Photocopiers operate according to the same principles as a laser printer, with just a few differences. Photocopiers get their images from sheets of paper, not computers. They scan a page by reflecting light off of it. A photocopier creates its electrostatic image through a technique called "write-white." The copier shines light onto the page being copied. The light reflects off of the white background and onto the photoreceptor, and it's absorbed by the dark areas of the text. The light from the background discharges those corresponding areas on the photoreceptor while leaving a positive charge from the areas that absorbed the light, and those areas attract toner.
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