What is Proximity sensor

What is Proximity sensor? 

Proximity sensor 

The smartphone has a function that turns off the screen during a call if you notice something near the proximity sensor. The proximity sensor turns off the screen when you put the phone over the ear so that it does not activate the touch screen. This sensor is to the left or right of the headset depending on the device model.

Usually the proximity sensor is found in every touchscreen phones. 

See in the image above.

How do proximity sensor work?

The proximity sensor has two LED light one that emits an infrared ray, invisible to the human eyes and another that detects it back when it bounces on a surface. simply when the emitter detects that the light beam has bounced and returns very fast, that means that the object is very close. If the light beam takes longer to return, it is far away and therefore, the proximity sensor will not activate functions such as turning off the screen. 

Benefits of proximity sensor. 

Due to proximity sensor, battery is saved when calling. Because the screen light is turned off, then battery life extend.