Smartphones operate with an integrated system of hidden sensors that perform vital tasks without the user noticing, most notably the “proximity sensor,” which is an essential component during phone calls.
The primary role of this small sensor is to detect objects approaching the upper part of the device – especially the user’s face when raising the phone to the ear – to immediately issue a command to turn off the screen and temporarily disable the touch feature.
This mechanism prevents any unintentional pressure on the screen during a call, such as accidentally ending the call, activating the number pad, or opening external applications, and the sensor returns to turn on the screen and restore its functions as soon as the phone is removed from the ear.
Most proximity sensors rely on infrared technology; It emits an invisible signal and measures the extent of its reflection from nearby objects, regardless of the nature of those objects.
The sensor is usually located near the call speaker at the top of the device, but modern designs of some phones now integrate it behind the screen or within the edges to become invisible to the user.
If the sensor malfunctions, the screen may remain lit while the phone is placed on the ear, or turn off with abnormal images. The cause of this malfunction is often due to the dirtiness of the area surrounding the sensor, or the presence of a screen protector that blocks its operation, in addition to the possibility of other software or technical problems.
