Laser irradiation device, laser irradiation system, and method for removing coating or adhering matter

A coating removing method for removing a coating of a surface of a structure by laser irradiation from a laser irradiation apparatus for focusing a laser beam outputted from a laser oscillator and irradiating it to the surface of the structure, characterized in that:

• the laser irradiation apparatus has an optical system comprising a first deflecting means for deflecting the laser beam with respect to an optical axis of the focused laser beam at a predetermined angle and a second deflecting means for deflecting the focused laser beam deflected by the first deflecting means at a predetermined angle;
• the irradiation point of the focused laser beam through the second deflecting means is subjected to rotary scanning so as to draw a trajectory of a substantially circle having a constant radius r2 around a circumference of a substantially circle having a constant radius r1 on the surface of the structure;
• and
• the laser irradiation apparatus is moved with respect to the structure to keep a distance between the laser irradiation apparatus and the surface of the structure to be treated substantially constant.

A coating removing apparatus for removing a coating of a surface of a structure by laser irradiation from a laser irradiation apparatus for focusing a laser beam outputted from a laser oscillator and irradiating it to the surface of the structure, characterized in that:

• the laser irradiation apparatus has an optical system comprising a first deflecting means for deflecting the laser beam with respect to an optical axis of the focused laser beam at a predetermined angle and a second deflecting means for deflecting the focused laser beam deflected by the first deflecting means at a predetermined angle;
• the irradiation point of the focused laser beam through the second deflecting means is subjected to rotary scanning so as to draw a trajectory of a substantially circle having a constant radius r2 around a circumference of a substantially circle having a constant radius r1 on the surface of the structure;
• and
• the laser irradiation apparatus is moved with respect to the structure to keep a distance between the laser irradiation apparatus and the surface of the structure to be treated substantially constant.