In recent years, the use of full-color LED displays in sports venues, road traffic, advertising, leasing, etc. has shown a rapid growth trend. Judging from the current market demand analysis, the necessity of proofreading is becoming more and more prominent.

 

The uniformity proofreading is summarized as: factory proofreading, repair proofreading, service area proofreading and on-site proofreading.

In general, when the LED display screen is used for a period of time, the LED tube will have different degrees of brightness attenuation, and the attenuation of the three colors is different. Therefore, their brightness will be lower than that of the factory.

However, the photoelectric properties of each light-emitting tube are different, resulting in an inconsistent degree of light attenuation. Therefore, when the display is used for a period of time, the brightness of the light-emitting tubes will be different, resulting in uneven brightness.

Compared with the display just shipped from the factory, the presented picture will have a grainy feeling or low brightness. At the same time, the degree of attenuation of the tri-colour tubes will lead to changes in white balance and colour temperature.

 

 

In fact, performance degradation of the display is almost inevitable due to light attenuation of the LED lamps and changes in ambient temperature. It is almost impossible to return an installed LED display to the factory for calibration. Given this situation, display owners need to calibrate on-site to ensure optimal performance throughout the life of the display.

 

1.Proofreading method based on LED running time

This was an early field calibration method that calibrated the display by recording the runtime of each LED module. By roughly calculating the operating time of each LED, the respective brightness degradation is deduced to estimate different calibration levels, which are then sent to each LED module for adjustment. This method requires no human intervention.

However, this approach ignores a very important issue, namely that the LED decay frequency estimated from runtime is not appropriate for each LED, and that the fluctuation in LED decay will increase as the runtime increases. Calibrating uniformly will bring some LEDs closer to normal, but will make the deviation more pronounced in others. Since the brightness levels differ between modules, it is not possible to effectively adjust for brightness mismatches.

As a result, a number of problems arise when uniformity is adjusted for modules with different running times. Most importantly, this method cannot calibrate the brightness of individual pixels. As a result, after calibration is completed, the display gives the impression that there is a mosaic phenomenon that does not improve the uniformity of the display.

 

2.According to the site’s common proofreading method

In order to completely solve the problem of display uniformity, it is necessary to use a special device to quickly collect the optical information of each pixel of the LED display screen in the field, and correct the actual attenuation of each LED tube through the relevant algorithm. Proofreading in the true sense. This proofreading will restore the display to its optimum state.