tractor-feed paper. The name has been given such since they look like the wheels on a tractor. Note that printers can use duplex assemblies as well. Duplex assemblies enable the pages to have print on both sides. Some of the printers include this feature and come in built-in, while others require additional hardware that helps flip the paper for the printer.