A fax appeared. What is a fax and what is it for? From numbers to waves

In 1843, Scottish physicist Alexander Bain demonstrated and patented his own design for an electric telegraph, which allowed images to be transmitted over wires. Bain's machine is considered the first primitive fax machine.

In 1855, Italian inventor Giovanni Caselli created a similar device, which he called the Pantelegraph, and offered it for commercial use. The first commercial Pantelegraph line between Paris and Lyon became operational in 1865, 11 years before the invention of the telephone by Alexander Bell. Caselli's apparatus transmitted an image of text, a drawing or a picture drawn on lead foil with a special insulating varnish. The contact pin slid along this set of alternating areas of high and low electrical conductivity, “reading” the image elements. The transmitted electrical signal was recorded on the receiving side electrochemically on moistened paper soaked in a solution of potassium iron sulfide (red blood salt). The pantelegraph was used on communication lines Moscow - St. Petersburg (in -1868), Paris - Marseille, Paris - Lyon.

The technological breakthrough is associated with the discovery of the photoelectric effect and its laws at the end of the 19th century. German inventor Arthur Korn demonstrated the first photoelectric system for transmitting still images in 1902, which he called Bildtelegraph. The device became famous on March 17, 1908, when a photograph of a wanted criminal was transmitted from Paris to London in 12 minutes, playing a decisive role in his arrest. However, due to the inertia inherent in all selenium photocells, it was not possible to increase the transmission speed of the device. Almost simultaneously in France, Edouard Belen constructed the Belenograph, which was subsequently used for the first transmission of a photograph across the Atlantic Ocean. The belenograph did not contain any photocells, but read the relief obtained by tanning the chrome-plated gelatin of special photographic paper. Despite the specific printing technology, the belenograph gained popularity in Europe for several decades due to its high image transmission speed.

For several decades, the technology was a standard in news photojournalism, where it was used for the rapid delivery of photographic information from the scene of an event, as well as for its distribution to customers. Regular use of the technology began with the Associated Press agency, which on February 12, 1935 transmitted an image from the west to the east coast of the United States. In the 1930s, the USSR created its own phototelegraph devices (for example, ZFT-A4, FT-37, FT-38), which worked on the same principle. Since that time, photo telegraphs have appeared in law enforcement agencies, transmitting orientations to criminals, handwriting samples and other wanted information. In 1959, the Japanese newspaper Asahi transferred finished pages by phototelegraph from the Tokyo editorial office to the Sapporo printing house, marking the beginning of the technology of decentralized printing of daily newspapers. In the same way, weather maps intended for ship crews began to be distributed. An additional incentive for the development of phototelegraphy in the USSR was the expansion of contacts with the PRC, where documents contained hieroglyphs, the transmission of which by conventional telegraph was difficult. In the USA, Ticketfax machines were used to transfer train tickets from central ticket offices to city and suburban ones.

After demodulation in the receiving apparatus, the received signal was fed to a device that presses a lead or ink pen to a sheet of plain paper wound on the same rotating drum.

This principle of operation has become obsolete with the spread of digital technology and charge communication devices, which have simplified image scanning. In Group 4 faxes, a CCD array of 1782 reading elements is used for this, installed opposite a drum that moves the transmitted sheet at low speed. When the original is moved past the ruler, the frame memory forms a file with the entire image. The revolution in fax transmission was carried out in the late 1960s by the Dacom DFC-10 device, which used technology developed by Lockheed Corporation to receive photographs from satellites to compress the digital stream. This made it possible to reduce page transfer time without the need to improve the communication channel. In 1980, Group 3 of the first digital facsimile standards was adopted, based on the modified Huffman code. The acceptance process has also been simplified by the use of thermal printing on special paper since the late 1970s. In the 1990s, roll-to-roll thermal printing gave way to flat-plate inkjet printers or similar thermal transfer devices that do not require expensive thermal paper and support color printing.

Before the introduction of modern digital standards and printers, most fax machines were only capable of transmitting and receiving line-color originals and did not produce high-quality copies of halftone images. This was due to the difficulty of reproduction by prevailing printing methods and, mainly, the purpose of fax, which serves to transmit text and handwritten documents. Modern faxes are capable of transmitting and reproducing not only halftone, but also full-color images that are scanned with a flatbed scanner.

As the cost of computer equipment and access to the Internet becomes cheaper, a general-purpose computer connected to the network with a printer and scanner is increasingly used to transfer images. Depending on the purpose of use, this type of computer is sometimes called an “Office Computer.” In some cases, the use of such a computer specifically in the process of transmitting images is also called “fax communication.”

The main advantage over traditional fax is the absence of the need for synchronous and in-phase operation of all elements of the communication path. Thanks to the created fax gates, the exact boundary between traditional fax communication and such computer communication is completely absent. The development of computer technology and mathematics has made it possible to “save” line capacity. For example, the Canon Fax B215C transmits b/w images using standard fax protocols MH, MR, MMR, JBIG, and color images with compression using the JPEG standard. The transmission time for a color page is about 4 minutes. for color image and 3 min. for a medium quality halftone image. [ ]

Modulation

The transmitting device modulates the carrier frequency with a video signal in accordance with one of the selected communication protocols, thereby achieving maximum compatibility with a specific type of channel.

In analog fax communications, as a rule, amplitude modulation is used, less often - frequency modulation. With the spread of digital faxes, corresponding protocols for data transmission also appeared.

The first of them were developed specifically for fax communications, but later the generally accepted ones in computer networks began to be used more often. Most modern fax equipment receives and transmits images using some modem protocols.

Communication channels

The main difference between modern fax and other image transmission technologies is the ability to use the public telephone network with small bandwidth, which allows you to make the type of communication publicly available.

The latest fax technologies are based on the use of the Internet, allowing economical use of network traffic to transmit images of any quality.

In this case, the decoded information is recorded in the form of a graphic file on a computer, file server or in the memory of specialized equipment, where it is stored until the user requests for visualization or printing.

The listed programs allow you to receive and send faxes from a PC equipped with a fax modem.

• PamFax for Skype
• Fax Gwise
• Fax4Word
• Fax4Outlook
• Joy Fax Server
• Joyfax Server
• ActFax

Quantitative indicators

The following parameters are used to compare traditional fax systems.

• Transmitted Image Size. There are two main standards:

• 220×290 mm - a size close to the format and used in office work;
• 422×600 mm - size for transmitting newspaper strips in A2 format.

• Speed, measured in the number of lines transmitted per minute. For telephone and radiotelephone communication lines, standard speeds are 60, 120 and 250 lines per minute. Newspaper strips are transmitted at speeds of 178, 1500 or 2250 lines per minute.
• Image transmission time depends on the transmission speed and is: for the 220×290 mm format - from 6 to 25 minutes; for a newspaper page - from 2.8 to 50 minutes.
• Definition, or resolution (in equipment instructions the term lineature is sometimes used, but this use is inaccurate) - determines the quality of reproduction of small image details. It is measured as the maximum number of lines per 1 mm (in Europe - per inch) line length, which are reproduced separately, without merging, by the receiver. The clarity value in conventional fax machines is 5 lines per mm, and in equipment for transmitting newspaper strips it is from 13 to 16 lines per mm. In English-language literature, the unit of measurement is lpi (English). lines per inch).
• Number of gradations- for halftone devices: how many gradations of optical density are separately reproduced on the received copy.

Main manufacturers

See also

Notes

1. Studiner M. A. Dictionary of exemplary Russian accent. - M.: Iris-press, 2009. - P. 514. - 576 p. - ISBN 978-5-8112-3590-2.
2. Zarva M.V. Dictionary of accents of the Russian language. - M.: Publishing house NC ENAS, 2001. - P. 543. - 600 p. - ISBN 5-93196-084-8.
3. Features of the construction of fax equipment (Russian). Basics of radio communications and television. Bank of lectures. Retrieved January 22, 2016.
4. All about faxes (Russian). Articles. Imperium Service Center. Retrieved January 11, 2016.
5. IL PANTELEGRAFO DI CASELLI(Italian) . I. T. I. S.. Accessed January 5, 2016.
6. , With. 8.

Fax is an abbreviation of English facsimile - exactly, the same. Facsimile is a technology for transmitting images or text using electrical signals. Although the first faxes were invented in the middle of the 19th century, they became widespread only in recent decades. A modern receiving and transmitting fax machine is a complex electromechanical device consisting of a scanner, modem and printer. The fax uses a sheet-fed scanner with an automatic sheet feeder. When you send a document, the sending fax scanner reads the information from the page, digitizes it, and sends it to the modem. The modem converts digital information into an analog signal and sends it to the receiving fax modem over the telephone line. The receiving fax modem demodulates - converts the analog signal into digital form and transmits the information to the printer. The printer prints - creates an exact copy of the original document. This is how a regular standalone telefax works.

The most widespread are faxes with image output on thermal paper. This is due to the simplicity of the device design and the low cost of consumables. However, thermal paper fades over time and fax documents cannot be stored for long periods of time. A roll of thermal paper is enough to print approximately one hundred A4 pages.

Thermal film fax machines transfer ink to a blank page of regular office paper, much like carbon paper printing. Original thermal film is much more expensive than thermal paper. The thermal film roll resource is 150 pages.

An inkjet fax machine can produce color images of document copies. Inkjet faxes have a high cost of consumables and all the problems associated with using cartridges: ink drying out and print head clogging. Prints need time to dry and are sensitive to moisture. The cartridges are enough for approximately 900 pages.

Laser faxes are the most expensive, but high-quality printing is cheaper than inkjet. The cartridge resource is 2000 pages.

There are also multifunctional faxes - MFPs. An MFP may include a flatbed scanner, an automatic sheet feeder, a telephone, memory for sent and received faxes, automatic switching of the device to various modes, and an interface for connecting to a computer.

In the office, faxing is used mainly for sending documents with printed and handwritten text.

The main disadvantage of such traditional fax communication is the low productivity and high labor intensity of the process. Everyone in the office knows how long it will take to send several multi-page documents to several numbers. It happens that it is difficult to get through, sometimes not all pages go through and you have to call back, clarify, and resend.

With intensive use, fax scanners quickly become dirty, and the sheet transport mechanisms wear out. As a result, we send contaminated pages with distorted text and images, and in return we may receive the same ones.

A rational solution is to use a fax modem. Through a fax modem we connect to a telephone line and fax from a computer. A fax modem is a relatively inexpensive device, internal or external. An internal or built-in fax modem is installed on the computer's system board, and an external one is connected to the system board externally. There will be a corresponding lesson on how to install a fax modem, how to configure Windows XP and Windows 7 to send and receive faxes.

The boom in the use of fax technology occurred in the 80s of the last century. Today it is believed that faxes are being widely replaced by more modern means of communication - e-mail and other methods of sending files. However, the decline in the role of faxes in modern business is happening quite slowly. This is explained by the widespread use of fax machines and the ease of their development and use. There are currently more than 80 million telefaxes and fax modems in the world.

Fax and fax communication: history of occurrence, principle of operation.

is a device designed to transmit graphic images and text documents using a telephone line or the Internet. The word comes from Latin fac simile, which means “do the same”, “do the same”.

Fax has a rich history, beginning almost 2 centuries ago in 1843, when the first electric telegraph was patented. The device of the Scottish physicist Alexander Bain was a very primitive fax machine. 12 years later, an Italian scientist-inventor proposed using his “fax” model - Pantelegraph . The pantelegraph became the first commercial fax device, connecting cities such as Moscow and St. Petersburg, Paris and Lyon. The images were first transferred onto lead foil using an insulating varnish. Thanks to this, the device read places with different electrical conductivity and translated them into an electrical signal.

At the end of the 19th century, with the discovery of the photoelectric effect, photoelectric devices appeared for sending various documents. They were relatively fast - transferring 1 page took about 12 minutes. Following the invention of vacuum tubes, there was another leap in the development of fax machines, so in the 20s of the 20th century it was invented phototelegraph , which received graphic information on photosensitive material.

The fax we know and use was developed in 1964 by the company Xerox. At that time, it weighed 21 kilograms, but was easy to use and transmitted a page of information in a record time of 6 minutes. Since the mid-20th century, faxes have appeared in offices around the world, and data transfer times have been reduced to 3 minutes. Nowadays, multifunctional devices that combine a printer, copier, telephone and fax are very popular on the market.

How does a fax work?

The principle of fax operation is quite simple: photosensitive elements read a pixel-wide document line, then the received information is converted into an electrical signal and sent to the subscriber. Depending on the type of communication, an electrical signal consisting of 0s and 1s is sent as a data packet over a digital channel or converted into a wave signal if the communication is over a telephone line. Strings are sent and received sequentially. The receiving fax machine plays all the above steps in reverse order and the user receives the image.

Modern faxes come in both monochrome and color, allowing you to use four types of printing: on, on, and inkjet printing. Devices using thermal transfer technology are cheaper, but in this case the image quality suffers. Inkjet faxes are inexpensive devices with good print quality, but have one drawback - not very high reliability. High speed and at the same time excellent quality are provided by laser fax devices, however, due to their cost, printing becomes quite expensive.

Fax paper also varies. This can be regular office paper for an A4 printer, thermal paper or paper in a roll. When choosing paper, it is necessary to take into account its optical density so that printed documents remain readable longer. The optimal optical density is from 1.05 D.

Fax Features

Despite their simplicity, most faxes have a whole arsenal of useful functions:

Fax Specifications

It is believed that faxes are gradually becoming a thing of the past, giving way to email. In fact, this is not the case and many businesses still use fax technology to transfer documents and images. The convenience is that any paper document can be quickly and easily transferred to the recipient as a copy.

However, nowadays you can send a fax via the Internet, sending electronic data to any fax machine around the world, or receive a fax without even having the appropriate device. Modern faxes easily connect to the network, saving documents as images on a computer or server. Documents are stored on the server until the file is received by the recipient, by printing or viewing it.

One of the leading manufacturers of fax machines at the moment is a company that produces mono and multifunctional faxes for various purposes and operating principles. The catalog of the company's online store presents the most popular models, as well as. To buy a fax, contact our managers by phone listed on the website.

Office equipment always causes some difficulties for new employees. In particular, work such as using a fax can confuse a person. Although in reality everything is very simple. After all, controlling this complex device is reduced to manipulating just a few buttons on the panel.

A fax is a device through which you can receive and send printed messages in color or black and white. Fax is a multifunctional device, and it can be configured for different operating modes. For example, to receive messages automatically, manually or in answering machine mode.

How to properly use a fax set to manual mode?

It is quite difficult to give specific advice on setting up fax modes, since there are so many nuances to the number of models of these devices. Refer to your fax manual to find out exactly what buttons to press to put your MFP (multifunction device) into manual fax mode.

After this, messages will be received as follows: a fax rings, you pick up the phone, the subscriber tells you that he is sending a fax. You press the “Start” button and wait for a sheet of paper to appear from the machine. You take it out, check that everything is clearly printed, say goodbye and put the phone back in its place.

To send a fax, you take the required document, insert it into the bottom tray of the device, and dial the subscriber's number. When he picks up the phone, introduce yourself and tell him that a fax is coming. Then press the “Start” button. Don't hang up. While the fax is being sent, there will be silence on the receiver. At this time, you can calmly chat with colleagues on any topic; the person on the other end of the line still won’t hear you. As soon as the fax has passed through and a characteristic beep is heard on the handset, the connection between you and the subscriber is restored again. Give the person a minute to check the print quality before saying goodbye and hanging up.

How do I use a fax machine that is set to receive messages automatically?

When the fax machine is set to automatic mode, the Auto Answer button is lit. The fax automatically turns on to receive messages as soon as a certain number of rings have passed. That is, if, for example, the phone rings 10 times and none of the employees picks up the phone, the mode for receiving fax messages is activated. The number of rings is set manually in the Options menu.

Using a fax in answering machine mode

If you call a company on weekends or at night when employees are not on site, you may often get an answering machine. He will greet you and ask you to send a fax after the beep. A similar function is also set in the “Options” menu and is available in all modern faxes.

Among the features of modern faxes are also: sending group messages, fax forwarding, blocking unwanted messages, speed dialing, phone book and much more. You can set certain parameters on many faxes using just 2-3 buttons.

There are many types of fax devices today. The creators of faxes made sure that the device interface was simplified as much as possible. Therefore, you will definitely not have any difficulties in terms of how to use a fax correctly. After purchasing the device, carefully read the instructions, which describe in detail the capabilities of this fax and its settings.

In this article I will try to answer these and other questions that will interest you when buying a fax. The first question that needs to be answered is, do I need a fax? Modern communication services, such as e-mail, video conferencing, etc., are noticeably more efficient than fax communications, however, no one has yet abandoned the familiar fax, which has long become an integral attribute of the workplace of a secretary or office manager.

First, let's define what is Fax?

Fax or telefax is a means of communication that is capable of transmitting typewritten texts and images over the telephone network. Once communication with the recipient is established, the image is scanned, a special electronic device transmits a signal to the recipient, and the recipient's fax printer prints the image.

A modern fax is always more than just a fax. It combines many different functions useful for an office worker. Therefore, faxes can be divided into two types: monofunctional and multifunctional. The capabilities of monofunctional faxes are limited to a basic set that allows you to receive and send fax messages, make simple copies of individual sheets, and, of course, perform basic actions with the telephone module, in particular, manage the phone book, various mailing lists, and so on. But a multifunctional fax combines the functions of a printer, copier, scanner, fax, telephone and even a modem.

Faxes are available in monochrome and color. There are also faxes on thermal paper, thermal film, laser, and inkjet.

The operating principle of faxes operating on thermal paper The image is burned using a thermal ruler on special heat-sensitive paper. The advantage of this type of fax is its low price and fairly high reliability. The disadvantages include the low quality of the resulting image and high cost. This is the most common type of fax.
Faxes to thermal film accept documents and perform copier functions on plain A4 paper. Thermal transfer fax machines print on special rolls of thermal film. The printing process itself involves rewinding a roll from one reel to another.

However, the best quality and speed of work differ laser faxes, which also allow you to use regular printer paper. In addition, they have a wide range of additional functions. If you are interested in high quality documents, only a laser fax can satisfy you and greatly facilitate office work. Undoubtedly, the future lies in laser quality.

Inkjet faxes are similar in function to regular inkjet printers. The main disadvantage is low reliability and rather expensive color printing.

Which fax machine to choose depends on your goals and budget. I will only note that Panasonic faxes are now the most popular.

Fax is not the only way to transmit images. There is a relatively inexpensive computer accessory - a fax modem. It connects the computer to a regular telephone line and costs $100-200.

However, with the advent of inexpensive MFPs (multifunctional devices that combine the functions of a printer, scanner and copier), people use scanned and emailed documents in business communications. This does not require telephone lines, which are often busy, documents are not distorted and, upon receipt, look indistinguishable from the original.

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