It’s not a problem, I just pressed the wrong key, just reboot.
A fax machine is a communication device that uses scanning and photoelectric conversion technology to convert still images such as documents, charts, and photos into electrical signals, transmit them to the receiving end, and copy them in the form of records.
The fax machine decomposes the original document to be sent into many tiny units (called pixels) through the optical scanning system in a specified order, and then converts the brightness information of these tiny units into electrical signals in sequence by the photoelectric conversion device. The signal is amplified, encoded or modulated and sent to the channel. The receiver amplifies, decodes or demodulates the received signal and creates a copy of the original in recorded form at the same scanning speed and sequence as the transmitter. Fax machines can be divided into black and white fax machines according to the color they transmit. According to the occupied frequency band, they can be divided into narrowband fax machines (occupying one voice channel frequency band), broadband fax machines (occupying 12 voice channels, 60 voice channels or wider frequency bands). ). Document fax machines that occupy one voice channel can be divided into the following categories according to different transmission speeds and modulation methods: ① Those that use double-sideband modulation technology and have a transmission speed of about 6 minutes per page (16 kilobytes) are called Class I machines ; ② Those that use band compression technology and the transmission speed of each page is about 3 minutes are called Class II machines; ③ those that use digital processing technology to reduce the redundancy of the source and the transmission speed of each page is about 1 minute are called Class III machines; ④ Fax machines that can be connected to a computer network, can store information, and have transmission speeds close to real-time are classified as Category 4 machines. According to the purpose, it can be divided into weather map fax machine, photo fax machine, document fax machine, newspaper fax machine, etc. Recording methods include electrolysis, electromagnetism, cautery, photography, thermal and electrostatic recording, etc.
The fax machine can reproduce the original work intuitively and accurately, and can transmit charts and photos that are difficult to express in words. It is easy to operate and is widely used in military communications. In 1842, the British A. Bain proposed the principle of fax. In 1913, Frenchman E. Belland (also translated as Edward Belland) developed the first fax machine. With the application of large-scale integrated circuits, microprocessor technology, and signal compression technology, fax machines are developing in the direction of automation, digitization, high speed, confidentiality, small size, and light weight.
Laser multi-function fax machine
Function: laser/print/copy/fax
Dimensions: 400mm*385mm*221mm
Weight : About 9kg (including accessories)
Consumables:
Using FX-9 toner cartridge, based on standard A4 size, 5% coverage; initial random consumables have a lifespan of about 1,000 pages, and consumables will be purchased later. Lifespan is about 2000 pages.
Type introduction
There are many types of fax machines, and the classification methods are also different. According to its use, it can generally be divided into the following types:
Photo fax machine
It is a kind of continuous tone image used to transmit the entire optical density range including black and white. , and a fax machine that uses photographic recording methods to produce copies that meet certain tone density requirements. Photo fax machines are mainly suitable for use by news, military, medical and other departments.
Photo fax machines transmit continuous-tone images (the entire range of optical densities, including black and white), and the receiving end uses photographic paper (or film) for photosensitive recording. In order for the copy to achieve a certain tone density level, tone correction measures are taken within the receiver. There are two types of photo fax senders: fixed desktop and portable, using roller scanning; most receivers are fixed desktop, using roller or flat scanning. On the telephone circuit, AM or FM transmission can be selected as needed. Photo fax machines are mainly suitable for use by news, public security, military, medical and other departments.
Newspaper fax machine
It is a fax machine that uses scanning to send a full-page newspaper proof, and the receiving end uses a photographic recording method to copy the film for plate making and printing.
In order to ensure the timeliness and accuracy of newspaper news, there are high requirements for the copy quality and transmission rate of newspaper fax machines. Analog newspaper fax machines mainly use cable or microwave carrier telephone system broadband base group or supergroup channel transmission, and can also be equipped with data compression equipment to transmit on analog or digital channels. Digital newspaper fax machines mainly use digital channel transmission of satellite communication systems.
There is also a newspaper fax machine, called a user newspaper fax machine, which is installed in a home or office and is usually used to receive fax programs (full-page newspaper information or weather forecasts) broadcast by radio stations or television stations. etc.), record and display directly on paper.
Weather fax machine
It is a fax machine used to transmit weather cloud maps and other weather charts. It is also called weather chart fax machine and is used in meteorology, military, aviation, navigation and other departments. Transfer and copy weather maps, cloud maps, etc. The transmission format is larger than a newspaper, but the resolution requirements are not as high as that of a newspaper fax machine. Mainly uses wireless broadcasts to send and receive signals. The receiver is controlled remotely by the transmitter and can automatically start, stop, select scanning parameters, and adjust reception levels. In addition, there is a satellite cloud image fax machine that receives cloud photos and infrared images taken by meteorological satellites, which has high requirements for resolution and color tone.
There are two transmission methods for weather fax, weather wireless fax broadcast using shortwave (3-30 MHz) and point-to-point weather transmission broadcast using wired or wireless circuits. Weather fax broadcasts are one-way transmissions, and most weather fax machines are only used for reception.
Color fax machine
For news or military departments to transmit and copy color photos or color maps, etc.