Ideally, we considered LED display screen as unformity if every pixel on the screen has the same brightness and color. However, in practical producing,the uniformity of LED display screen will be affected by many outor fctors, that's why we have to make a correction adjustment ensure the LED display screen have a good quality in images. There are a lot of reasons could cause uneveness of a LED display screen. For example:

LED itself the discreteness of birth defects:

1. LED lamps themselves have brightness and color difference. 

2. Spatial distribution characteristics of LED luminous intensity differences will cause different perspectives on LED luminous intensity with respect to the optical axis inconsistencies on the attenuation value.

Many other factors has been intrduced into the manufacturing process:

1. Flatness of the module assembling;

2.Flatness of cabinet assembling;

3. The flatness of shield as well as the discreteness of ink;

4.Uneven heat distribution inside the module;

5. The optical axis deviation from the normal direction of the display in LED welding especially for DIP LED axis control.

Therefore, every LED display screen after manufactured need pixel-correction technique for processing in sake of the uneveness problem existance.

Why does a used LED display screen still need pixel-level correction？ Because after the LED display screen used for a session,the uniformty of a screen will be deteriorated and show up some large pits, bright and dark spots and even mosaic which we called unevenness phenonmenon.

There is a very high demanding in images quality of the LED commmercial advertising display. In theory, the lefespan of a LED display screen is over 100,000 hours. But in practical using, a LED display screen will deteriorated after operating 5000～10000 hours and it may without any commercial value after using 15000～20000 hours and also cause great waste of social resources.

No matter the large is under production or used for a period of time, pixel-level correction technique will greatly improving the the uniformity and image quality of your LED display screen in a very short time and loew costs.This correction technique is a useful way to improve product quality and develop profit margin in production. It will also prolong LED display screen's lifespan and create more business value for customers, reduce the waste of resources.

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