| 摘要 |
<p>A method and apparatus for engraving or exposing anilox or gravure rollers (2) to form substantially oval cells (C) having a predetermined ovality. This gives a reduced area of unengraved roller. The cells (C) may be formed by engraving or exposing the surface of the roller (2) with a focused laser beam having a clipped or compressed cross section. The apparatus includes a means for supporting the roller (2), and allowing the roller to rotate about its longitudinal axis, an engraving head (7) which is movable along a plane generally parallel to the axis of the roller (2), the engraving head (7) including a focusing lens (L). A beam modifying means is included in the path of the laser beam before the focusing lens (L) to modify the cross section of the laser beam so that the dimension in one direction is greater than that in an orthogonal direction.</p> |
