Interpretation of the eight quality assurance technologies and maintenance of LED displays
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Công cộng Nhóm
Interpretation of the eight quality assurance technologies and maintenance of LED displays
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Interpretation of the eight quality assurance technologies and maintenance of LED displays
In terms of display technology, the LED display is a display composed of light-emitting diodes. How to produce high-quality LED display? A good use method and environment are also very important for the long-term maintenance of high-quality LEDs. To produce high-quality LED displays, it is necessary to do a good job in the following aspects of technical control, anti-static, drive, heat dissipation design, etc. What I mentioned above are some details in the production process of LED display screens. Daily maintenance and maintenance are also very critical. The technical team of Guanjin Display will introduce several basic LED display quality assurance technologies and methods of daily maintenance to users. for reference only.
To produce a good quality LED display, it is necessary to do a good job in technical control in the following aspects:
1. Anti-static LED display electronic display assembly factories should have good anti-static measures. Special anti-static floor, 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. .
2. Drive circuit design The layout of the drive IC on the drive circuit board on the LED display module will also affect the brightness of the LED. Since the output current of the driver IC is transmitted too far on the PCB, the voltage drop of the transmission path will be too large, which will affect the normal working voltage of the LED and reduce its brightness. We often find that the LED brightness around the led screen wall design (ledcoms.com site) display module is lower than that in the middle, which is the reason. Therefore, in order to ensure the consistency of the brightness of the display screen, it is necessary to design the distribution diagram of the driving circuit.
3. Design current value The nominal current of the LED is 20mA, and it is generally recommended that the maximum operating current be no more than 80% of the nominal value, especially for a display with a small dot pitch, due to poor heat dissipation conditions, the current value should also be reduced . According to experience, due to the inconsistent attenuation speed of red, green and blue LEDs, the current value of blue and green LEDs should be reduced in a targeted manner to maintain the consistency of white balance after the display is used for a long time.
4. Mixed lights LEDs of the same color with different brightness levels need to be mixed, or inserted according to a discrete pattern designed 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 screen will be inconsistent, which will directly affect the display effect of the LED display screen.
5. Control the verticality of the lamp. For in-line LEDs, there must be sufficient technology to ensure that the LEDs are perpendicular to the PCB board during the furnace. Any deviation will affect the brightness consistency of the LEDs that have been set, and color blocks with inconsistent brightness will appear.
6. The temperature and time of wave soldering must be strictly controlled. The temperature and time of wave soldering must be strictly controlled. The suggestion is: the preheating temperature is 100°C±5°C, and the maximum is not more than 120°C. The temperature is 245°C±5°C, and the soldering time is recommended not to exceed 3 seconds. 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, which is determined by the characteristics of the LED. Overheating or fluctuating temperature will directly damage the LED or cause hidden dangers to the quality of the LED, especially for small-sized round and oval LEDs such as 3mm.
7. False welding control When the LED display does not light up, there is a probability of more than 50% that it is caused by various types of false welding, such as LED pins, IC pins, and pin headers. Wait. The improvement of these problems needs to be solved by strictly improving the process and strengthening the quality inspection. The vibration test before leaving the factory is also a good inspection method.
8. Heat dissipation design The LED will generate heat when it is working, and the high temperature will affect the decay speed and stability of the LED. Therefore, the heat dissipation design of the PCB board and the ventilation and heat dissipation design of the box will affect the performance of the LED.
Daily maintenance of LED display
1. LED display display part
The display part of the LED display is mainly to regularly remove dust from the surface of the display, especially for outdoor LED displays. Particles of acid or other chemical factors corrode the surface of the display under wet conditions, thereby improving the service life of the LED display.
2. LED display box part
The inspection of the box part mainly includes the following links:
1. Check whether the power supply is working normally and whether the AC220 line is loose;
2. Whether the fan is running normally, and clear the dust on the fan impeller;
3. Check the receiving card: check whether the DC5V line powered by the receiving card is loose, whether the receiving card is in good contact with the adapter card, whether the cable on the adapter card is loose, etc.;
4. Visual inspection to see if there is a DC5V line or loose cable between the modules inside the box;
5. Check whether the ventilation opening of the cabinet is blocked by sundries, etc., and if so, remove the dust-proof net for cleaning.
3. Others
Check the decoration of the LED display to ensure the safety of the display;
The ladder for entering the LED display maintenance channel should be at least three meters above, and it is necessary to install a protective door, and there are relevant warning signs;
For outdoor LED displays, if necessary, install effective lightning protection measures for the display.