Reporter / Gao Gong LED Zeng Cong
Liad is one of the long-established LED display companies in China. At the 50th and 60th anniversary celebrations of the National Day, the company's display shines. At the opening ceremony of the Olympic Games, the scrolls made by Liard were even more memorable. On November 5th, Gao Gong LED reporters talked with Mr. Lu Changjun, Technical Director of Liard, to understand the development history and technical status of the company, analyze the various problems encountered in the production process of the Olympic and National Day celebration screens, and his technical trends. the opinion of.
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Lu Changjun, Technical Director, Beijing Liard Electronic Technology Co., Ltd.
   High-tech LED: When did Liard start to make a full-color screen?
   Lu Changjun: Liard started from the LED display. At the beginning, he mainly used two-color screens for railway stations, bus stations and other occasions. At that time, the lumen efficiency was still relatively low, and the full color screen could not be done. Liad's early team came from Beijing Lantong Company and founded the Liard Company in 1995. When I joined the company in 1996, there were about forty or fifty people.
   We made the first full-color screen in 1998, which was done for Kunming Telecom. The screen area is nearly 200 square meters. I remember using 3 red 1 pure green 2 yellow green 1 blue at that time, the green light was very expensive at that time, now you only need to use three tubes of red, green and blue. At that time, the LED technology was still immature, mainly using a pixel tube. The dot pitch was 26 mm. The effect was worse when viewed from a close, but the effect was far from good at a distance, but at the time it was the largest in China and the best display. The off-camera LED full color display.
   High-tech LED: At that time, what other companies can do full-color LED display?
   Lu Changjun: Some enterprises have already started to do it, such as Nanjing Luopu.
   High-tech LED: What are the milestones in your development?
   Lu Changjun: For example, in 1998, we launched the self-developed display control IC “LEYARD2000â€. Liard pioneered the introduction of a 256-level grayscale full-color display in China, and many companies were still in 16-level grayscale. Most companies are still 256-level grayscale, and there are very few that can really do ten.
   At the 50th anniversary of the National Day, the special-shaped display float was made by us. This is the world's first special-shaped LED outdoor display that can continuously play video images on the move.
   In 2004, the company obtained the "Computer Information System Integration Qualification Certificate" issued by the Ministry of Information Industry, which means that we can not only do the screen itself, but also provide customers with a complete solution. At present, there are not many companies that can do computer system integration in China. Many companies can only do screens.
   Take the 60th Anniversary National Day celebration screen as an example. It is not only to provide the screen part, but also to provide solutions for customers from image production, image processing to image transmission. This is a systematic project, we can provide comprehensive solutions.
   High-tech LED: There is a display screen in the 60th anniversary celebration made by Shenzhen Zhouming. Can it provide this comprehensive solution now?
   Lu Changjun: I am not very clear about this, but at least in the National Day Memorial's display project, its entire image playback system, power distribution system, and monitoring system are provided by Liard, and the screen is made by themselves. If they have this ability, there should be no more experience than us.
   High-tech LED: When did your Olympic reel start?
   Lu Changjun: We started research and development in August 2007. Our company has a farm in Beijing, and then dozens of R&D personnel have closed the research and development for half a year.
   High-tech LED: What problems did you encounter when doing this display?
   Lu Changjun: bearing problems, simultaneous display problems, and abnormal display problems. At that time, a lot of equipment was placed on the stage, and the structure was complicated. We collaborated with Jin Lixiang to make the picture. The circle in the middle and the axes on both sides were made by us. The other part was done by Jin Lixiang. The part that Jin Lixiang did was only to lay the display on the ground. The part we made was the part to be moved and the structure was complicated.
   The Olympic reel, the part of the circle drawn in the picture is developed and produced by Liard.
   When we first took this task in 2007, it felt more difficult. Although we have strong technical strength, but have not done it before. We are the only bidder for this project. Many things are the world's first. Although the idea comes from Zhang Yimou, it is still done by engineers.
   You should remember when the Olympics, when Liu Huan and Sarah Brightman sang, the stage rose, and the structure was quite complicated.
Complex structure in the center of the scroll
   This structure is quite complicated, and the large round sleeve is a small circle, which is a special-shaped display screen, and the image connection between multiple screens is maintained during the movement. This screen took two months to disassemble 72 times. I think I can apply for the Guinness Book of Records.
   High-tech LED: What are the main highlights of the display made by Liard during the 99th National Day?
   Lu Changjun: The highlight of the time was that we made a special-shaped display because the displays at the time were square. This was a very complicated thing 10 years ago. Now that electronic components have improved, it is ok with an FPGA. Now use a problem that can be solved, using 5 to 10 pieces at the time.
The float display made by Liard on the 50th anniversary of the National Day celebration
   This non-rectangular screen is very difficult to do, I was a project manager at the time. Controlling this screen is spelled out bit by bit. Because it is oblique, we divide it into several blocks, rectangles and triangles. Almost every control board is different. I don't know what it would be like at the time.
   High-tech LED: You made three screens at the celebration of the 60th anniversary of the National Day. What technical difficulties did you encounter at that time?
   The National 60th Anniversary Celebration shared four large LED displays, three of which were provided by Liard. Another piece was installed by Qin Shang and Zhou Ming, and Liard provided the control system.
   Lu Changjun: At the National Day of the 60th National Day, the LED display on the float was not as fresh as the 50th National Day. The big display we made was a highlight. One of the difficulties encountered at the time was the simultaneous display of the two screens, and we focused on solving this problem.
   We did a lot of work in terms of reliability, because if there was a problem with the display at the time, it was not only the face of the company but also the face of the country.
   In terms of power supply, we used dual power supplies, one plus one backup, even if one power supply is broken, the machine can automatically switch to another power supply, which is not visible outside.
   In terms of display, the front-end player is also one plus one backup. When one signal source breaks the signal, it will automatically turn to another signal, which requires strong technical force to support.
   The original display is a unidirectional link. If the middle is broken, some of the modules will be out of control. We have adopted a ring backup technology, which only adds one line and the reliability is improved geometrically.
   Also, what if all the signals are broken? In order to ensure that the screen is not black, we have solidified a picture of "warning the 60th anniversary of the founding of the People's Republic of China". This way the outside world will not feel that our signal has failed.
   In terms of power supply, 220V dual power supply is used, and the power is 100 kW. Two power lines come out of the two substations, greatly increasing reliability. In case the two-way power supply is broken, our screen will not be black, because it can be used for 1.5 hours of UPS, and 1.5 hours is just the time of the National Day parade.
   Throughout the National Day celebrations, our screens have been running reliably and reliably, and all backup methods have not been used.
   High-tech LED: Are you mainly using domestic chips or foreign chips?
   Lu Changjun: Both domestic and foreign chips are used. We have to evaluate and see the results. Now the LED display of Nichia is indeed better than the domestic chip. However, Nichia's products are about twice as expensive as domestic brands, and we will tell them to customers to choose. Even with domestic chips, we guarantee quality and can't have bad lights. In general, it is still used abroad, and most of the high-end products are used abroad.
   High-tech LED: The threshold for producing display screens is not high now. Is it possible to dig some technicians in other factories to do it?
   Lu Changjun: LED display is a system engineering, just like the original PC is better than the one assembled by itself, the reason is the same. To do well or to have a deep foundation.
   High-tech LED: How is the current display in terms of waterproof and clarity?
   The overall waterproofing technique is not difficult. After all, everyone has been doing this for so many years. Liard's box was thrown into the water without any problem. When testing, inject three atmospheres into the box, and it would be OK without leaking.
   In theory, our leading 3G image processor is more effective than LCD TV. The LCD can display ten-digit images, and the LED display can display 16-digit images. Some domestic companies think that it is ok to connect the display screen to the computer. Some foreign companies use professional video processing equipment. We draw on foreign experience and achieve the best results in terms of picture quality, gray scale and color.
   High-tech LED: In the field of LED display is not like LED chip, the core patents are abroad?
   Lu Changjun: I think that in the field of LED display technology, the gap between domestic and foreign is not big, and the domestic is getting better and better. Now most of the screens are made in China, and China's application electronics industry is not behind.
   Liard has always paid attention to patents and currently has fifty or sixty invention patents. When I first started doing display, I paid attention to patents. We have an action called "checking new" and then bypassing them by other means. Although some of the products we make are very similar to BACRO, they are actually different.
   I feel that no matter what I do, I have to check it out, so I can bypass other people's patents, avoid unnecessary disputes, and provide a reference for my own design. At the same time, I also feel that we must respect other people's patents and respect the labor results of others.
   High-tech LED: What is the current profit of the LED display industry?
   Lu Changjun: Overall, the profit of LED display is higher than the average profit of the electronics industry, but as the competition intensifies, the profit is getting smaller and smaller. I feel that the future will develop in the direction of grouping, because the profits are low, and small enterprises are naturally eliminated.
   High-tech LED: What do you think of the future high-end products?
   Lu Changjun: From the application point of view, some luxury brand advertisers, some high-end occasions, and some creative products, this is a direction of the high-end market.
   High-tech LED: As far as we know, Liard is now also doing LED lighting. What is the current situation?
   Lu Changjun: Our LED street lights have been installed on a road in Zhongguancun Science Park. They are designed according to the standards of street lamps. In the future, the company's share of lighting will increase.
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