Apple iPhone - Cancel touch screen during call

Reference this image:
http://www.myitablet.com/gallery/files/2/iphone-sensor.jpg

That shows where the sensor is (hard to see unless in right angle and right light)

But if that gets covered (even partially) it messes up the the ability to know move the phone to your ear to talk.

It has to be the case... the sensor should turn the screen off while the phone is up to your ear, then if you lower the phone the screen will cut back on automatically. This is not only to avoid the accidental pressing of functions, but also to conserve battery power.

I don't use a case, just a screen protector, and I've never had a problem.

Wow, I just checked with a flash light and yes, you can notice the 2 sensors, one is in-call ear sensor and then there's anotherone next to it. That must be the light sensor which is used to automatically adjust the screen brightness.

There is a proximity sensor above the ear speaker that locks the screen when it's against your face. Do you have a case on your phone that might be blocking that sensor?

-SB

Do you have your iPhone in a case? It is possible that it is covering the sensor near the receiver that detects when your face is near the phone.