PURPOSE: To make the motion of the user of the display device free, to attain a cordless way and to save the installing space of a display device by providing a mechanism where a display part can be freely set at the periphery of the eyes of a user.

CONSTITUTION: A light transmitting part 3 modulates the video signal 5 edited in a terminal system and outputs the signal 5 after modulating it into an optical signal 6. A photodetecting part 4-1 receives the signal 6 from the part 3, and a demodulating part 4-2 demodulates the signal 6 received at the part 4-1 into the signal 5. A display part (small-sized monitor) 4-3 displays an image based on the signal 5 demodulated at the part 4-2. Under such conditions, the part 4-3 can be set at the periphery of the eyes of a user and therefore the user can finely view the image shown at the part 4-3. Thus the sides of the parts 4-1, 4-2 and 4-3 are connected to the terminal system and the part 3 without using any cord and with use of the signal 6. At the same time, the user wearing the part 4-3 at the periphery of his eyes can move in an easy and free way. Furthermore the installing space of a display device can be saved.