Abstract: An exposure system for light sensitive materials held in a vacuum frame includes an electrical light source and a power supply to the light source, the power supply having a power consumption monitor so it can modify the power supplied to the light source to compensate for any fluctuations in power consumption by the light.The light source is supported in a housing having air exhaust openings proximate the mid-portion of the light source. A blower cools the light source with a helical airflow. The voltage drop across the electrical light source is used to control the speed of the blower to maintain the voltage of the light source at a desired level. The housing has an open face and a removable pane. An indicator indicates the presence of the pane. A metal shutter in the housing has a black ceramic surface adjacent the light source to selectively expose light sensitive materials. A control means closes the shutter when the indicator senses removal of the pane while power is being supplied to the light source.

Abstract: A vacuum frame for exposing a light-sensitive sheet to a light pattern according to a negative includes a blanket frame having peripherally bonded thereto a platen and a blanket with the platen being bowable and the blanket being flexible. The platen and blanket are peripherally sealingly bonded to one another, forming a vacuum chamber therebetween. A light transmissive frame mounted to the blanket frame for movement toward and away from the blanket and a spacing and sealing means peripherally interposed between the blanket and the light transmissive frame when the light transmissive frame is moved toward the blanket define an exposure chamber with the blanket. The exposure chamber is adapted to receive a light sensitive sheet and negative.A first vacuum inlet means connects the vacuum chamber to an evacuation means, and a second vacuum inlet means connects the exposure chamber to an evacuation means.