How to disable android phone's display? Hi im looking for method to disable my android phones display running on pie. I don't want to use tap to sleep, power button or simulate that option but I want to simply disable display completely and then turn it back on when I need it. I have rooted my phone already. 

Example: I want to watch a YouTube video with only audio. So if I disable the display it can save my battery but pressing power button stops the buffering.

it's just an example for what I want to do this. I don't want it. I'm aware of youtube vanced..
Thanks @mnd I found solution for the problem.
The following app works smoothly. It disables only display 

https://forum.xda-developers.com/android/apps-games/app-screen-backlight-off-xda-exclusive-t3037380

Thanks stackexchange family.
Source: How to make an app behave the same way with screen off, as with screen on?