Electrostatics
Photocopier
How It All Started
(OnScience9)
How It Works
The original copy is placed onto a sheet of glass.
The image of the page is projected onto a positively charged drum.
The drum has a coating that conducts electricity when light falls on it.
Parts of the drum which are lit by the projected image lose their electrostatic charge when they start to conduct.
The black toner is negatively charged.
This toner is attracted to the positively charged parts of the drum.
The drum rotates and rolls against a piece of copier paper.
The toner is transferred from the drum to the paper making a black and white image of the original.
Finally, the paper is heated, which makes the toner stil to it ("fixing" the image)
(Bitesize)
THe parts of a photocopier
Platen / Document Feeder
The photocopier's platen is the glass plate on which you place the document to be copied.
Image Capture
A lens or scanner lies below the platen. Most photocopier models available today are digitally based and use a scanner to capture the image. Historically, image capture was done by a lens and a mirror.
Toner
Toner is the "ink" used by the photocopier. In most cases, it's a powder-like component specially formulated to carry and electrical charge.
Paper Input
Paper is held in either a tray or a drawer.
Drum
Once the image is captured by the lens or scanner, its inscribed onto a photoreceptive device called the drum. As a central component, the drum receives the image from the input and transfers it to the paper. It is charged electrostatically.
Fuser
The fuser is made up of a heat roller and a pressure roller. After the toner is transferred to the paper, the sheet passes between the two rollers. The combination of heat and pressure literally bake the toner into the sheet of paper making the image permanent.
Citations
"Electrostatic Charge." Gcisscience. Web. 20 Feb. 2013.
http://www.gcsescience.com/pse10-electrostatic-photocopier.htm
"Copiers: A Playful Look at How They Work." Youtube.com. Web. 20 Feb. 2013.
http://www.youtube.com/watch?v=BJXOBfWz7yA
Blake, Leesa, Michael Mazza, Alex Mills, Frank Mustoe, Jim Ross, Thomas Stiff. "Photocopiers, Laser Printers, and Scanners." On Science 9. 2009. Print.
"Parts of a Photocopier." EHow. Web. 20 Feb. 2013.