OPTICAL SCANNING SYSTEM USING A POLYGONAL ROTATING MIRROR

摘要

An optical scanning system for scanning a code pattern comprising several parallel lines provided on an article is disclosed. The system includes a light source, such as a laser, which directs a beam of light at a polygonal rotating mirror which has several reflecting surfaces. Several stationary mirrors are located in the path of beam reflection from the rotating mirror to derive several light-beam scanning lines which intersect each other on the surface of conveyor belt carrying articles bearing the code to be scanned. All of the code bars of each article is completely scanned by at least one of the scanning lines. The lengths of the scanning lines may be increased by tilting the reflecting surfaces of the rotating mirror with respect to each other. The invention ensures that the code on each article will be scanned completely in one stroke irrespective of the orientation of the code with respect to the conveyor.