Duplicating machines were the predecessors of modern document-reproduction technology. They have now been replaced by digital duplicators, scanners, laser printers and photocopiers, but for many years they were the primary means of reproducing documents for limited-run distribution. The duplicator was pioneered by Thomas Edison and David Gestetner, with Gestetner dominating the market up until the late 1990s.
One of the polygraphs used by Thomas Jefferson, a portable version
A James Watt & Co. copying press, in Thinktank, Birmingham Science Museum.
Iron letter copying press, late 19th century, Germany
The Rapid Roller Damp-Leaf Copier in use
A photocopier is a machine that makes copies of documents and other visual images onto paper or plastic film quickly and cheaply. Most modern photocopiers use a technology called xerography, a dry process that uses electrostatic charges on a light-sensitive photoreceptor to first attract and then transfer toner particles onto paper in the form of an image. The toner is then fused onto the paper using heat, pressure, or a combination of both. Copiers can also use other technologies, such as inkjet, but xerography is standard for office copying.
A Xerox digital photocopier in 2010
DADF or Duplex Automatic Document feeder - Canon IR6000