The laser printer is certainly the most popular type of electrophotographic printer. A cylindrical printer drum is coated with a film of photosensitive material. A laser source, guided by a mirror or prism assembly, electrostatically charges the drum in a pattern according to the image defined by the computer. The drum rotates past the light and then past a ~toner~ reservoir. Particles of toner are attracted to the charged spots on the drum, and are then transferred to an oppositely charged sheet of paper. Finally, a heated roller bonds the toner permanently on the paper to prevent smearing.
Laser printers are very versatile, offering high-quality graphics and text. This does not come without a price however, as high-end laser printers can cost thousands of dollars. The toner cartridges are expensive as well, especially compared to the ribbon of a |dot-matrix| or the cartridge of an |inkjet| printer.
