How does a Photocopier work?
How is Electrostatic Charge used in a Photocopier?
A photocopier uses electrostatic charge to produce a copy.
The original (the page you want copied) is placed onto a sheet of glass.
An image of this page is projected onto a positively charged drum.
The drum has a coating that conducts electricity when light falls
on it. The parts of the drum which are lit by the projected image
lose their electrostatic charge when they start to conduct.
A black powder(called toner) is negatively charged.
The 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 by passing it between heating drum which makes the toner stick to it. This is called "fixing" the image.
When you use a photocopier you can feel that the copier paper is still warm.
