To detect yarn defects such as protruding filaments, broken filaments, ringers, fuzzballs, stripbacks and the like, a yarn sheet 9 traveling in a plane is scanned by light beams from at least two light barriers 10, 11. The bearing means has a guide part with a bearing passage for receiving the stroke bar, wherein the bearing means is mounted by an elastic secondary bearing element in a receiving passage in the housing. A second dielectric layer is formed on the metal layer and the first dielectric layer. A processing unit identifies the vision output device within the reference frame of the captured image and localizes the vision output device within the reference frame of the captured image for identifying an absolute position and orientation of the vision output device within the reference frame of the captured image. The invention also provides pharmaceutical compositions comprising the compounds of the invention, processes for preparing the compounds and methods of using the compositions in the treatment of various disorders.