How to remove the black shadow on the mobile phone screen?

Take an Android phone as an example, the specific operation steps are as follows:

1. First turn on the phone and find the [Settings] function, as shown in the figure below.

2. Secondly, click Display and Brightness, as shown in the figure below.

3. Next, slide the adjustment line under 【 Screen Brightness 】 to the right, adjust it to the appropriate brightness, eliminate the black in the software background, and return to normal, as shown in the figure below.