[josephlord]

A touchscreen is an invention but people managed to use touchscreens without slide to unlock for years. That is a separate and dependent invention.

Either the designers didn't think about this approach or thought it wasn't the best solution. If anyone produced such a solution or documented it the patent should be invalidated for prior art.

My initial reaction to the patent was probably that is a bit trivial but better than many that get granted and that there should be plenty of workarounds. The slide to unlock definitely seems obvious once you have seen it but I'm not sure it is so obvious before you have seen it (it's quite hard to unwind your mind to a state of unknowing). You certainly need to asking the right questions: how can we remove all the buttons, how do you prevent it waking too easily.

There is no need for touchscreen phones to go completely buttonless. That is a design choice not an essential feature to exist in the market.