Fax (short for facsimile - from Latin "fac simile", "make similar", i.e. "make a copy" - or telefacsimile) is a telecommunications technology used to transfer copies of documents, especially using affordable devices operating over the telephone network. The words telecopy and telefax are also used as synonyms. Telecommunication is the extension of communication over a distance. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Synonyms (in ancient Greek syn συν = plus and onoma όνομα = name) are different words with similar or identical meanings. ...

Overview

A fax machine is essentially an image scanner, a modem, and a computer printer combined into a highly specialized package. The scanner converts the content of a physical document into a digital image, the modem sends the image data over a phone line, and the printer at the other end makes a duplicate of the original document. In computing, a scanner is a device which analyzes a physical image (such as a photograph, printed text, or handwriting) or an object (such as ornament) and converts it to a digital image. ... A modem (a portmanteau word constructed from modulator and demodulator) is a device that modulates an analog carrier signal (sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information. ... A computer printer is a computer peripheral device that produces a hard copy (permanent human-readable text and/or graphics, usually on paper) from data stored in a computer connected to it. ...

Obviously, a very high-quality fax machine with some additional electronics can connect to a computer, and can be used to scan documents into a computer, to print documents from the computer, and to make photocopies. Such high-end devices are called multifunction printers and cost more than fax machines. A multifunctional printer An MFP (Multi Function Printer/Product/Peripheral), multifunctional, all-in-one (AiO), or mopier, is an office machine that includes the following functionality in one physical body, so as to have a smaller footprint in a home or small-business setting (the SoHo market segment), or to...

Modern fax technology became feasible only in the mid-1970s as the sophistication and cost of the three underlying technologies improved to a reasonable level. Fax machines first became popular in Japan, where they had an clear advantage over competing technologies like telex; it is faster to write Japanese ideographs than to type them. Over time, they gradually became affordable and were very popular around the world by the mid-1980s. This article provides extensive lists of events and significant personalities of the 1970s. ... Telex can refer to more than one thing: For the communications network, see Telegraphy. ... // Events and trends The 1980s marked an abrupt shift towards more conservative lifestyles after the momentous cultural revolutions which took place in the 60s and 70s and the definition of the AIDS virus in 1981. ...

However, although most businesses still maintain some kind of fax capability, the technology appears increasingly dated in the world of the Internet.

Capabilities

Fax machines transfer one or a few printed or handwritten pages per minute in black-and-white (bitonal) at a resolution of 100x200 or 200x200 dots per inch. The transfer rate is 14.4 kilobits per second (kbit/s) or higher(but fax machines support speeds beginning with 2400 bits/s). The transferred image formats are called ITU-T (formerly CCITT) fax group 3 or 4. The word resolution has several meanings, depending on context. ... This article is about the unit of information. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... ITU-T is the telecom standardization organization of the International Telecommunication Union (ITU). ...

The most basic fax mode transfers black and white only. The original page is scanned in a resolution of 1728 pixels/line and 1145 lines/page (A4). The resulting raw data is compressed using a modified Huffman code optimized for written text, achieving average compression factors of around 20. Typically a page needs 10 s for transmission, instead of about 3 minutes for the same uncompressed raw data of 1728×1145 bits at a speed of 9600 bit/s. The compression method uses a Huffman codebook for run lengths of black and white runs in a single scanned line, and it also uses the fact that two adjacent scanlines are usually quite similar, saving bandwidth by encoding only the differences. This article needs to be cleaned up to conform to a higher standard of quality. ... A comparison of different paper sizes A4 is a standard paper size, defined by the international standard ISO 216 as 210×297 mm (roughly 8. ... In computer science, data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than a more obvious representation would use, through use of specific encoding schemes. ... In computer science, Huffman coding is an entropy encoding algorithm used for lossless data compression. ...

The codes used for sending facsimiles are: Modified Huffman(MH), Modified READ(MR) (known also as CCITT Group 3 fax encoding or CCITT T.4 ) and Modified Modified READ(MMR)(known also as CCITT Group 4 fax encoding or CCITT T.6). Modified Huffman coding is used in fax machines to encode black on white images (bitmaps). ...

There are different fax classes, including Class 1, Class 2 and Intel CAS.

Several different telephone line modulation techniques are used by fax machines. They are negotiated during the fax-modem handshake, and the fax devices will use the highest data rate that both fax devices support, usually a minimum of 14.4 kbit/s. A modem (a portmanteau word constructed from modulator and demodulator) is a device that modulates an analog carrier signal (sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information. ... For the greeting habit, see handshake. ...

Fax machines from the 1970s to the 1990s often used direct thermal printers as their printing technology, but since the mid-1990s there has been a transition towards thermal transfer printers and inkjet printers. Phase-shift keying (PSK) is the overarching name for a number of digital modulation schemes that convey data by changing (modulating) the phase of a reference signal (the carrier wave). ... Quadrature amplitude modulation (QAM) is a modulation scheme which conveys data by changing (modulating) the amplitude of two carrier waves. ... In telecommunication, trellis modulation (also known as trellis coded modulation, or simply TCM) is a modulation scheme which allows highly efficient transmission of information over band-limited channels such as telephone lines. ... Quadrature amplitude modulation (QAM) is a modulation scheme which conveys data by changing (modulating) the amplitude of two carrier waves. ... Direct thermal printers create an image by selectively heating coated paper when the paper passes over the thermal print head. ... Thermal wax transfer printers function by adhering a wax-based ink onto paper. ... Ink jet printers are the most common type of computer printer; and industry and commerce also use them extensively for special-purpose applications. ...

One of the advantages of inkjet printing is that inkjets can affordably print in color; therefore, many of the inkjet-based fax machines claim to have color fax capability. There is a standard called ITU-T30e for faxing in color; unfortunately, it is not yet widely supported, so many of the color fax machines can only fax in color to machines from the same manufacturer. Color is an important part of the visual arts. ...

Alternatives

A modern alternative for sending a fax is sending an email with one or more image files as attachments. This allows color and is more versatile with respect to resolution. E-mail, or email, is short for electronic mail and is a method of composing, sending, and receiving messages over electronic communication systems. ... In common usage, an image (from Latin imago) or picture is an artifact that reproduces the likeness of some subject—usually a physical object or a person. ... A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... The term attachment has multiple meanings: An email attachment Psychological attachment: see Attachment theory Attachment as a vice in Buddhism; see Buddhism This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

At the receiving end, much research has occurred into how to more efficiently process incoming faxes, now that digital storage is much cheaper than it was in the 1970s, and junk faxes have become a common problem (and an enormous waste of paper).

Some high-end communications servers do not automatically print out all incoming faxes, but instead integrate them into a single in-box along with other forms of store and forward communications like email and voice mail (see unified messaging). Store and forward is a communications technique in which messages are sent to a intermediate station where they are kept and sent at a later time to the final destination or to another intermediate station. ... E-mail, or email, is short for electronic mail and is a method of composing, sending, and receiving messages over electronic communication systems. ... Voicemail (or voice mail; abbreviated v-mail or vmail) is a specific application of an interactive voice response system. ... Unified Messaging (or UM) is the integration of different streams of messages (email, Fax, voice, video, etc. ...

History

Scottish inventor Alexander Bain is often credited with the first fax patent in 1843. He used his knowledge of electric clock pendulums to produce a back-and-forth line-by-line scanning mechanism. Alexander Bain (October 1811 – January 2, 1877), was a clockmaker who invented an electric clock, the electric printing telegraph and a facsimile machine. ... 1843 was a common year starting on Sunday (see link for calendar). ... A clock (from the Latin cloca, bell) is an instrument for measuring time. ... Simple Gravity Pendulum assumues no air resistance and no friction of/at the nail/screw. ...

In 1861 the first fax machine, Pantelegraph, was sold by Giovanni Casselli - before even the invention of workable telephones. 1861 is a common year starting on Tuesday. ...

As a designer for the Radio Corporation of America (RCA), in 1924, Richard H. Ranger invented the wireless photoradiogram, or transoceanic radio facsimile, the forerunner of today’s "Fax" machines. A photograph of President Calvin Coolidge sent from New York to London in November 1924 became the first photo picture reproduced by transoceanic radio facsimile. Commercial use of Ranger’s product began two years later. Radio fax is still in common use today for transmitting weather charts and information. RCA, formerly an initialism for the Radio Corporation of America, is now a trademark used by two companies for products descended from that common ancestor: Thomson Consumer Electronics, which manufactures RCA-branded televisions, DVD players, video cassette recorders, direct broadcast satellite decoders, camcorders, audio equipment, telephones, and related accessories; and... Richard Howland Ranger (1899-1961) was an American electrical engineer and inventor. ... A radiofax or also called WEFAX is communication mode for transmitting high resolution black and white images over short waves. ... John Calvin Coolidge, Jr. ...

An early method for facsimile transmission, the Hellschreiber, was invented in 1929 by Rudolf Hell, a pioneer in mechanical image scanning and transmission. The Hellschreiber or Feldhellschreiber was a facsimile-based teleprinter invented by Rudolf Hell. ... 1929 was a common year starting on Tuesday (link will take you to calendar). ... Rudolf Hell (December 19, 1901 – March 11, 2002) was a German inventor. ...

In 1985 Dr Hank Magnuski, founder of GammaLink, produced the first computer fax board, called GammaFax. 1985 is a common year starting on Tuesday of the Gregorian calendar. ... Prior to founding NCast, Dr. Hank Magnuski was cofounder and CEO of GammaLink. ... GammaLink Inc. ... The first computer fax board, GammaFax, was produced in 1985 by GammaLink. ...

See also

• error correction mode (ECM)
• junk fax
• multifunctional fax
• telautograph
• fax effect

Error correction mode (ECM) is an optional transmission mode built into Class 1 fax machines or fax modems. ... Junk faxes are unsolicited advertising via fax transmission. ... A multifunctional printer An MFP (Multi Function Printer/Product), multifunctional, all-in-one, or mopier, is an office machine that includes the following functionality in one physical body, so as to have a smaller footprint in a home or small-business setting (the SoHo market segment), or to provide better... The telautograph is an analog precursor to the modern fax machine. ...

External links

• What is Fax and History of Fax
• FAQ: How can I send a fax from the Internet?
• DEATH OF THE FAX MACHINE!
• Network fax technology A fax server buyers' guide, this paper describes the features you need to look for in fax server software and why (PDF).
• GFI FAXmaker for Exchange/SMTP Network fax server for Exchange/SMTP
• Facsimile Books & other digitally enhanced Works from the University of Georgia libraries (searchable DjVu format)