Shenzhen Lianchengfa Technology Co., Ltd.

Since the introduction of LED displays in the 1990s, with the advancement of display technology and the reduction of costs, the display has gradually moved from the outdoors to indoors. The emergence of small-pitch technology has further broadened the application field of LED displays. Pitch display screens are moving from the initial professional field to the commercial field, and are beginning to lead the rapid development of the industry. The application scenarios continue to make breakthroughs. Some cinemas have begun to try to use small-pitch LED displays to replace traditional screens, bringing better benefits to consumers. audio-visual experience, the rental market is also booming with the expansion of the commercial performance market. The types of display screen products are becoming more and more diverse, which can meet the diverse needs of different customers. The display screen industry has gradually developed and grown, and has a very broad space for development.

With the advantages of true seamless splicing, high cost performance, and outstanding display effects, small-pitch LED displays have been increasingly used in key occasions such as control rooms, command halls, and conference centers. Therefore, small-pitch LED displays Structural design is an important subject.

1. Structural design requirements for small-pitch LED displays

Small pitch LED display refers to indoor LED display with LED dot pitch below P2.5. Compared with other indoor display devices, the small-pitch LED display has the advantages of seamless splicing, modular maintenance, natural and true colors, better display uniformity, and wider color gamut space. Great potential.

2. The structure design of small-pitch LED display mainly has the following requirements:

2.1 16:9 standard resolution requirements

16:9 refers to the aspect ratio of the display, that is, the ratio of the width of an image divided by its height, usually expressed as "x:y" or "x×y", where the colon and the cross indicate the Chinese "" than" means.

According to ergonomic research, it is found that the field of view of two human eyes is a rectangle with a length-to-width ratio of 16:9, so the TV, monitor, and LED display industries design products according to this golden ratio.

2.2 Requirements for seamless splicing

The LCD splicing large-screen display technology has been unable to avoid the influence of the physical frame while meeting the needs of customers to the greatest extent.

Due to the imaging principle, DLP's screen joint gap is much smaller than that of LCD splicing. Before the appearance of high-definition LED small-pitch large screens, DLP can be called seamless, but its optical joints are inevitable. The human optic nerve and its sharpness make this optical patchwork still a bottleneck for large-screen display.

Throughout the LED small-pitch display, its luminous brightness is high, and in the occasions where the brightness requirement is not high, the power consumption is lower under the same brightness; its display surface is non-reflective and has high contrast, which is suitable for high-end applications such as conference rooms, and LED small-pitch display can achieve truly seamless splicing.

2.3 Anti-collision technical requirements

At present, there is no device to protect the lamp around the LED box, because with the increasing demand in the market, the spacing is getting smaller and smaller, so the LED lamp beads are also made smaller and smaller, and the result is that the lamp beads are made smaller and smaller. It is very fragile, and the lamp beads are accidentally knocked down during installation, especially the lamp beads on the edge are more likely to be damaged. The same thing happens when packing and shipping, so be sure to research a device that protects the light in a way.

2.4 Backup technical requirements

As the use of small-pitch LED displays gradually matures, with its unique advantages in display effects, its application places have developed from ordinary conference rooms, monitoring rooms, and exhibitions to national-level conference centers, monitoring centers, CCTV, and large-scale events. For example, last year's G20 conference, this year's Zhurihe military parade, and the Tianjin National Games, LED small-pitch displays are everywhere. However, whether it is a new product or a high-density device, the excellent display effect is accompanied by the risk of stability. Once a black screen appears in the main venue, it will cause political incidents or major international impacts in China, such as the 5th ring of the Tianjin National Games. There are 4 rings, so when choosing a small spacing as the main screen of the venue, the stability assessment is the top priority, and the most important one is that the screen cannot be black.

3. Structural design of small-pitch LED display

The LED display usually takes the box as the basic unit, and the box is spliced into a large screen. The structural design of each box is the same, so the structural design of the display product is carried out in units of boxes, and the structure of the box is designed, and the solution is analyzed and optimized with the help of samples and software.

3.1 Definition of box size

"Adhering to the promotion and popularization of 55-inch large-screen LCD TVs is an important part of a feasible plan to promote LCD popularization in China." This is a summary of a domestic color TV R&D expert who returned from the CES. After more than ten years of development, with the continuous decline of the overall cost, the continuous upgrading and improvement of technology, and the continuous expansion of application fields, it has achieved remarkable results in many fields such as security monitoring, multimedia advertising and public information release, three-dimensional imaging systems, and video conferencing. Fei's results. And the small-pitch LED display has many advantages when used in the monitoring and command center that LCD and DLP cannot surpass.

3.2 Implementation of seamless splicing

The seam is the stubborn problem of the small-pitch display screen, and it is a problem that DLP and CLD cannot completely solve. Not easy to detect.

Therefore, this problem must be solved on the LED display, because the LED display is welded on the PCB through the lamp beads one by one, and the center distance of the LED lamp beads at the edge of the box is the same as the distance between the inner lamp beads. The same, so the center distance is the same when the two cabinets are spliced together, which will eliminate the influence of the gap. However, all products are processed by CNC, and even the best precision will have deviations. In this case, an adjustable structure must be used to achieve a better display effect.

3.3 Anti-collision technology design

The LED display light board is encapsulated with a lot of small LED light beads. Because the light beads on the edge of the box are easily damaged during handling or installation, and the small spacing LED light beads are also very difficult to repair, so the structure A structure must be designed above to avoid and reduce the damage of the lamp beads. As shown in Figure 5 below, adding bosses and guide rails on the side and bottom of the box can achieve its function.

3.4 Backup technology design

In the device failure, the switching power supply failure is the first, so for advanced backup places (TV stations, monitoring centers) generally dual power backup, that is, two power supplies output at half at the same time, which reduces the workload of the power supply and prolongs the service life of the power supply. It also avoids the power grid shock caused by the cold switching of the power supply, and the display jitter or the third harmonic caused by the equipment restart. At the same time, the power supply status is monitored in real time on the software side, and it can be quickly replaced during the maintenance period to eliminate faults.

The dual signals form 2 independent signal loops, which can ensure that when one loop fails, the other loop can be switched over immediately, and the actual switching is less than 0.1ms. The power connector realizes dual power supply and dual signal on the screen, and outputs 2 independent copy signals to 2 sending boxes through the backup board at the splicer end.

4 Conclusion

In the actual small-pitch LED display structure design, it is usually not enough to limit to the above four-point design. It is also necessary to combine the application environment of the large screen to ensure that the module, power supply and system card can be fully maintained front and rear, and the cabinet must be free of External wiring can reduce the damage to the wire caused by other external environments, resulting in abnormal display on the display. Therefore, the structure design of the small-pitch LED display needs to be repeatedly scrutinized, and the actual application test can make the product display more perfect and perfect.

LCF Group takes LED display and related software control system as the core technology, develops LED display product research and development, production, sales and engineering services, and provides all-round LED for government and corporate image projects, commercial advertising projects, and service information broadcasting platforms. Engineering Solutions.