APPARATUS FOR OPTICAL MONITORING OF THE SURFACE OF ROD-SHAPED SMOKING ARTICLES AND/OR FILTER RODS FOR THE TOBACCO INDUSTRY

An apparatus for optical monitoring of the surface of rod-shaped smoking articles and/or filter rods for the tobacco industry comprises a conveying means transporting the rods perpendicularly to their longitudinal direction and a high-pressure lamp which serves as light source and which is connected via an optical fibre cable to a sensor block; the optical fibre cable is divided amongst at least two cross-section transformers with strip-shaped light exit regions whose light rays are directed via a further optical system from above and below respectively onto the line-shaped region of the surface of the rod. In addition the sensor block contains a row of photoelectric transducers which simultaneously the line-shaped surface region in the longitudinal direction of the rod and thereby pick up the light reflected at the surface of the rod. An arrangement controlled by the production cycle clock pulse determines by comparison surface faults from the output signals of the photoelectric transducers dependent on the reflectivity of the line-shaped region of the surface.