A projector is disposed inside a seatback of a front seat as a vehicle seat; therefore, when a driver as an occupant seated in the front seat checks the rear side with a rearview mirror or the like, the projector can be restrained from entering the field of view of the driver. Accordingly, different from the case in which the projector is disposed on a ceiling of the vehicle cabin or the like and exposed into the vehicle cabin, it is possible to restrain the projector from blocking the field of view of the driver.