| 摘要 |
<p>A blackboard eraser device of the present invention comprises: a housing; a friction roller combined to the housing and formed to come in contact with a blackboard and rotate; a wiping roller combined to the housing to allow one side thereof to be exposed and formed to come in contact with the blackboard and rotate for wiping the blackboard while rotating in the opposite direction of the friction roller; a dusting portion which reciprocatively rotates around a rotating shaft inside the housing and in which a hitting portion for hitting the outer circumferential surface of the wiping roller is formed on a surface toward the wiping roller; a first medium for mediating the movement of the friction roller and the wiping roller; and a second medium for mediating the movement of the friction roller and the dusting portion.</p> |
