| 摘要 |
<p>The roller display has two rollers (1,2) driven by asynchronous motors (4,5) driving a display strip (3) wound on the rollers. The display is kept under tension in a fixed position by operating the two motors at a reduced feed frequency. When moving the strip to change the display, one motor is operated at a reduced feed frequency, providing a brake and the other motor has the normal feed frequency.</p> |
