Principle of fax machine (how fax machine transmits documents)

Using scanning and photoelectric conversion technology, still images such as files, charts and photos are converted into electrical signals, which are transmitted to the receiving end and copied in the form of records.

The working principle of fax machine is very simple, that is, the document to be sent is scanned and converted into a series of black and white dot information, and then converted into audio signals, which are transmitted through traditional telephone lines. After the receiver's fax machine "hears" the signal, it will print out the corresponding point information, so that the receiver will receive a copy of the original. However, the four fax machines have different printing effects after receiving the signal.

(1) The thermal paper fax machine melts and discolors the thermal materials on the printing medium through the thermal print head to generate the required text and graphics.

(2) The thermal transfer fax machine is developed from thermal sensitive technology. By adding a thermal transfer ribbon, the ink coated on the ribbon is transferred to paper to form an image.

(3) Laser fax machine is a kind of fax machine that uses toner to attach to paper for imaging. Its working principle is mainly to use a selenium drum in the body to control the laser beam. By controlling the on and off of the laser beam, a charged image area is generated in the selenium drum. At this time, the toner in the fax machine will be attracted by the charge and attached to the paper to form words or images.

(4) The working principle of inkjet fax machine is similar to dot matrix printing. The inkjet head is driven by a stepping motor to move left and right, and the ink sprayed by the inkjet head is sprayed on ordinary paper in turn to complete the printing work.