| 摘要 |
PURPOSE:To obtain an accurate slit width at all times, by a method wherein the backlash amount and the driving direction of a slit in the previous operation are stored by employing a computer, and when the slit is driven in the direction different from that in the previous operation, the slit is driven by an extra amount corresponding to the backlash amount. CONSTITUTION:Edges 1 and 2 in combination define a slit part 5 by the gap therebetween and are screwed on a driving shaft 3. Threads are cut so as to be opposite in direction to each other with respect to the edge 1 and 2, respectively. Accordingly, the edges 1 and 2 are opened and closed by the rotation of the driving shaft 3. A motor 4 is controlled by a computer 6, which stores the backlash amount of the slit and the driving direction in the previous slit operation, and is programmed so as to drive the slit by an extra amount corresponding to the backlash when the driving direction is different from that in the previous operation. |
