A system comprising: a remote control device for remotely controlling a hidden external apparatus; a control device for controlling the external apparatus; and a display device electrically connected with the hidden external apparatus comprising: a display; an optical receiver comprising optical receiving circuitry; an input/output unit comprising input/output circuitry configured to be connected with the control device via a cable; and a processor configured to control the display, the optical receiver and the input/output unit, wherein the processor is configured to analyze first control information for the hidden external apparatus received from the remote control device through the optical receiver, generate a second control information corresponding to control of the hidden external apparatus from the first control information, and transmit the second control information to the control device through the input/output unit, wherein the control device is configured to generate third control information in response to the first control information being received from the remote control device, and transmit the third control information to the display device, wherein the processor is configured to generate, in response to the third control information being received from the control device within a time after reception of the first control information, fourth control information by modifying a header of the second control information, and transmit the fourth control information to the control device through the input/output unit, wherein the control device is configured to stop an operation of an optical receiver of the control device in response to the fourth control information being received from the display device. a remote control device for remotely controlling a hidden external apparatus; a control device for controlling the external apparatus; and a display device electrically connected with the hidden external apparatus comprising: a display; an optical receiver comprising optical receiving circuitry; an input/output unit comprising input/output circuitry configured to be connected with the control device via a cable; and a processor configured to control the display, the optical receiver and the input/output unit, wherein the processor is configured to analyze first control information for the hidden external apparatus received from the remote control device through the optical receiver, generate a second control information corresponding to control of the hidden external apparatus from the first control information, and transmit the second control information to the control device through the input/output unit, wherein the control device is configured to generate third control information in response to the first control information being received from the remote control device, and transmit the third control information to the display device, wherein the processor is configured to generate, in response to the third control information being received from the control device within a time after reception of the first control information, fourth control information by modifying a header of the second control information, and transmit the fourth control information to the control device through the input/output unit, wherein the control device is configured to stop an operation of an optical receiver of the control device in response to the fourth control information being received from the display device.