Laser printers are best known for their high volume , high printing quality , and clear output. The technology used in photocopy machines is also used in laser printers. It does not use any ribbon or liquid ink. A special type of powder ink called toner is used. This method focuses the laser beam on a photoelectric belt or drum , which produces an electrical charge, which enters the developer unit as the drum rotates. The developer unit charges the toner somewhat, thus attracting the undamaged part of the drum and charging more than is given on paper. As a result, the toner is transferred to the paper as it passes through the bottom of the drum. Finally the paper is passed through two heated rotating cylinders to place the toner attached to the paper so that the image / writing falls on the paper.