Laser Printers- Jack Welch 9C

How Laser Printers and Photocopiers Work

This picture shows how a laser printer would work if it was laid out flat.
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This is how a laser photocopier works normally. The paper is put face down on the photocopier then the lid of the printer is shut. A selenium coated drum inside gets a positive charge because of the darkness. Then light is shinned on the paper and goes through everywhere on the paper except where there is ink (the ink blocks the light from passing through) this light takes the charge away from the drum except where the light does not hit and this is where there is ink. As the light is being shined on the paper the drum is spinning. The the toner brush is then pushed against the drum and the negative ink is then attracted to the positive parts of the drum and then the ink is put on the drum as it spins and as this is hapening the paper is put against the spinning drum.
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The video below shows how a laser printer works.
How a laser printer works
The positive ink is attracted to the negative drum because the law of electrostatics states that opposites attract and like charges repel. This is because opposite charges want to trade electrons to become neutral.

The History of the Laser Printer

The technology was first proven in 1969 by Gary Starkweather and ten years later in 1979 the first black and white laser printer was produced by IBM. It wasn't until 1995 that Apple produced the first colour laser printer. The Image below shows the size of the first laser printer.
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