| 摘要 |
A back lit alphanumeric sign module having a printed web which includes opaque and transparent regions that define alphanumeric characters. The web is trained between end plates having illumination cutouts and which support a spring biased take-up-roller, drive roller, a pair of transparent idler rollers and tie rods. A spiral wound spring at the take-up roller continuously tensions the web. A biased latch arm and slot at the take-up and drive rollers define web stop limits. A split, spring biased ratchet collar is provided in manual modules. The split ratchet collar at the manual drive roller provides a one-way geared rotation and cooperates with a pole engaged loop to vary rotation and sign information. A pulse modulated motor controller drive is provide at the electric module. A remote controller at the electronic module provides programmed and operator entered spread spectrum drive signals over a power line carrier circuit to the drive motor to vary sign information. Sensed position indicia at the web center the characters to a viewing window of the back lit enclosure. The modules are constructed to be rack mounted in a variety of stacked organizations.
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