How it works: proximity sensor.

I recently had a phone screening for a company I really want to be a part of. I prepared myself by writing down the answers to the questions I thought I would be asked. Of course I wasn’t asked any of those questions. I was caught totally off guard and did not know the answer to several of the questions they did ask. Sucks right? No, it was awesome! Why? Because, “I don’t know is how you grow.” I now have the opportunity and motivation to learn something new, not only learn it but become an expert on it and share my newly acquired knowledge.

The question I got asked that most struck me and most piqued my curiosity was the following:

How does your iPhone screen know to shut itself off when you are on a call and you put the phone to your ear?

The answer is simple, a proximity sensor.

The proximity sensor. The proximity sensor works by pulsing an infrared LED and measuring the amount of reflectance. Put more simply, the proximity sensor shines a light onto your skin, the sensor sees the light bouncing back, knows your face is there and sends a signal to the operating system telling it to shut down the screen. When the light doesn’t bounce back the proximity sensor sends a signal to the OS telling it to put the screen back on. The proximity sensor has been part of the iPhone ever since it was first released in 2007; its function is extremely important because not only does it prevent you from unintentionally touching buttons while trying to have a conversation, but it also saves precious battery life. The operation and design of the proximity sensor is not only brilliant technologically but also brilliant in terms of product design. It solved a problem before it even became a problem. Not only that, but the fact that it all happens automatically is what truly makes it brilliant. Imagine how annoying it would be if you had to manually turn off your phone’s screen before putting it to your ear and then turn it back on to read a text, then off again when you put it to your ear, then on again to check who is calling on the other line etc, etc.

Today is January 1, one resolution we should all have is to appreciate the little things, like your phone’s screen turning on and off automatically.