Printers are common in use in all the offices and organizations. Mainly there are three types of printers. They are dot matrix printers, inkjet printers and laser printers. Dot matrix printer is an impact printer (a printer which works by physically striking an ink ribbon that is placed on the paper) while inkjet printers and laser printers are non-impact printers. In a dot matrix printer, a hammer print head which consists of pins represents the character or the image. Dot matrix printers are bi-directional printers. The speed of the dot matrix printer is measured in characters per second and normally it ranges from 60 to 600 cps. Some other impact printers which are rarely used are line printer and band printer. In an inkjet printer, characters and images are sprayed in small drops of ink on the paper. Inkjet print quality is high and up to 30 pages can be printed in a minute. Laser technology is used in laser printer which is a high speed high quality printer. The major components of a laser printer are mirror, laser scanning unit, toner, photoreceptor drum, fuser and a paper tray.
