Chester Carlson invented the first photocopier. The design was eventually purchased entirely by the Haloid Company. The company changed its name to "Xerox Electrostatic Copiers." The first copier was put on the market in 1950.
American physicist Chester Carlson devised a process in the 1930s in which electrostatic charges were induced on paper. Light shining on the original reflects on the paper, which changes its charge. When a colored day powder - a "color enhancer" - is charged and passed over the paper, it is attracted to the image template but not to the background, resulting in a copy.
Carlson filed a patent application for a photocopier in 1939. But that was more than a dozen years before photocopiers were commercially available.
Copiers in modern offices serve many purposes. They can copy on different sizes of paper as needed, enlarge images, and some can even reproduce in color.
Copiers use heat to fix the image to the paper, or make it permanent on the paper. That's why copies feel warm to the touch when they come out of the copier.