Patent ID: 7617772

Claim:
A balancing system for balancing a drum of a printing plate exposer, the balancing system comprising: at least one movable mass element moving substantially in a circumferential direction of the drum to reduce an imbalance of the drum, said at least one movable mass element being disposed on at least one end of the drum, said at least one movable mass element being substantially ring-shaped or disk-shaped and having an eccentric mass center of gravity, said at least one movable mass element including an engagement or groove; at least one movable positioning element having a position correlating with a circumferential extent of a printing form held by the drum, said at least one movable mass element being coupled to said at least one movable positioning element such that a circumferential position of said at least one movable mass element being adjusted automatically on a basis of the circumferential extent of the printing form; and at least one driver coupling said at least one movable mass element to said at least one positioning element, said at least one driver engaging said engagement or groove.