LASER PROCESSING DEVICE

To suppress error of measurement due to regular reflection in measuring a distance up to a work-piece having a curve part formed therein.SOLUTION: A laser processing device L comprises: a ranging light emitting part 5A that emits ranging light; a ranging light receiving part 5B that receives the ranging light emitted from the ranging light emitting part 5A and reflected by a work-piece W; a distance measuring part 103 that measures a distance up to a circumferential surface Wa of a work-piece W' by a triangulation method, on the basis of a position where the ranging light is received in the ranging light receiving part 5B; a control part 101 that scans ranging light so that the ranging light is irradiated to a plurality of places lined in a direction orthogonal to a curvature radius of the circumferential surface Wa; and a position specifying part 104 that specifies a light receiving position X0 due to diffusion reflected light, out of a plurality of light receiving positions in the ranging light receiving part 5B. The distance measuring part 103 measures a distance up to the circumferential surface Wa of the work-piece W' on the basis of the light receiving position X0 specified by the position specifying part 104.SELECTED DRAWING: Figure 14 【課題】曲面部が形成された被加工物を測距対象とした場合に、正反射に起因した測定誤差を抑制する。【解決手段】レーザ加工装置Ｌは、測距光を出射する測距光出射部５Ａと、測距光出射部５Ａから出射されてワークＷにより反射された測距光を受光する測距光受光部５Ｂと、測距光受光部５Ｂにおける測距光の受光位置に基づいて、三角測距方式によりワークＷ'の円周面Ｗａまでの距離を測定する距離測定部１０３と、円周面Ｗａの曲率半径と直交する方向に並んだ複数箇所に測距光が照射されるように、測距光を走査する制御部１０１と、測距光受光部５Ｂにおける複数の受光位置の中から、拡散反射光に起因した受光位置Ｘ０を特定する位置特定部１０４と、を備える。距離測定部１０３は、位置特定部１０４により特定された受光位置Ｘ０に基づいて、ワークＷ'の円周面Ｗａまでの距離を測定する。【選択図】図１４