Detector for use on sewing machines

摘要

One or a plurality of photoelectric detector plates are mounted on a coupling fixed to an arm shaft of a sewing machine, and have predetermined light shields. A light-emitting means is disposed on one side of the photoelectric detector plates for emitting light toward the photoelectric detector plates, and a photodetector means is disposed on the other side of the photoelectric detector plates for receiving the light emitted from the light-emitting means. Conditions of the sewing machine can be detected by the manner in which the photodetector means receives the light.