Laser printer





A laser printer is a common type of computer printer that produces good
quality printing, and is able to produce graphics.

The process is very similar to the type of dry process photocopier first
produced by Xerox.

An electric charge is first sprayed onto a revolving drum by a corona wire.
The drum has a surface of a special plastic or garnet. Electronics drives a
system that writes light onto the drum. The light causes the electrostatic
charge to leak from the exposed parts of the drum. The surface of the drum
passes through a bath of dry plastic powder. The charged parts of the drum
electrostaticaly attract the particles of powder. The drum then deposits the
powder on a piece of paper. The paper passes through a fusor, which bonds
the plastic powder to the paper.

Each of these steps has numerous technical choices. One of the more
interesting choices is that most "laser" printers actually use a linear
array of light-emitting diodes to write the light on the drum. The toner can
be either wax or plastic. The paper can be oppositely charged, or not. The
fusor can be an infrared oven, a heated roller, or (on some very fast,
expensive printers) a xenon strobe.

The slowest printers of this type print about four pages per minute, and are
inexpensive. The fastest print mass mailings (commonly for utilities) at
several thousand pages per minute.

The cost of this technology depends on a combination of costs of paper,
toner replacement, and drum replacement. Often printers with soft plastic
drums can have a very high cost of ownership that does not become apparent
until the drum requires replacement. Follow manufacturer's instructions on
replacing these components.

One helpful trait is that in very high volume offices, a duplexing printer,
that prints both sides, can often halve paper costs, and reduce filing
volumes and floor weight as well.

Many premium units also have a toner-conservation mode. It can be
substantially more economical at the price of only slightly lower contrast.

Aside from these components, typical maintenance is to vacuum the mechanism,
and eventually clean or replace the paper-handling rollers. The rollers are
rubber, and eventually become covered with slippery paper dust. They can
usually be cleaned with a damp lint-free rag.