US Patent 11269286 Free stop based hinge apparatus

A hinge apparatus is provided. The hinge apparatus includes a rotation axis device configured to pivotably support a part of a display, and a free stop hinge device configured to pivotably support an other part of the display coaxially spaced apart from the part of the display. The rotation axis device includes a curved protrusion for controlling an eccentricity between a central axis line of the rotation axis device and a central axis line of the free stop hinge device.