Heating system for vacuum coating apparatus

In an elongated vacuum coating apparatus having a deposition chamber, the improvement comprising:

• a pass-through heating device comprising means including walls forming a heating chamber having an inlet and an outlet along the longitudinal axis of the vacuum coating apparatus, at least one heating means inside the heating chamber, means disposed parallel to the longitudinal axis of the vacuum coating apparatus and forming a thermal barrier between the heating means and the walls of heating chamber, movable means disposed transverse to the longitudinal axis of the vacuum coating apparatus for forming a thermal barrier at the inlet and the outlet of the heating chamber when a substrate is to be heated therein;
• a substrate rack;
• and transport means for moving the substrate rack along the longitudinal axis of the vacuum coating apparatus into the heating chamber for heating and therethrough into the deposition chamber for deposition comprising a cantilevered transport shaft having the substrate holder connected at one end thereof, a movable box-shaped frame disposed in the heating chamber and having a thermal barrier facing the interior of the heating chamber and means for moving the frame into a closing position in the heating chamber when the substrate holder is in the deposition chamber to substantially close the sides and ends of the heating chamber to prevent a decrease in temperature and loss of energy.