Projection type video display
A shutter device 21 can switch between a state where illuminating light from a lamp of an illuminating device 1 is cut off (referred to as a closing state of the shutter device) and a state where illuminating light passes through (referred to as an opening state of the shutter device). A system control circuit 40 instructs a lamp power source 44 to decrease power supplied to the lamp, when receiving information indicating that the shutter device 21 is in the closing state from the detecting portion 47. After receiving this instruction, the lamp power source 44 decreases the power supplied to the lamp.