Optical thread breakage monitoring apparatus

Optical thread breakage monitoring apparatus for tufting machines comprising a laser beam scanning device which generates a laser beam which executes a continually repeating rapid scanning movement perpendicular to the needles of the needle row and which, when it impinges onto a retroreflecting strip arranged behind the threads being worked by the needles,, as a result of a thread breakage or as a result of passing through the thread gaps, is reflected back on itself and is incident in the laser beam scanning device on a photoreceiver connected to an electronic processing circuit which, in the event of a change of the normally present periodic signal generates a fault signal, characterised in that the retroreflecting strip (11) is secured above the eyes (12) of the needles (13) to the front side of the needle beam (14).