Patent ID: 7830357

Claim:
An image display device, comprising: a display section which includes a light source and displays an image based on a visible light output from the light source; and a controller for having the display section display the image at a predetermined frame rate, modulating an intensity of the visible light with a frequency higher than the frame rate, and having the visible light carry predetermined information; wherein: the predetermined information includes multiple types of information for modulating the intensity of the visible light with multiple types of frequencies higher than the frame rate; the display section includes a plurality of display areas; said image display device further comprises light receivers for receiving visible lights output from the display areas of the display section which are reflected off an object; and the controller controls the light source such that visible lights having the intensity modulated using the multiple types of information are output from different display areas, and specifies a position of the object based on a phase difference among reflected light received by the light receivers.