Patent ID: 6823045
Filing Date: 2004-11-23
Classification: A61N,G21K

Abstract:
A multi-leaf collimator comprising a first leaf plate driving body provided on a first side of the collimator and a second leaf plate driving body provided on a second side of the collimator, the first and second leaf plate driving bodies each including a plurality of movable leaf plates, the plurality of leaf plates of said leaf plate driving body on the first side and the plurality of leaf plates of said leaf plate driving body on the second side being disposed in an opposing relation to form an irradiation field of a radiation beam between the opposing leaf plates, wherein:each of said first and second leaf plate driving bodies comprises one rotating device for moving said plurality of leaf plates along one direction by engaging with a gear portion provided respectively at each of said plurality of leaf plates, and a driving force transmitting/cutoff device for transmitting a driving force of said rotating device to said plurality of leaf plates at the same time during a certain period by moving said plurality of gear portions along a direction substantially perpendicular to said one direction and engaging them with said rotating device and cutting off said driving force to a selected one of said plurality of leaf plates by disengaging said gear portion of said selected leaf plate from said rotating device.