Printers

  • It is an external output device that takes data from a computer and generates output in the form of graphics/text on a paper.
Types:
  • Impact Printers
  • Non Impact Printers

Impact Printers:

  • It makes contact with the paper.
  • It is usually forms the prints the image by representing an inked ribbon against the paper using a hammer or pins.
  • There are 6 types of impact printers.

1. Dot Matrix Printers:

  • This uses print heads containing from 9 to 24 pins.
  • These pins produces the patterns of dots on the paper to form characters.
  • The 24 pins dot matrix printer produces more than 9 pin printer, which result  in much better quality and clear characters.
  • It printing speed of 100-600 characters per second.



2. Daisy Wheel Printers:

  • In order to get quality of type found on typewriters, a daisy wheel impact printer can be used.
  • It is looks like daisy.
  • At the end of each "Petal" is a fully formed character which produces solid line.
  • Its printing speed of 25-55 characters per second.


3. Drum Printers:

  • Drum printer consists of a solid, cylindrical drum that has raised character in bands on its surface.
  • It contains 80-132 print positions.
  • Its printing speed of 300-2000 lines per minute.



4. Line Printers:
  • Line printer used for print a whole line at once.
  • It range of 1200 to 6000 lines per minute.
  • Drum, Chain, and Band printers are line printers.


5. Chain Printers:
  • Chain printer uses a chain of print characters wrapped around two pulleys.
  • Like the drum printer, there is one hammer for each print position.
  • Its printing speed of 400-2500 characters per minute.



6. Band Printers:
  • It is operates similar to chain printer except it uses a band instead of a chain and has fewer hammers.
  • Band printer has a steel band divided into five sections of 48 characters each.
  • Font style can easily be changed by replacing band or chain.



Non Impact Printers:
  • Non impact printers do not use a striking device to produce characters on the paper and because these printers do not hammer against the paper.
  • There 2 types of non impact printers.

1. Inkjet Printers:

  • It is work same as dot matrix printer.
  • The dots are formed by tiny droplets of ink.
  • It form characters on paper by spraying ink from tiny nozzles through an electric field that arranges the charged ink particles into characters.
  • Its speed range is 250 characters per second.



2. Laser Printers:
  •  It is work like a photocopy machine.
  • It produce images on paper by directing a laser beam at a mirror which bounces the beam onto a drum.
  • The drum has a special coating with ink powder.
  • Its printing speed is 21000 line per minute.



Advantages:
  • Laser printers speed, efficiency, and print quality is high compare to other printers.
  • It does not produce any noise.
  • It also produce color prints.
Disadvantages:
  • Cost is high.
  • It emits Ozone and are hazardous to health and the atmosphere.
My notes images: