Patent ID: 7441903

Claim:
A power on/off system of a thin projector including an optical system arranged in a housing with a panel shape having lateral sides and a front side having an area larger than an area of each lateral side, the optical system including a lamp, a display, and a projection lens, comprising: a door which opens/closes an air inlet or an air outlet allowing air to pass through the interior of the housing; at least one fan which is arranged in the interior of the housing, and is adapted to cool the lamp; a shutter which opens/closes the projection lens externally exposed from the housing; a first sensing unit which senses malfunctions of the lamp, the fan, the door, and the shutter; a second sensing unit which senses an internal temperature of the housing; and a controller which sequentially controls, in response to power-on of the thin projector, operations of opening the door and the shutter, driving the fan, and determining whether or not there is a malfunction associated with the opening of the door and the shutter, through the sensing units, driving the lamp, and determining whether or not there is a malfunction associated with the driving of the lamp and the fan, and sequentially controls, in response to power-off of the thin projector, operations of turning off the lamp, driving the fan, turning off the fan after a predetermined time elapses, closing the door and shutter, and determining whether or not there is a malfunction associated with the closing of the door and shutter, through the sensing units.