Types of Printer
1) Dot Matrix Printer:
Dot matrix Printers are often used to print multipart forms. It prints a character in the form of a group of dots called matrix. If you look very closely at the characters printed on a DMP, you can see dots.
The print head consists of printing pins arranged in the form of a matrix. A signal from the computer causes certain pins to hit the ribbon, creating a pattern of dots a dots and hence a character on the paper. The print head goes on printing the characters by shifting itself in a appropriate manner. The quality of printing is determined by the number of pins on the on the printer head. More the number of pins better is the quality of printing. Dot matrix printer with two types of print heads, one with 9 pins and other with 24 pins are available. The 24 pin DMP has facility to print in colour. The speed of printing of these type of printers is about 240 – 300 characters per second (cps).
Basically line printer is also a DMP but, the number of heads used is more than one. Thus, a single line is printed by a number of heads simultaneously increasing the speed of printing. The printing speed of these printers is of the order of 60 -100 lines per minute. (lpm).
In inkjet printers, characters are printed on a paper by squirting ink through an array of tiny nozzles of an ink cartridge costs more than ribbon. Because there is no impact noise from the pins striking the paper, inkjet printers are quite.
Laser printers have become increasingly popular where high quality is required. Laser printer operates much like a photocopier. A laser beam scans a bit mapped image of the page on to an electrostatic drum, in a process called exposure. Toner is then attracted to the charged areas, in a process called development. It is then transferred electro statically to the paper, and fused by using hot pressure rollers.
Laser printers are more complex than other types of printers, and consequently expensive. In recent years, both their size and cost is decreasing.