How does a fax machine work?
A modern fax machine uses telephone lines to transmit copies of documents. At the sending end, there is some sort of sensor to read the document. It encodes white and black spots that the fax machine sees on the paper and transfers it to the receiving end. The encoded data is compressed before sending. At the receiving end it is decoded, uncompressed and reassembled into the scanned lines of the original document and then printed. This machine has a rotating cylinder, a source projecting a light beam and a photo electric cell. Usually, a fax machine has a paper-feed mechanism for sending multi-page faxes.
