fax

Fax is a technology that transmits images through telephone lines. The earliest fax machines used phototubes to convert images into electrical signals, which were sent over telephone lines and then restored to images at the receiving end. This technology ushered in a new era of image communication in the late 19th and early 20th centuries, and was an important extension and development of communication technology after the invention of the telephone.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

Fax machine technology first emerged in the 1840s, which can be said to be earlier than the birth of the telephone. In 1841, Alexander Bain, an Englishman, researched the production of electrically controlled pendulum structures and invented the fax machine; In 1850, British inventor F. Beckar made significant improvements to the structure of the fax machine by using a "drum and screw" device instead of a clock and pendulum. This improved structure works a bit like a lathe, with the drum rotating rapidly and the draft roll sent by fax rotating along with it. The scanning needle slowly advances along the axial direction of the drum along the screw, and performs a spiral scan on the surface of the drum. This drum type fax machine has been in use for over a hundred years.