A photocopier is a device that (seemingly magically) instantly makes copies of images or text on a paper. To make copies, a process called xerography is employed. Xerography is the same process used by laser printers. Xerography was invented by Chester F. Carlson in 1937. Xerography is the process of changing the static charge of a specially coated surface using light. In photocopiers, a mirror image of the original page is shone onto this surface, and the copy is created.

The cool thing about xerography is that it is totally dry. The processes that were used before photocopiers required liquids. Chester Carlson, the guy who invented xerography, was a patent attorney and physicist. In 1947, the Haloid Company agreed to market xerography, and got the rights to Carlson's invention. The company was renamed to Xerox. The first automatic copier was available in 1959. In 1970, color xerography was developed.

Photocopiers vary greatly in their ability. For example, the copier I have built into my HP OfficeJet 710 is slow, and color copying is not possible without the assistance of a computer. Special features in advanced copiers include:

  • speeds of up to 2 pages/second
  • automatic feeders
  • staplers
  • collators
  • double-sided copying/printing
  • document enlarging/shrinking
  • color copying
  • My science teacher in 7th grade had one of these advanced copiers. She had 30 worksheets she wanted each of us to do. She inserted the worksheets, pushed a few buttons, and the copier went to work. Within two minutes, there were 26 packets with 15 pages each (a worksheet on either side), and each packet was stapled. The warmth of the newly copied page felt so cool... (oxymoron alert!)

    Anyway, you probably want more detail on how this magical thing works. Well, it's quite easy:1

    1. A drum is coated with light sensitive material charged with static electricity.
    2. Light is reflected from the original through a lens.
    3. A positively charged image forms on the light sensitive surface.
    4. The toner gets dusted on the drum and sticks to the image.
    5. The image is then passed onto positively charged paper and heated for a moment.
    6. The heat melts the toner and creates a copy.

    Photocopiers have major implications on copyright law. Before photocopiers, if you wanted to copy a book, you needed to either own a printing press or write down the entire book by hand. Photocopiers made it as easy as one, two, three! Copyright law was tightened after photocopiers became available. Also, photocopiers had major implicationss on the way people communicated. Whenever you sign any major document, you expect a copy, right? Well, before photocopiers, you probably wouldn't get an exact copy. Photocopiers also allowed people to share the exact same info on different pieces of paper without the use of a printing press.

    So, now that you've heard about this magical thing, you probably want to use it, right? Well, most public photocopiers work in a uniform fashion. Follow the following steps:

    1. Insert the correct amount of $$
    2. Lift the lid and insert the document you wish to copy, face-down
    3. Enter the number of copies you want on the keypad
    4. Press Start! (or a green button resembling it)

    Isn't that a great deal? You put in money and you get a piece of paper with some ink on it! If you have a copier at home, it probably works differently (you probably don't have to put in $$), so check the User Manual to see how to use it.

    1 From The History of the Photocopier by Matthew Flenley: http://home.vicnet.net.au/~twt/photocopier.html