xerox machine

In 1938, after 20 years of experimentation, American physicist (a scientist specializing in the interaction between energy and matter) Chester F. Carlson (1906-196 developed a method of copying that used dry powder, electric charge, and light. Because nothing moist was used, the procedure was called "xerography" Greek for "dry writing." Initially there was little interest in the industrial world for Carlson's invention. It wasn't until 1947 that a small photographic company, the Haloid Company of Rochester, New York, acquired his patent (A patent is a government document that grants an inventor the sole right to manufacture his or her invention for a certain period of time.) The company, which later became the Xerox Corporation, gave the first public demonstration of a copier at the annual meeting of the Optical Society of America, in Detroit, Michigan, on October 22, 1948.