Patent ID: 6927750

Claim:
An external display device of a refrigerator comprising: a display unit on a door in the refrigerator, showing information on the state of the refrigerator; at least one user-select key on the door; a sub control unit at the door, said sub control unit receiving and transmitting signals generated by pressing the key and controlling the display unit; a main control unit at a main body of the refrigerator, said main control unit controlling operations of internal devices in the refrigerator and communicating with the sub control unit; a hinge unit mounted on the refrigerator and supporting the door; and a communication means having a voltage supply line for supplying the supply voltage for the main control unit, the sub control unit and the display unit, and a signal line for transmitting data to each other, said communication means passing through the hinge unit, said sub control unit and said main control unit determining whether a right of data transmission is assigned to themselves before transmitting data to each other.