Fax

Sometimes an invention is made many years before there is any demand for it. This is what happened with the fax machine. The basic idea came to German inventor Arthur Korn in the early 1900s, but fax machines only became common in the 1980s. Korn invented a process called ‘telephotography’. This enables any kind of image, either writing on a page, or an actual picture, to be broken up into a signal that can be sent on a wire and be ‘redrawn’ at the other end.

Korn’s idea was taken up by a Frenchman, Edouard Belin, in the 1920s. In Belin’s system, the image is scanned by a beam of light. The changes in the beam’s intensity are picked up by a photoelectric cell and converted into electrical signals that can travel along a wire. The machine at the other end converts the signals back into an image.

Corporations such as RCA, Sharp and Rank Xerox developed Belin’s system over the following decades.