Rotation dependent frictional hinge mechanism

An electronic device (10) has a foldable housing (11) including a base unit (12) and a cover unit (14). The cover unit is rotatably joined to the base unit by a hinge mechanism. Within cover unit is a frictional hinge mechanism including a cam member (30), a cam follower (32) and an o-ring (34). The cam member has an attachment post (38) connected to an attachment gear on base unit such that the cam member is fixed to the base unit. The cover unit rotates against noticeable friction produced by o-ring rubbing between cover unit and cam member while cover unit is at angles of rotation larger than a pre-set angle, and cover unit rotates against minimal friction at angles of rotation smaller than the pre-set angle. The friction allows cover unit to maintain a multiplicity of positions with respect to base unit within a preselected range of angles larger than pre-set angle.