Abstract: The present invention discloses a partition is incorporated into the case of the projector so as to separate the optical system and the circuitry system. A circuitry fan is used to cool the circuitry system. The optical system is cooled by a suction fan. The cooling air is drawn in by the suction fan and directed to a lamp case through an air duct so as to cool a burner within the lamp case. The heat air is then directed to manifold duct. A first outlet of the manifold duct is directed through an exhausting duct to an exhausting fan. The other outlet of the manifold duct is directed to the circuitry fan. As a result, the heated air is discharged out of the case by those two cooling fans so as to evenly discharge the heated airflow from the lamp case, reducing the heat load of the fan and prolongs the lifespan of the fan.