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facsimile machine

Fax machines are dedicated terminals for remote copying. Depending on the conceptual orientation, fax machines may integrate the functions of fax servers. When sending, fax machines scan the supervisory originals line by line with a line sensor and transmit the scanned information to the receiving fax machine.

For the scanning process, the original is illuminated and the reflected light is focused with a rod lens to the line sensor. As a rule, fax machines have an automatic document feeder( ADF) through which several documents can be fed one after the other. They also support various fax services.

The receiving fax machine acts as a printer and prints the data line by line on paper. Comparable transmission functions to those offered by fax machines can also be performed by fax modems, fax cards and fax servers.

Fax machine, photo: Philips

Fax machine, photo: Philips

According to the fax groups, fax machines are also divided into performance classes. These differ in transmission speed and resolution. Black-and-white faxes usually work with a horizontal resolution of 203 dpi or 204 dpi, but with different vertical resolutions. The two relevant groups for faxing are fax groups 3 and 4.

Group 3 fax machines: machines for analog connection to the telephone network or adapted connection to ISDN with standardized transmission speeds of 2400, 4800, 7200 and 9600 bit/s (depending on the quality of the connection). The typical transmission time for one page DIN A4 is about 1 minute.

Fax machines of group 4: Devices for digital connection to ISDN with 64 kbit/s, partly designed as bimodal fax machines, which can also work together with fax machines of group 3. Typical transmission time for one page DIN A4 approx. 5 to 10 seconds.

The functions of fax machines can also be integrated in modern multifunction devices.

Informations:
Englisch: facsimile machine
Updated at: 15.01.2013
#Words: 281
Links: remote, line, sensor, information, process
Translations: DE
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