Technology Tip Number 122
Printer Principles

So how does a printer work anyway?

The Printer's Progress:

In the beginning there was the pen, paper and a room full of monks.  Eventually this was replaced by thetypewriter and carbon paper (if you’ve never heard of carbon paper before here’s a link to:  The Exciting History of Carbon Paper).  When computers came out there was a great urge to create “hardcopies” or printouts of whatever the computer did.  Initially they connected teletype machinesto early computers but these were eventually replaced with dot matrix printers.  By the late 1980’s the old dot matrix printers, with their messy ink ribbons and uniform letter spacing, were being replaced by better technologies.

Today there are basically two kinds of printers, Laser Printers and Ink Jet Printers.  The laser printers are the best choice for large scale printing while the ink jets are better for small scale printing.  Chances are you have an ink jet printer at home for example.

How they Work:
Ink Jet Printers – They spray tiny drops of ink onto the paper to create the image.  The dots are as small as 50 microns.  A human hair is about 70 microns for reference, so don’t bother looking for them.  For more information about how ink jet printers work we recommend this website: http://www.howstuffworks.com/inkjet-printer.htm   

Laser Jet Printers – They use static electricity to stick plastic powder (toner) on the paper and then melt it onto the paper using a hot roller.  That’s right, laser jets don’t use ink they use toner which is a very fine plastic powder.  For more information about how these printers work I recommend this website: http://computer.howstuffworks.com/laser-printer.htm   There are color laser jet printers by the way.  They use toner that is black, cyan, magenta and yellow to create all the colors of the rainbow.

PRACTICE ACTIVITY:  Try to identify whether the printers you use are Laser Jet Printers or Ink Jet Printers.

TO KEEP ON LEARNING:  You can learn more about computer printers by searching the internet for:

Computer Printer History
Ink Jet Printers
Laser Jet Printers

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