Portable digital communication apparatus with reversible dual-axis hinge

A portable digital communication apparatus comprising:

• a first housing extending along a longitudinal direction of the apparatus and having a first upper surface and a first lower surface opposite the first upper surface;
• a second housing which is shorter than the first housing in the longitudinal direction and which is adapted to open away from and close onto the first housing through sliding and rotational motions, the second housing having a second upper surface and a second lower surface opposite the second upper surface, the second lower surface facing the first upper surface when the apparatus is in a closed state in which the second housing is closed onto the first housing;
• and
• a dual-axis hinge device having a hinge upper surface, a hinge lower surface opposite the hinge upper surface, a first hinge axis for rotatably connecting the hinge device and the first housing, and a second hinge axis parallel with the first hinge axis and for rotatably connecting the hinge device and the second housing, the dual-axis hinge device being adapted to rotate to allow the hinge upper and hinge lower surfaces to be reversed in orientation facilitated by the sliding motion of the second housing.