PROBLEM TO BE SOLVED: To provide a method and a device which can directly monitor axis deviation of laser beam caused by a temperature drift and the like during laser irradiation, that is, during processing a work piece in a final optical unit including a galvano mirror optical system.SOLUTION: In a laser beam irradiation method, while a work piece 70 is supported on a support member 61 with an aperture 60, laser beam 13 is applied through the aperture 60 on the work piece 70. The work piece 70 is processed while an imaging device 30 images an irradiation state of the laser beam 13 on the work piece 70. A light source 12 and the imaging device 30 are arranged so that an irradiation axis of the laser beam 13 and an optical axis of the imaging device 30 are coaxial. An image of an irradiation sign of the laser beam 13 in the work piece 70 and the support member 61 in the coaxial state is simultaneously obtained by the imaging device 30, and a distance from a reference position to the irradiation sign 71 in the support member 61 is measured to obtain deviation amount of the irradiation position of the laser beam 13. Existence of the deviation is determined to correct it.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】ガルバノミラー光学系を含む最終光学ユニットに温度ドリフト等の原因で生じるレーザー光の光軸ずれをレーザー照射中、すなわち被加工物の加工中に直接モニターできる方法及び装置の提供。【解決手段】開口部60を有する支持部材61上に被加工物70を支持させた状態下、開口部60を通じ被加工物70に向けてレーザー光13を照射して、被加工物70におけるレーザー光13の照射状態を撮像装置30によって撮像しながら被加工物70を加工する。レーザー光13の照射軸と撮像装置30の光軸とが同軸となるように、光源12及び撮像装置30を配置しておく。被加工物70におけるレーザー光13の照射痕の画像及び支持部材61の画像を、撮像装置30によって同軸状態で同時に取得し、支持部材61における基準位置から照射痕71までの距離を求めて、レーザー光13の照射位置のずれ量を求め、ずれの有無を判断し、補正する。【選択図】図1
