If you're a Mac user, then there are probably a few features that make you feel slightly superior to PC users. Late night final paper session has you searching for words to come to light on the page? Well, at least your Mac keyboard is backlit so you can type without turning on the light and waking up your grumpy roommate.

The glow-in-the-dark keyboard feature is probably one of the coolest things us Apple users take for granted. While the concept is simple – the keys glow in low-light situations – Apple actually when out of its way to patent each detail in this keyboard feature.

Apple filed a patent entitled "Legend Highlighting" in 2013, which explained how the keyboard letters glow. In the patent, Apple says that although the process in which a graphic is backlit has worked well in the past, "there is always a desire to provide new and improved designs or techniques that result in even more aesthetically pleasing graphics."

Apple's goal with the patented technique was to generate a sufficient amount of light, while still providing contrast to unetched surfaces.

In order for the keys to be backlit the Apple way, Apple starts with a keycap that has a partially or fully transparent covering. An opaque coating is first applied to the surface of the keycap, followed by a second layer of coating on top of that.

Then the first coating layer is etched off a part of the key to create "first depth," allowing light to seep through. A portion of that etched area is then etched again to create a "second depth."

Etching not one, but two portions of the keycap allows far more illumination, and can also result in different effects — such as making the letter "S" light up as well as having the keycap backlit.

This patent allowed us to learn two things: how Apple gets its keyboard to glow in the dark, and that Apple is obsessed with patents.

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Photo: Juan Lupión | Flickr

Diagram pictures courtesy of the United States Patent and Trademark Office.