【School】 projector weak Detailed terms of the input terminals】..

<br> VGA Input: VGA interface uses a non-symmetrical distribution of the 15pin connection, it works: It is within the memory image stored in digital format (frame) signal in through the simulation in the RAMDAC analog modulated high frequency signal, and then .output to the projector image, so that the signal at the input VGA (projector), you do not like the other video signal decoding circuitry that has to go through the conversion matrix. .Video imaging principle from the front VGA video transfer process we can see is the shortest, so the VGA interface, has many advantages, such as crosstalk-free circuit synthesis without separation of wear and tear. .<BR> DVI Input: DVI port is mainly used with a digital display output connected to the computer graphics to display the computer's RGB signal. .DVI (Digital Visual Interface) digital display interface, by September 1998, at the Intel Developer Forum on the Digital Display Working Group established (Digital Display Working Group referred to as the DDWG), the development of digital display interface standard. .<BR> DVI digital signal terminal is better than the standard VGA terminal, digital interface to ensure that the entire contents of the digital format for transmission to ensure that the host to monitor the integrity of the data transmission process (the introduction of non-interference signal), can be more clearly .image. .<BR> Standard video input (RCA): also known as the AV port, often pairs of white and yellow audio interface, video interface, it is usually RCA (commonly known as the Lotus head) in connection with the lotus only need to use .the standard AV cable with the head connected to the corresponding interfaces. .AV interface separation of audio and video transmission, which avoided because the audio / video mixing interference caused decline in image quality, but the AV interface transfer is still a luminance / chrominance (Y / C) video mix .signal, still need to display its bright / color separation and chroma decoding can imaging, this first mixture and then the color separation process will inevitably result in the loss of signal, chrominance signal and luminance signal will be a great opportunity to each other .interference thus affecting the final output image quality. .AV also has a certain vitality, but because of its own Y / C mix this is not and can not overcome the shortcomings of the limits in a number of occasions in pursuit of visual use. .<BR> S Video Input: S-Video specific English name is called Separate Video, in order to achieve better video quality, people began to explore a more efficient and higher quality HD video transmission, which is currently flourishing in the S-Video .(also called two-component video interface), Separate Video Video significance is to separate the transmitted signal, which is the basis of the interface will be in the AV chroma signal C and luminance signal Y separation, and then were transferred to a different channel, it .appeared and developed in the late 90 century, usually the standard 4-pin (without sound) or the extended 7-cell (with sound). .S-Video interface with graphics and video equipment (such as analog video capture / editing card, monitor TV and quasi-professional TV card / TV box and video projection equipment, etc.) currently has more common, compared with the AV interface, because it does not .then the Y / C hybrid transmission will no longer be so bright separation and decoding, and the use of separate transmission channel to avoid the video equipment to a large extent the signal distortion resulting from crosstalk greatly improve image .clarity, but S-Video still the two color difference signals (Cr Cb) chrominance signal mixed to the way C, for transmission and then decoded in the display device for the Cb and Cr within the processing, so that will bring a certain number of .signal loss and distortion (this distortion is small but in broadcast video equipment, strict testing are still being found under), and because of the mixed Cr Cb chroma signal bandwidth led to certain restrictions, so although the S-Video .has been relatively good but still far from perfect, S-Video, while not the best, but considering the current market conditions and other factors such as overall cost, it is the most common video interface. .<BR> Video Component Input: currently available in a number of professional video workstation / professional video editing card, high-end DVD players and other devices or appliances to see a YUV YCbCr Y / BY / BY interfaces such as identification tags, although the labeling method .and the joint appearance with different but they are referring to an interface component port (also known as component video interface). .It is usually identified by both YPbPr and YCbCr, the former said the progressive scan component output, which said the interlaced component output. .We can see from the above relations, we only need to know the value of Y Cr Cb to be able to get the value of G (the fourth equation is not necessary), so the video output and color processing to ignore the green uniform Cg leaving only the poor .Y Cr Cb, which is the basic definition component output. .S-Video as the advanced products, S-Video Component output chroma signal transmission component C is decomposed into Cr and Cb, thus avoiding the two color mixing process of decoding and re-separation, but also to maintain the color .maximum bandwidth of the channel, just after anti-matrix decoding circuit can be reduced to RGB RGB signal imaging, which minimizes the video source to display the video signal path between the imaging, avoiding the cumbersome transfer process due to .image distortion caused by, so color output of the interface mode is the best variety of video output interface of a. .<BR> BNC port input: coaxial cable typically used for workstations and connectors, the standard professional video equipment, input and output ports. .There are 5 BNC cable connectors for receiving red, green, blue, horizontal sync and vertical sync signals. .BNC connector is different from the ordinary standard 15-pin D-SUB connector of the special display interface. .By the R, G, B primary color signals and horizontal sync, vertical sync signals of five separate joint composition. .Mainly used to connect workstations and other high frequency requirements on the scanning system. .BNC connector can be cut off from the video input signal, the signal to reduce interference with each other, and the signal bandwidth is large compared with ordinary D-SUB, can achieve the best signal response effect. .<BR> RS232C serial ports: RS-232C standard (agreement) stands for EIA-RS-232C standards, EIA (Electronic Industry Association) on behalf of American Electronics Industry Association, RS (ecommeded standard) on behalf of recommendation, 232 is the identification number, .C on behalf of the latest in a modified RS232 (1969), before that, there RS232B, RS232A. .. .It provides cable and mechanical, electrical properties, function and signal transmission process. .There is another common physical standard EIA � RS-232-C, EIA � RS-422-A, EIA � RS-423A, EIA � RS-485. Here only EIA & .; # 0; RS-232-C (referred to as 232, RS232). .Computer input and output interfaces, is the most common serial interface, RS-232C standard interface rules, 25 lines and 4 data lines, control lines 11, three time lines, 7 stand-by and defined lines, used only .9, commonly used with the 25-pin D-sub ports together with the maximum transmission rate of 20kbps, up to 15 meters cable. .RS232C port is used to control the projector computer input. .<BR> Audio input interface: can the computer, VCR and other audio signal input in, through the built speakers. .<BR>.