Optical scanning apparatus for generating a helical scanning patern on an external (cylindrical) surface

摘要

An optical scanner having at least a light source (1), an internal helical scanning line generator (1, 6, 7) for generating a scanning beam defined by a beam focus which in use follows a helical pattern, beam shape conversion means (9; 11; 12; 15, 15a; 16) for receiving the scanning beam from the internal helical scanning line generator and converting its direction in order to make the scanning beam propagating substantially along a virtual conic or cylindrical surface around a scanning axis (T), and deflection means (10; 14; 15b) for receiving the scanning beam from the beam shape conversion means (9; 11; 12; 15, 15a; 16) and deflecting it substantially to the scanning axis (T). Such an optical scanner is particularly suited for reading bar codes on an external cylindrical surface, e.g. on a bottle.