Overview of the development of LED display control system

At the end of the 1980s, my country's LED display screen was born, and the LED control system, which is the core component of the LED display screen, was also born at the same time. The LED display is a flat-panel display composed of independent LED devices or LED module panels to display information such as text, images, and videos. The system that controls the LED display unit to achieve correct display according to user needs is the LED display control system. LED display control system, also known as LED display controller, LED display control card. It is the core component of the LED display, and is mainly responsible for receiving the picture and video display information from the computer serial port or DVI interface, putting it into the frame memory, and generating the serial display data and information that the LED display can recognize according to the partition driving method. Scan control timing. Through the analysis of the dot matrix module and the control circuit, the components of the LED display are determined; through the analysis of the single-chip microcomputer and the intelligent control module, the composition structure and scanning driving mode of the LED display are determined to realize the display of the LED display. With the development of LED display screens from single and dual primary colors to full-color and to ultra-high-definition with smaller pitches, more subdivided fields such as transparent screens, light pole screens, advertising machines and commercial all-in-one machines have been developed. LED display control In response to development needs, the system is developing towards higher performance and more flexibility, and is becoming more and more subdivided. So far, it has developed into a professional LED display control market (including video processors) worth 3 billion to 3.5 billion yuan.

1. Basic concept of control system

1. What is a control system?

LED Display Control System (LED Display Control System) is a system that controls the correct display of LED large screens according to user needs. According to the networking mode, it is divided into two categories: networked version and stand-alone version. The networking version is also called the LED information release control system, which can control each LED terminal through the cloud system. The stand-alone version is also called LED display controller and LED display control card. It is the core component of the LED display. It is mainly responsible for converting external video input signals or onboard multimedia files into digital signals that are easy to recognize on the large LED screen. , so as to light up the large LED screen equipment, which is similar to the graphics card in the home PC, the difference is that the monitor in the PC is a CRT/LCD, etc., and the display in this system is a large LED screen.

According to the access signal mode, it can be divided into synchronous system and asynchronous system. The concepts of synchronous and asynchronous originated from synchronous display screens and asynchronous display screens, which can be traced back to 1992, when Luopu grandly launched multi-color and full-color display screens with 256-level grayscale VGA resolution. Mr. Li Xilin, the chief engineer of the Pu company, proposed the concept of "synchronous screen", which means that it is very convenient to use the Luopu LED display. display effect. Later, they called Lantong's stock quote display screen and similar relatively simple monochrome or three-color bar text display screens "asynchronous screens"! Since then, the industry has adopted this concept for publicity and promotion, synchronous, Asynchronous control systems are then known.

The synchronous control system is mainly used to display video, graphics, notifications, etc. in real time. Mainly used for indoor or outdoor full-color large-screen display. The LED display synchronous control system controls the working mode of the LED display is basically equivalent to the monitor of the computer. It maps the image on the computer monitor in real time at a refresh rate of at least 60 frames per second, and usually has a multi-gray color display. Ability to achieve the effect of multimedia advertising. Its main features are: real-time, rich expressiveness, complicated operation, and high price. A set of LED display synchronous control system is generally composed of sending card, receiving card and DVI graphics card.

Depuda Synchronous Sending Box

Asynchronous control system is also called LED display offline control system or offline card. It is mainly used to display various texts, symbols and graphics or animations. The information displayed on the screen is edited by the computer, pre-installed into the frame memory of the LED display through the RS232/485 serial port, and then displayed and played screen by screen, and the display mode is rich and varied. Its characteristics are: simple operation, low price and wide application range. The simple asynchronous control system of LED display can only display digital clock, text and special characters. In addition to the functions of a simple control system, the LED display graphic asynchronous control system has the biggest feature that it can control the content of the display screen in different regions, supports analog clock display, countdown, picture, table and animation display, and has timing switch and temperature control. , humidity control and other functions.

There is also a division method on the market, that is, single (double) color control system and full color control system. Most of the playback content of single (dual) color LED display screens are text files, such as the text displayed on the door of many stores, as well as conferences, monograms, etc. The files of this kind of playback content are relatively small, and most of them are It is a few K, up to 1~2M, and the required memory is relatively small, so the control system of single and double-color LED displays is mostly asynchronous cards. The transmission methods of the control system include serial port, network port, USB port, and more and more popular mobile phone WiFi transmission.

The playback content of the full-color LED display is mostly pictures, videos, PPT and other files with relatively large data. According to the playback requirements, either a synchronous playback system or an asynchronous playback system can be used. The synchronous playback system is mostly used to play video and PPT. Its main function is to display the playback content synchronously with the computer monitor, that is, what is played on the computer and what is played on the LED display. It is mainly used in conferences, offices, stages, and large exhibition halls. Generally, it is set to "copy mode" in the computer display settings (or a few multi-screen synchronous playback requires "extended mode"). The asynchronous playback system is mostly used to loop notifications, advertisements, promotional pictures, and promotional videos. Its main function is to send the content such as text, pictures, or videos to be played to an asynchronous memory card for loop playback. It is mostly used in small exhibition halls and on the street. Advertising screens, door screens, traffic guidance screens, street column screens and other scenarios.

2. The composition and working principle of the LED display control system

The LED control system is mainly composed of two parts, the sending card and the receiving card. After the sending card obtains the video stream data from the DVI interface on the PC, after relevant data processing, it sends it to the receiving card through the Ethernet network, and the receiving card sends the received data to the receiving card. After relevant processing, drive the LED screen to display. For full-color LED displays, the number of receiving cards can be calculated according to the number of boxes. Generally, there is one card per box, that is, one box is equipped with one receiving card. It can be said that the receiving card is essential for the LED display to display the picture normally.

However, there are also companies in the industry that promote the industry’s first LED display project without a receiving card—Jinzhan International Jewelry Plaza, which directly integrates the receiving system into the light board, completely eliminating the need for the LED screen to be equipped with a receiving card. The space of the LED display unit is saved, and the thickness of the LED display is reduced to only 33mm. In fact, it is not that there is no receiving card, but that the receiving card is integrated into the display screen. This publicity is a bit confusing, but the innovation of integrating it into the display light board is worthy of recognition. At present, there are two-in-one and three-in-one products in the industry. The system, in fact, is also taking the integrated route, which makes the LED display more foolish to play and easier for users to use. Industry insiders predict that in the future, the control system will become thinner and thinner, and it may become a chip integrated on the display screen, which will save a lot of unnecessary trouble.

The usage of sending cards is less than that of receiving cards. Generally, a screen only needs to be equipped with one sending card. Now most manufacturers’ sending cards are integrated into the processor, and only a few companies are selling separate sending cards.

2. The development history of my country's LED display control system

1. From independent research and development of display screen manufacturers to professional control system manufacturers

The development history of the LED display control system is as long as that of the LED display. It has a history of more than 30 years. It was originally independently developed by the display manufacturers. At that time, the control systems developed by each display factory were only for their own displays. There are few professional control systems in circulation. For enterprises that want to enter this field, it forms a high technical barrier. Due to the inconsistent technology or interface, the control systems of related screen factories cannot be compatible with each other. Since then, companies such as Depuda, Zhongqingwei, and Lingxingyu have launched general-purpose control cards, which can be used universally on most LED displays, directly lowering the technical threshold of the control system, and attracting a large number of companies to enter this field. The system is gradually independent of the display market and has developed into an important core component of the display.

In fact, the technical content of the LED control system is indeed relatively high. The early display factory independently developed the control system, which required a large amount of manpower and material resources of the enterprise. Considering the considerations, we will still choose the more general control system on the market. In addition, most display small and medium-sized enterprises do not have control system research and development capabilities, and are highly dependent on professional control system manufacturers, which also provides opportunities for the development and growth of the control system industry.

Early professional control system manufacturers include Depuda, Zhongqingwei, Lingxingyu, etc. At present, some early control system manufacturers have gradually withdrawn from the market, followed by emerging manufacturers such as Nova, Colorlight, Kystar, and Grayscale Growing rapidly, together supporting the LED display control system industry.

2. Emerging technology manufacturers join to promote the rapid development of the LED control system industry

The growth of the LED display industry not only attracts a large number of enterprises to enter this field, but also allows more enterprises with technical strength to set their sights on the professional LED display control system market. Nova, Colorlight, Kystar, Emerging technology manufacturers such as Shanghai Lingxin and Mosier joined in, which greatly strengthened the technical strength of the LED control system industry. As Nova introduced the correction technology into the system, the LED display can display better, which expands the scope of the control system to a certain extent.

At present, the main brands in the field of LED control systems are: Nova, Colorlight, Lingxingyu, Kystar, Grayscale, Maiprovision, Mosier, Shanghai Xixun, Shanghai Lingxin, Weiao Video, Shicheng, Yangbang, AVIC and other brands. It is worth mentioning that both Nova and Colorlight have submitted listing applications. The latest news says that Colorlight’s IPO has been accepted. Perhaps in the near future, there will be one or two LED display control systems in the securities market. listed companies in the industry. It is reported that since its establishment in 2012, Colorlight has gradually extended to other fields based on the display control system. At present, it has created three major product types: LED display control system, video processing equipment, and cloud network player.

As a leading enterprise of LED display control system, Nova has played an important role in promoting the development of the entire LED display control system industry. It introduces point-by-point correction technology into the field of control systems, which can be said to be a technological innovation for the industry.

So what is point-by-point correction technology? As we all know, the uniformity of brightness and chromaticity of LED display screens has always been a major problem that plagues the industry. Chromaticity unevenness cannot be corrected, it can only be improved by subdividing and screening the LED color coordinates. As people's requirements for LED display screens are getting higher and higher, only subdividing and screening LED color coordinates can no longer satisfy people's critical eyes. It is achievable to carry out comprehensive correction processing on the display screen to improve the uniformity of chromaticity. of. Nova itself is a leader in the field of calibration systems. It has successfully introduced point-by-point calibration technology into the LED control system to solve the above problems. After its calibration, the picture quality of the LED display is obviously clearer, the color is brighter, and the grayscale is more accurate. , Watching the big screen for a long time will also reduce the damage to people's eyes, which is very popular among users.

With the advancement of LED display technology, people have higher and higher requirements for display functions. In order to meet customer needs, control system manufacturers have long been no longer limited to the development of LED control systems, but have expanded their business to more fields, such as video processors, splicers, and more. At the same time, video processor R&D companies also respond to development needs and deploy control systems. At present, relevant video processor companies such as Maiprovision, Weiao Video, and Vision have entered the field of control systems. In the future, the trend of combining the control system and video processor industries will become more and more obvious.

3. The development of the control system field is divided, and some enterprises are beginning to develop in the direction of subdivision

In recent years, the form of LED display has undergone tremendous changes, from a single form to a diversified development mode such as transparent screen, 3D, VR, creative display, etc., which has also put forward higher requirements for control system manufacturers, prompting some control system manufacturers to start to move towards Develop in a more subdivided direction. For subdivided fields, control system manufacturers have proposed ultra-large resolution solutions, indoor small-pitch solutions, stage rental solutions, fixed installation solutions, special-shaped screen solutions, conference/education all-in-one machine solutions, and XR virtual shooting solutions , 3D display control solutions, cloud networking cluster management solutions, smart light pole screen solutions, vehicle advertising screen solutions and other control system products that meet market demand.

As a technology-based industry, innovation plays a pivotal role in development. Therefore, some manufacturers were forced to withdraw from the historical stage because they could not keep up with market changes. Some companies with strong innovation capabilities occupy important positions in the market instead.

At present, LED display technology is in a state of flourishing, COB, four-in-one, Mini/Micro LED, etc. have enterprise layout. Known for its innovation, Nova is very optimistic about the Mini/Micro LED field, and believes that it is the future development trend of the display industry. Nova started from multiple dimensions and continuously improved the brightness and color consistency of the display to better meet the ultra-high image quality requirements of Mini/Micro LED displays. In addition, Nova is also actively deploying 8K products, and participated in the formulation of the world's first AVS3 video standard, which is at the forefront of the industry. Today, Nova's control system has been successfully applied to the Spring Festival Gala, Beijing Daxing Airport, China International Import Expo and other scenarios. Faced with the development trend of the LED display industry, Colorlight also believes that the popularization and application of 5G+8K in the future will provide excellent market opportunities and a good development environment for the company's product expansion and business growth. Shanghai Xixun and grayscale control systems have penetrated into application fields such as smart light pole screens and vehicle screens.

4. Based on customized requirements, the rise of self-developed control systems

As the saying goes, "When divided for a long time, we must unite, and when we unite for a long time, we must divide." When professional control system manufacturers are "eaten everywhere" in the general LED display market, some customized projects with special needs are struggling to find a matching control system. As LED displays are developing towards subdivision, there are many differences in the requirements for LED control systems in various scenarios, which eventually forced some LED display manufacturers to embark on the self-developed route again. For example, Alto Electronics has developed its own control system for the current virtual reality, naked-eye 3D and other markets. The 8K control system developed by Aoto Electronics not only has a series of world-leading technologies such as 24-bit processing depth technology, 8K ultra-clear display technology, 48G video data transmission and processing technology, wide color gamut video display technology, ultra-large bandwidth/optical fiber transmission technology, etc. At the same time, it also has the characteristics of fast screen construction, high color depth display, high processing depth, wide color gamut display, 3D technology, HDR10, flexible and convenient configuration, and WE server login control. In addition, Aoto Electronics also announced that it launched a 64K controller with completely independent intellectual property rights in 2018, which has been applied to the Outernet, a large landmark building in London abroad, creating an example of a 360° panoramic immersive LED display experience space.

The UCM control management system independently developed by Unilumin can fully integrate the splicing controller, LED receiving card, LED playback controller, PLC distribution box and peripheral equipment to help users realize the management and control of various signal windows and small-pitch display systems. Schedule various business applications to be displayed on the wall to build a "display ecology". Shanghai Sansi also has its own adaptation solutions for smart light pole screens and traffic screens. Huida Smart Display has also developed an independent LED display control system based on the needs of light pole screens.

In the face of market changes, some screen companies have embarked on the road of independent research and development of control systems, but compared with the beginning of the industry's development, they are not the same. The current display screen manufacturers that can independently develop control systems are all strong and open-minded. They can not only share their own technology, but also cooperate with some professional control system manufacturers to jointly develop some advanced products and jointly provide continuous input for the industry. motivation.

3. Changes and challenges in the field of control systems

Because of the epidemic, the development and innovation of the control system was also severely hindered this year. According to the analysis of a professional in the industry, LED control system chips have risen sharply, and control system manufacturers dare not easily increase prices due to survival. This is one of the cost increases that come. Second, due to the price increase of display screens, many customers are waiting and watching, and control system manufacturers are also implicated. Some control system manufacturers have been in the off-season for two or three months this year. Third, due to insufficient production capacity of upstream driver IC chips, some low-quality chips in the early inventory flowed into the market. The low-quality chips will inevitably bring many problems to the LED display. Control system manufacturers spend more energy on remedial work, such as strengthening calibration, and many failures will occur later, and control manufacturers need to debug many times, which invisibly increases the cost of system manufacturers. Therefore, this year is very difficult for control system manufacturers, and the industry faces many challenges.

1. Generalization and customization coexist, and the segmented demand market is becoming more and more fragmented

As LED displays are becoming more and more subdivided, in order to meet market demand, some control system manufacturers have adopted a strategy of specializing in subdivided fields, some focusing on small-pitch large screens, vehicle-mounted screens, smart light pole screens, and some focusing on advertising machines, transparent Screen, etc., so as to gain recognition in a certain market segment and maintain stable growth. It is understood that in 2020, Grayscale has deeply cultivated the segmented market of vehicle-mounted LED screens and smart light pole screen control systems, successfully lighting up smart light poles in Wuhan, Xi'an, Xining and other places, and vehicle screen projects have also landed in various parts of the country. Coincidentally, Shanghai Xixun is also making efforts in this field. Its vehicle-mounted screens and smart light pole screens have more and more projects, occupying a certain market share in the market.

It is understood that there are 1.5 million taxis in operation in China, and the number reaches 3 million in the world. If 10% of the taxis are installed on the car, there are 300,000 taxis in the world that need to install display screens and control systems. , The rear window screen of shared cars, this market prospect is also very impressive. Li Long, sales director of Shanghai Xixun, shared that in the future, the taillights of taxis can also be made into LED screens, which can warn or remind the vehicles behind not to approach and other information. This is also an incremental market. In addition, fields such as smart light pole screens are very important growth points for the control system.

In the past two years, the country has intensively introduced a number of strategies such as "transportation power" and "new infrastructure", and vigorously promoted the construction of "smart street lights + vehicle-road coordination" smart roads, and a wave of smart light poles has been set off across the country. Last year, the smart light pole projects in 4 municipalities directly under the central government and 13 provinces in my country have been implemented. According to statistics, the global smart light pole market in 2020 will be about 8.95 billion U.S. dollars, and it is expected to grow to 10.35 billion U.S. dollars in 2021. From 2020 to 2026 The global smart light pole market will grow to about 21.88 billion US dollars, with a compound annual growth rate of about 16.06%. Not only China has implemented smart light poles in various cities, but many countries around the world have explored and piloted smart light pole projects, including the United States, Singapore, India, Germany, Spain, South Korea, etc., to realize intelligent management of road traffic through LED street lights. With the maturity of the technology and the success of the pilot, the popularization of smart light poles is just around the corner.

With the rise of transparent screens, LED all-in-one machines, movie screens and other fields, the demand for control systems is also increasing. At present, the six major listed companies have deployed transparent screen projects. Because of the popularity of landscape lighting and night travel economy, the market development speed of transparent screens in this field has been boosted. At present, transparent screens have become an important driving force for the LED display industry. LED all-in-one machines also perform strongly in conferences, education, party building, finance, new retail and other fields, which are the focus of control system manufacturers. However, some control system manufacturers said that the current price of LED all-in-one machines is still high, and the sales volume is far less than that of LCD all-in-one machines, but the future prospects are very good, so they have developed corresponding control systems now, but they are not the current key promotion areas. As for the movie screen market, after Unilumin and Leyard entered this field following Samsung's footsteps, it is believed that more companies will lay out this potential market. At present, there are about 30,000 movie theaters in my country, and there are about 80,000 screens in the country. It is expected to exceed 100,000 in 2023. According to the per capita index of the US market, the domestic market can accommodate at least 130,000 to 160,000. The Chinese movie screen market Reaching the 100 billion level, the control system field is expected to have a market share of 5 billion yuan.

In addition, with the expansion of LED display application fields, emerging applications such as 3D and XR have arrived, and there will be more subdivided fields in the future. Control system manufacturers also need to continuously develop new solutions to meet the new needs of the market. In the small-pitch ultra-high-definition field, with the advantages of 5G, the demand for synchronous control systems is large, and the products are relatively generalized. However, in the face of new subdivisions, customization requirements are high, which is a new challenge.

2. The integration trend of control system and video processing system is obvious

With the advancement of LED display technology, the demand for integrated LED display products is getting higher and higher, and the supporting control system and video processing system also need to develop in the direction of integration and intelligence. Like the LED display control system, the video processor is a key device of the LED full-color display, and its pros and cons directly affect the display effect of the LED display. The binding use of LED video processors and display screens greatly facilitates the wide application of end users and improves the depth of use of LED display screens. For a long time, the control system and video processor, as important supporting equipment for LED displays, have always existed independently. As the technical level and integration of display screens become higher and higher, it is inevitable that the control system and video processor will be more closely integrated, and the dividing line between the functions of the two will become more and more blurred. In addition, in terms of functional control, cost and efficiency, mutual integration is also inevitable.

In 2019, Nova launched a 2-in-1 video processor, which combines all the functions of the video processor and an independent main control (sending card), reduces intermediate links, and perfectly solves the problem of compatibility. One device can easily meet various engineering needs. In addition to Nova, companies such as Colorlight, Shanghai Lingxin, Yangbang, and Grayscale have also launched "three-in-one" and "two-in-one" video processors. At present, the entire industry has recognized this trend, and there are even "all-in-one systems". For example, Yicai launched a five-in-one intelligent controller at this year's isle exhibition, which is also the first five-in-one new product in the field of control systems in the industry, and is the result of the integration and intelligence of the control system. According to Wang Biao, general manager of Yicai, the five-in-one intelligent controller launched by Yicai has significant advantages of high integration and intelligence, and is a very forward-looking product in the industry. Users can switch between multiple signals through a wireless remote control. They can watch TV, cast screens on mobile phones, play from U disks (videos, pictures, PPT, tables), switch between multiple computer screens, etc. If it meets the conditions, it can present 2K/4K high-quality images. Compared with traditional video processors that require external set-top boxes, screen projectors and other equipment, the five-in-one intelligent controller series products greatly simplify the operation process, enhance the convenience of use, and increase the added value of the product. All conventional LED The display screen becomes a smart large screen in seconds.

3. The development of Mini/Micro LED technology challenges the traditional LED display control system

As a new type of display technology, Mini/Micro LED has always been very optimistic. The current layout of enterprises includes Samsung, Sony, BOE, Leyard and other international and domestic giants. Last year, they invested 39.4 billion yuan in the development of this field. The future is expected Usher in trillion-level market demand. However, currently only Mini LED backlight products are commercialized, and a small number of Mini LED direct display products and Micro LED products are available. It is expected to take three to five years to really explode. Because the market prospects in this field are very attractive, some control system manufacturers have already made arrangements in advance.

Opportunities and challenges often coexist. Due to the change of the driving method, the glass substrate will replace the traditional PCB as the carrier board, which also brings great challenges to the control system manufacturers. As we all know, the chips of Mini LED direct display and Micro LED are very small and cannot be directly soldered on the traditional PCB board. are directly bonded to the glass). A few days ago, BOE officially launched the P0.9 COG Mini LED direct display product at ICDT. This product adopts the industry-leading glass-based display technology and advanced micron-level packaging technology. Accuracy, active drive, no screen flicker, not easily deformed by heat, high flatness, large-scale substrate, etc. In fact, this also represents the development direction of Mini LED direct display and Micro LED in the future.

Because the smaller the chip, the more serious the mixed light phenomenon on the LED screen, and the inaccurate gray scale and color performance need to be solved by the control system, which poses challenges to the industry. However, for these, Nova has developed image quality engine technology. Dr. He Guojing of Nova once said that from a technical point of view, image quality can be decomposed into five dimensions: spatial resolution, grayscale resolution, time resolution, color gamut, and dynamic range. These five dimensions form Nova’s technology group and support The high-quality display of Mini/Micro LED enables Mini/Micro LED to gain a larger market share in the process of competing with LCD, projection, and OLED. At present, some control system companies are also planning, but they are still in the exploratory stage.

All in all, after more than 30 years of development, the LED control system has made great progress, from single and double primary colors to full-color, from synchronous to asynchronous, from single function to integration and intelligence... for the prosperity and development of the LED display industry important contribution to development. In recent years, the LED display industry is developing towards subdivision and specialization. LED control system manufacturers and businesses are also catering to the market trend and developing towards a specialized market. At present, a complete industrial chain has been formed. At present, in order to avoid homogeneous competition, it is a good strategy for some manufacturers to specialize in certain subdivisions, so as to gain a stable position in the market. Although affected by the epidemic, the LED control system ushered in the most difficult year in history, but with the rise of 5G+8K, movie screens, XR, 3D, smart light poles, car screens, Mini/Micro LED and other market segments, The future can be expected!