LASER WELDING QUALITY EVALUATION METHOD AND APPARATUS THEREFOR

摘要

A difference processing circuit (22) receives an input of a welding time image captured by a CCD camera (8) in real time, subtracting the power monit oring time image stored in a memory (21) from the welding time image, and th ereby acquires a difference processing reflected light image. By this differ ence processing, foreign matter images included in the welding time image an d the power monitoring time image are canceled, and the difference processin g reflected light image does not include any foreign matter image. A quality judging device (17) judges the welding quality by using the difference proc essing reflected light image. As stated above, since the difference processi ng reflected light image does not include any foreign matter image, the qual ity judging device (17) can perform good evaluation of the welding quality w ithout being influenced by any foreign matter adhering to a protective glass (15).