Patent attributes
According to an aspect of an embodiment, a mobile terminal device includes a lower casing, an upper casing, and an intermediate casing, an intermediate casing connected to the lower casing by a hinge structure which enables the intermediate casing to rotate about an axis, the intermediate casing supporting a back surface of the upper casing by a front surface of the intermediate casing, wherein the upper casing has a first groove formed in a vertical direction with respect to the rotation axis on a surface facing the intermediate casing, the intermediate casing has a first portion protruding from a surface facing the upper casing and fitting the groove of the upper casing, and the upper casing is rotatable with respect to the intermediate casing for the portion being guided by the groove.