With the rapid development of the LCD industry in the era, various new concepts and new technologies are constantly updated. However, the LCD panel and data interface have been stagnant, and there is not much change at the previous level. The current liquid crystal display industry is developing rapidly, the product update iteration speed is fast, and various new concepts and new functions are emerging one after another. In sharp contrast, the LCD panel and data interface at the core position are almost unchanged for a long time except for the normal generation. This time we will share some information about the origin classification, standardization, transmission principle, channel bandwidth, version generation and Other information of the display data interface. Data interface type principle analysis For a long time, LCD manufacturers have strictly classified the interface types according to the application direction and market positioning of the products, and even have obvious differences on the attached transmission wires. This is a common marketing strategy used by manufacturers to divide product grades. In the past, when full HD resolution dominated the mainstream market, it was not meaningful to talk about the display interface, because at that time, both the analog interface and the digital interface could easily handle the whole. The channel bandwidth transmission pressure brought by HD. High refresh rate high resolution display is popular nowadays However, with the passage of time and the rise of the LCD industry, especially in the current high-speed high-resolution display, there are many display interfaces that are stretched to cope with the huge data transmission pressure brought by high resolution. What's even more embarrassing is that some LCD manufacturers have added a lot of interface types to some new LCD products in order to make the product grade positioning more clear, which reduces the consumer's experience in the subsequent use. Therefore, it is very necessary to have a clear understanding of the data interface. Next, we go straight to the topic, according to a certain logical order, each type of display data interface origin classification, standardization, transmission principle, channel bandwidth, version generation, and even further subdivided into a comprehensive system in-depth introduction. Even with the criticism of many users, the market of mainstream interfaces is huge, and the chances of being eliminated are small and small. Therefore, the main purpose of this paper is to make it easier for everyone to choose the interface requirements in future display purchases. A variety of display interface types First of all, the history is extremely long. In the era of CRT cathode ray tube, it has been red-faced. The VGA (also known as D-Sub), the VGA full name of Video Graphics Array, is translated into video graphics array. It was led by IBM in 1987. An industry display standard that uses analog signals. This is a color difference analog data transmission interface that transmits red, green, and blue analog signals as well as synchronization signals (horizontal and vertical signals). The built-in 15 pin transmission electrodes are arranged in three columns of D-shape. Another difference between VGA and other interfaces is that VGA has only one interface standard and is not further subdivided. Specific signals transmitted by each VGA pin in a three-row D-type arrangement The VGA interface has a long history and is listed as standard on various display devices, and has a broad market audience base. But the defect is also very obvious, VGA can theoretically support the data transmission pressure of 2048*1536@60HZ, but the fatal is VGA as the data interface for transmitting analog signals. In the CRT era, it can be said that it is tailor-made level of adaptability, but After entering the LCD era, the analog signal will inevitably undergo two DAC signal conversions at the graphics card end and the display end, and there will be an inevitable loss in the signal on the transmission line. DVI (Digital Visual Interface), the most popular digital interface in the LCD market, is available in almost all high- and low-end price displays. The DVI standard was developed by the Digital Display Working Group (DDWG), which was established at the Intel Developer Forum in September 1998. In 1999, IBM, HP, NEC, Fujitsu, SiliconImage, Intel, Compaq and other companies officially launched the DVI data transmission interface standard. DVI-D and DVI-I have single and dual channels The DVI interface is a digital signal interface, and the channel bandwidth and anti-interference ability are significantly improved compared with the VGA. The DVI interface can be further divided into three types, DVI-A, DVI-D, and DVI-I. DVI-A can be understood as a variant of VGA for soup change, which is basically disappearing, while the mainstream DVI-D and DVI-I have single channel and dual channel, and the channel bandwidth is twice as wide. Dual version of DVI-D and DVI-I DVI can be said to be a mainstream interface with the growth of LCD monitors. Because DVI transmits digital signals, there is no need to convert signal types on the graphics card and display terminals, and the screen is further improved on the premise of ensuring that the signals are not attenuated. Response time, effectively reducing the appearance of screen smear and other phenomena. However, since the development time is relatively mature at the same time, it is unlikely that the channel bandwidth will be further improved. Even the dual-channel version of the DVI interface limit stops at the 8bit panel 2560*1440@60HZ. HDMI (High DefiniTIon MulTImedia) is a new digital video/audio transmission standard established in 2002 by HDMI organizations established by seven companies including Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson and Toshiba. The initial version is HDMI 1.0, and the 1.3 standard was issued at the end of 2006. HDMI is compatible with DVI on the pins, but the package specifications are different, but HDMI greatly increases the channel bandwidth compared with DVI, and easily responds to the current high-end market high-resolution high refresh rate band. The pressure of data transmission. HDMI has a variety of interface packages HDMI has the power to fully suppress DVI, but it does not occupy the mainstream market, because HDMI is not an open standard. Any manufacturer using HDMI must pay royalties to the HDMI Standards Development Association in exchange for a production license. This royalty is in the form of an annual fee, which is subject to a license fee of $15,000 per year. What is even more unreasonable is that a manufacturer's license fee of $0.15 is payable per HDMI interface manufacturer. This also proves from the side that any closed thing will not have great development prospects, but the real purpose of the members of the association to collect money has been achieved, and it can be regarded as a win-win situation. Schematic diagram of HDCP working principle HDMI comes with another ribbed HDCP content protection mechanism. If the manufacturer is a member of the HDCP Content Protection Agreement, each product with an HDMI interface will only pay a license fee of $0.04. But if manufacturers use HDCP HD digital content protection in their products, they must pay an annual fee of $15,000 plus a smaller key fee per product. All in all, for the manufacturer, this is an interface standard that looks cheap and expensive to use. Under the cost pressure, manufacturers automatically filter out the choice of HDMI in the new product development of the main cost-performance market. The final mainstream interface is known as the industry's top DP (DisplayPort) interface, and now commonly used is DisplayPort and Apple's miniDP. The DP interface start standard was issued in 2006 and is fully developed by the Video Electronics Standards Association (VESA). DisplayPort has a comprehensive quality that goes beyond HDMI. The key point is that it is open and free to use, and has won the support of AMD, Intel, NVIDIA, Dell, HP, Samsung and other industry giants. Common interface types are DisplayPort and miniDP developed by Apple. The development of DP is very advanced. In the current 2K picture is not popular, VESA has released a variety of specifications of 1.2a, 1.3, 1.4a in succession. The channel bandwidth is up to 8K@60HZ, and the 10K panel is 4K resolution. 120HZ runs without pressure. DP's forward-looking strength is worthy of the strongest mainstream display interface. The essential interface in high-end graphics cards is DP DP is favored by the giants. For example, in the multi-screen output of a single graphics card, both N and A require at least one DP interface. But the drawbacks are also obvious. It is well known that HDMI is based on DVI standards. HDMI can be seen as a strengthening and extension of DVI. Both can be compatible with each other in theory and practice, but DP is a new data transmission standard and only supports The DP transmits to the HDMI in one direction, and there is no case where the HDMI to DP is used, and the use is limited. In theory, hot plugging is supported, but it is not recommended to do so. At the same time, the use of the DP interface is small, and it is basically limited to the high-end market, and its development prospects are limited. Finally came to Apple's lightning interface, although Apple's products are basically well received by consumers (not including Apple Watch, which lasts for 18 hours, hahaha), but the closed technology strategy does hinder the entire industry. Development, of course, is not all Apple's responsibility, because the original lightning interface concept was proposed by Intel, codenamed Light Peak, later renamed Thunderbolt, which belonged to Apple's proprietary technology before February 2012. Limited to high patent royalties, the actual effect is weak. The original lightning interface concept was proposed by Intel. Thunder and lightning interface has been available for many years, the interface of a vast majority of external devices is also very good, and the paper data is also very good, but it has been in a tepid situation, this is a closed strategy with Intel and Apple Directly related. Perhaps Apple, which has been able to make money with a small upgrade, has no intention of pushing the lightning interface to the mainstream market. However, the resistance encountered in the subsequent promotion is very inconvenient for users to use. USB Developer Forum is promoting the new version of USB 3.1 Thunderbolt has almost stagnated in the development of many years, but it will always be surpassed if it is not working hard. Currently, the USB Standardization Organization USB Developer Forum is promoting the new version of USB 3.1, adding a new type called USB type-c. Connector, this new type of interface that can be reversed and inserted, is very likely to become the industry standard for future transmission. VESA also announced that the DP interface supports the standby mode. In short, the USB type-c can transmit DP video signals. After seeing this situation, Apple and Intel are considering incorporating the technical features of USB type-c into the new version of the lightning interface. At present, there are many mainstream interfaces. At the same time, each interface basically has a further detailed division. Some standards of different interface types have the same similarities. The author, as a non-existing person outside the industry, thinks that it is necessary to clearly sort out these things and make the majority of consumption. The person is more purposeful in the purchase process. Motorola Repeater,Motorola Radio Repeater,Motorola Dmr Repeater,Motorola Uhf Repeater Guangzhou Etmy Technology Co., Ltd. , https://www.digitaltalkie.com
