LG G Vista 2 -H740 User Manual page 13

When receiving and making calls, the proximity sensor automatically turns the backlight off
and locks the touch screen by sensing when the phone is near your ear. This extends battery
life and prevents you from unintentionally activating the touch screen during calls.
Placing a heavy object on the phone or sitting on it can damage the display and touch screen
functions. Do not cover the proximity sensor with screen protectors or any other type of
protective film. This could cause the sensor to malfunction.
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