Patent Number: 
Section: claims

1. A charged particle irradiation apparatus that performs a scan with a charged particle beam to irradiate an irradiation target spot by spot, the charged particle irradiation apparatus comprising:a collimator apparatus provided in an irradiation nozzle that emits the charged particle beam to the irradiation target; anda collimator control unit that controls the collimator apparatus,wherein the collimator apparatus comprisesa collimator mechanism comprising one or more arm-shape collimators extending from a base part, anda drive mechanism that moves the collimator mechanism on a plane (YZ plane) perpendicular to a traveling direction (X-axis direction) of the charged particle beam,wherein each of the arm-shape collimators comprises a plurality of movable leaves that rotate independently of each other on the perpendicular plane (YZ plane), andwherein by moving the collimator mechanism and/or rotating the movable leaves so that the one or more arm-shape collimators are arranged along a shape of an edge of the irradiation target on the perpendicular plane (YZ plane), the collimator control unit causes the one or more arm-shape collimators to block the charged particle beam that would otherwise irradiate outside of the edge of the irradiation target. 2. The charged particle irradiation apparatus according to claim 1,wherein the one or more arm-shape collimators comprise at least two arm-shape collimators extending from the base part, and each of the arm-shape collimators comprises a plurality of the movable leaves connected to each other in series, andwherein by moving the collimator mechanism and/or rotating the movable leaves, respectively, so that the arm-shape collimators are arranged along the shape of the edge of the irradiation target, the collimator control unit causes the one or more arm-shape collimators to block the charged particle beam that would otherwise irradiate outside of the edge of the irradiation target. 3. The charged particle irradiation apparatus according to claim 2,wherein the charged particle irradiation apparatus comprises at least two of the collimator apparatuses, andwherein by moving the collimator mechanisms, respectively, and/or rotating the movable leaves, respectively, so that each of the arm-shape collimators of the collimator apparatuses are arranged in cooperation along a whole shape of the edge of the irradiation target, the collimator control unit causes each of the arm-shape collimators to block the charged particle beam that would otherwise irradiate outside of the edge of the irradiation target. 4. The charged particle irradiation apparatus according to claim 1,wherein the plurality of movable leaves are connected to the base part and arranged adjacently in the traveling direction (X-axis direction), andwherein each of the movable leaves has at least one joint part and is configured to rotate about the joint part.