| 摘要 |
A laser marking apparatus for marking a moving workpiece such as a wire or cable 12 directs a substantially constant rapidly pulsed beam of laser radiation in the U.V. band towards a low inertia, low mass rotatable mask (26, Figure 2, not shown) with character apertures disposed around its periphery. The mask is driven asynchronously and slaved to the laser to present successive character apertures in the beam at each pulse. The drive system has a pre-stored drive profile for each possible angular increment to ensure that mask is very rapidly indexed between characters. Also disclosed is an optical transformation scheme (P1, P2, L1, L2) for manipulating the mask characters to reduce the mask size, and a solid state spatial light modulator (30, Figure 4, not shown) for obviating the need for a rotatable mask. |
