| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laser beam machining device which can prevent the surface of a protective cover from staining and can wash out the stain. <P>SOLUTION: This laser beam machining device is equipped with: a laser source for emitting laser beams; a galvano-mirror for changing the direction of the laser beam emitted from the laser source; a convergence lens 14 for converging the laser beam from the galvano-mirror and irradiating on an object to be machined; and a protective lens 21 with transparency for protecting the convergence lens 14 while passing the laser beam from the convergence lens 14. A multi-layer coating 24, including a photocatalyst layer 24a comprising titanium dioxide and a distinct refractive index layer 24b comprising silicon dioxide with a refractive index different from the photocatalyst layer 24a, is provided on the surface of the protective lens 21 at the emitting side thereof. And the laser beam machining device is equipped with a UV-light emitting unit 31 emitting UV-light for inducing the photocatalyst layer 24a to initiate a photocatalytic reaction. <P>COPYRIGHT: (C)2013,JPO&INPIT |
