laser printer, a computer printer that produces high-resolution output by means of a process that is similar to photocopying. In place of reflected light from an image (as is used in xerography), a laser printer uses data sent from a computer to turn a laser beam on and off rapidly as it scans a charged drum. The drum then attracts toner powder to the areas not exposed to the light. Finally, the toner is fused to paper over a belt by heated rollers. In a write-black printer the laser positively charges the printed areas to attract the toner, which gives better detail than a write-white printer. In a write-white printer, the beam negatively charges the areas not to be printed to repel the toner, which gives a denser image. Faster, quieter, and capable of producing more attractive results than standard printers, laser printers have become an important means of printing business documents since they became more generally available (1984) for personal computers. See also desktop publishing.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.