Patent ID: 8730394

Claim:
A video display system comprising a video display device and a portable video display device, connected to each other for communication, wherein the video display device comprises: own device video data producing means for producing own device video data to be displayed on the video display device; own device sound data producing means for producing own device sound data to be reproduced on the video display device; video and sound output means for displaying the produced own device video data and reproducing the produced own device sound data; other device video data producing means for producing other device video data in a data format different from a data format of the own device video data; other device sound data producing means for producing other device sound data in a data format different from a data format of the own device sound data; and data sending means for sending the other device video data and the other device sound data to the portable video display device, a storing area that temporally stores the other device video data and the other device sound data, wherein content realized by the other device video data and the other device sound data is changed by an instruction of the user, and the portable video display device comprises: data receiving means for receiving the sent other device video data and the sent other device sound data; a memory area that receives and stores data acquired from said video display device, wherein the size of said memory area is reduced when the portable video display device instructs the video display device to output video and sound related to a video game, and video and sound output means for displaying the other device video data temporally stored and reproducing the received other device sound data.