Uses of fax machines
Photo fax machine
It is a kind of fax machine used for transmitting continuous tone images of the whole range of optical densities, including black and white, and reproducing a copy that meets the requirements of certain tone densities by the photographic recording method. Photo facsimile machines are mainly suitable for news, public security, army, medical and other departments.
Newspaper facsimile machine
It is a kind of facsimile machine which sends a clear sample of a full-page newspaper by scanning, and reproduces a copy of the film for plate printing by using the photographic recording method at the receiving end. There is also a type of newspaper facsimile machine called a subscriber newspaper facsimile machine, which is installed in a home or office, and is usually used to receive facsimile programs (full-page newspaper information or weather forecasts, etc.) broadcast by a radio or television station, and to record and display them directly on a piece of paper.
Weather fax machine
It is a kind of fax machine for transmitting weather cloud charts and other weather charts, also known as a weather map fax machine, which is used for transmitting and reproducing weather maps in meteorological, military, aviation, and marine departments. Transmission of the amplitude than a version of the newspaper, but the resolution requirements are not as high as for the newspaper fax machine. Meteorological facsimile has two transmission methods, the use of short-wave (3 ~ 30 MHz) meteorological wireless facsimile broadcasting and the use of wired or wireless road point-to-point meteorological transmission broadcasting. Weather fax broadcasting is a one-way transmission method, and most weather fax machines are used only for reception.
Document facsimile machine
It is a facsimile machine that reproduces originals in both black and white optical density levels. It is mainly suitable for long-distance reproduction of handwritten, typed or printed documents, charts and diagrams, as well as reproduction of halftone images with limited levels of color tone range between the two boundaries of black and white, and it is widely used in the office, business processing and other fields. In accordance with the document fax machine using telecommunications networks, signal processing and processing technology and transmission of standard-format originals of different times, can be divided into a class of fax machines used on the public telephone network, two types of fax machines, three types of fax machines, as well as in the use of public data networks, such as four types of fax machines. One, two, three types of fax machines usually use the telephone circuit transmission, transmission of a page of A4 (large 16 open) format documents, respectively, about 6 minutes, 3 minutes and 1 minute. Four types of machines to transmit documents fast (about a few seconds to a dozen seconds), as a data terminal, mainly used for public data communications network, but if the appropriate modulation, can also be used for public telephone exchange network. Three, four types of fax machines also known as high-speed fax machines.
In the signal characteristics, one or two types of fax machines are different from three or four types of fax machines. One or two types of fax machine signal characteristics are analog; three or four types of fax machine signal characteristics of digital, so there are many features and advantages of digital communications (for details, see "electronic Feihong words track" in the "from analog transmission to digital transmission" section). It is the main document fax machine and the direction of development.
According to the document fax machine and the installation of the object of service and the location of the classification, usually divided into two categories of public fax machine and user fax machine. The former is installed in the public **** place, for the public service; the latter is installed in the hand household office or home, directly for the user service.
Three types of fax machines is currently the most common use, the greatest demand for a digital fax machine. It is a collection of optics, electronics, precision machinery, data communications and microprocessing technology, such as the latest achievements in one, with other fax machines are not as many features.
One is more functional. Three types of fax machines due to electronic computers involved in the control of fax information processing, machine automation is very high. Currently used three types of machine functions up to dozens of kinds, for example:
Automatic detection (diagnostic) function. When the machine malfunctions, it can automatically display the fault phenomena and parts. Such as when sending manuscripts or recording paper jam phenomenon, in addition to the text display on the machine, the corresponding indicator light, the user can always be based on the display troubleshooting.
Unattended function. Unattended operation saves personnel, especially for international fax communications with large time differences. Unattended can usually be distinguished into three categories: unattended on the receiving side, unattended on the sending side and unattended on both sides. Receiving party unattended refers to the receiving side of the fax machine can not be operator, the sending party to dial the receiving side of the phone number can automatically start the receiving side of the fax machine, and receive the sending side of the transmission of the manuscript, print out the management report for the receiving side to view. Sender unattended refers to when the sender user to leave due to temporary emergencies and the need to pass the manuscript to the other side, you can send all the manuscripts on the fax machine into the board, in accordance with the prior statute, the receiving party dialed the phone number of the sender, that is, automatically start the sender's fax machine, to be verified by both sides to formulate a password beforehand, will be sent to the receiving side of the manuscripts sent in order in turn. Both unattended is to send and receive both sides of the fax machine can not operator, the sender will be sent to the manuscript in order on the feeder board, and adjust the message sending time, to the scheduled time, the sender's fax machine to start by itself, through the dialing call, start the receiver's fax machine, to be verified by both sides of the pre-established password, will be sent to the other side of the manuscript.
Automatic image reduction and expansion function. As mentioned before, the document fax machine is like a long-distance copying, sometimes the size of the document sent may not be exactly matching with the recipient's record paper, which is fine. If you send a wider text, and the recipient's record paper is narrower, then you can adjust the text proportionally smaller. By the same token, if you send a narrow text with small words that are hard to read, and the recipient's fax machine has wide paper, the text can be automatically enlarged.
Automatic feeding and cutting. Three types of fax machines can be placed on the paper table 50 or so sheets of manuscript paper, controlled by the machine's automatic feeder, in order to automatically send in order. During transmission, if you want to know the quality of transmission, you can check the printed report. The automatic paper cutter on the fax machine is designed to make the received copy the same length as the sent copy to prevent the copy from being wasted due to the long paper and losing text if the paper is short.
Color tone selection function. Some of the three types of fax machines in addition to the transmission of black and white two shades of color, but also can transmit dark gray, medium gray and light gray and other intermediate tones, so that the transmission of the picture picture layers, rich in three-dimensional sense.
The function of selecting and sending manuscripts. Sometimes some fields in the text are not sent to the other party, as long as some specific symbols next to these fields, the content of these fields will be automatically deleted in the received message.
"White space" function.
Data Ready
Data Ready
Data Ready is a video ready to run when you need it. With "jump white" function of the three types of fax machines encountered between the word and the word or line and the line has a blank, it will automatically jump over, so you can greatly improve the low-density text transmission efficiency of the manuscript. The use of three types of fax machines to transmit a manuscript of A4 format, the normal transmission time of 1 minute, with the "jump white" function, can be increased to 40 seconds, 30 seconds, 20 seconds, or even a few seconds.
Reduced bit dialing function. For some frequent fax objects, you can replace the phone number with more digits with a 1 to 2 digit self-coding code. For example, the user registered with the telephone office with "86" two-digit instead of the other side of the phone number 82420772, then, before faxing the user as long as the provisions of the key "86" can be automatically connected to the called user 82420772 phone.
Copier function. Three types of fax machines receive and send one, not only can fax, but also when the copier to use. Some three types of fax machines will "copy" called "self-test", through which to detect the fax machine working condition is normal.
Failure to build a file function. Three types of fax machines can be used in the process of each obstacle automatically stored in the machine's memory, the automatic establishment of "medical records" file, when needed, you can pull out the "medical records" to analyze and repair.
In addition, the three types of fax machines also have the function of selecting the density of the scanning line as well as call request and other functions.
The second is easy to operate and use. Operators do not need to be specially trained, in a very short period of time will be able to master the use and operation.
Third, small size and light weight. The latest class III fax machine weighs only a few kilograms, and small, can be easily carried.
Fourth, the transmission method is flexible. Class III fax machine can use the existing public telephone exchange network or a dedicated telephone line for transmission to half-duplex mode of operation.
Fax is a common means of office automation, but also a powerful communication assistant at home. The current application of the fax machine is mostly black and white fax, it transmits the image only black and white color difference, there is no color information. Accompanied by the development of science and technology, can transmit both image brightness information and can transmit the image chromaticity information color fax will jump into the communication arena. It is more real and infectious than black and white fax.
The principle of color fax is not complicated, we know that the natural world, despite the colorful, colorful, but the vast majority of colors of light can be broken down into red, yellow, blue 3 colors, in turn, according to a certain amount of proportion will be reconciled together, can be synthesized into a variety of colors, which is known as the "principle of the three basic colors ". For example, white is by the right amount of red, yellow, blue synthesis, cyan is by the right amount of yellow, blue synthesis. Color television sets work on the basis of the three-color principle.
To send color pictures by fax, there are basically two methods: one is the use of "sequential transmission", that is, the first color image information is broken down into red, yellow, blue 3 kinds of basic information, and then in accordance with the order of transmission, and then at the receiving end of the 3 basic colors mixed together, reproduced with the sender of the same color image. This method of transmission requires three times the transmission time of sending a black-and-white image, and if black is included, it takes four times as long. Alternatively, "simultaneous transmission" is used, where separate signals for each color are transmitted at the same time, but this requires an increase in the bandwidth of the circuit.
The fundamentals of color faxing are not new. As early as April 1925, there was a sample of a color facsimile in the frontispiece of the "Bell System Technical Guide," and in August 1945, at the Potsdam Conference, color photographs of Stalin, Truman, and Adlai were radioed to Washington by facsimile machine. The question now was how to improve the efficiency and quality of the transmission of color photographs. Scientists predict that the use of image compression technology, in the near future, can be transmitted in the band of black and white faxes, to the same speed transmission of color faxes. With the development of image technology, the widespread use of color fax is just around the corner.