A first light source illuminates a first region. A second light source is configured to provide lower luminance than that of the first light source. The second light source illuminates a second region that overlaps the first region, and that has a larger area than that of the first region. A lighting circuit drives the first light source and the second light source according to a common lighting instruction. The lighting circuit gradually turns on the first light source and the second light source with different gradual changing time periods in response to the lighting instruction.