APPARATUS FOR TESTING ROD-SHAPED PRODUCTS OF THE TOBACCO PROCESSING INDUSTRY

摘要

Apparatus for optically scanning a moving cigarette rod for the presence of defects in its external surface has two annularly arranged groups of diodes which emit green light in the wavelength range of between 0.49 and 0.58 mu and direct such light from the opposite sides of a plane that is normal to the moving rod so that the incident light is reflected by successive annular portions of the external surface of the rod into the aforementioned plane. The reflected light is focused by systems of lenses upon discrete photosensitive transducers through discrete slit diaphragms on the transducers themselves or on a thin metallic ring which is adjustably mounted on the support for the diodes and the systems of lenses.