Ultraviolet shutter

A system for exposing curable material to high intensity ultraviolet (UV) light through shutters which open and close to control the timing and duration of exposure, the improvement comprising:

• at least four shutter segments each having longitudinally opposed ends, front and back edges, and top and bottom solid surfaces, wherein each segment is adjacent at least one other segment, the segments are arranged with the front and back edges of each segment in parallel along a first direction, and one of the front or back edge of each segment substantially abuts an adjacent segment;
• a drive hub rigidly connected to each segment, respectively;
• and
• a drive train engaging all said drive hubs, for simultaneously actuating said hubs and connected shutter segments rotatively through actuation angles of no more than about 90 degrees to open and no more than about 90 degrees to close, around respective axes of rotation which are parallel and coplanar along said first direction.

A method for operating a shutter assembly interposed between a UV curing light source and a work piece positioned by an indexing conveyor at a particular location beneath the source, comprising:

• closing a configuration of at least four shutter segments by rotating the segments simultaneously toward each other such that adjacent segments overlap and block UV light at said location;
• while the shutter configuration is closed, conveying a work piece to said location;
• opening the shutter configuration by rotating the segments simultaneously through an actuation angle of no more than about 90 degrees, thereby exposing the work piece to light;
• closing the shutter configuration by rotating the segments simultaneously toward each other through said actuation angle in reverse such that adjacent segments overlap and block the UV light at said location.