CIGARETTE MANUFACTURE

摘要

A laser perforation system includes an electrically driven laser beam deflector (14) which is controlled to cause the beam to be directed in sequence along a number of paths (10A-D) leading to a perforation zone (8). The beam deflector may be an acousto-optical device (14). A frequency modulated control signal may be applied to the beam deflector to cause it to deflect the beam along different paths (10A-D). Switching of the beam by an acousto-optical device produces higher definition pulses than are generally obtainable from a laser pulsed at source or by a mechanical device. The control signals for the beam deflector may be amplitude modulated to vary beam intensity. The target cigarettes (4) may be rotated in the perforation zone (8), so as to receive circumferential rows of perforations from beams on said paths (10A-D).