Patent ID: 10953496

Abstract:
The invention relates to a method for introducing a defined tear line via material removal on a cover material (20), which has a visible side (22) and a rear side (21) opposite the visible side (22), wherein a pulsed laser beam (31) from a laser (30) is directed to the rear side (21) of the cover material (20) and is guided along a path (50) and at least one observation unit (11) is provided for monitoring the weakening process, wherein a hollow chamber (32) is provided on the visible side (22) of the cover material (20) which has a scattering and/or reflecting inside surface (33) and at least one observation unit (11) is provided on the hollow chamber (32), wherein the light (40) emerging on the visible side (22) of the cover material (20) during the laser irradiation is incident on the inside surface (33) of the hollow chamber (32) and is scattered and/or reflected at least in part on the at least one observation unit (11) and the light incident on the at least one observation unit (11) is used to control the laser (30). A luminescent inside surface (33) can also be used as a hollow chamber (32).