iPhone 4 senors, whats this? (not the light senors by the ear piece!)

[grooveattack]

i was just looking at the tech specs of the iphone 4 and noticed something odd

Sensors:
3-axis gyro
Accelerometer
Proximity sensor
Ambient light sensor

what does it mean my 'Proximity sensor'??
it knows when your near it or something?

 

[geko29]

The proximity sensor IS that grill over the earpiece on the white model (it's there on the black too, just not as visible). It detects when your face is next to the phone and turns the display off, to save battery life and keep you from doing random **** with your cheek.

 

[grooveattack]

oh right, i was thinking that worked with the light senor.