Explanation of four video interfaces of LED display_Shenzhen full color LED display manufacturer|Huaze Optoelectronics
The application of led display screen is becoming more and more extensive, and the content that needs to be displayed as a display device is also diverse, and the display content output format is also many. This article mainly introduces the current mainstream led display video interface. 1. AV input interface The AV interface (also known as the RCA standard video input interface) is an earlier interface, composed of red, white, and yellow lines. The yellow line is the video transmission line, and the red and white are responsible for the left and right sounds. The sound transmission of the Tao. RAC lotus head is generally used for connection. The AV interface realizes the separate transmission of video and audio, avoiding the degradation of image quality caused by the mixing and interference of the two types of signals. However, because this type of interface transmits a luminance/chrominance (Y/C) mixed video signal, it requires further luminance and color separation and chrominance decoding to be imaged, which will inevitably cause the loss of color signals, which will ultimately affect the output image quality. In short, the AV interface separates audio and video transmission, avoiding mutual interference. However, there is still transmission loss, so the AV interface is basically abandoned for high-definition video playback. 2. VGA input interface The VGA interface adopts asymmetrically distributed 15pin connection mode. The working principle is that the image signal stored in the digital format in the video memory is analog modulated in the RAMDAC (digital-to-analog converter) into an analog high-frequency signal, and then output Image on the LED screen. Since VGA decomposes the video signal into the three primary colors of R, G, B and HV line and field signals for transmission, the loss in transmission is quite small. The VGA interface has the advantages of no crosstalk, no circuit synthesis and separation loss. 3, DVI input interface DVI interface is mainly used to connect with a computer with a discrete graphics card to display the computer's RGB signal. The DVI digital interface transmits all content in digital format, and no interference signal is introduced during the transmission process, which ensures the transmission quality from the host to the LED screen, and can get a clearer image. 4, HDMI input interface HDMI (High Definition Multimedia Interface) is based on DVI technology and is a fully digital image and sound transmission interface that can transmit uncompressed audio and video signals. HDMI can provide 10Gbit/s data transmission bandwidth to meet the requirements of high-definition picture quality. At the same time, the HDMI interface does not need to perform digital-analog-digital conversion, which can ensure high-quality video and audio signal transmission. The HDMI cable can transmit audio signals and can be used to eliminate digital audio wiring. In addition, there are S-Video, video component input interface, BNC interface, RS-232C serial port and other categories among the input interfaces of the led display. Because they are being replaced by high-definition interfaces, they will not be introduced due to space limitations. In summary, as people's requirements for the image quality of LED displays are getting higher and higher, analog transmission is being replaced by high-definition digital. I believe that 4K and other image quality will also be wonderfully displayed on the LED display in the near future.