Photocopier

A photocopier is a machine that makes copies of documents and other visual images onto paper or plastic film quickly and cheaply, and most modern photocopiers use xerography, a dry process that fixes toner to paper using an electrostatically charged photoreceptor, heat and pressure. It was invented by the American patent attorney Chester Carlson, who was motivated by the pain that arthritis caused him during manual document copying to experiment with electrophotography, producing the first photocopy in 1938 using a sulfur-coated zinc plate; after Carlson's process was rejected by more than twenty companies, the Battelle Memorial Institute helped refine it, and the Xerox Corporation commercialized the first practical xerographic copier, the Model A, in 1949.