Difference between HDMI and DVI interface of LCD driver
Date:2019-07-19
The general signal interface of industrial LCD driver board is 2-channel CVBS signal input, 1-channel VGA, 1-channel HDMI / DVI, 1-channel YPbPr, 2-channel USB (which can read high-definition video pictures), 1-channel CVBS output and other signal interfaces. The HDMI interface and working principle of LCD driver were introduced before. Today we will explain the difference between HDMI and DVI interface of LCD driver.
VGA interface is that the information processed by the graphics card is ultimately output to the display. The output interface of the graphics card is the bridge between the computer and the display, which is responsible for outputting the corresponding image signal to the display. CRT display can only accept analog signal input because of its design and manufacture, which requires the graphics card to input analog signal. VGA interface is the interface of analog signal output on the graphics card, VGA (Video Graphics Array) interface, also known as D-sub interface. Although LCD can directly receive digital signals, many low-end products use VGA interface in order to match with VGA interface graphics card.
VGA interface is a kind of D-type interface. There are 15 empty pins on it, which are divided into three rows with five in each row. VGA interface is the most widely used interface type on the graphics card, most of the graphics cards have this kind of interface. Some graphics cards without VGA interface and with DVI (Digital Visual Interface) interface can also be converted from DVI interface to VGA interface through a simple adapter, which is usually attached to graphics cards without VGA interface.
At present, most computers and external display devices are connected through analog VGA interface. The display image information generated in the computer is converted into R, G, B primary color signal and line and field synchronization signal by the digital / analog converter in the display card, and the signal is transmitted to the display device through the cable. For analog display devices, such as analog CRT display, the signal is directly sent to the corresponding processing circuit to drive and control the kinescope to generate images. For LCD, DLP and other digital display devices, the corresponding a / D (analog / digital) converter should be configured in the display device to convert analog signal into digital signal. After D / A and a / D2 conversion, some image details are inevitably lost. There is nothing wrong with the application of VGA interface in CRT display, but when it is used to connect LCD and other display devices, the image loss in the conversion process will slightly reduce the display effect.
Compared with DVI, HDMI interface has smaller volume and can transmit audio and video signals at the same time. The cable length of DVI should not exceed 8 meters, otherwise the picture quality will be affected, and HDMI can transmit up to 15 meters. As long as one HDMI cable can replace up to 13 analog transmission lines, it can effectively solve the problem of messy wiring behind the home entertainment system.
advantage:
HDMI interface can transmit uncompressed high-resolution video and multi-channel audio data in digital form while maintaining high quality. Its outstanding performance surpasses all previous products.
HDMI connectors use single wire connections, replacing the complex cables behind the product.
There is no length limit for cables with HDMI interface. For example, the cable length of DVI should not exceed 8 meters, otherwise the picture quality will be affected, while products conforming to HDMI specifications do not have this problem.
HDMI specification can be combined with broadband digital content protection (HDCP) to prevent unauthorized reproduction of copyrighted audio-visual content.
DVI to HDMI adapter
Another big difference is object-oriented. The traditional DVI interface standard is for general PC users, while HDMI interface standard is for people who use consumer electronic products, such as DVD player, home theater equipment and so on.
Users are most concerned about the performance of the new interface, while content publishers are more concerned about copyright protection measures. New HDMI interface with advanced HDCP copyright protection technology（ High bandwidth digital copy protection is a technology developed by Intel.
