Fax

The purpose of fax is to transmit and reproduce a still image from a distance. Schematically, the sender captures the image and transmits it over a network, while the receiver receives and reproduces it.

First developed in 1843, fax was almost exclusively reserved for the press and the military until the 1960s. It then developed with the arrival of transistors and microprocessors, and today benefits from the explosion in communications networks.

The fax has become a part of everyday life. In industrialized countries, devices combining telephone, fax and sometimes answering machine have replaced the traditional telephone in 10% of households, and almost all businesses are now equipped with them. In 2000, there were some 80 million fax machines worldwide, including around 4.3 million in France.

The aim of this document is to provide an overview of the fax domain. We'll start with the definition and presentation of a functional model, then look at the work of standards bodies and the optional features provided by standards. We'll then look at the particularities imposed by the different networks, then at the technical solutions chosen to build the equipment and the coding used. Finally, we'll look at the role of fax and its foreseeable development.

Readers are invited to consult the glossary at the end of the article.