Abstract: A first illuminance sensor acquires the illuminance of environmental light outside a vehicle, and a second illuminance sensor acquires the illuminance of environmental light inside the vehicle. An image presentation unit controls the luminance of image display light generated from image signals of an image to be displayed, based on the luminance of environmental light acquired by the first illuminance sensor or the second illuminance sensor, and projects the image display light. The image presentation unit selects either the first illuminance sensor or the second illuminance sensor, based on a comparison result, which indicates a magnitude relation between the illuminance of environment light outside the vehicle acquired by the first illuminance sensor and an illuminance to be compared. And the image presentation unit controls the luminance of image display light, based on the illuminance of environmental light acquired by the selected illuminance sensor.