Head-mounted display device, control method for head-mounted display device, and image display system

An image display system comprising:

• an information apparatus;
• and
• a head-mounted display device of a transmission type that causes a user to visually recognize an image representing specific information transmitted from the information apparatus, wherein
• the head-mounted display device includes
• a position detecting unit configured to detect a present position;
• and
• a signal transmitting unit configured to transmit a control signal to the information apparatus when the present position detected by the position detecting unit is within a specific geographical region,
• upon receiving the control signal transmitted from the signal transmitting unit, the information apparatus transmits the specific information to the head-mounted display device,
• the head-mounted display device further includes
• an information receiving unit configured to receive the specific information transmitted from the information apparatus;
• and
• a control unit having, as an operation mode for causing the user to visually recognize an image, a first mode for causing the user to visually recognize a plurality of selectable images in positions other than the center in an image generable region, which is a region where the head-mounted display device can generate the image and a second mode for causing, when a singularity of the selectable image is selected out of the plurality of selectable images on the basis of the operation, the user to visually recognize an associated image associated with the one selectable image and representing the specific information as an image larger than the one selectable image in the first mode.