Transcription: Xerography is based on the principle that a certain material can retain an electrostatic imprint of a brightly lit image. When a document is placed in a copier, a bright light is bounced off the paper, through a lens, and onto a specially coated drum. The coating becomes electrostatically charged with a mirror image of the document. As the drum rotates, the fine black particles that make up the ink, called toner, are attracted to the charged areas on the drum, the same areas that would be the print on the paper. As copy paper is rolled over the drum, a heat roller fuses the toner from the drum ...
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