Leading the way indoor full-color LED display solution experts, a good use method and environment are also very important for the long-term maintenance of high-quality LEDs:
The display assembly factory should have good anti-static measures. Dedicated anti-static ground, anti-static floor, anti-static soldering iron, anti-static table mat, anti-static ring, anti-static clothing, humidity control, equipment grounding (especially cutting machine), etc. are all basic requirements, and should be checked regularly with a static meter .
2, wave soldering temperature and time
The temperature and time of wave front welding must be strictly controlled. It is recommended that the preheating temperature is 100℃±5℃, and the highest temperature should not exceed 120℃, and the preheating temperature must rise smoothly. The welding temperature is 245℃±5℃. It is recommended that the time should not exceed 3 seconds, and do not vibrate or shock the LED after the furnace until it returns to normal temperature. The temperature parameters of the wave soldering machine should be checked regularly. This is determined by the characteristics of the LED. Overheating or fluctuating temperature will directly damage the LED or cause hidden quality problems, especially for small-sized round and oval LEDs such as 3mm.
3, design current value
The nominal current of the LED is 20mA. Generally, it is recommended that the maximum use current be no more than 80, which is the nominal value. Especially for displays with small dot pitch, the current value should be lowered due to poor heat dissipation conditions. According to experience, due to the inconsistency of the attenuation speed of the red, green, and blue LEDs, the current value of the blue and green LEDs should be reduced in a targeted manner to maintain the consistency of the white balance after the display screen is used for a long time.
4, mixed lights
The LEDs of the same color and different brightness levels need to be mixed, or inserted according to the light insertion diagram designed according to the discrete law to ensure the consistency of the brightness of each color on the entire screen. If there is a problem in this process, the local brightness of the display will be inconsistent, which will directly affect the display effect of the LED display.
5. Control the verticality of the lamp
For in-line LEDs, there must be sufficient process technology to ensure that the LED is perpendicular to the PCB board when passing the furnace. Any deviation will affect the brightness consistency of the LED that has been set, and color blocks with inconsistent brightness will appear.
6, heat dissipation design
LED will generate heat when it is working, too high temperature will affect the attenuation speed and stability of the LED, so the heat dissipation design of the PCB board and the ventilation and heat dissipation design of the cabinet will affect the performance of the LED.
7, virtual welding control
When the LED display does not light up, there is often a probability of more than 50 that is caused by various types of virtual soldering, such as LED pin soldering, IC pin soldering, pin header soldering, etc. The improvement of these problems requires strict improvement of the process and strengthened quality inspection to solve. The vibration test before leaving the factory is also a good inspection method.
8. Drive circuit design
The arrangement of the drive circuit board driver on the display module will also affect the brightness of the LED. Since the output current of the driver is transmitted too far on the PCB board, the voltage drop of the transmission path will be too large, which will affect the normal operating voltage of the LED and cause its brightness to decrease. We often find that the brightness of the LEDs around the display module is lower than in the middle, which is the reason.
Therefore, to ensure the consistency of the display brightness, it is necessary to design a good drive circuit distribution diagram.
Before buying an LED display, we need to consider a problem in advance, some things that must be paid attention to.
一. LED display installation environment
Where should the LED display be installed indoors or semi-indoors? In what direction is it installed outdoors? Should you sit south facing north or sit north facing south? Maybe you think this kind of thing is simple, just buy it back! In fact! otherwise. Different installation environments have different requirements for the brightness of the LED display. Generally speaking, the requirements for the brightness of the LED display are as follows:
1. Indoor: >800CD/M2
2. Semi-indoor: >2000CD/M2
3. Outdoors (sit south and face north): >4000CD/M2
4. Outdoor (sit north and face south): >8000CD/M2
Changzhi indoor full-color LED display solution expert Choosing the installation location in advance will not only help us choose the right LED display, but also enable the supplier to design the most suitable solution and display effect for us.
2. Installation site size
Before buying, measure the size of the place where the display is installed. This will help you choose the size of the screen and your actual budget. Generally speaking, the factors that consider the allowable screen area of the user site are:
1. The relationship between the effective viewing distance and the actual site size;
2. Pixel size and resolution;
3. Unit is the base area estimation;
4. Screen mechanical installation and maintenance operation space;
5. The influence of the inclination of the screen on the distance.
What content is played on this LED display, is it text display, picture display, or video display? Because different display content has different requirements for LED display, specifically, it can be divided into the following aspects:
1. Text display: It depends on its text size and resolution requirements;
2. Ordinary video display: 320×240 dot matrix;
3. Digital standard DVD display: ≥640×480 dot matrix;
4. Complete computer video: ≥800×600 dot matrix;
Therefore, before purchasing an LED display, we must first consider the installation environment, the size of the installation site, and the content to be played, so that we can choose a more suitable LED display.
When using the led display screen, we sometimes have a black screen in the process of controlling the system. What is the reason for this? I think most people will have this question. Obviously I started to use it well, but the screen went black all of a sudden? Of course, this phenomenon is not clear for the time being. This phenomenon may be caused by a variety of different reasons. The process of using led display screens will also vary due to different operations or different environments. For example, it becomes black as soon as it is plugged in. Maybe it turns black during the loading process. These reasons are related to some extent.
When encountering this phenomenon, how do we judge the black screen of the led display? The following mainly looks at this failure from 5 aspects.
1. Make sure that all hardware including the control system has been correctly powered on, and do not connect reversely or wrongly.
2. Check and confirm whether the LED display screen and the HUB distribution board connected to the main control card are tightly connected and whether they are inserted backwards.
3. Check and double-check whether the serial port cable used to connect to the controller is loose or falling off.
4. Please check and confirm whether the 50-core cable connecting the Lingxin control card and the HUB distribution board is loose or inserted reversely.
5. If your display interface definition does not match the provided HUB board, a black screen will appear. Please recheck whether your jumpers are loose, open or short-circuited.
Changzhi indoor full-color LED display solution expert The above are 5 solutions, as long as the black screen appears, carefully check the above aspects, then the black screen problem will be solved naturally!
The structure of the LED display screen is the primary issue that needs to be considered in the design of the LED display screen. The display screen needs to be matched with the building where it is installed, and the building site should leave enough space for the installation of the display screen. If this problem is not resolved, the original plan for the display screen will not be implemented.
LED display can be divided into two types according to the maintenance method: front maintenance and rear maintenance. The post-maintenance methods can be divided into two types: ordinary post-maintenance and mobile post-maintenance. The indoor screen unit board is adsorbed on the mounting bar by the magnet column feet, and the unit board can be removed from the front of the display screen during maintenance. This is a typical front maintenance structure. There is also a structure in which the screws used to fix the module on the box body can be removed from the front of the module, so that front maintenance can be achieved. Usually the LED display is repaired from behind. In the process of designing large-scale LED display screens, it is necessary to consider leaving enough space on the back of the screen for maintenance personnel to enter. This space is called maintenance space. The space in the outdoor screen is usually made into a closed type, supported by a steel frame and then surrounded by plates to play a waterproof role.
Some LED displays are small in weight and are temporarily fixed to the wall. Remove the display from the wall when repairing. The display screen can also be installed on a mechanism that can be moved within a certain range, and the mechanism can be moved when maintenance is needed to generate space for maintenance. A typical outdoor LED display waterproof method is to enclose the frame structure of the screen body, the side and the back of the screen with edging materials, and glue the joints between the front box and the box to protect the box from rain. Commonly used outdoor screen edging materials are aluminum-plastic panels, and aluminum or stainless steel panels can also be used.
Outdoor LED display can achieve waterproof function by using a waterproof box. In this case, there is no need to enclose the back space of the display screen, thereby saving material. However, the cost of this type of cabinet is higher than that of ordinary cabinets, and the waterproof effect is worse than that of ordinary display screens. The outdoor LED display produces a lot of heat during the work process, and the temperature of the cabinet will rise significantly due to the external sunlight. Usually, the door cover of the box is equipped with an exhaust fan to exchange air with the outside to dissipate heat. However, this heat dissipation method still cannot meet the needs of high-power display screens. Therefore, in some cases, it is necessary to install an air conditioner in the maintenance space of the display screen to meet the needs of the screen body for heat dissipation.
At present, LED display light pollution is generally divided into three categories in the world, namely, white light pollution, artificial daylight pollution and color light pollution. At present, China only has relevant regulations on the glass curtain wall in the pollution of white light, and there are no relevant regulations on artificial daylight and color light pollution. However, considering that color light pollution does cause people to feel uncomfortable, it is necessary to consider the prevention and control of display screen light pollution when designing LED display screens.
1. Adopt a brightness adjustment system that can be automatically adjusted by the system
We know that the brightness of the environment varies greatly during the day and night, at different times and places. If the playback brightness of the LED display is greater than 60% of the ambient brightness, we will obviously feel that the eyes are uncomfortable, which means that it causes light pollution to people. Through the outdoor brightness collection system, the ambient brightness can be collected at any time. The display level control system automatically converts the broadcast brightness suitable for the environment through the software by receiving the system data.
2. Multi-level gray correction technology
The 8bit color display gradation adopted by the ordinary display screen system, so that the color is stiff in some low grayscale and excessive color. It will also cause inadaptability of colored light. The new LED large-screen control system uses 14bit color display levels, which greatly improves the hardness of the color. So that people can feel the color soft when watching. Avoid people's discomfort with light
3. Reasonable selection of installation location and reasonable planning of display area
There is an empirical plan for viewing distance and viewing angle and display area. At the same time, image research has specific design requirements on the viewing distance and viewing angle of the display screen. When designing the display screen, it should meet the design requirements as much as possible and plan reasonably.
Fourth, the selection and design of broadcast content
The large LED screen is a public medium, including public welfare, advertising, instruction, etc. When we choose the content to be broadcast, we must reach an agreement with the public's requirements to avoid the mentality of refusal to watch it. This is also an important aspect of preventing and controlling the light pollution of the display screen.
Leader's indoor full-color LED display solution expert LED diode itself is a green light source, although the large-scale LED display screen used in clusters does cause a certain degree of color due to design considerations and application requirements. Light pollution, but this contradiction is inevitable and cannot be completely eradicated. Only by adopting technical means and policies and regulations to minimize color light pollution, and to coordinate the needs of advertisers and the viewing psychology of the people. At the same time, we have also seen that compared with today’s neon lights and white light box advertisements, the light pollution of LED displays has been greatly reduced, and LED electronic displays also have the advantages of energy saving and rich colors, which will definitely replace neon lights in outdoor lighting, the message states.
As far as the LED display is concerned, what we look at most is the outdoor large LED screen (which can be seen almost everywhere in big cities), which is more familiar than the indoor LED display. Today we will learn about indoor LED display system knowledge.
One, system composition
This system is composed of computer special equipment, display screen, video input port and system software.
1. Computer and special equipment: Computer and special equipment directly determine the function of the system, and different types can be selected according to the different requirements of users on the system.
2. Display screen: The control circuit of the display screen receives the display signal from the computer, drives the LED to emit light to produce the picture, and outputs the sound by adding power amplifiers and speakers.
3. Video input port: provide video input port, the signal source can be VCR, DVD player, camera, etc., support NTSC, PAL, S_Video and other formats.
4. System software: Provide special software for LED playback, powerpoint or ES98 video playback software.
2. System function:
1. With the computer as the processing control center, the electronic screen corresponds to a certain area of the computer monitor (VGA) window point by point, the display content is synchronized in real time, the screen mapping position is adjustable, and the size of the display screen can be easily and freely selected.
2. The display dot matrix adopts ultra-high brightness LED light-emitting tubes (red and green dual primary colors), 256 gray levels, 65536 color combinations, rich and vivid colors, and supports VGA24-bit true color display mode.
3. Equipped with graphic information and three-dimensional animation playback software, which can play high-quality graphic information and three-dimensional animation. The playback software can display information in more than ten forms, such as covering, closing, opening the curtain, alternating colors, and zooming in and out.
4. Using special program editing and playing software, you can edit, add, delete and modify text, graphics, images and other information through different input methods such as keyboard, mouse, scanner and so on. The arrangement is stored in the hard disk of the control host or server, and the sequence and time of the program playing can be integrated and alternately played, and they can be superimposed on each other.
3. System features:
1. Simplicity: Because the system uses the internal logic of the chip to convert data, it makes the system very simple.
2. Easy maintenance: Since system maintenance becomes the elimination of complex control parts, junior personnel can complete system maintenance work, which reduces overall maintenance costs and improves user satisfaction.
3. High reliability: Since the integrated chip technology is several times more stable than the separation technology, the system control part is much more reliable.
4. High cost performance: The system image display is vivid and natural, and achieves the same display control effect. This is because the performance is reliable and the control of the screen's primary color 4096-level grayscale is realized.
5. Unitized and structured design: The large-scale LED stage screen adopts a unitized screen structure, which makes the continuity intuitive and simple. The screen size can be adjusted according to the needs. It can also make the installation, height and maintenance of the system very simple and reduce The invisible failure rate of the display system.
6. Industrial reliability design: The reliability and stability of the indoor full-color LED display system in Shenzhen have been greatly improved.
The above is the sharing of the editor today. I believe you have gained something. A good use method and environment are also very important for the long-term maintenance of high-quality LEDs. If you want to learn more about indoor full-color LED displays, you can continue. Follow this site!