How it works: The virtual distance sensor is achieved through the accelerometer of the phone and the upper part of the touch screen. The way it works is that the acceleration sensor detects that the user is answering, and then the touch screen detects the distance between the phone and the face. The screen will turn off when the distance is less than or equal to 1 cm.
The detection method: The phone dials the phone number, then the phone close to the face (preferably fit to the face) to see if the screen will turn off normally, and if it will turn off normally after leaving. Do not place directly on the table to cover the screen to judge.