Categories of printer:
Non impact printer
Laser printer is a non impact printer.
Laser printer stand for light amplification by stimulated
emission of radiation.
Laser printer invented by gray Starweather at in 1969 when
American Xerox Corporation held a dominant position in
the copier market In 1960.
Laser printer contained:
A laser beam which is
contain negative charge.
Mirror or lens.
Toner hopper attached
with developing roller.
Drum core is called
receptor of light.
When data given to the computer then electronics
circuit activates Corona wire which is contain positive
charge gives to the drum.
When laser beam strike with the drum then erase the
positive charge and creates the negative charge .
Corona wire falls positive charge on drum . When laser
beams which is contain negative charges fall on drum
and strike with on positive charges then erase the
positive charges and drawing letters and images which
is to be printed on this drum. It is also known as
Toner contain a fine black powder. Since it has a
positive charge, the toner clings to the negative
discharged areas of the drum, but not to the positively
Before the paper rolls under the drum. This charge is
stronger than the negative charge of the electrostatic
image, so the paper can pull the toner powder away.
The photoreceptor is pressed or rolled over paper,
transferring the image.
The speed of paper passing through drum is very slow
and according to the speed of drum.
The paper passes through rollers in the fuser assembly
where heat of up to 200 °C (392 °F).
One roller is usually a hollow tube (heat roller) and the
other is a rubber backing roller (pressure roller). A radiant
heat lamp is suspended in the center of the hollow tube,
and its infrared energy uniformly heats the roller from the
Some printers use a very thin flexible metal fuser roller, so
there is less mass to be heated and the fuser can more
quickly reach operating temperature.
If paper moves through the fuser more slowly, there is more
roller contact time for the toner to melt, and the fuser can
operate at a lower temperature. Smaller, inexpensive laser
printers typically print slowly, due to this energy-saving
design, compared to large high speed printers where paper
moves more rapidly through a high-temperature fuser with
a very short contact time.
When the print is complete, discharge lamp removes
any electron on photoreceptor.
It is very fast printer.
It is no noise during the printing.
A typical laser printer provides a resolution of 1200 dpi
It printing speed is higher than inkjet printer.
The black and white printing cost of laser printer is
less than inkjet printer