| 摘要 |
PROBLEM TO BE SOLVED: To provide an observation window protection mechanism capable of maintaining transparency for a long period of time, while being less likely to cause collision of a projection agent, etc.SOLUTION: A projection agent ejected from a nozzle collides with the surface of a workpiece and a portion thereof is reflected to scatter toward an observation window 8, when removing the coating, etc., on the surface of the workpiece 3 by using nozzles 4 or 5. Then, the projection agent is captured by an air curtain ejected from a lower edge part of the observation window 8 and directed upward, when approaching the observation window 8, so as to go up through without colliding against the observation window 8. |
