Patent ID: 8048229

Claim:
An apparatus for depositing an organic layer, the apparatus comprising: a crucible positioned in a deposition chamber, the crucible being adapted to contain organic materials for evaporation, a heating unit including first and second heat sources for applying heat to the crucible, wherein the first heat source is positioned near a first side of the crucible and the second heat source is positioned near a second side of the crucible, wherein a temperature of the second heat source is lower than the glass transition temperature of the organic materials in the crucible, the heating unit further comprising a first power source for supplying power to the first heat source, a second power source for supplying power to the second heat source, and a controller for independently controlling the first and second power sources, and for comparing a measured deposition rate to a reference deposition rate using a sensor unit, wherein the controller is configured to fix the power supplied to the second heat source and adjust the power supplied to the first heat source when the measured deposition rate reaches about 10% to about 70% of the reference deposition rate, a first housing generally surrounding the heating unit and the crucible for isolating the heat emitted from the heating unit, an outer housing generally surrounding the first housing, the outer housing configured to anchor the crucible, and a nozzle for spraying the materials contained in the crucible onto a substrate.