Winn L. Rosch Hardware Bible, Sixth Edition

Technology

In a classic fax system, you start using fax by dialing up a distant fax system using a touch pad on your fax machine, just as you would any other telephone. You slide a sheet of paper into the fax's scanner, and the page curls around a drum in front of a photodetector. Much as a television picture is broken into numerous scan lines, a fax machine scans images as a series of lines, takes them one at a time, and strings all of the lines scanned from the document into a continuous stream of information. The fax machine converts the data stream into a series of modulated tones for transmission over the telephone line. After a connection is made at the receiving end, another fax machine converts the data stream into black and white dots ...