A video projector includes a shell case, which accommodates optical components, and a cooling system, which directs ambient air toward the optical components. The cooling system includes a turbulent flow generator arranged in an intake duct. The turbulent flow generator includes a diagonal upstream surface that smoothly changes the direction of an air flow and generates a turbulent flow at the downstream side of the turbulent flow generator. Fine dust particles suspended in the turbulent flow adheres on a downstream surface of the turbulent flow generator and are removed from the air flow.