Apple announced the new iOS 4.1 update last week which will, among other things, finally fix the Proximity Sensor problem that caused the touch screen on the iPhone 4 to remain live even when it connected to a call. When it finally comes out in the next week, iPhone 4 users will no longer have to worry about muting or disconnecting calls accidentally.
The proximity sensor is a small sensor in the top part of the iPhone 4 just to the left of the speaker. When a user holds his or her phone up to the face to talk, it senses when light is reduced and turns off the display. It can be tested by covering it with a finger. In my own tests it works the majority of the time, but on occasion, I have had a call muted or disconnected accidentally because the sensor failed and the screen was on as it touched my face. As the video below shows, the issue is that the sensor is not sensitive enough. Older iPhones turn off the screen when the sensor is blocked from further away. The software fix coming likely turns up the sensitivity.
There are no shortage people dealing with this issue. A look at Apple’s forums will find over thirty pages of people complaining about it. With the update coming next week, this issue should be fixed so that users can hold their phone up to their ear without worrying.
To fix the Proximity Sensor issue you will need to connect your iPhone to your PC and install the iOS 4.1 update when it is available in the next few days. The process will be similar to upgrading to iOS 4.0, as shown in this guide, but won’t likely take as long.