Patent attributes
A multileaf collimator includes a first leaf block group including plural leaf blocks, a second leaf block group including plural leaf blocks arranged in the same direction as the first leaf block group and disposed opposite the leaf blocks of the first leaf block group, plural magnetic layers located on the respective leaf blocks of the first and second leaf block groups so as to be positioned on faces of the leaf blocks along a moving direction of the leaf blocks, plural magnetic sensors mounted on the respective leaf blocks and varying output signals when the respective leaf blocks are moved in an oncoming direction or a departing direction, and a control device controlling drive mechanisms according to the output signals delivered by the respective magnetic sensors so that spacing between the leaf blocks of the first and second leaf blocks is adjusted into a target configuration.
