| 摘要 |
<p>A transfer apparatus includes a transfer member, for example, a transfer drum (18) with a line of small closely spaced laser drilled vacuum holes (58) to hold a receiving sheet to the drum surface. To maintain the continuity of a transfer field but be free from clogging, the holes are narrow near the surface of the drum but wider as they extend deeper in the drum. Conical holes are drilled in the drum by a laser. In one embodiment, a short focal length lens (56) focuses a laser beam (57) near the surface of the drum which beam spreads below the surface to form a conical hole.</p> |
