fax(redirected from Fascimile)
Also found in: Dictionary, Thesaurus.
facsimile (făksĭmˈəlē) or fax, in communications, system for transmitting pictures or other graphic matter by wire or radio. Facsimile is used to transmit such materials as documents, telegrams, drawings, pictures taken from satellites, and even entire newspapers. The surface of the material to be sent is traversed by a light-beam and a photodiode that translates the light and dark areas of the material thus scanned into electric signals for transmission. A receiving station reproduces the transmitted material by a variety of means. Newspapers and television stations have long transmitted and recorded news photographs using a process in which the received electric signals activate a variable lamp that is used to scan a photographic film.
A modern office fax machine scans a page to make an electronic representation of its text or graphics, compresses the data to save transmission time, and transmits it to another fax machine (or computer emulating a fax machine). The receiving machine decrypts the signal and uses a printer (usually built in) to make a facsimile of the original page. Because of the adoption of Group 3 digital standards in 1980 by the CCITT (International Telegraph and Telephone Consultative Committee), facsimile devices have become extremely prevalent in offices. These machines work over the public telephone network; they use digital modems and transmit at data rates up to 9600 bits per second. Images are produced with a resolution of 200 dots per inch. Personal computers can emulate Group 3 facsimile machines if they are equipped with a fax modem, printer, and appropriate software. Facsimile machines that produce higher-resolution images or color and gray-scale images are also available.
fax(FACSimile) Originally called "telecopying," it is the communication of a printed page between remote locations. Fax machines scan a paper form and transmit a coded image over the telephone system. The receiving machine prints a copy (a facsimile) of the original. A fax machine is made up of a scanner, printer and modem with fax signaling.
Group 1, 2, 3 and 4
Fax standards were developed starting in 1968 and are classified by Groups. Groups 1 and 2, used until the late 1980s, transmitted a page in six and three minutes respectively. Group 3 transmits at less than one minute per page and uses data compression at 9,600 bps. The Group 3 speed increase led to the extraordinary rise in usage in the late 1980s. Group 3 resolutions are 203x98 dpi in standard mode, 203x196 in fine mode and 203x392 in super fine mode.
Group 3 is the common standard, but Group 4 machines can transmit a page in just a few seconds and provide up to 400x400 resolution. Group 4 requires 56 to 64 Kbps bandwidth and needs ISDN, Switched 56 circuits or DSL lines. See fax/modem, Internet faxing and email.
|A Different Kind of Fax Machine|
|This earlier portable fax machine from Reflection Technology weighed eight ounces, worked with most cellphones and stored 25 fax pages. Its virtual display simulated a 12" monitor, and its "virtual keyboard" (lever and buttons on top) let you select menu options. (Image courtesy of Reflection Technology, Inc.)|