Chinese name: output device mbth: output device properties: the main devices that output data and information to the computer: the functions of output devices such as monitors, printers and stereos. , the role of output equipment, the types of output equipment, the classification of output equipment, monitors, printers, plotters, development prospects, the role of output equipment. Output devices are the general names of devices that transmit information from the outside to the computer and devices that return processing results to the outside. These returned results may be intuitively experienced by the user, or may be the input of other devices controlled by the computer: for a robot, the output of the control computer is basically the robot itself, such as making various behaviors. The function of the output device The function of the output device is to output the information processed by the computer to the memory in a form acceptable to people or other devices. There are also many types of output devices. The output devices commonly used in computers include various printers, drilling output devices, display devices, plotters and so on. Printers and display devices have become necessary devices for every computer and most terminals. Paper tape perforator output equipment for computer. Computer output information is represented by small holes in perforated paper tape. This can not only save the information on the paper tape for a long time, but also input it into the computer with punched paper tape. Card punching output device for computer. Punched cards are easy to read, can be stored for a long time, and can also be used as computer input. Display, also known as monitor, is the main tool to realize man-machine dialogue. It can not only display the commands or data input by keyboard, but also display the results of computer data processing. There are usually two main types of displays used for black and white displays. One is CRT(Cath-odeRayTube) display, which is used for general desktop computers; The other is LiquidCrystalDisplay (LCD for short), which is used for portable computers. The following mainly introduces CRT display. According to color, it can be divided into monochrome (black and white) display and color display. Color display is also called graphic display. It has two basic working modes: character mode and graphic mode. In character mode, the display content is based on standard characters. The font of a character consists of a dot matrix, which is stored in the font generator. In graphics mode, the display content is in pixels, and the brightness and color of each point (pixel) on the screen can be controlled by the program, so high-quality graphics or images can be displayed. The resolution of the display can be divided into three types: high, medium and low. The index of resolution is expressed by the product of the number of pixels per line on the screen and the number of lines per frame (screen). The bigger the product, that is, the smaller the pixels, the higher the resolution and the clearer and more beautiful the graphics. The display adapter, also known as the display controller, is an interface component between the display and the host, which is inserted into the motherboard in the form of a hardware card. The resolution of the display is not only determined by the cathode ray tube itself, but also related to the logic circuit of the display adapter. Commonly used adapters are: color display (1) CGA (color graphic adapter), commonly known as CGA card, which is suitable for low-resolution color and monochrome displays. The display modes it supports are: 40 columns× 25 rows, 80 columns× 25 rows, and 4 colors or 2 colors in graphic mode. 640×200, 2 colors. (2) EGA (Enhanced Graphics Adapter) Enhanced graphics adapter, commonly known as EGA card, is suitable for color graphics displays with medium resolution. The display modes it supports are: 80×25 columns in character mode, 256 colors in graphic mode, 640× 350, 16 super EGA cards, and 840× 358+06 colors are supported. 16 color. (3) VGA (videographcarray) video graphics array, commonly known as VGA card, is suitable for high-resolution color graphics display. The standard resolution is 640× 480,256 colors. Most of them are enhanced VGA cards, such as SuperVGA cards, with a resolution of 800×600, 1024×768 and 256 colors. LCD (4) Chinese display adapter In the process of developing Chinese character system, China has developed some display adapters that support Chinese characters, such as GW- 104 card, CEGA card, CVGA card and so on. The problem of fast display of Chinese characters is solved. A printer is an output device that prints the processing results of a computer on paper. People usually refer to the output of the monitor as soft copy and the output of the printer as hard copy. It is a device that converts computer output data into printed fonts. From the perspective of use, it can be divided into two categories. One has keyboard input function, which is slow, but has the ability to talk to the computer. It is cheap, not only commonly used in computers and terminals, but also as a conventional device in communication systems. The other one has no keyboard input function. This kind of printer can be divided into bar printer, narrow line printer, serial printer, line printer and page printer. According to the physical structure, printers can be divided into impact type and non-impact type. Printer printer classification can be divided into character printers that print one character at a time, line printers that print one line at a time, and page printers that print one page at a time. It can be divided into impact printers and non-impact printers. Impact printers can be divided into word mode printers and dot matrix printers. Non-impact printers can be divided into inkjet printers, laser printers, thermal printers and electrostatic printers. Dot matrix printers are most commonly used in microcomputers. Dot matrix printers are characterized by simple structure, small size, low price, unlimited character types, low requirements for printing media and the ability to print multi-layer media. Structure: print head and carriage; Paper feeding mechanism; Ribbon mechanism; Controller: Similar to the display controller. Its print head is equipped with several needles. When printing, you can control different needles to print paper through the ribbon to get corresponding characters and graphics. Therefore, it is usually called a stylus printer. Most of the printers used in daily life are 9-pin or 24-pin printers, mainly 24-pin printers. Printers inkjet printers and laser printers are also widely used. The inkjet printer controls the deflection of a beam of very fine ink through a magnetic field, and at the same time controls whether the ink is ejected. You can get the corresponding characters or graphics. The laser type uses the principle of electrophotography to aim the controlled laser beam at the surface of the photosensitive drum, adsorb toner with different thickness at different positions, and print corresponding characters or figures on paper under the action of temperature and pressure. It is very similar to an electrostatic copier. Laser printers have high resolution, and the printed fonts are clear and beautiful, but they are expensive. Ink-jet printer is similar to writing with ink, which can directly spray ink on ordinary paper to print. There are two kinds of inkjet technologies for inkjet printers: continuous inkjet technology and random inkjet technology. At present, most popular printers on the market use random inkjet technology. However, early inkjet printers and current large format printers use continuous inkjet technology. Performance of laser printers The printing resolution of ordinary laser printers can reach 300DPI (300 dots per inch), 400DPI or even 600DPI. Especially for Chinese characters or graphics/images, it is an ideal output device. Laser printers are called "page output devices" and are expressed in pages per minute (PPM for short). High speed/kloc-above 0/00 ppm, medium speed 30~60PPM. They are mainly used in large computer systems. The low speed is 10~20PPM, even lower than 10PPM, which is mainly used in office automation systems and text editing systems. Thermal transfer printer The printing quality of thermal transfer printer is better than dot matrix printer and equivalent to inkjet printer. The printing speed is relatively fast, the serialization can generally exceed 6 pages/minute, and the resolution reaches 360DPI. Printing principle The print head in thermal transfer printer is a thin film head made of semiconductor integrated circuit technology, which has a heating resistor and is composed of thin film materials that can withstand high power density and high temperature. The thermal transfer ribbon is formed by coating ink with thermal sensitivity on the polyester base film, and the ribbon is located between the thermal print head and the recording paper. When printing, the pulse signal heats the heating resistor in the print head to several hundred degrees (for example, 300℃), and the print head presses on the polyester film, so that the ink on the film base is melted and transferred to the recording paper, leaving color dots composed of characters, graphics or images. If you print Chinese characters, you can print them directly to a printer equipped with Chinese character files, and the printing speed is fast. If there is no Chinese character file, you need to install the Chinese character driver of this printer in the microcomputer, which uses the Chinese character file of the microcomputer, and the printing speed is slow. The printer has two working modes: online and offline. Online, you can receive and print information sent by the host. Offline means cutting off contact with the host. When offline, you can perform self-check or automatic paper feeding/discharging. These two states are controlled by the online key on the printer panel. Printer controller, also known as printer adapter, is the control mechanism of printer. It is also the interface component between the printer and the host computer, and it is inserted into the motherboard in the form of a hardware card. The standard interface is a parallel interface, which can transmit multiple data at the same time, which is faster than the serial interface. The plotter is directly connected with the electronic computer. You can work online or offline. It is a peripheral device widely used in computer-aided drawing and computer-aided design. Common drawing methods are divided into tracking plotter (such as pen plotter) and scanning plotter (such as electrostatic scanning plotter, laser scanning plotter and inkjet scanning plotter). According to the mechanical structure, it can be divided into drum plotter and flat plotter. The transmission mode of NC plotter is steel wire or steel belt transmission; Ball screw or rack and pinion drive; There are also motor drives, such as linear stepping motors with open-loop control and servo motors with closed-loop control. Plotter is a kind of equipment that can automatically draw graphics according to people's requirements. It can output computer output information in the form of graphics. Mainly can draw all kinds of management drawings and statistical drawings, large maps, architectural design drawings, circuit wiring drawings, various mechanical drawings and computer-aided design drawings. The most commonly used is the X-Y plotter. Modern plotter has intelligent function, it has its own microprocessor, can use drawing commands, and has the functions of line and character calculation and self-detection. The plotter can also be equipped with a variety of standard interfaces for connecting with computers. Plotter Plotter is a hard copy device that outputs graphics. Plotter, with the support of drawing software, draws complex and accurate graphics after class, which is an indispensable tool for various computer-aided designs. The performance indexes of plotter mainly include the number of drawing pens, drawing size, resolution, interface form and drawing language. Plotter is generally composed of driving motor, interpolator, control circuit, drawing table, pen holder, mechanical transmission and other parts. In addition to the necessary hardware equipment, the plotter must also be equipped with rich drawing software. Only the combination of software and hardware can realize automatic drawing. Plotter There are many kinds of plotters, which can be divided into two categories according to their structure and working principle: ① Drum plotters. When the X-direction stepping motor drives the drum to rotate through the transmission mechanism, the sprocket drives the traction to move, thus realizing the movement in the X direction. The movement in Y direction is realized by the pen holder driven by Y stepping motor. The plotter has compact structure and large drawing format. But it needs a special kind of drawing paper with chain holes on both sides. ② Platform plotter. A cross beam is installed on the drawing platform, a pen container is installed on the cross beam, and drawing paper is fixed on the platform. The x-direction stepping motor drives the beam and the pen holder to move in the x direction; The Y stepping motor drives the pen holder to move in the Y direction along the beam guide rail. There are three methods to fix the drawings on the platform, namely vacuum adsorption, electrostatic adsorption and magnetic strip compaction. Platform plotter has high drawing accuracy, no special requirements for drawings and is widely used. Development Prospect Output Devices The types of output devices of the first generation computers are very limited. The usual input device is a card reader with punched cards, which is used to input instructions and data into memory; The output device used to store the results is usually a magnetic tape. With the progress of science and technology, the richness of input and output equipment has been improved. Take a personal computer as an example: keyboard and mouse are the main tools for users to input information directly into the computer, while monitors, printers, speakers and headphones return the processing results. In addition, there are many input devices that can accept other different kinds of information, such as digital cameras that can input images. Among the input and output devices, there are two types worthy of attention: the first type is secondary storage devices, such as hard disks, optical disks or other devices with slow speed but large capacity. The second is the computer network access equipment, through which the direct data transmission between computers greatly enhances the value of computers. The Internet enables tens of millions of computers to transmit various types of data to each other.