Dot Matrix Printers

These machines produce characters and illustrations by striking pins against an ink ribbon to produce closely spaced dots in an appropriate shape. Dot matrix printers are relatively expensive and do not produce high-quality output. However, they can print to multi-page forms (that is, carbon copies or carbonless copies), something laser and inkjet printers cannot do. Dot matrix printers are also more flexible than daisy wheel printers, because they can print graphics and text in many typefaces. Although reasonably expensive to buy, they are far cheaper to operate than lasers or inkjets, because their ribbons are non-proprietary commodities, and so to not require the “technological rent” one must pay for ink or toner cartridges. That is why this is the technology of choice for ATM machines, cash registers and many other point-of-sales terminals.

Another reason for their widespread use is that they are highly durable and relatively easy and cheap to repair, and when not used for a long time, their ink tends not to dry out. Also, they are capable of using continuous paper feed rather than requiring individual sheets, so there may be far fewer paper misfeeds, and they stand up well to adverse industrial conditions that might put other print technologies out of business. Their main uses are in areas of intensive transaction processing systems that churn out a lot of printing.

Dot-matrix printers vary in two important characteristics:

· speed: refers to characters per second (cps), which can vary from about 50 to over 500. Most machines offer different speeds depending on the quality of print desired; as quality goes up, speed naturally goes down.

· print quality: Determined by the number of pins (the mechanisms that print the dots), which can vary from 9 to 24. The best dot-matrix printers have 24 pins, can produce near letter-quality type, although one can still see a difference upon close examination.

· noise: Compared with laser and ink-jet printers, dot-matrix printers are notorious for making quite a racket. Noise deadening is available, and should be considered part of the overall purchase price.

Also take into account the input tray or trays, the amount of memory, and the printer’s compatibility with your operating system.