The projector lamp turns off after one hour. - InFocus Proxima DP5900 Multimedia Projector

Very likely the air vent is block or you will need to clean the air vent. The system track the hours of usage and when it is time to clean the air vent filter it will stop working. A clogged air vent will make the temperature of the equitpment rise. To protect the circuits and projector expensive light component it will stop working automatically. After cleaning up the air vent, see the manual how to reset the clock/timer for air vent cleaning timing, so that the lamp would not turn off.