| 摘要 |
<p>A visual display unit such as may be used to indicate the destination or route number of a passenger vehicle comprises a casing (1) defining a window area (5) through which a portion of a blind (6) bearing visually presented information is visible from the exterior of the casing (1). Two guide rollers (10) are located within the casing (1) and are each positioned at one of two opposed sides of the window area (5), respectively. The blind (6) passes over the guide rollers (10) and its ends are wound around the two spool rollers (8, 9) which are also located within the casing (1). An endless drive belt (11) driven by a drive means (14) contacts a predetermined length of the blind (6) to move the blind (6) frictionally over the guide rollers (10) from one spool roller (8, 9) to the other (9, 8) and vice versa as the drive belt (11) is itself driven thereby to change the information visible in the window area (5). Preferably, the drive belt (11) has an elastic nature whereby at least that portion of the blind (6) which is visible in the window area (5) is tensioned and held substantially taut as the blind is moved by the belt (11).</p> |
