A hinge assembly includes a follower member, a rotary member, two swing rods, a resilient member and a main shaft. The follower member includes a cam surface. The rotary member includes a latching cam surface. The two swing rods engage with the rotary second member. Each swing rod includes a contact area engaging the cam surface, and each swing rod is rotated to allow the follower member to automatically rotate relative to the latching cam surface. The resilient member provides an elastic force for the follower member abutting against the rotary member. The main shaft, the follower member, the rotary member, the resilient member are placed around the main shaft.