| 摘要 |
An automatic blackboard erasing apparatus reciprocates, or moves back and forth, horizontally on a blackboard. The automatic blackboard erasing apparatus incorporates a housing, right and left erasing elements each having one or more brushes and one or more wiper members, a variable contact element for controlling the contact state of the erasing elements relative to the blackboard, a washing liquid supplier for providing washing liquid between the brushes and the surface of the blackboard, and a controller for controlling the operation of the erasing apparatus. When the erasing apparatus traverses to the right of the blackboard to erase the blackboard, the left erasing element is in contact with the blackboard, and the right erasing element is not in contact with the blackboard. When the erasing apparatus traverses to the left of the blackboard to erase the blackboard, the right erasing element is in contact with the blackboard.
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