Xerox copier was patented in 1938 by Chester Carlson of American nationality. For more than 100 years of its birth, the inventor of the xerography, man whom the form would change of radical way to preserve and to share information. The xerography is the technological base of the laser printer, digital printer of production and of course of Xerox copier. After graduating in physics, dumb to New York, obtaining itself a use like assistant of a patent attorney. Frequently it had to by hand realise enough copies of drawings, work that became tedious and that taking into account its myopia and arthritis, its work was still more heavy. Carlson identified of immediate way the necessity of a method simple and practical to make copies. And like which it at heart was inventor; it was put to investigate which one would become, Xerox copier.

In the Public Library it found technical publications with information on the reproduction of photographies and account occurred that the process was taken and required of use of many chemical agents. Carlson was wondered if it could do it by means of an electrical method, since it knew that the charged particles adhere to a surface with opposite load. The problem was how to obtain that the particles paid attention to identical form to the one of an image illuminated on a paper. Electrofotografa presented/displayed a request for a patent by the basic concept of , but to not yet it was able to realise a correct impression in dry. Then the decisive discovery took place. It covered a plate with zinc with sulfide it rubbed, it with a cotton rag to create a load of static electricity, placed in front of a transparency with written words and exposed the two to the heat of a lamp. It cleared the slide, it dusted the plate with esporas of moss, pressed paper butter against the dust, applied heat and it retired the paper.