An optical scanning head-mounted display includes a head mount unit including a light source that emits a light beam, an optical scanner that scans the light beam to irradiate the light beam onto a projection plane, an image capturing device that outputs image data of a captured image as the image data in a first format, and an interface that converts the image data in the first format obtained from the image capturing device into the image data in a second format and outputs the image data in the second format; a transmission cable that transmits the image data in the second format; and a controller that receives the image data in the second format through the transmission cable and controls the emission of the light beam from the light source based on the image data in the second format.