The features that seem to be more prominent in mobile devices in recent times seem to be targeted towards health. Smartphones and smartwatches now include sensors that along with some others dedicated to locating users, can calculate how many steps users walk in a period of time as well as some other physical activities. Sony has an app for their Xperia devices called Lifelog that can count how much time a user has run or walked, and it even tracks transport usage for commutes and how their sleep is. It can also calculate how many calories were burnt every day. Not only that, but it can monitor the usage of smartphones by analyzing how many pictures were taken and where, how much gaming has been done and the time the users spends communicating with others or listening to music, among other uses. All of this data can be seen in a colorful, simple and intuitive interface.
Now, Sony has filed a strange patent consisting in monitoring the face of a user at all times by using a camera, although it is not specified which devices will be compatible, it might as well be any camera in a smartphone or even devices like Google Glass, which include this kind of hardware. The images would then be sent to a server over a secure network and a system would analyze them and detect the different emotional states that the user had throughout the day, filtering the pictures that depict a neutral face, as they don't tell much about the emotions. Then, users could search for a specific emotion and the system would show the pictures that depict that particular state, also, graphic timelines may be created to check the different emotions that the user had in a day. At night, cameras will still monitor the user's expressions in order to search for patterns or gestures that may help to verify the quality of their sleep.
It sounds like the use for the patent may be to expand the offerings of the aforementioned app, but clearly additional hardware will be required, specially to monitor users in their sleep, as current cameras are not able to take pictures in total darkness or follow the movement of the face in case the user decides to turn his head.