Patching phenomenon of LED display
In the box photo above, the last two are the two well-known listed manufacturers in the industry. Although the plaque phenomenon has been improved, it is also obvious.
So how do LED display plaques come about? The following analysis of materials and shapes will draw conclusions:
The back of the LED module mask is flat, and the front is designed with striped protrusions and the brim of the lamp because of the light type. That is to say, our design focuses on the front light type; precisely because of our design , And the shrinkage of PC materials is not fully considered, which leads to the imbalance of the surface stress distribution caused by the shrinkage of the material (shrinkage refers to the shrinkage rate of the material after molding, and the shrinkage rate of different materials is different), the stripes on the front of the mask The shape of the protrusion shrinks more than the rear plane shrinks, and the stress generated in the front is also greater than the stress generated in the back. The front and back imbalance of the stress causes the mask to dent to the rear;
What about the phenomenon? Because of the unbalanced stress distribution between the front and rear of the mask caused by material shrinkage and design defects, and the surface stress of the module mask is unevenly distributed, the stress generated by the shrinkage in the middle part of the module mask is greater than the edge of the mask, so the mask Generally, it is more concave in the middle to the back.
Some people might say that the module mask is soft, I use the module bottom shell to lift the middle of the mask, this phenomenon should disappear? But the conclusion is ruthless-"no".
Another phenomenon is that due to the shrinkage of the material, the surface of the mask also has an effect on the reflection curvature of the light, so it visually increases the perception of the patch of the display screen.
From the above analysis, we can conclude that the cause of the plaque of the display screen is caused by the material and design defects of the mask, so how to solve this problem?
At present, the two manufacturers in the industry behind the above picture coincidentally use the ink color of the mask to make a fuss, which is to use ink as much as possible to blur the plaque feeling, but this method cannot completely solve the display screen. Due to the harsh requirements for ink color, it also brings difficulties to the supplier in processing and production, which will invisibly increase the cost; and in the application process of the display screen due to the accumulation of dust on the surface of the screen and other factors This plaque feeling will become stronger and stronger.
So can this problem be solved completely? The answer is yes!
Method 1: Increase the thickness of the mask appropriately so that the shrinkage stress caused by the protrusion of the front of the mask is negligible. This can be solved. However, for this solution, one is to accurately calculate the thickness of the module mask. It may cause other problems. The third is to have a good grasp of the materials.
Method 2: Design the same protrusions on the front and back of the simplest mask. That is to say, what kind of optical protrusions are designed on the front of the module mask, and what kind of protrusions are designed at the same position at the back, so that the front and back shrinkage of the mask is balanced. , So that the stress generated by shrinkage in the front and back of the mask is balanced, and the deformation of the mask can be easily solved.
