Electrostatics
The Photocopier
How the Photocopier works Using Electrostatics
The Six Steps:
1. Image being copied is placed on glass plate face down and when copied the selenium-coated drum is given a positive charge in the darkness
2. A light gets projected onto the image and moves across the paper
3. Light reflects white portions of the paper being copied. Electrons from the aluminum base of the drum move to these light areas, which neutralizes the charge that was there. Dark areas on the drum, representing the information that is being copied, and retaining a positive charge. The surface of the drum contains an electrostatic image of the information being copied.
4. The machine spreads toner over the surface of the drum. Toner is a fine black powder, consisting of pigments that coat tiny plastic beads. The toner is attracted to the positive parts of the drum, which represent an image of the paper being copied.
5. As the drum rotates, it pulls a sheet of paper from the input trays. The sheet of paper is given a larger positive charge than the drum. The toner is transferred to the paper as the paper presses against the drum
6. The paper then passes through heated Teflon rollers. The heat melts the plastic beads in the toner, and the rollers press the black powder into the paper. As the copy finishes and leaves the inner workings of the machine, it is still warm.
Diagram of the Photocopier
History of the Photocopier
Why Electrostatics are used in a Photocopier
The Photocopier Cycle
References
-France , Colin . "Electrostatic Charge ." (2013): n.pag. Web. <http://www.gcsescience.com/pse10-electrostatic-photocopier.htm>.
-Meeker-O'Connell, Ann. "How Photocopiers Work ." (1998): n.pag. Web. <http://home.howstuffworks.com/photocopier1.htm>.
-"Uses of electrostatics ." BBC (2013): n.pag. Web. <http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/radiation/electrostaticsusesrev1.shtml>.