Patent ID: 8615848

Claim:
A hinge apparatus for an electronic device comprising: a first plate; a second plate; a cam unit; and a gear unit; wherein the cam unit includes a first cam shaft configured to rotate with and be connected to a first cam bracket fixed to the first plate, a first cam mechanism, including a first spring, that causes the first cam shaft to generate a first torque upon rotation of said first cam shaft, a second cam shaft configured to be independently rotatable relative to the first cam shaft and connected to a second cam bracket fixed to the second plate, a second cam mechanism, including a second spring, that causes the second cam shaft to generate a second torque upon rotation of said second cam shaft, and a cam cover configured to contain an arrangement of the first cam shaft, the second cam shaft, the first cam mechanism and the second cam mechanism, wherein the gear unit includes a first gear shaft configured to rotate with and be connected to a first gear bracket fixed to the first plate, a first gear part arranged on the first gear shaft, a second gear shaft configured to rotate with and be connected to a second gear bracket fixed to the second plate, a second gear part arranged on the second gear shaft, the first gear part, the second gear part and a pair of gears meshed with the first and second gear parts, are configured to synchronize and rotate the first gear shaft and the second gear shaft via the pair of gears, and a gear cover configured to contain an arrangement of the first gear shaft, the second gear shaft, the first gear part, the second gear part and the pair of gears, wherein the cam unit is positioned adjacent to one edge of the first and second plate and the gear unit is positioned adjacent to an opposite edge of the first and second plate, the first and second plates being rotatable relative to each other, wherein the cam unit and the gear unit are independent units that are independently connected to the first and second plates.