To actualize a liquid crystal projector device, equipped with a filter device, which makes it easy to take emergency measures against an abnormal situation such as a fault of a cooling fan itself for suppressing a rise in internal temperature.

The projector device is equipped with an internal temperature detecting means, a rotational speed detecting means for a self-cooling fan, and an internal circuit which controls the driving of the self-cooling fan by monitoring their detection signals and the filter device monitors the rotational speed detecting means for the cooling fan and its detection signal to suppress a rise in the temperature in the liquid crystal projector. When it is judged that the internal temperature detection signal or rotational speed detection signal that the internal circuit of the liquid crystal projector or the control circuit for the filter device detects is abnormal, the liquid crystal projector is powered off; and a display means is also provided to indicate a replacement period according to an operation time integration result.