The history of the Fax Machine
This entry was posted on February 5, 2013.
Ready to learn the history of the Fax Machine?
What is a Fax?
The word fax comes from a Latin derived term "facsimile" which means "make like". In it's basic form a fax machine combines the functions of a digital scanner, a modem and a printer. The scanner scans the original document and converts it into electric pulses, the modem sends these series of pulsing over a telephone line to a fax machine at the recipients location and the printer in the recipients fax machine prints out the data so that a copy of the original document is produced.
Fax machines can transmit and reproduce photographs, drawings, maps and written or printed words to high standard. This ability to recreate documents to a high standard has made the fax machine popular with many industries including news services to send news articles and photographs to newspaper offices and television companies, banks and financial companies for sending through important personal information and legal documentation and by many other businesses as an aid in the handling of data handling and records.
It is hard to believe that the history of the fax machine goes back to the mid-19th century, well before telephones and morse code were used. In 1843, a Scottish inventor called Alexander Brain first developed a machine that could detect the dark areas of a metal plate document by passing a stylus on the end of a pendulum over the document The receiving machine would receive the electric signals sent down the telegraph line and convert them into a copy of the original by staining chemically treated paper using it's own pendulum and stylus set up. Brain was granted a patent for his creation back in 1843 and his original concept is still the basis for modern fax machines.
In the modern fax machine, the scanning of a document is performed in a manner similar to that used in television. An original document such as a photo, is examined under illumination in small adjacent areas called pixels. The light reflected from each pixel is received, measured and converted into an electric current by a device such as a photodiode or charge-coupled device (CCD). There are three ways that this process can work - rectilinear scanning, array scanning or multispot scanning.
In rectilinear scanning, a single device is used to scan one pixel after another, row by row, from top to bottom until the entire image has been translated into electric signals. In array scanning, the process is done in the same fashion but the pixels are scanned a row at a time by a battery of devices.
Multispot scanning consists of an array of devices arranged vertically, moving over the image and examining the document pixels column by column. A set of current pulses is created for each device as it moves down the document.
The separate currents created by the scanning method are then transmitted over a single circuit to the receiving fax machine.
Standards of Fax Machines
To reproduce fine detail in a fax, it is necessary to use very small pixels. As time went on and fax machines became more and more advanced, the International Telegraph and Telephone Consultative Committee ( CCITT ) identified "Groups" of fax machines according to their capabilities. Group 1 fax machines, now obsolete, are able to scan at a resolution of 98 scan lines per inch and take approximately 6 minutes to transmit a single page fax. Group 4 fax machines are at the other end of the scale from Group 1 and are designed to work with digital ISDN lines. They can scan with a resolution of 400dpi as used in engineering drawings.
Fax Machines Today
The variety of brands, styles and abilities for fax machines allows the user to pick one which would best suit their needs. simple fax machines are available for those who occasionally require the use of a fax machine but without which, a vital source of communication would be unavailable. There are fax machines that can act as a stand alone scanner or copier as well as offering the benefits of fax communication. There are high specification fax machines as mentioned above, these are generally used for documents that demand high resolution scanning to maintain the quality of the original document.