PURPOSE: To reduce electric power consumption and noises by controlling the cooling capacity of a fan by interlocking or sharing the brightness controller of a television picture projector.

CONSTITUTION: In proportion to the brightness of projector tube 3 supplied with video signals, the rotational frequency of fan motor 5 varies. Then, when the temperature of the tube surface rises with high brightness, the rotational frequency is increased to improve the cooling effect and when with low brightness, the tube surface temperature does not rise much, so the rotational frequency is lowered to attain efficient cooling. Thus, the cooling which corresponds to the brightness of projector tube 3 is possible, the electric power consumption can be reduced and noises due to the fanl etc., can also be reduced.