The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook American Heritage Coll.
Impact printers use a mechanical hammering device to produce each character.
Although noisy, impact printers can produce multiple copies of business forms simultaneously using carbon or carbonless techniques. 1 Nonimpact printers use thermal and electrostatic, rather than mechanical, techniques. Laser printers form an image of the output on a selenium-coated drum using laser light that is turned on and off by data from the computer and then transfer the output from the drum using photocopying techniques. Nonimpact printers are quieter than impact printers and produce higher quality output, especially of graphics, but at a greater cost per page. See also laser printer .